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Relevant bibliographies by topics / Carbonyl compounds – Spectra

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Academic literature on the topic 'Carbonyl compounds – Spectra'

Author: Grafiati

Published: 4 June 2021

Last updated: 10 February 2022

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Journal articles on the topic "Carbonyl compounds – Spectra"

1

Coleman, W. M., and Bert M. Gordon. "Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds. Part V." Applied Spectroscopy 41, no. 8 (1987): 1431–38. http://dx.doi.org/10.1366/0003702874447284.

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MI/FT-IR spectral data have been collected on selected types of organic compounds containing the carbonyl group. By the varying of the ratio of the matrix gas to the compound ( M/E) as well as the matrix gas (Ar vs. Xe), the observed splitting of the carbonyl absorption band was attributed to both conformer isolation and aggregation in the matrix. The splitting of the carbonyl group of methyl acetate was attributed to aggregation, while conformer isolation was found to exist for phenyl acetate and trimethylacetaldehyde. The magnitude of the splittings found in this study, 3–30 cm−1, is within

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2

Lin, Zhong-Ping, and Walter A. Aue. "Gas-phase luminescence of aromatic carbonyl compounds in excited nitrogen at atmospheric pressure." Canadian Journal of Chemistry 78, no. 1 (2000): 95–117. http://dx.doi.org/10.1139/v99-203.

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Certain types of aroyl compounds such as benzaldehyde, acetophenone, benzophenone, and anthraquinone produce intense gas-phase luminescence in excited nitrogen at atmospheric pressure. This luminescence was measured in pressure ranges of 1.001.67 atm and temperature ranges of 343473 K. A novel, radioactively (Ni-63) stimulated, high-voltage( [Formula: see text]1750 V/mm), low-current ( [Formula: see text]35 nA) discharge in high-purity nitrogen was used for gas chromatographic detection and spectral excitation. The gas-phase luminescence spectra of about sixty aroyl compounds - introduced as

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3

Coleman, W. M., and Bert M. Gordon. "Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part III." Applied Spectroscopy 41, no. 7 (1987): 1163–69. http://dx.doi.org/10.1366/0003702874447671.

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Matrix-isolated (MI) Fourier transform infrared spectra (FT-IR) have been collected on a series of esters and ketones. The values for the carbonyl absorption are intermediate between the values for vapor-phase (VP) and solid-state (SS) phases. The spectra reveal a splitting or broadening of the carbonyl absorption in the majority of cases for both compound types. The splitting, on the order of 5 to 10 cm−1, does not appear to be a function of concentration at ≤20 ng on the cryogenic disk. The splitting is also not unequivocally due to steric hindrance about the carbonyl group. Compounds with l

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4

Nyquist, Richard A. "Factors Affecting Infrared Group Frequencies: Carbonyl Stretching Absorption Bands." Applied Spectroscopy 40, no. 3 (1986): 336–39. http://dx.doi.org/10.1366/0003702864509105.

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The data presented show that infrared group frequencies are only applicable for specific spectra structure identification when the infrared spectrum of the unknown material is recorded in the same manner as that used to record the infrared spectra used to build the IR group-frequency data base. IR spectra recorded of compounds in different phases such as the liquid, solution, and vapor phase are useful in helping one to determine whether a compound exists in more than one rotational molecular configuration such as rotation of a CHCl2 group about a C-C=O single bond in compounds of form CHCl2-C

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5

Coleman, W. M., and Bert M. Gordon. "Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part VI." Applied Spectroscopy 42, no. 1 (1988): 101–8. http://dx.doi.org/10.1366/0003702884428545.

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Matrix isolation Fourier transform spectral evidence is presented that documents the isolation of rotational isomers in an argon matrix. The spectral evidence is based on the presence of split carbonyl absorption bands in the spectra of selected derivatives of methyl acetate which do not vary in intensity with changes in the matrix-to-eluate ratios. The results compare very favorably with FT-IR data on the identical compounds obtained in the vapor phase. The low temperature of the matrix isolation experiment (10 K) allows for the observance of rotational isomers not seen at the high temperatur

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Coleman, W. M., and Bert M. Gordon. "Examination of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part II." Applied Spectroscopy 41, no. 7 (1987): 1159–62. http://dx.doi.org/10.1366/0003702874447446.

