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Journal articles on the topic 'Protic solvents'

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Published: 24 April 2022

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1

Shabanian, Meisam, Hassan Moghanian, Mohsen Hajibeygi, and Azin Mohamadi. "Theoretical Investigation of Solvation Effects on the Tautomerism of Maleic Hydrazide." E-Journal of Chemistry 9, no. 1 (2012): 107–12. http://dx.doi.org/10.1155/2012/976161.

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A DFT study is used to calculate structural data of tautomers of maleic hydrazide (MH) in the gas phase and selected solvents such as benzene (non-polar solvent), tetrahydrofuran (polar aprotic solvent) and methanol (protic solvent), dimethyl sulfoxide (polar aprotic solvent) and water (protic solvent) using PCM model. All tautomers are optimized at the B3LYP/6−31++G(d,p). The results show that the tautomer MH2except in methanol is more stable than the other tautomers but in methanol MH5(Diol) is more stable. In addition, stability of the tautomers in deferent solvents shows interesting results. Variation of dipole moments and NBO charges on atoms in the solvents were studied.
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2

da Silva, Guilherme C. Q., Thiago M. Cardozo, Giovanni W. Amarante, Charlles R. A. Abreu, and Bruno A. C. Horta. "Solvent effects on the decarboxylation of trichloroacetic acid: insights from ab initio molecular dynamics simulations." Physical Chemistry Chemical Physics 20, no. 34 (2018): 21988–98. http://dx.doi.org/10.1039/c8cp02455c.

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3

Nikolic, Jasmina, Gordana Uscumlic, and Vera Krstic. "Reactivity of cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids with diazodiphenylmethane in aprotic solvents." Journal of the Serbian Chemical Society 65, no. 12 (2000): 839–46. http://dx.doi.org/10.2298/jsc0012839n.

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Rate constants for the reaction of diazodiphenylmethane with cyclohex-1-enylcarboxylic acid and 2-methylcyclohex-1-enylcarboxylic acid were determined in nine aprotic solvents, as well as in seven protic solvents, at 30?C using the appropriate UV-spectroscopic method. In protic solvents the unsubsituted acid displayed higher reaction rates than the methyl-substituted one. The results in aprotic solvents showed quite the opposite, and the reaction rates were considerably lower. In order to explain the obtained results through solvent effects, reaction rate constants (k) of the examined acids were correlated using the total solvatochromic equation of the form: log k=logk0+s?*+a?+b?, where ?* is the measure of the solvent polarity, a represents the scale of the solvent hydrogen bond donor acidities (HBD) and b represents the scale of the solvent hydrogen bond acceptor basicities (HBA). The correlation of the kinetic data were carried out by means of multiple linear regression analysis and the opposite effects of aprotic solvents, as well as the difference in the influence of protic and aprotic solvents on the reaction of the two examined acids with DDM were discussed. The results presented in this paper for cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids were compared with the kinetic data for benzoic acid obtained in the same chemical reaction, under the same experimental conditions.
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4

Xin, Hong-Xing, Qi Liu, Hong Yan, and Xiu-Qing Song. "Stability and decarbonylation of 1,3-dialkyl-2-formylimidazolium perchlorate in solution." Canadian Journal of Chemistry 91, no. 6 (June 2013): 442–47. http://dx.doi.org/10.1139/cjc-2012-0497.

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The stability of 1,3-dialkyl-2-formylimidazolium perchlorate 1 in solution was studied in detail and found to be related to its structure and the solvent character and temperature. 1 was stable in common solvents at room temperature and unstable in protic solvents under reflux. In protic solvents, such as H2O, MeOH, EtOH, and AcOH, 1 decarbonylated into 1,3-dialkylimidazole perchlorates 2, which was confirmed by 1H NMR, 13C NMR, HRMS, and X-ray spectroscopy. The decarbonylation of 1 was proposed to occur via its hemiacetal formed by the addition of solvents based on the tracking NMR spectra of 1 in deuterated reagents.
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5

Bakalova, Snezhana. "Solvent Effects on the Fluorescence Properties of Methyldihydroquinolinones." Zeitschrift für Naturforschung A 46, no. 9 (September 1, 1991): 823–28. http://dx.doi.org/10.1515/zna-1991-0913.

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Abstract The absorption and fluorescence spectra and the fluorescence quantum yields of two methyl-2,3- dihydro-4(1H)-quinolinones in various solvents are reported. In some solvents deuteration-induced fluorescence enhancement has been observed. The solvent effects in aprotic solvents are consistent with the general type of solvent interaction. For protic solvents, solute-solvent complexation in the excited state is suggested
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6

Marinkovic, Aleksandar, Sasa Drmanic, Bratislav Jovanovic, and Milica Misic-Vukovic. "Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents, Part I: Pyridine mono-carboxylic acids." Journal of the Serbian Chemical Society 70, no. 4 (2005): 557–67. http://dx.doi.org/10.2298/jsc0504567m.

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Rate constants for the reaction of diazodiphenylmethane with isomeric pyridine carboxylic acids were determined in chosen protic and aprotic solvents at 30 ?C, using the well known UV spectrophotometric method. The values of the rate constants of the investigated acids in protic solvents were higher than those in aprotic solvents. The second order rate constants were correlated with solvent parameters using the Kamlet-Taft solvatochromic equation in the form: logk = logk0 + s?*+ a? + b?. The correlation of the obtained kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The signs of the equation coefficients were in agreement with the postulated reaction mechanism. The mode of the influence of the solvent on the reaction rate in all the investigated acids are discussed on the basis of the correlation results.
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7

Chastrette, M., and J. Carretto. "Étude statistique des effets de solvant. III. Calcul et interprétation de paramètres empiriques de polarité à partir de propriétés physicochimiques des solvants purs." Canadian Journal of Chemistry 63, no. 12 (December 1, 1985): 3492–98. http://dx.doi.org/10.1139/v85-572.

