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Journal articles on the topic 'Aromatic nucleus'

Author: Grafiati

Published: 5 June 2025

Last updated: 1 August 2025

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1

Shevchenko, V. V., I. M. Tkachenko, and O. V. Shekera. "Nucleus-fluorinated aromatic polyethers." Polymer Science Series B 52, no. 7-8 (2010): 408–30. http://dx.doi.org/10.1134/s1560090410070055.

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2

Badr, M. Zarif A., and A. E. Abdel-Rahman. "Alkylation of the aromatic nucleus." Journal of Applied Chemistry and Biotechnology 24, no. 4-5 (2007): 247–53. http://dx.doi.org/10.1002/jctb.2720240408.

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3

Wang, Miaomiao, and Yanlan Wang. "Advances for Triangular and Sandwich-Shaped All-Metal Aromatics." Molecules 29, no. 4 (2024): 763. http://dx.doi.org/10.3390/molecules29040763.

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Much experimental work has been contributed to all-metal σ, π and δ-aromaticity among transition metals, semimetallics and other metals in the past two decades. Before our focused investigations on the properties of triangular and sandwich-shaped all-metal aromatics, A. I. Boldyrev presented general discussions on the concepts of all-metal σ-aromaticity and σ-antiaromaticity for metallo-clusters. Schleyer illustrated that Nucleus-Independent Chemical Shifts (NICS) were among the most authoritative criteria for aromaticity. Ugalde discussed the earlier developments of all-metal aromatic compoun

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4

Fliegl, Heike, Maria Dimitrova, Raphael J. F. Berger, and Dage Sundholm. "Spatial Contributions to 1H NMR Chemical Shifts of Free-Base Porphyrinoids." Chemistry 3, no. 3 (2021): 1005–21. http://dx.doi.org/10.3390/chemistry3030072.

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A recently developed methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities is used for studying spatial contributions including ring-current contributions to 1H nuclear magnetic resonance (NMR) chemical shifts of aromatic and anti-aromatic free-base porphyrinoids. Our approach allows a visual inspection of the spatial origin of the positive (shielding) and negative (deshielding) contributions to the nuclear magnetic shielding constants. Diatropic and paratropic current-density fluxes yield both shielding and deshielding contributions implying that not mer

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5

Mahajan, Shivani, Sadhika Khullar, Sanjay K. Mandal, and Inder Pal Singh. "A one-pot, three-component reaction for the synthesis of novel 7-arylbenzo[c]acridine-5,6-diones." Chem. Commun. 50, no. 70 (2014): 10078–81. http://dx.doi.org/10.1039/c4cc03079f.

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A one pot domino protocol for an efficient synthesis of 7-arylbenzo[c]acridine-5,6-diones, with a novel nucleus, has been developed by reacting 2-hydroxynaphthalene-1,4-dione, aromatic aldehydes and aromatic amines using environmentally benevolentp-toluene sulphonic acid as a catalyst.

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Peksoz, Ahmet, Aytac Yalciner, and Mehmet Akif Cimenoglu. "A Low Field Fluorine-Electron Double Resonance Study for GALV and BDPA in Some Aliphatic and Aromatic Solvents." Zeitschrift für Naturforschung A 64, no. 7-8 (2009): 477–84. http://dx.doi.org/10.1515/zna-2009-7-810.

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AbstractDynamic nuclear polarization experiments were performed to study the solutions of the stable free radicals Galvinoxyl and α,γ -Bisdiphenylene-β -phenyl allyl complex with benzene (1 : 1) in some highly fluorinated aliphatic and aromatic solvents. The measurements were performed at four different temperatures to test the dipolar and the scalar part of the coupling between the fluorine nucleus (19F) and the unpaired electron. It was found that in the samples with Galvinoxyl the dipolar interactions are more effective for the aromatic solvents, while the scalar interactions are more effec

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7

Zhang, Hong-Hai, Peter V. Bonnesen, and Kunlun Hong. "Palladium-catalyzed Br/D exchange of arenes: selective deuterium incorporation with versatile functional group tolerance and high efficiency." Organic Chemistry Frontiers 2, no. 9 (2015): 1071–75. http://dx.doi.org/10.1039/c5qo00181a.

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8

Chu, Wenchao, Yi Yang, Shangshang Qin, et al. "Low-toxicity amphiphilic molecules linked by an aromatic nucleus show broad-spectrum antibacterial activity and low drug resistance." Chemical Communications 55, no. 30 (2019): 4307–10. http://dx.doi.org/10.1039/c9cc00857h.