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Matrix-isolated (MI) Fourier transform infrared spectra have been collected on a series of aliphatic ketones. The values for the carbonyl absorptions maxima are intermediate between vapor-phase (VP) and solid-state solution (SS) phases. The data reveal a stereochemical influence on the position of the ketone carbonyl absorption when the carbons that are in the alpha position with respect to the carbonyl group contain alkyl snbstituents vs. protons. Steric bulk causes the frequency of the absorption to decrease. The position of the ketone carbonyl absorption was also shown to decrease as the ca

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7

Kohls, Emilija, and Matthias Stein. "VIBRATIONAL SCALING FACTORS FOR Rh(I) CARBONYL COMPOUNDS IN HOMOGENEOUS CATALYSIS." Contributions, Section of Natural, Mathematical and Biotechnical Sciences 38, no. 1 (2017): 43. http://dx.doi.org/10.20903/csnmbs.masa.2017.38.1.100.

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Metal carbonyl complexes are an important family of catalysts in homogeneous industrial processes. Their characteristic vibrational frequencies allow in situ tracking of catalytic progress. Structural assignment of intermedi-ates is often hampered by the lack of appropriate reference compounds. The calculation of carbonyl vibrational fre-quencies from first principles provides an alternative tool to identify such reactive intermediates. Scaling factors for computed vibrational carbonyl stretching frequencies were derived from a training set of 45 Rh-carbonyl complexes using the BP86 and B3LYP

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8

Yue, Wang, Liu Ju-Zheng, Jiang Shi-Mei, and Liang Ying-Qiu. "Spectra Studies of Titanium and Vanadium-Pentadienyl-Carbonyl Compounds." Acta Physico-Chimica Sinica 10, no. 04 (1994): 319–23. http://dx.doi.org/10.3866/pku.whxb19940407.

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9

Zaki, Dr Remon M., Prof Adel M. Kamal El-Dean, Dr Nermin A. Marzouk, Prof Jehan A. Micky, and Mrs Rasha H. Ahmed. "A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE." JOURNAL OF ADVANCES IN CHEMISTRY 12, no. 1 (2015): 3910–18. http://dx.doi.org/10.24297/jac.v12i1.845.

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Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carb

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Bratu, I., F. Veiga, C. Fernandes, A. Hernanz та J. M. Gavira. "Infrared spectroscopic study of triacetyl‒β‒cyclodextrin and its inclusion complex with nicardipine". Spectroscopy 18, № 3 (2004): 459–67. http://dx.doi.org/10.1155/2004/727869.

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Infrared spectra of inclusion compounds of triacetyl‒β‒cyclodextrin with nicardipine hydrochloride were compared and analysed with those corresponding to their physical mixture and the pure compounds, respectively. Different O–H stretching vibrations, assigned to water molecules, were located in the Fourier Transform Infrared (FT IR) spectra of triacetyl‒β‒cyclodextrin, and its inclusion complex with nicardipine obtained by spray‒drying (SD) method. Water molecules involved in various hydrogen bonds environments change their status during complexation process. Evidences are observed of the for

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Dissertations / Theses on the topic "Carbonyl compounds – Spectra"

1

Keiller, B. T. "The vibrational spectra of metal cluster compounds containing organic ligands." Thesis, University of East Anglia, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383722.

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Filipczyk, Grzegorz Paweł. "Ferrocenyl-Alkynes and Butadiynes: Reaction Behavior towards Cobalt and Iron Carbonyl Compounds." Doctoral thesis, Universitätsbibliothek Chemnitz, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-231913.