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Using multivariational statistical methods, the calculation and interpretation of empirical parameters of the polarity of solvents has been reexamined. The size of the sample used (57 aprotic solvents and 24 protic solvents) assures that it is representative. For each solvent, the data tabulated include some physical constants (dielectric constants, dipole moments, refractive indices, molar refractions, boiling points, Hildebrand's δ parameters) or theoretical values (energy levels of frontier orbitals). The methods used are factorial analysis and multiple regression. The results obtained show that, for the aprotic solvents, the parameter ET is a measure of the polarity, of the polarizability, and of the cohesion of the solvent to the extent of 43, 39, and 18% respectively. For the parameter π*, these proportions are respectively 53, 18, and 29%. For the protic solvents, the parameter ET is explained by the same variables except for 5 solvents more acidic than water; this anomaly is explained by the basicity of the oxygen of the betaine used to define ET.
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8

Assoumatine, Tokouré, Brigitte L. Yvon, and James L. Charlton. "The complex photochemistry of 2,3-dibenzylidenesuccinates." Canadian Journal of Chemistry 82, no. 12 (December 1, 2004): 1663–67. http://dx.doi.org/10.1139/v04-143.

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The photochemistry of diethyl E,E-2,3-(3,4,5-trimethoxybenzylidene)succinate (8) is solvent dependent. In both protic and aprotic solvents, there is a photoequilibrium established between 8 and its E,Z-isomer (9). In chloroform at high light intensity, very little 9 is formed and the main product is 1,4-dihydronaphthalene (10), formed via photoinduced intramolecular [1,3]-sigmatropic hydrogen shift within an intermediate 1,8a-dihydronaphthalene (11). In protic solvents, irradiation of either 8 or 9 ultimately gives primarily the cis-1,2-dihydronaphthalene product (13), along with smaller amounts of the trans isomer (14). By using deuterated solvents, it was shown that 13 and 14 are formed by solvent protonation (or deuteration) of the 1,8a-dihydronaphthalene intermediate (11 or 12). Key words: 2,3-dibenzylidenesuccinate, photocyclization, dihydronaphthalene, lignan.
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9

Perusic-Janjic, Nada, Jevrem Janjic, and Sanja Podunavac-Kuzmanovic. "Solvent effect on electronic absorption spectra of some 2-aminobenzimidazoles." Acta Periodica Technologica, no. 33 (2002): 93–99. http://dx.doi.org/10.2298/apt0233093p.

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The effect of protic and aprotic solvents on electronic apsorption spectra of 1-(3-X-benzil)-2-aminobenzimidazoles (X=CH3;OCH3; Cl) was examined. UV-apsorption spectra (200-400 nm) were recorded in five protic and four aprotic solvents. Batochromic shift of absorption maxima, ?max, occurs from the solvent with the highest proton-donor ability to the proton acceptor solvent (from water to DMSO). Positions of absortion maxima in various solvents are in correlation with the dielectric constant of the solvent. In order to explain the obtained results, the ultraviolet absorption frequences of the electronic transitions of the compounds were correlated using a total solvatochromic equation of the form: ?max = ?0 + s?* + a? + b?, where??* is the measure of solvent polarity. Prepresents the scale of solvent hydrogen bond acceptor basicities and ? represents the scale of solvent hydrogen bond donor acidities. Correlation of spectroscopic data was carried out by means of multiple linear regression analysis.
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10

Drmanic, Sasa, Bratislav Jovanovic, Aleksandar Marinkovic, and Milica Misic-Vukovic. "Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents: Part II: Pyridine mono-carboxylic acid N-oxides." Journal of the Serbian Chemical Society 71, no. 2 (2006): 89–101. http://dx.doi.org/10.2298/jsc0602089d.

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The rate constants for the reaction of three isomeric pyridine mono-carbocylic acid N-oxides with diazodiphenylmethane were determined at 30 ?C in thirty two protic and aprotic solvents by the well known UV spectrophotometric method. The rate constants are generally higher than for pyridine mono-carboxylic acids in a similar range of solvents, except for picolinic acid N-oxide, and also higher in protic than in aprotic solvents. The determined rate constants were correlated with solvent parameters using the Kamlet-Taft solvatochromic equation bymeans of multiple regression analysis. The sign of the equation coefficients were in agreement with the postulated reaction mechanism. The mode of the influences of the solvent is discussed on the basis of the correlation coefficients, taking into account the specific structures of the pyridine mono-carboxylic acid N-oxides.
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11

Verma, Pragya, Arnulf Rosspeintner, Bogdan Dereka, Eric Vauthey, and Tatu Kumpulainen. "Broadband fluorescence reveals mechanistic differences in excited-state proton transfer to protic and aprotic solvents." Chemical Science 11, no. 30 (2020): 7963–71. http://dx.doi.org/10.1039/d0sc03316b.