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9

Rajeshkumar, Venkatachalam, and Mihaiela C. Stuparu. "A photochemical approach to aromatic extension of the corannulene nucleus." Chemical Communications 52, no. 64 (2016): 9957–60. http://dx.doi.org/10.1039/c6cc04910a.

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10

Kantlehner, Willi, Ralf Kreß, Franziska Zschach, et al. "Orthoamide, LXIII [1]. Tris(dichlormethyl)amin, ein neues breit anwendbares Formylierungsmittel für Aromaten / Orthoamides, LXIII [1]. Tris(dichloromethyl)amine, a New Formylating Reagent for Aromatic Compounds of Wide Scope." Zeitschrift für Naturforschung B 61, no. 4 (2006): 448–63. http://dx.doi.org/10.1515/znb-2006-0412.

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The reagent system formed from tris(dichloromethyl)amine (5) and aluminium chloride allows the formylation of aromatic compounds. The scope of the method is comparable with that of the Olah formylation and the Groß-Rieche procedure, since benzene and even chlorobenzene can be formylated. One formyl group is transferred from 5 to the aromatic nucleus. In order to find optimal reaction conditions, the molar amounts of aromatic compounds, 5 and aluminum chloride were varied as well as reaction temperatures and solvents. The activation of 5 with other Lewis acids is also described

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11

da Silveira Pinto, Ligia S., Thatyana R. Alves Vasconcelos, and Marcus V. N. de Souza. "Eco-Friendly Methodologies for the Synthesis of Quinoline Nucleus." Mini-Reviews in Organic Chemistry 16, no. 6 (2019): 602–8. http://dx.doi.org/10.2174/1570193x16666181228101137.

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The quinoline nucleus is a very important class of heterocyclic aromatic compounds present in several drugs on the market, with synthetic methodologies being necessary to prepare its nucleus and derivatives. Considering that fact, the aim of this review is to describe the development of eco-friendly methodologies for the synthesis of quinoline nucleus and its derivatives in the last five years. Thus, throughout the text are presented varios reagents and catalysts used in the synthesis of quinoline nucleus, the reaction conditions, the advantages of the described methodologies, along with the r

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12

Barbier, Thibaut, Alexia Barbry, Jérémy Magand, et al. "Synthesis and Biological Evaluation of Benzo[b]thiophene Acylhydrazones as Antimicrobial Agents against Multidrug-Resistant Staphylococcus aureus." Biomolecules 12, no. 1 (2022): 131. http://dx.doi.org/10.3390/biom12010131.

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The benzo[b]thiophene nucleus and the acylhydrazone functional group were combined to prepare three new series of compounds for screening against Staphylococcus aureus. The reaction of substituted benzo[b]thiophene-2-carboxylic hydrazide and various aromatic or heteroaromatic aldehydes led to a collection of 26 final products with extensive structural diversification on the aromatic ring and on position 6 of the benzo[b]thiophene nucleus. The screening lead to the identification of eight hits, including (E)-6-chloro-N’-(pyridin-2-ylmethylene)benzo[b]thiophene-2-carbohydrazide (II.b), a non-cyt

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13

Huan, Xuan, Yuegang Tang, Jingjie Xu, and Miaoxin Xu. "Nano-level resolution determination of aromatic nucleus in coal." Fuel 262 (February 2020): 116532. http://dx.doi.org/10.1016/j.fuel.2019.116532.

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14

Osman, A. M., M. Z. A. Badr, M. M. Aly, and H. A. H. El-Sherief. "Thermal alkylation of aromatic nucleus with aryl benzyl ethers." Journal of Applied Chemistry and Biotechnology 24, no. 6 (2007): 319–29. http://dx.doi.org/10.1002/jctb.2720240603.

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15

Prins, H. J. "The mechanism of substitution reactions in the aromatic nucleus." Recueil des Travaux Chimiques des Pays-Bas 44, no. 2 (2010): 166–72. http://dx.doi.org/10.1002/recl.19250440212.

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16

West, Robert. "Novel aromatic species containing group 14 atoms." Pure and Applied Chemistry 80, no. 3 (2008): 563–69. http://dx.doi.org/10.1351/pac200880030563.

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The dianions of tetraphenylsilole and tetraphenylgermole behave as aromatic species, as shown by the equalization of C-C bond lengths in these rings and by nucleus-independent chemical shift (NICS) calculations. Similarly, the dianions of 9-silafluorene and 9-germafluorene are aromatic. In the latter species, the heteroatom five-membered rings are more aromatic than the attached benzene rings. Also to be recognized as aromatically stabilized compounds are the stable unsaturated diiminocarbenes, diiminosilylenes, and diiminogermylenes. Evidence for the aromatic delocalization in these molecules

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17

Vann, Kendra R., Yashavantha L. Vishweshwaraiah, Nikolay V. Dokholyan, and Tatiana G. Kutateladze. "Searching for methyllysine-binding aromatic cages." Biochemical Journal 478, no. 19 (2021): 3613–19. http://dx.doi.org/10.1042/bcj20210106.