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Die vorliegende Dissertation beschreibt die Synthese und Charakterisierung von neuartigen perferrocenylierten, cyclischen Komplexen unter Anwendung der Cobalt-vermittelten Cyclomerisierung in Kombination mit einer C-H-Bindungsaktivierung als auch die Bildung von ferrocenylierten Phosphinoalkinid-Komplexen mit Eisen- und Cobaltcarbonylen. Die elektrochemischen Eigenschaften und die Elektronentransfer-prozesse zwischen den terminalen Ferrocenyleinheiten in den unterschiedlichen cyclischen Verbindungen wurden unter Einbeziehung der Struktur/chemischen Zusammensetzung der Brückenbausteine ermittel

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Malard, L. M., D. Nishide, L. G. Dias, et al. "Resonance Raman study of polyynes encapsulated in single-wall carbon nanotubes." American Physical Society, 2007. http://hdl.handle.net/2237/11303.

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Brookes, Matthew Daniel. "High resolution infrared spectroscopy of jet-cooled molecules." Thesis, University of Oxford, 1995. http://ora.ox.ac.uk/objects/uuid:81958380-6230-454d-bb44-bfb57d887749.

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The development and implementation of a high resolution, direct absorption, rapidscanning infrared diode laser spectrometer incorporating a supersonic jet expansion source is described. High sensitivity is achieved by directly modulating absorption signals at frequencies in excess of 50 kHz, enabling their separation from lower frequency mechanical and diode 1/f noise. This is accomplished by rapidly scanning the diode laser across a small frequency window (~0.5-1.5cm<sup>-1</sup>) synchronously with a pulsed supersonic expansion in a time period of 1 or 2 ms. Absorptions appear as small atten

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Ngono, Bernadette. "Organométalliques à carbonyle masqué : quelques propriétés du lithio-1 triméthylsiloxy-2 éthylène." Rouen, 1989. http://www.theses.fr/1989ROUES021.

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La condensation du lithio-1 triméthylsiloxy-2 éthylène avec les chlorotrialkylsilanes et le triflate de t-butyldiméthylsilyle conduit aux éthers d'énols silyles -silyles. L'hydrolyse acide de ces derniers permet d'isoler le t-butyldiméthylsilyl acétaldéhyde. D'autre part, la condensation du lithio-1 triméthylsiloxy-2 éthylène avec les chlorures d'acides non énolisables conduit a des esters d'énols de -cétoaldéhydes

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Brodbeck, Claude. "Transitions doubles induites par collisions dans des melanges gazeux comprimes." Paris 6, 1987. http://www.theses.fr/1987PA066285.

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Etude des transitions doubles (simultanees) correspondant a l'absorption d'un seul photon par deux molecules en interaction pour les systemes gazeux comprimes : h::(2) + cf::(4) ou sf::(6), o::(2) ou n::(2) + sf::(6), n::(2) + co::(2). Determination de coefficients d'absorption binaire integres et des profils normalises que l'on compare aux valeurs theoriques calculees en utilisant le moment dipolaire induit et l'intensite de la transition induite en fonction des regles de selection sur les nombres quantiques. Choix des differents parametres caracterisant les deux molecules et leur potentiel d

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Clowes, Steven Kenneth. "Experimental studies of surface-adsorbate interactions and surface magnetism." Thesis, University of York, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323531.

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Cantalapiedra, Nuria Aboitiz. "Intramolecular hydrogen-bonding studies by NMR spectroscopy." Thesis, University of Liverpool, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.366715.

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Campbell, Susan Christina. "Pharmaceutical polymorphism : an investigation using solid-state nuclear magnetic resonance spectroscopy." Thesis, Durham University, 1998. http://etheses.dur.ac.uk/5021/.

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The study of two pharmaceutically active systems that each display polymorphism has provided a platform upon which to develop and apply solid-state NMR techniques in order to increase the understanding of the solid-state structure of small organic molecules. The multidisciplinary approach adopted has highlighted the advantages of solid-state NMR as a non-invasive probe of molecular conformation and crystallographic packing.Carbon-13 CP/MAS spectra of the two polymorphs of BRL55834 - a fluorinated benzopyran derivative - immediately suggest the presence of one and three molecules in the asymmet

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Sun, Xue-Zhong. "Fast infrared spectroscopy in supercritical fluids." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311743.