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12

Adamoczky, Anita, Lajos Nagy, Miklós Nagy, Miklós Zsuga, and Sándor Kéki. "Conversion of Isocyanide to Amine in The Presence of Water and Hg(II) Ions: Kinetics and Mechanism as Detected by Fluorescence Spectroscopy and Mass Spectrometry." International Journal of Molecular Sciences 21, no. 15 (August 4, 2020): 5588. http://dx.doi.org/10.3390/ijms21155588.

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Aromatic isocyanides including isocyanonaphthalene derivatives have been proven to be very effective fluorescent sensors for the quantification of Hg(II) ions in water. Thus, the reaction of 1,5-isocyanoaminonaphthalene (1,5-ICAN), which is one of the most important members of this family, with water and HgCl2 as the oxidation agents, was studied by fluorescence spectroscopy and mass spectrometry in order to get deeper insight into the kinetics and mechanistic details of this complex reaction. The reactions of 1,5-ICAN with water and HgCl2 were performed in various water/co-solvent mixtures of different compositions. The co-solvents used in this study were both aprotic solvents including tetrahydrofuran, acetonitrile and N,N-dimethylformamide and protic solvents, such as ethanol and 2-propanol. It was found that in aprotic solvents the conversion of the isocyano group to amino moiety takes place, while in protic solvents the corresponding carbamate (urethane) group is formed in addition to the amino moiety. The variation of the resulting fluorescence intensities versus time curves were described using an irreversible, consecutive reaction model, in which the formation of isocyanate and carbamic acid intermediates, as well as diamino and carbamate (in the case of protic solvents) products were assumed. The formation of these intermediates and products was unambiguously confirmed by mass spectrometric measurements. Furthermore, by fitting the model to the experimental fluorescence versus time curves, the corresponding rate coefficients were determined. It was observed that the overall rate of transformation of the isocyano group to amino moiety increased with the water concentration and the polarity of the co-solvent. It was also supported that formation of diamino and carbamate derivatives in protic solvents takes place simultaneously and that the ratio of the amino to the carbamate function increased with the increasing water concentration. In addition, with an extension, the model presented herein proved to be capable of describing the kinetics of the transformation of 1,5-diisocyanonaphthalene (1,5-DIN) into 1,5-diaminonaphthalene (1,5-DAN) in the mixtures of water/aprotic solvents.
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13

Closca, V., N. Puica-Melniciuc, M. Closca, I. M. Avadanei, and D. O. Dorohoi. "Spectral Study of (4´-Phenyl)-1,2,4-Triazol-1-Ium-Phenacylid (PTPhY) in Ternary Solutions." Ukrainian Journal of Physics 63, no. 7 (August 2, 2018): 592. http://dx.doi.org/10.15407/ujpe63.7.592.

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The molecule of (4 ′-phenyl)-1,2,4-triazol-1-ium-phenacylid (PTPhY) is studied in two types of ternary solutions. In the first category, the binary solvent contains two hydroxyl miscible liquids, and the second one contains one protic and one non-protic solvents. The potential energy in pairs of the type hydroxyl solvent-ylid is estimated in the frame of the statistical cell model of ternary solutions. From the viewpoint of interactions in the first ylid solvation shell, the statistical average weight of the active solvent differs from its molar fraction in the binary solvent.
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14

Jankulovska, Mirjana, Lidija Šoptrajanova, Ilinka Spirevska, Katica Čolančevska-Ragenoviќ, and Saško Ristovski. "Investigation of solvent effects on electronic absorption spectra of some substituted 1,2,4-triazoline-3-thiones." Macedonian Journal of Chemistry and Chemical Engineering 29, no. 1 (June 15, 2010): 43. http://dx.doi.org/10.20450/mjcce.2010.171.

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The influence of the polarity of the solvent and hydrogen bonding on the electronic absorption spectra of some previously synthesized substituted 1,2,4-triazoline-3-thiones was studied. The electronic absorption spectra of investigated compounds were recorded in the region from 190 nm to 360 nm in eight protic (water, ethylene glycol, methanol, ethanol, propan-1-ol, propan-2-ol, butan-1-ol and tert-butanol) and five aprotic (acetonitrile, chloroform, dimethylsulfoxide, dimethylformamide and dioxane) solvents. Their absorption maxima appeared in the region between 250 nm and 260 nm as a result of the electron transitions in the 1,2,4-triazoline-3-thione ring. Using the method of linear solvation energy relationships (LSER), the effects of solvent polarity and hydrogen bonding on the electronic absorption spectra were interpreted. The results have shown that the influence of the aprotic solvents is more significant compared to that of the protic solvents.
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15

Dimova, Vesna B., and Nada U. Perišić-Janjić. "Solvatochromism studies on UV spectra of 4,5-disubstituted-1,2,4-triazoline-3-thiones." Macedonian Journal of Chemistry and Chemical Engineering 31, no. 1 (June 15, 2012): 89. http://dx.doi.org/10.20450/mjcce.2012.60.