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Methylation of lysine residues plays crucial roles in a wide variety of cell signaling processes. While the biological importance of recognition of methylated histones by reader domains in the cell nucleus is well established, the processes associated with methylation of non-histone proteins, particularly in the cytoplasm of the cell, are not well understood. Here, we describe a search for potential methyllysine readers using a rapid structural motif-mining algorithm Erebus, the PDB database, and knowledge of the methyllysine binding mechanisms.

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18

Itoh, Akichika, Shouei Hashimoto, Tomohiro Kodama, and Yukio Masaki. "Aerobic Photooxidation of Methyl Group at Aromatic Nucleus with LiBr." Synlett, no. 13 (2005): 2107–9. http://dx.doi.org/10.1055/s-2005-871942.

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19

Zhou, Yang, Jun-Liang Du, Xin-Ping Long, and Yuan-Jie Shu. "Impact sensitivity and nucleus-independent chemical shift for aromatic explosives." Molecular Simulation 39, no. 9 (2013): 716–20. http://dx.doi.org/10.1080/08927022.2012.762096.

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20

Bisagni, Emile, Marilys Rautureau, Martine Croisy-Delcey, and Christiane Huel. "Nouvelle synthèse de chloro-1 méthyl-5 isoquinoléines fusionnées à divers systèmes aromatiques par leur liaison [g]." Canadian Journal of Chemistry 65, no. 9 (1987): 2027–30. http://dx.doi.org/10.1139/v87-337.

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Lithiation of 4-acetyl 2-chloro pyridine ethylene glycol ketal by exchange with lithium diisopropylamine (LDA) led to 4-acetyl 2-chloro 3-lithio pyridine ethylene glycol ketal. This lithio derivative was reacted with aromatic aldehydes giving the expected alcohols, which were reduced by triethylsilane and trifluoroacetic acid at room temperature. The resulting 4-acetyl 3-arylmethyl 2-chloro pyridine ethylene glycol ketals were hydrolysed and cyclized in acidic medium, leading to polycondensed heterocyclic systems that have a 1-chloro 5-methyl isoquinoline nucleus fused by its [g] bond to the s

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21

Ismail, Wael, and Johannes Gescher. "Epoxy Coenzyme A Thioester Pathways for Degradation of Aromatic Compounds." Applied and Environmental Microbiology 78, no. 15 (2012): 5043–51. http://dx.doi.org/10.1128/aem.00633-12.

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ABSTRACTAromatic compounds (biogenic and anthropogenic) are abundant in the biosphere. Some of them are well-known environmental pollutants. Although the aromatic nucleus is relatively recalcitrant, microorganisms have developed various catabolic routes that enable complete biodegradation of aromatic compounds. The adopted degradation pathways depend on the availability of oxygen. Under oxic conditions, microorganisms utilize oxygen as a cosubstrate to activate and cleave the aromatic ring. In contrast, under anoxic conditions, the aromatic compounds are transformed to coenzyme A (CoA) thioest

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22

Frank, H. G. "Mechanisms and products of azo coupling in histochemical protease procedures based on primary aromatic amines as unspecific moieties." Journal of Histochemistry & Cytochemistry 38, no. 9 (1990): 1295–300. http://dx.doi.org/10.1177/38.9.2201736.

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It is presumed that the azo dyes generated by histochemical protease reactions are formed by substitution of a reactive aromatic carbon. They are referred to as dyes of the C-azo series. To confirm this assumption, the absorption spectra between 330 and 630 nm of azo dyes resulting from coupling between various aromatic amines of the aniline and naphthylamine series and the diazonium salts Fast Blue B and Fast Garnet GBC were studied in test tube experiments. Some of the amines were blocked by methylation to prevent coupling either at the amino group (N-methylated) or at the aromatic nucleus (

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23

Stewart, Richard A., Zhihao Ding, Ung Seop Jeon та ін. "Wnt target gene activation requires β-catenin separation into biomolecular condensates". PLOS Biology 22, № 9 (2024): e3002368. http://dx.doi.org/10.1371/journal.pbio.3002368.