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Books on the topic "Carbonyl compounds – Spectra"

1

Nyquist, Richard A. IR and NMR spectral data-structure correlations for the carbonyl group. Sadtler Research Laboratories, 1986.

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2

Tielens, A. G. G. M., Tokunaga Alan Takashi 1949-, and United States. National Aeronautics and Space Administration., eds. Solid carbonyl sulphide (OCS) in W33A. National Aeronautics and Space Administration, 1995.

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3

Keller, Cornelius, Rudolf Keim, Michael Bickel, et al. Th Thorium: General Properties. Spectra. Recoil Reactions. Springer, 2013.

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Book chapters on the topic "Carbonyl compounds – Spectra"

1

Mayo, Dana W. "Spectra of Carbonyl Compounds of All Kinds (Factors Affecting Carbonyl Group Frequencies)." In Course Notes on the Interpretation of Infrared and Raman Spectra. John Wiley & Sons, Inc., 2004. http://dx.doi.org/10.1002/0471690082.ch7.

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Heath, Graham A., and David G. Humphrey. "The Optical Spectra and Voltammetry of Mixed Halide / Nitrile / Carbonyl Osmium(III) Complexes. Additive and Non-Additive Effects." In Molecular Electrochemistry of Inorganic, Bioinorganic and Organometallic Compounds. Springer Netherlands, 1993. http://dx.doi.org/10.1007/978-94-011-1628-2_54.

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3

Maskevich, A. A., V. I. Stepuro, S. A. Maskevich, A. A. Solodunov, and I. I. Stepuro. "Study of Spectral Properties and Redox Reactions of Ferro and Ferri Forms of Modificated by Carbonyl Compounds Hemoglobin under Visible and UV Light Aging." In Spectroscopy of Biological Molecules. Springer Netherlands, 1995. http://dx.doi.org/10.1007/978-94-011-0371-8_110.

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4

METZLER, C. M., R. VISWANATH, and D. E. METZLER. "Equilibria and Absorption Spectra of Tryptophanase." In Enzymes Dependent on Pyridoxal Phosphate and Other Carbonyl Compounds As Cofactors. Elsevier, 1991. http://dx.doi.org/10.1016/b978-0-08-040820-0.50063-7.

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5

Leenheer, Jerry A., and T. I. Noyes. "Acquisition and Interpretation of Liquid-state 1H NMR Spectra of Humic and Fulvic Acids." In Nuclear Magnetic Resonance Spectroscopy in Environment Chemistry. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195097511.003.0023.

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Fourier Transform nuclear magnetic resonance (NMR) spectrometers have become available to many researchers studying humic substances over the last decade. As a result, liquid-state proton (1H) NMR spectrometry has been commonly used to determine the nonexchangeable proton distribution in humic and fulvic acids. The high sensitivity of the 1H nucleus to NMR spectrometry allows spectra to be obtained on a relatively small quantity of sample (10-100 mg) in a short time (10-30 min). 1H NMR spectrometric profiles of humic substances are useful to environmental scientists in determining the source, properties, and degree of transformation (humification) of organic matter that is operationally classified as humic substances. These 1H NMR spectrometric profiles, which provide information about hydrogen distributions in humic substances, are more useful for structural and biogeochemical studies when combined with 13C NMR spectra, which provide information on carbon distributions, and infrared spectra, which provide information on oxygen distributions. These three spectra, in conjunction with elemental composition, molecular weight, and titrimetric data, can then be synthesized to provide average structural characteristics that can be related to source, properties, and degree of humification of the organic material being studied. Special challenges, that are not met when obtaining the spectra of pure compounds, are encountered in obtaining 'H NMR spectra of natural humic substances. These challenges include (1) lack of complete dissolution of macromolecular humic substances at the high concentrations required for NMR studies; (2) significant concentrations of exchangeable protons giving broad peaks that obscure portions of the spectrum; (3) broad peaks of non-exchangeable protons over the entire spectrum that cause difficulties in correct phasing; (4) unstable structures that oxidize, hydrolyze, and structurally rearrange at the high pH conditions under which humic substances are the most soluble; and (5) the presence of unusual structures that complicate straightforward assignment of structure from handbook data. The purposes of this chapter are to describe methods of sample preparation and to provide generally applicable structural assignments whereby 1H NMR spectra suitable for quantitative studies of humic substance structure may be obtained and interpreted.