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The influence of a series of organic solvents on the UV spectra of investigated 1,2,4-triazoles, was studied by implementing solvatochromic theory. As a part of our efforts to interpret the effects of solvent polarity and hydrogen bonding on the absorption spectra of previously synthesized 1,2,4-triazoline-3-thiones, the study design was based on the linear solvation energy relationship (LSER) concept using Kamlet-Taft solvatochromic parameters: π*, α and β. Accordingly, by dividing the solvents into two groups (protic and aprotic) it was ascertained that improved solvatochromic three-correlation models for the group of protic solvents were obtained. The results show that the solvent effect on UV absorption spectra of investigated thiones was very complex and strongly dependent on the nature of the substituent in positions 4 and 5 in 1,2,4-triazole moiety. Moreover, the statistical evaluation of the models (R, SD, Q2 and PRESS/SSY) showed satisfactory values.
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16

Vu Bao, Khanh, Phat Huynh Van, Truc Nguyen Kim, An Tran Nguyen Minh, Cuong Nguyen Van, and Khoa Phung Thanh. "The effect of protic solvents in the conversion of lignin from Earleaf Acacia tree." Vietnam Journal of Catalysis and Adsorption 11, no. 1 (October 5, 2021): 122–25. http://dx.doi.org/10.51316/jca.2022.019.

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Lignin is one of main components of lignocellulosic along with cellulose and hemicellulose. It is a by-product of the paper and pulp industry, and has aromatic backbones making them an ideal renewable feedstock of aromatic compounds for a range of applications. Catalytic conversion of lignin from Earleaf Acacia tree was performed using high pressure/temperature reactor with Ru/C catalyst and protic solvents. The results showed that the conversion of lignin depends on the solvent polarity of protic solvents, and Ru/C catalyst enhanced the lignin conversion. Phenolic compounds are the main components of lignin conversion. Those compounds can be applied as a basement for bulk chemical and fuels.
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17

Nikolic, Jasmina, Gordana Uscumlic, and Vera Krstic. "Solvent effect on electronic absorption spectra of cyclohex-1-enylcarboxylic and 2-methylcyclohex-1-enylcarboxylic acids." Journal of the Serbian Chemical Society 65, no. 5-6 (2000): 353–59. http://dx.doi.org/10.2298/jsc0006353n.

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The ultraviolet absorption spectra of cyclohex-1-enylcarboxylic acid and 2- methylcyclohex-1-enylcarboxylic acid were determined in six protic and nine aprotic solvents in the wavelength range from 200 to 400 nm. The position of the ?max of the two examined acids showed that the ultraviolet absorption maximums of cyclohex-1-enylcarboxylic acid were at consistently longer wavelengths in protic solvents than those of methylcyclohex-1-enylcarboxylic acid. The opposite was true in aprotic solvents. In order to explain the obtained results, the ultraviolet absorption frequencies of the electronic transitions in the carboxy carbonyl group of the examined acids were correlated using a total solvatochromic equation of the form: v = v0 + s?* + a? + b?, where ?* is a measure of the solvent polarity, ? represents the scale of solvent hydrogen bond acceptor basicities and a represents the scale of solvent hydrogen bond donor acidities. The correlation of the spectroscopic data was carried out by means of multiple linear regression analysis. The opposing solvent effects on the ultraviolet absorption maximums of the two examined acids were discussed.
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18

Jiao, Shu Fei, Yan Zhen Yin, Xiong Gan, Xiao Xi Hu, Zhong Feng Shi, and Yun Wang. "Solvent-Dependent Catalytic Behavior of Hydrophobic Guest Artificial Glutathione Peroxidase Determined Using H2O2 and 4-Nitrobenzenethiol as Substrates." Advanced Materials Research 926-930 (May 2014): 230–33. http://dx.doi.org/10.4028/www.scientific.net/amr.926-930.230.

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Using H2O2 and 4-nitrobenzenethiol as substrates, the catalytic behavior of a hydrophobic guest artificial glutathione peroxidase (GPx) (ADA-Te-ADA) was detailed investigated. The relation between the catalytic rate of ADA-Te-ADA and the property of solvent used in the determination of catalytic rate was revealed. Typically, Ethanol, DMSO, DMF and CH3CN were selected as the co-solvents in the determination of catalytic rates. It indicated that ADA-Te-ADA exhibited the typical solvent-dependent catalytic behavior. Especially, the higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial GPx. Additionally, the strong polarity of polar aprotic solvent plays an important role in the enhancement of GPx catalytic activity. This study bodes well for the understanding of the catalytic behavior of hydrophobic guest artificial GPx .
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19

Yin, Yan Zhen, Shu Fei Jiao, Xiong Gan, Zhong Feng Shi, Xiao Xi Hu, and Yun Wang. "Investigation of Solvent-Dependent Catalytic Behavior of a Hydrophobic Guest Artificial Glutathione Peroxidase." Advanced Materials Research 940 (June 2014): 20–23. http://dx.doi.org/10.4028/www.scientific.net/amr.940.20.

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The investigation of the catalytic behavior of a hydrophobic guest artificial glutathione peroxidase (GPx) (ADA-Te-ADA) was carried out employing H2O2 and 3-carboxyl-4-nitrobenzenethiolas (TNB) as substrates. The relation between the catalytic rate of ADA-Te-ADA and the property of solvent used in the determination of catalytic activity was revealed. Typically, the co-solvents including ethanol, DMSO, DMF and CH3CN were employed in the determination of catalytic rates. It indicated that ADA-Te-ADA exhibited the typical solvent-dependent catalytic behavior. Especially, the higher catalytic rate was observed when polar protic solvent (ethanol) was used compared with other co-solvents. It suggested that polar protic solvent was the appropriate co-solvent for the assay of catalytic activity of hydrophobic artificial GPx. Additionally, the strong polarity of polar aprotic solvent plays an important role in the enhancement of GPx catalytic activity. This study bodes well for the understanding of the catalytic behavior of hydrophobic guest artificial GPx.
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20

Lavendomme, Roy, Lionel Marcélis, Johan Wouters, Michel Luhmer, and Ivan Jabin. "A nano-sized container for specific encapsulation of isolated water molecules." Chemical Communications 52, no. 98 (2016): 14109–12. http://dx.doi.org/10.1039/c6cc08096k.