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The Wnt/β-catenin signaling pathway plays numerous essential roles in animal development and tissue/stem cell maintenance. The activation of genes regulated by Wnt/β-catenin signaling requires the nuclear accumulation of β-catenin, a transcriptional co-activator. β-catenin is recruited to many Wnt-regulated enhancers through direct binding to T-cell factor/lymphoid enhancer factor (TCF/LEF) family transcription factors. β-catenin has previously been reported to form phase-separated biomolecular condensates (BMCs), which was implicated as a component of β-catenin’s mechanism of action. This fun

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24

Cárdenas, Abel, Zexin Jin, Yong Ni, et al. "Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity." Beilstein Journal of Organic Chemistry 21 (February 5, 2025): 277–85. https://doi.org/10.3762/bjoc.21.20.

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Oxidized states of polycyclic aromatic hydrocarbons are of importance as they represent charged conductive species in organic semiconductor substrates. In this work, we investigated the properties of radical cations and dications of linear and angular [3]naphthylenes, consisting of fused aromatic naphthalenoid and antiaromatic cyclobutadienoid moieties and containing different degrees of paratropicity. Electronic absorption and vibrational Raman spectroscopies were used to describe the more relevant bonding changes. Stretching force constants were evaluated to monitor the aromatic–antiaromatic

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25

Gaidarzhy, I. I., L. A. Motnyak, and B. V. Kunshenko. "Synthesis of procaine analogues containing pentafluoroethoxy groups in the aromatic nucleus." Voprosy Khimii i Khimicheskoi Tekhnologii, no. 3 (May 2021): 64–72. http://dx.doi.org/10.32434/0321-4095-2021-136-3-64-72.

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In order to synthesize procaine analogs containing one or two pentafluoroethoxy groups, a method for the synthesis of benzoic acids containing a pentafluoroethoxy group in the ortho-position of the benzene nucleus has been developed. An effective method for the synthesis of procaine structural analogues containing one or two pentafluoroethoxy groups has been proposed. It has been shown that the replacement of the amino group by the pentafluoroethoxy group in the procaine molecule leads to a significant increase in the local anesthetic activity of the obtained compounds. The most active compoun

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26

Kilymis, Dimitrios, Albert P. Bartók, Chris J. Pickard, Alexander C. Forse, and Céline Merlet. "Efficient prediction of nucleus independent chemical shifts for polycyclic aromatic hydrocarbons." Physical Chemistry Chemical Physics 22, no. 24 (2020): 13746–55. http://dx.doi.org/10.1039/d0cp01705a.

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27

de Barry Barnett, Edward, and James Wilfred Cook. "Note on the mechanism of substitution reactions in the aromatic nucleus." Recueil des Travaux Chimiques des Pays-Bas 43, no. 4 (2010): 262–65. http://dx.doi.org/10.1002/recl.19240430405.

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28

de Barry Barnett, Edward, and Marcus A. Matthews. "The mechanism of substitution reactions in the aromatic nucleus. Part I." Recueil des Travaux Chimiques des Pays-Bas 43, no. 8 (2010): 530–41. http://dx.doi.org/10.1002/recl.19240430803.

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29

de Barry Barnett, Edward, and James Wilfred Cook. "Note on the mechanism of substitution reactions in the aromatic nucleus." Recueil des Travaux Chimiques des Pays-Bas 43, no. 12 (2010): 897–98. http://dx.doi.org/10.1002/recl.19240431209.

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30

de Barry Barnett, Edward, James Wilfred Cook, and Marcus Aurelius Matthews. "The mechanism of substitution reactions in the aromatic nucleus. Part III." Recueil des Travaux Chimiques des Pays-Bas 44, no. 8 (2010): 728–39. http://dx.doi.org/10.1002/recl.19250440807.

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31

de Barry Barnett, Edward, James Wilfred Cook, and Marcus Aurelius Matthews. "The mechanism of substitution reactions in the aromatic nucleus. Part IV." Recueil des Travaux Chimiques des Pays-Bas 44, no. 9 (2010): 818–26. http://dx.doi.org/10.1002/recl.19250440914.

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32

de Barry Barnett, Edward, James Wilfred Cook, and Marcus Aurelius Matthews. "The mechanism of substitution reactions in the aromatic nucleus. Part V." Recueil des Travaux Chimiques des Pays-Bas 44, no. 10 (2010): 894–99. http://dx.doi.org/10.1002/recl.19250441010.

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33

de Barry Barnett, E., M. A. Matthews, and J. L. Wiltshire. "The mechanism of substitution reactions in the aromatic nucleus. Part VII." Recueil des Travaux Chimiques des Pays-Bas 45, no. 8 (2010): 558–63. http://dx.doi.org/10.1002/recl.19260450805.