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Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. "The Theoretical Basis for Assignment by NMR." In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.003.0004.

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The nuclear magnetic resonance (NMR) spectra of two enantiomers are identical. Thus, the first step in using NMR to distinguish between two enantiomers should be to produce different spectra that eventually can be associated with their different stereochemistry (i.e., the assignment of their absolute configuration). Therefore, it is necessary to introduce a chiral reagent in the NMR media. There are two ways to address this problem. One is to use a chiral solvent, or a chiral agent, that combines with each enantiomer of the substrate to produce diastereomeric complexes/associations that lead to different spectra. This is the so-called chiral solvating agent (CSA) approach; it will not be further discussed here [33–34]. The second approach is to use a chiral auxiliary reagent [13–15] (i.e., a chiral derivatizing agent; CDA) that bonds to the substrate by a covalent linkage. Thus, in the most general method, the two enantiomers of the auxiliary CDA react separately with the substrate, giving two diastereomeric derivatives whose spectral differences carry information that can be associated with their stereochemistry. The CDA method that employs arylalcoxyacetic acids as auxiliaries is the most frequently used. It can be applied to a number of monofunctionals [14–15] (secondary alcohols [35–43], primary alcohols [44–46], aldehyde [47] and ketone cyanohydrins [48–49], thiols [50–51], primary amines [52–56], and carboxylic acids [57–58]), difunctional [13] (sec/sec-1,2-diols [59–61], sec/sec-1,2-amino alcohols [62], prim/sec-1,2-diols [63–65], prim/sec-1,2-aminoalcohols, and sec/prim-1,2-aminoalcohols [66–68]), and trifunctional (prim/sec/sec-1,2,3-triols [13, 69–70]) chiral compounds. Its scope and limitations are well established, and its theoretical foundations are well known, making it a reliable tool for configurational assignment. Figure 1.1 shows a summary of the steps to be followed for the assignment of absolute configuration of a chiral compound with just one asymmetric carbon and with substituents that, for simplicity, are assumed to resonate as singlets. Step 1 (Figure 1.1a): A substrate of unknown configuration (?) is separately derivatized with the two enantiomers of a chiral auxiliary reagent, (R)-Aux and (S)-Aux, producing two diastereomeric derivatives.

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Hota, Surabhi. "Synchrotron Based Techniques in Soil Analysis: A Modern Approach." In Technology in Agriculture [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.99176.

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Soil is a highly heterogenous system where a number of physical, chemical and biological processes are taking place. The study of these processes requires analytical techniques. The electromagnetic radiations in the form spectroscopy, X-Ray diffraction, magnetic resonance etc. have been used in the field of soil analysis since decades. The study of soil nutrients, mineralogy, organic matter and complex compounds in soils use these techniques and are successful tools till date. But these come with a limitation of lesser spatial and spectral resolution, time consuming sample preparation and destructive methods of study which are mostly ex-situ. In contrast to the conventional spectroscopic techniques, the synchrotron facility is of high precision and enables non-destructive study of the samples to a nano scale. The technique uses the high intensity synchrotron radiation which is produced in a special facility, where the electrons are ejected using very high voltage and accelerated in changing magnetic field, at a speed of light resulting in a very bright radiation that enables a very précised study of the subject. For example, in studying the dynamics of P and N in soils, SR aided XAS are used to study the K-edge spectra of these nutrients, without any matrix interference, which used to be a problem in conventional SEM, IR or NMR spectroscopy. These radiations provide high energy in GeV, which imparts high sensitivity and nanoscale detection. Basically, the SR facility improves the precision of the existing spectroscopic techniques. This chapter discusses how the Synchrotron radiations aid to improve precision in various field of soil analysis such as, carbon chemistry, nutrient dynamics, heavy metal and contaminant speciation and rhizosphere study. However, the technique also come with major limitations of requirement of very high skill for preparation of samples, inadequate availability of references for studies related to absorption spectrum and control of radiation damage. Applications and limitations of the technique thoroughly reviewed in this chapter with an aim to provide a brief idea of this new dimension of soil analysis.