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21

Alshahateet, Solhe F., Mohan M. Bhadbhade, Roger Bishop, and Marcia L. Scudder. "Different solvents yield alternative crystal forms through aromatic, halogen bonding and hydrogen bonding competition." CrystEngComm 17, no. 4 (2015): 877–88. http://dx.doi.org/10.1039/c4ce02109f.

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X-ray crystallography shows that entirely different structures are produced when the dichlorodiquinoline derivative is crystallised from aprotic dimethylformamide or from protic solvents like methanol or acetic acid, demonstrating the importance of solvent choice in yielding alternative crystal forms.
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22

Pytela, Oldřich, Taťjana Nevěčná, and Miroslav Ludwig. "Solvent effects on kinetics and mechanism of acid-catalyzed decomposition of 1,3-bis(4-methylphenyl)-triazene II. Reactions in aprotic solvents." Collection of Czechoslovak Chemical Communications 55, no. 1 (1990): 156–64. http://dx.doi.org/10.1135/cccc19900156.

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The effect of aprotic solvents (hexane, cyclohexane, dichloromethane, 1,2-dichloroethane, benzene, acetonitrile, acetone, 1,2-dimethoxyethane, ethyl acetate, dioxane) on kinetics and mechanism of acid-catalyzed decomposition of 1,3-bis(4-methylphenyl)triazene has been studied with trichloroacetic acid as the acid catalyst. It has been found that beside the non-dissociated monomer of the acid also its dimer acts as the catalytic species. With regard to the results obtained in protic solvents (the catalysis by proton and general acid) three cases can be encountered of the dependence of observed rate constant on analytical concentration of the acid. The effect of solvents (inclusive of the protic ones) on the catalytic rate constant of the reaction with the non-dissociated monomer of acid is best interpreted by the equation suggested by Koppel and Palm and by the solvent scale suggested by us earlier. The solvent acidity and polarity have positive effect, whereas its basicity has negative effect. The catalytic rate constant of the reaction with the acid dimer decreases with increasing solvent basicity and polarity, due predominantly to the decrease in the equilibrium constant of dimerization.
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23

Pavlovich, Vladimir S. "Gas-phase energy of the S2←S0 transition and electrostatic properties of the S2 state of carotenoid peridinin via a solvatochromic shift and orientation broadening of the absorption spectrum." Photochem. Photobiol. Sci. 13, no. 10 (2014): 1444–55. http://dx.doi.org/10.1039/c4pp00124a.

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The solvent effect on the position and the shape of the absorption spectrum of peridinin for 12 protic and aprotic solvents as well as the temperature effect for methanol were studied using a solvatochromic theory based on the Onsager sphere cavity model.
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24

Bakuru, Vasudeva Rao, Debabrata Samanta, Tapas Kumar Maji, and Suresh Babu Kalidindi. "Transfer hydrogenation of alkynes into alkenes by ammonia borane over Pd-MOF catalysts." Dalton Transactions 49, no. 16 (2020): 5024–28. http://dx.doi.org/10.1039/d0dt00472c.

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25

Wijaya, Emmy C., Frances Separovic, Calum J. Drummond, and Tamar L. Greaves. "Micelle formation of a non-ionic surfactant in non-aqueous molecular solvents and protic ionic liquids (PILs)." Physical Chemistry Chemical Physics 18, no. 35 (2016): 24377–86. http://dx.doi.org/10.1039/c6cp03332f.

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Micelle formation of a non-ionic amphiphile, C12E6, was investigated in a diverse range of molecular solvents and protic ionic liquids (PILs). A link between the solvent cohesive energy density and the free energy of micellization was discussed.
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26

Pithan, Phil M., David Decker, Manlio Sutero Sardo, Giampietro Viola, and Heiko Ihmels. "Synthesis and fluorosolvatochromism of 3-arylnaphtho[1,2-b]quinolizinium derivatives." Beilstein Journal of Organic Chemistry 12 (May 2, 2016): 854–62. http://dx.doi.org/10.3762/bjoc.12.84.

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Cationic biaryl derivatives were synthesized by Suzuki–Miyaura coupling of 3-bromonaphtho[1,2-b]quinolizinium bromide with arylboronic acids. The resulting cationic biaryl derivatives exhibit pronounced fluorosolvatochromic properties. First photophysical studies in different solvents showed that the emission energy of the biaryl derivatives decreases with increasing solvent polarity. This red-shifted emission in polar solvents is explained by a charge shift (CS) in the excited state and subsequent solvent relaxation. Furthermore, the polarity of protic polar and aprotic polar solvents affects the emission energy to different extent, which indicates a major influence of hydrogen bonding on the stabilization of the ground and excited states.
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27

Roopesh Kumar, L., N. R. Sagar, K. Divya, C. Madhu, and Vommina V. Sureshbabu. "Synthesis of an amino phosphinodiselenoic acid ester and β-amino diselenides employing P2Se5." New Journal of Chemistry 44, no. 18 (2020): 7261–64. http://dx.doi.org/10.1039/d0nj00012d.