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Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. "Assignment of the Absolute Configuration of Monofunctional Compounds by Double Derivatization." In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.003.0006.

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The assignment of secondary alcohols can be carried out by using one of several CDAs [13–15]. The most used and most reliable ones are MPA, 9-AMA, and MTPA [35–40]. Figure 3.1 shows their structures, the correlation models, and a summary of the experimental conditions. MPA and 9-AMA esters share the same conformational composition [37, 39] and only differ in the intensity of their shieldings; therefore both auxiliaries present the same correlation between sign distribution and stereochemistry. MTPA has a different conformational composition and correlation model [38]. As shown in Chapter 1, MPA esters of secondary alcohols and other AMAA esters (e.g., 9-AMA esters) are composed of two sp/ap conformers in fast equilibrium [37, 39]. The sp conformer is more stable than the ap conformer, and this allows the NMR spectrum of an AMAA ester to be interpreted as if it had originated from just the sp form: carbonyl, Cα, and methoxy groups in the auxiliary part and a methine group (Cα′-H) at the alcohol moiety are in the same plane. When we consider this conformation in the (R)- and the (S)-AMAA esters, the L1 group is located under the shielding cone of the aryl in the (R)-AMAA ester, while the L2 is shielded in the (S)-AMAA ester (we strongly recommended that the reader builds Dreiding, or similar, models to assist in visualizing this spatial array). A subtraction defined as the chemical shift in the (R)-AMAA ester minus that in the (S)-AMAA ester results in a negative value for L1 and a positive one for L2 (i.e., negative ΔδRS for L1 and positive ΔδRS for L2). Therefore, for any secondary alcohol derivatized as an AMAA ester, the protons showing a positive ΔδRS sign are located in the tetrahedron around the asymmetric carbon (Cα′) as L2 (at the back) while the protons resulting in a negative ΔδRS take the position of L1.

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Seco, Josi M., Emilio Quiqoa, and Ricardo Riguera. "Assignment of the Absolute Configuration of Polyfunctional Compounds." In The Assignment of the Absolute Configuration by NMR using Chiral Derivatizing Agents. Oxford University Press, 2015. http://dx.doi.org/10.1093/oso/9780199996803.003.0008.

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From a practical point of view, the assignment of the absolute configuration of sec/sec 1,2- and 1,n-diols does not require the separate derivatization (two different steps with the CDA of choice) of each one of the two hydroxyl groups present in the substrate; on the contrary, it can be carried out by simultaneous derivatization of the two hydroxyls (a single step), leading to the corresponding bis-(R)- and bis-(S)-CDA esters [13, 59–61]. The most used CDAs are 9-AMA and MPA [59, 60], although 1-NMA, 2-NMA, and MTPA are also appropriate [59, 60]. This assignment has an important difference compared to that of monofunctionalized compounds [15]; this is due to the presence in the bis-(R)- and bis-(S)-derivatives of two CDA units that produce distributions of ΔδRS and ΔδSR signs that do not follow the trends found in monoderivatized compounds [13, 15, 82]. This means that the NMR spectra of the bis-CDA derivatives cannot be interpreted as if they had originated from two isolated mono-CDA derivatives [82]. Thus, the correlations described for secondary alcohols [35–39] cannot be applied to diols [59–61] because the chemical shifts and ΔδRS values result from the combination of the anisotropic effects—usually shielding—from the two CDA units and not from a single unit, as happens with monoalcohols. A result of the combination of aromatic shielding effects [59, 60] in diols is that the diagnostic protons/signals for assignment are not always the same as in isolated monoalcohols (i.e., L1/L2). For instance, in acyclic syn-1,2-diols, the diagnostic signals [59, 60] are those corresponding to the protons at the alpha positions of the OH groups (i.e., the hydrogens linked directly to the asymmetric carbons) Hα(R1) and Hα(R2) exclusively. On the other hand, in acyclic anti-1,2-diols, the diagnostic signals are from Hα(R1)/Hα(R2) together with those from R1 and R2. As in the case of monofunctional compounds, the assignment consists [13, 59, 60] in the preparation of two bis-CDA derivatives from the two enantiomers of the chosen CDA, followed by comparison of the corresponding NMR spectra and calculation of the ΔδRS (or ΔδSR in the case of MTPA) signs for Hα(R1), R1, Hα(R2), and R2.

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Kaplan, O., and J. S. Cohen. "Nuclear Magnetic Resonance Spectroscopy Studies of Cancer Cell Metabolism." In Biological NMR Spectroscopy. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195094688.003.0030.

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Nuclear magnetic resonance spectroscopy (NMR) is a powerful technique that provides information on biochemical status and physiological processes both in-vitro and in-vivo. The metabolism of intact cells and tissues can be studied in a continuous manner, and thus, NMR is a unique non-invasive research tool enabling detection of the metabolic changes as they occur (Cohen et al., 1983; Morris, 1988; Daly and Cohen, 1989). The first NMR study of cellular metabolism was done some 20 years ago, when Moon and Richards reported on the diphosphoglyceric acid (DPG) and pH shifts in erythrocytes (Moon, and Richards, 1973). NMR studies of metabolism of tumor cells were initiated by Navon et al. who investigated phosphorylated compounds in Ehrlich ascites cells (Navon etal., 1977). The choice of the element and isotope for a specific study of metabolism depends on its NMR properties, and the required data. The proton has the highest NMR sensitivity, and is the most abundant nucleus in biological molecules. However, this may cause difficulties in the interpretation and assignment of the 1H NMR spectrum. Moreover, since metabolic studies are usually performed in aqueous solutions, the huge signal from the water protons should be suppressed. Similarly, the wide signals arising from proteins and membrane components should be suppressed. These problems can be addressed now by several innovative NMR methods (Daniels et al., 1976; van Zijl and Cohen, 1992). The most widely used nucleus in NMR studies of metabolism has been 31p (see reviews Cohen (1988); Kaplan et al. (1992)). Phosphorous NMR spectroscopy can provide data on energy metabolism and substrate utilization, phospholipid pathways, precise intracellular pH, and membrane permeability and ion and water distribution. The spectrum is easy to interpret, but the number of compounds which are detectable is limited. Carbon NMR is also useful for NMR studies of metabolism since it is found in most biological compounds; however, 13C has a natural abundance of only 1.1%, and 13C enrichment is necessary. Other nuclei which are used less often in NMR studies of cellular metabolism are 23Na (Gupta et al., 1984), 19F (Malet-Martino, et al., 1986), and rarely 15N (Legerton et al., 1983) and 39K (Brophy et al., 1983).

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Conference papers on the topic "Carbonyl compounds – Spectra"

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"Assessment of Formula-Based Structural Annotation of Humic Substances by Mild Chemical Derivatization and Mass Spectrometry." In Sixth International Conference on Humic Innovative Technologies "Humic Substances and Eco-Adaptive Technologies ”(HIT – 2021). Non-Commercial Partnership "Center for Biogenic Resources "Humus Sapiens" (NP CBR "Humus Sapiens"), 2021. http://dx.doi.org/10.36291/hit.2021.mikhnevich.002.