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28

Yalcin, Dilek, Andrew J. Christofferson, Calum J. Drummond, and Tamar L. Greaves. "Solvation properties of protic ionic liquid–molecular solvent mixtures." Physical Chemistry Chemical Physics 22, no. 19 (2020): 10995–1011. http://dx.doi.org/10.1039/d0cp00201a.

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In this study, we have investigated the solvation properties of binary mixtures of PILs with molecular solvents. The selected binary solvent systems are the PILs ethylammonium nitrate (EAN) and propylammonium nitrate (PAN) combined with either water, methanol, acetonitrile or DMSO.
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29

Dyker, Gerald, and Richard P. Kreher. "Struktur und Reaktivität von isoanellierten heterocyclischen Systemen mit 4nπ- und (4n+2)π-Elektronen, XVII [1] Diels-Aider- und Michael-Additionsreaktionen von 3-Alkoxy-2,4-dihydropyrrolo[3,4-b]indolen mit Ethindicarbonsäuredialkylestern / Structure and Reactivity of Isoannelated Heterocyclic Systems with 4nπ- and (4n+2)π-Electrons, XVII [1] Diels-Alder and Michael Addition Reactions of 3-Alkoxy-2,4-dihydropyrrolo[3,4-b]indoles with Dialkyl Acetylenedicarboxylates." Zeitschrift für Naturforschung B 43, no. 12 (December 1, 1988): 1656–61. http://dx.doi.org/10.1515/znb-1988-1221.

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Abstract The reactions of 2-rm-butyl-3-methoxy-4-methyl-2,4-dihydropyrrolo[3,4-b]indole (3) with dialkyl acetylenedicarboxylates are decisively influenced by the solvent. In the presence of alcohols as protic and polar solvents Michael addition is prefered, while in aprotic and less polar solvents like ether the Diels-Alder reaction is favoured. Based on stereospecific hydrolysis and isotopic labeling dipolar intermediates are discussed. The results are of current interest for mechanistic and theoretical reasons
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30

Chevreux, S., C. Allain, L. Wilbraham, K. Nakatani, P. Jacques, I. Ciofini, and G. Lemercier. "Solvent tuned single molecule dual emission in protic solvents: effect of polarity and H-bonding." Faraday Discussions 185 (2015): 285–97. http://dx.doi.org/10.1039/c5fd00054h.

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Phen-PENMe2 has recently been proposed as a promising new molecule displaying solvent-tuned dual emission, highlighting an original and newly-described charge transfer model. The study of the photophysical behaviour of this molecule was extended to include protic solvents. The effects of polarity and hydrogen bonding lead to an even more evident dual emission associated with a large multi-emission band in some solvents like methanol, highlighting Phen-PENMe2 as a promising candidate for white light emission.
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31

Ono, Fumiyasu, Hisayuki Watanabe, and Seiji Shinkai. "Structural optimization of super-gelators derived from naturally-occurring mannose and their morphological diversity." RSC Adv. 4, no. 49 (2014): 25940–47. http://dx.doi.org/10.1039/c4ra03096f.

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32

Nagareddy, V. Kartheek, D. Kurt Gaskill, J. L. Tedesco, Rachael L. Myers-Ward, Charles R. Eddy, Jonathan P. Goss, Nicolas G. Wright, and Alton B. Horsfall. "Temperature Dependent Chemical Sensitivity of Epitaxial Graphene." Materials Science Forum 717-720 (May 2012): 691–94. http://dx.doi.org/10.4028/www.scientific.net/msf.717-720.691.

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We investigated the chemical sensing mechanism of epitaxial graphene grown on 6H-SiC (0001) to different polar solvents and their behavior at higher temperatures. We show that at 300 K the sensitivity of the graphene sensor increases exponentially with the dipole moment of a solvent and decreases significantly as the temperature increased to 425 K. Using electrical measurements, we also show that graphene can effectively discriminate between polar protic and polar aprotic solvents with the shift in device electrical resistance at 300 K.
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33

Ramesh, B., D. Vijaya Bharathi, B. Kavitha, and P. Manikyamba. "Linear Solvation Energy Relationship in the Reaction between Phenacyl Bromide and 2-Mercaptobenzothiazole." Progress in Reaction Kinetics and Mechanism 34, no. 3 (August 2009): 239–48. http://dx.doi.org/10.3184/146867809x466195.

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The reaction between phenacyl bromide and 2-mercaptobenzothiazole was studied conductometrically in 17 different protic and aprotic solvents. The second order rate constants determined are found to be highly susceptible to changes in the solvation abilities of the solvents. Correlation of the rate constants with different solvent parameters indicated that the solvation of the reactants and the transition state is due to the electrophilicity, hydrogen bond donor ability, specific polarisability and a non-specific polarity of the solvent. by statistical analysis, a linear solvation energy relationship is derived and the percentage contributions of each type of solvation are estimated.
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34

Abdelhamid, Muhammad E., Graeme A. Snook, Tamar L. Greaves, and Anthony P. O'Mullane. "Electropolymerisation of N-Ethylanilinium Trifluoroacetate Ionic Liquid into Poly(N-Ethylaniline) and Control of its Morphology." Australian Journal of Chemistry 70, no. 9 (2017): 985. http://dx.doi.org/10.1071/ch17258.