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Natural organic matter (NOM) plays an important role in the environment and its chemical properties and molecular composition reflect balance between mineralization and sequestration of organic carbon. Ultrahigh resolution mass spectrometry (e.g., FTICR MS) provides essential molecular information about NOM. However, NOM molecular heterogeneity prevents application of tandem MS experiments and direct structural information is ultimately missing leaving opportunities to only ambiguous formula-based annotation. The main aim of this work was to develop a chemical workflow to reliably examine the

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Younan, Hua, Lo Keng Foo, N. Ramesh Rao, and Z. Q. Mo. "Studies on Fingerprints of EDX, FTIR, XPS and TOF-SIMS Techniques and Applications in Failure Analysis of Wafer Fabrication." In ISTFA 2004. ASM International, 2004. http://dx.doi.org/10.31399/asm.cp.istfa2004p0474.

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Abstract In failure analysis of wafer fabrication it is difficult to identify possible sources of carbon-related contaminants as most of them are from polymers, organic and complex compounds. In this paper, the fingerprints of EDX, FTIR, XPS and TOFSIMS techniques will be introduced so as to identify sources of carbon-related contaminants. For example, Si peak (1.740 keV) can be used as a fingerprint of EDX technique to identify the ink-related contaminant from the other carbon-related contaminants. FTIR spectra of more than 10 possible materials from wafer fab and assembly processes are discu

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Balintova, Magdalena, Stefan Demcak, Adriana Estokova, Marian Holub, and Petra Pavlikova. "Study of Thermal Reduction of Barium Sulphate for Barium Sulphide Preparation." In Environmental Engineering. VGTU Technika, 2017. http://dx.doi.org/10.3846/enviro.2017.004.

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Industrial wastewaters, particularly those associated with mining and mineral processing, can contain high con-centrations of sulphate. There are various methods of sulphate removal e.g. reverse osmosis, ion exchange, precipitation by lime, cements, and salts of barium and the biological removal process. The soluble salts of barium are most commonly used for precipitation of sulphate from aquatic acidic solutions to the insoluble product barium sulphate BaSO4. Benefits of precip-itation are high sulphate removal efficiency but limitations are toxicity of barium compounds and high economical co

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Andrade, Karine N. de, Amanda R. P. Costa, Rodolfo I. Teixeira, et al. "Photophysical characterization of 3-acyl-4-quinolones." In VIII Simpósio de Estrutura Eletrônica e Dinâmica Molecular. Universidade de Brasília, 2020. http://dx.doi.org/10.21826/viiiseedmol202006.

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4-quinolones derivatives can present fluorescent properties, depending on their substituents and on the chemical environment (e.g., acidic medium), allowing their application as ion sensors. We theoretically evaluated the photophysical properties of previously synthesized 3-acyl-4-quinolones to verify how different substituents (R1=H, NH2 and R2 = OEt, OH, NHPh) affect their absorption profiles and the emission profile of a reference compound, PB3. All DFT and TD-DFT calculations were performed at B3LYP-D3/6-311++G(d,p) level and continuum polarization model for simulated acetonitrile as solve

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Thiruvengadam, Arvind, Daniel K. Carder, Mohan Krishnamurthy, and Mridul Gautam. "Comparison of Regulated and Unregulated Exhaust Emissions From a Fleet of Multi-Fuel Solid Resource Collection Vehicles." In ASME 2010 Internal Combustion Engine Division Fall Technical Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/icef2010-35053.

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The refuse truck segment of the heavy duty diesel vehicle population has been identified as the most fuel inefficient sector. This is predominantly due to the stop and go driving pattern associated with these trucks. Constantly evolving emissions norms are forcing large truck fleet operators to explore the economic viability of alternative fueled vehicles to combat the increasing operating costs in terms of retrofit requirements of heavy-duty diesel vehicles. The objective of this study was to determine the emissions benefits and the economic viability of introducing liquefied natural gas (LNG

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