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In this paper, the electropolymerisation of pre-synthesised N-ethylanilinium trifluoroacetate, a protic ionic liquid (PIL), was carried out. The PIL served as the monomer precursor, solvent, and supporting electrolyte for the polymerisation process, and no additional acid was required due to the protic nature of the PIL. Two different morphologies of the poly(N-ethylaniline) were achieved by using different electropolymerisation approaches and the resultant films were soluble in the PIL precursor as well as a wide range of organic solvents. The use of anilinium based PILs, as polymerisation precursors, promises a greener approach for the production of polyanilines, as well as highly processable polymers.
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35

Chandramouli, Nagula, Mohammed Farrag El-Behairy, Guillaume Lautrette, Yann Ferrand, and Ivan Huc. "Polar solvent effects on tartaric acid binding by aromatic oligoamide foldamer capsules." Organic & Biomolecular Chemistry 14, no. 8 (2016): 2466–72. http://dx.doi.org/10.1039/c5ob02641e.

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36

Khalilian, M. Hossein, Saber Mirzaei, and Avat (Arman) Taherpour. "Comprehensive insights into the structure and coordination behavior of thiosemicarbazone ligands: a computational assessment of the E–Z interconversion mechanism during coordination." New Journal of Chemistry 39, no. 12 (2015): 9313–24. http://dx.doi.org/10.1039/c5nj02041g.

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The calculations transpired that the isomerization mechanism of thiosemicarbazones is influenced by the solvents, in which the inversion and tautomerization path is the likely mechanisms in aprotic and protic solvents, respectively.
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37

Tariq, Muhammad. "Electrochemistry of Br−/Br2 Redox Couple in Acetonitrile, Methanol and Mix Media of Acetonitrile–Methanol: An Insight into Redox Behavior of Bromide on Platinum (Pt) and Gold (Au) Electrode." Zeitschrift für Physikalische Chemie 234, no. 2 (February 25, 2020): 295–312. http://dx.doi.org/10.1515/zpch-2018-1321.

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AbstractElectro-oxidation of Br− on platinum and gold electrode was studied in acetonitrile, methanol and mix media of acetonitrile–methanol. The mechanism of Br− oxidation in these media was investigated using CV, Semi Integration Cyclic Voltammetry, and Digital Simulation technique. Since, Br− oxidation mechanism on platinum involves the formation of Br3− as intermediate, therefore, Kstab for Br3− formation in the mixed media was estimated using digital simulation, Nelson and Iwamoto method. Redox mechanism of Br− and Br2 on gold (Au) electrode was also investigated in protic solvent such as H2O, methanol, ethanol, 1-butanol, and formic acid. It was ascertained that Br− oxidation on gold (Au) electrode in these above protic solvents involve [AuBr2]− intermediate rather than Br3−.
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38

Mijin, Dusan, Dragana Zlatic, Gordana Uscumlic, and Petar Jovancic. "Solvent effects on photodegradation of CI Reactive Orange 16 by simulated solar light." Chemical Industry 62, no. 5 (2008): 275–81. http://dx.doi.org/10.2298/hemind0805275m.

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Organic solvents may appear in wastewaters and other industrial waste streams containing dyes, therefore, their photodegradation catalyzed by TiO2 should be investigated. Solvent effect on photodegradation of CI Reactive Orange 16 has been studied using simulated solar light and P-25 TiO2. Methyl, ethyl and isopropyl alcohol as well as acetone were used as solvents. Photodegradation reaction was faster in methyl than in ethyl alcohol while in water was the slowest. RO16 photodegradation efficiency and reaction rate decreased in the presence of small concentration of ethanol. Higher photodegradation efficiency was observed for higher ethanol concentration. For acetone, photodegradation decreased as concentration of acetone increased. It seems that protic solvents at higher concentrations promote reaction, while at low concentrations slow down reaction. Aprotic solvents slow down reaction.
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39

Zaman, Shazia, Owen J. Curnow, and Andrew D. Abell. "Development of Aqueous Metathesis Catalysts." Australian Journal of Chemistry 62, no. 2 (2009): 91. http://dx.doi.org/10.1071/ch08470.

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Recent developments (and some historical aspects) of protic solvent metathesis using ill-defined catalysts [e.g., RuCl3·H2O and Ru(H2O)6(tos)2] and also the more easily handled, well-defined ruthenium-based alkylidene complexes (based on 15, 16, and 17) are highlighted. Modification of these catalysts has been achieved for applications in protic solvents with the introduction of water-solubilizing ligands and by immobilization onto a suitable support. The introduction of water-solubilizing cationic and anionic phosphines is synthetically straightforward with various catalysts having been prepared in this way (see 18, 19, 29–32, 36). Immobilzation methods include tethering to a water-soluble polymeric support (see 39, 40) and modification of the benzylidene group (see 43–46). Ionic tags have also been attached to the benzylidene group (see 48–50, 52, 53). Several other approaches have also been reported as discussed here to prepare modified catalysts that display good activity in protic media (see 54–59).
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40

Sueishi, Yoshimi, and Yoko Takashima. "Kinetic and Mechanistic Studies of the Thermal Isomerization of Bismuth Dithizonate." Journal of Chemical Research 2000, no. 4 (April 2000): 193–95. http://dx.doi.org/10.3184/030823400103166922.

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The isomerization rates of bismuth dithizonate (Bi(HD Z)3) having three dithizone ligands have been measured in various kinds of solvents and at high pressures, and the reaction mechanisms in aprotic and protic solvents are discussed.
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41

WIEDERKEHR, Nadir Ana. "A model for specific interactions of manganese-phthalocyanine in protic media." Eclética Química 24 (1999): 45–59. http://dx.doi.org/10.1590/s0100-46701999000100004.

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Extinction coefficients (e) changes of manganese phthalocyanine (Mn-Pc) were studied in different organic solvents and related to solvent polarity scales; (Kosower's values (Z), Dimroth's values (E T), donor numbers (DN) and linear solvation energy relationships (LSER) or linear free energy relationships (LFER));, theoretical molecular orbital calculations and ligand/solvent coordination processes in order to predict molecular interaction with the medium and identification of predominant intermolecular forces.
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42

Falco, Guillaume, Nathanaël Guigo, Luc Vincent, and Nicolas Sbirrazzuoli. "FA Polymerization Disruption by Protic Polar Solvents." Polymers 10, no. 5 (May 15, 2018): 529. http://dx.doi.org/10.3390/polym10050529.

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43

Amaya, Toru, and Julius Rebek. "Hydrogen-Bonded Encapsulation Complexes in Protic Solvents." Journal of the American Chemical Society 126, no. 43 (November 2004): 14149–56. http://dx.doi.org/10.1021/ja0467770.

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44

Favier, Isabelle, and Elisabet Duñach. "New protic salts of aprotic polar solvents." Tetrahedron Letters 45, no. 17 (April 2004): 3393–95. http://dx.doi.org/10.1016/j.tetlet.2004.03.025.

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45

Rossini, Emanuele, and Ernst-Walter Knapp. "Proton solvation in protic and aprotic solvents." Journal of Computational Chemistry 37, no. 12 (January 19, 2016): 1082–91. http://dx.doi.org/10.1002/jcc.24297.

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46

Dib, Nahir, Juana J. Silber, N. Mariano Correa, and R. Dario Falcone. "Combination of a protic ionic liquid-like surfactant and biocompatible solvents to generate environmentally friendly anionic reverse micelles." New Journal of Chemistry 43, no. 26 (2019): 10398–404. http://dx.doi.org/10.1039/c9nj02268f.

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47

Alauddin, Md. "Effect of solvents and temperature on the structural, thermodynamic and electronic properties of capped phenylalanine: A computational study." Journal of Bangladesh Academy of Sciences 45, no. 2 (January 26, 2022): 205–15. http://dx.doi.org/10.3329/jbas.v45i2.57212.

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Effects of solvents and temperature on the structural, thermodynamic, and electronic properties of L-configuration of N-acetyl-phenylalaninyl amide (NAPA) were studied using density functional theory (DFT) and time-dependent density functional theory (TD-DFT) approach. Enthalpy (H), entropy (S) and specific heat capacity (Cv) were found to increase with the increase of temperature (100 K-1600 K) because of the increasing intensities of molecular vibration. On the contrary, Gibb’s free energy (G) was found to decrease with the increase of temperature. The UV-light absorption maximum, λmax, is red-shifted in the presence of polar protic, aprotic and non-polar solvents. On the other hand, calculation shows that dipole moment in polar solvents (protic and aprotic), non-polar solvents, and the gas phase are ~3.35, ~3.0, and 2.5 D, respectively. However, no significant change was found in the HOMO-LUMO energy gap in the presence of different types of solvents. J. Bangladesh Acad. Sci. 45(2); 205-215: December 2021
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48

Ono, Kosuke, Yohei Tohyama, Tatsuhiro Uchikura, Yuji Kikuchi, Kotaro Fujii, Hidehiro Uekusa, and Nobuharu Iwasawa. "Control of the reversibility during boronic ester formation: application to the construction of ferrocene dimers and trimers." Dalton Transactions 46, no. 7 (2017): 2370–76. http://dx.doi.org/10.1039/c6dt04845e.

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49

Hlaváček, Jan, Ivo Frič, Miloš Buděšínský, and Karel Bláha. "An alternative route to Nα-methylamino acid derivatives: Synthesis and conformation of some Nα-acetyl-Nα-methylamino acid methylamides." Collection of Czechoslovak Chemical Communications 53, no. 11 (1988): 2473–94. http://dx.doi.org/10.1135/cccc19882473.

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The methylation of tert-butyl- or isopropyl- esters of Nα-4-toluenesulfonyl-amino acids by dimethylsulfate in aqueous alkaline solution in the presence of a detergent gives the corresponding Nα-methylderivatives. Using this synthetic route the Nα-acetylderivatives of MeAla, MeLeu, MeOrn and MePhe methylamides have been prepared and the solution conformation of these dipeptide units has been investigated. 1H and 13C NMR spectra show that, while in dimethylsulfoxide the tertiary amide group is mostly in cis-conformation, in protic solvents the equilibrium is shifted towards trans-conformation. Circular dichroism spectra reveal some specific features (e.g. high band intensities in protic solvents) which cannot be explained solely on the basis of the increased rigidity caused by the Nα-methyl group. We tried to explain these effects supposing that the tertiary amide group is deviated from the planar arrangement (due to the interaction between the methyl groups, a substituent on Cα and a solvent molecule attached to the oxygen atom) and contributes to the observed circular dichroism as the inherently chiral chromophore.
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50

Baaqel, Husain, Ismael Díaz, Víctor Tulus, Benoît Chachuat, Gonzalo Guillén-Gosálbez, and Jason P. Hallett. "Role of life-cycle externalities in the valuation of protic ionic liquids – a case study in biomass pretreatment solvents." Green Chemistry 22, no. 10 (2020): 3132–40. http://dx.doi.org/10.1039/d0gc00058b.

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