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34

DUCHOWICZ, PABLO R., and EDUARDO A. CASTRO. "QSPR CALCULATION OF AROMATICITY IN SOME FIVE-MEMBERED HETEROAROMATIC COMPOUNDS." Journal of Theoretical and Computational Chemistry 03, no. 02 (2004): 145–53. http://dx.doi.org/10.1142/s0219633604000921.

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Aromatic stabilization energies (ASE) for a set of 29 five-membered heteroaromatic compounds are calculated using molecular descriptors such as magnetic susceptibility exaltation (Λ), nucleus-independent chemical shifts (NICS), and electrotopological indices (EI) via linear, quadratic and cubic fitting polynomials. Theoretical estimations compare fairly well with experimental data when three variables multilinear regression equations are employed.

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35

Ahmed, Faruk, Sourav Ranjan Ghosh, Soumi Halder, et al. "Metal–ligand ring aromaticity in a 2D coordination polymer used as a photosensitive electronic device." New Journal of Chemistry 43, no. 6 (2019): 2710–17. http://dx.doi.org/10.1039/c8nj05526b.

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14-Membered metal–ligand ring present in a photosensitive 2D coordination polymer, [Zn<sub>2</sub>(fum)<sub>2</sub>(4-phpy)<sub>4</sub>(H<sub>2</sub>O)<sub>2</sub>] (H<sub>2</sub>fum = fumaric acid and 4-phpy = 4-phenyl pyridine) shows aromatic character as evident by the nucleus-independent chemical shifts (NICS) calculation.

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36

Zhang, Peng, Yong Ming Fan, and Jian Min Gao. "The Influence of Ethanol Extraction in the High Temperature Steaming Induced Discoloration Process of Locust (Robinia pseudoacacia) Wood." Advanced Materials Research 538-541 (June 2012): 2194–98. http://dx.doi.org/10.4028/www.scientific.net/amr.538-541.2194.

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The purpose of the experiment is to get more ideal color and raise the value of Locust wood after heat treatment. We chose ethanol as the solvent and heated locust wood in vapor environment at 120°C for 24 hours. Compare the infrared absorption spectrum of heat treated powder and heat treated powder after extracted. It turned out that: (1) extraction could wipe out the great mass of substance with ethenyl(C=C), ether bond(C-O-C), hydroxy (-OH) and aromatic ring; (2) The synthetic reaction and decomposition reaction of ethenyl(C=C), ether bond(C-O-C), hydroxy (-OH) and aromatic ring would lead

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37

Yamagami, C., T. Sai, and N. Takao. "13C N.M.R. Spectra of ortho-Substituted Phenyl N,N-Dimethyl-Carbamates and N-Methyl Carbamates." Australian Journal of Chemistry 40, no. 12 (1987): 2005. http://dx.doi.org/10.1071/ch9872005.

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We measured 13C nuclear magnetic resonance spectra of O-substituted phenyl N,N- dimethyland N-methyl- carbamates and compared the results with those for the corresponding m- and p-substituted derivatives. The additivity relationship on the basis of the substituent chemical shift for monosubstituted benzenes ( scsphx ) did not hold well because of the ortho effect. However, the scs of C2(ipso), C3(ortho) and C5(para) was correlated excellently with scsphxX . Dual substituent parameter (DSP) analyses of the scs of C5 and the carbonyl carbon in the fixed side chain showed that correlation was ver

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38

Andjelkovic, Ljubica, Marko Peric, Matija Zlatar, and Maja Gruden-Pavlovic. "Nucleus-independent chemical shift profiles along the intrinsic distortion path for Jahn-Teller active molecules. Study on cyclopentadienyl radical and cobaltocene." Journal of the Serbian Chemical Society 80, no. 7 (2015): 877–88. http://dx.doi.org/10.2298/jsc141107025a.

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The aromatic/antiaromatic behavior of the cyclopentadienyl anion (Cp-), bis(?5-cyclopentadienyl)iron(II) (Fe(Cp)2), as well as of the Jahn-Teller (JT) active cyclopentadienyl radical (Cp?) and bis(?5-cyclopentadienyl)cobalt(II) (Co(Cp)2) has been investigated using Density Functional Theory (DFT) calculations of the Nuclear Independent Chemical Shifts (NICS). According to the NICS values, pentagon ring in Fe(Cp)2 is more aromatic than isolated Cp-. The NICS parameters have been scanned along the Intrinsic Distortion Path (IDP) for Cp? and Co(Cp)2 showing antiaromaticity, which decreases with i

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39

Hadki, Hamza El, Kenneth J. Koziol, Oum Keltoum Kabbaj, Najia Komiha, Isabelle Kleiner, and Ha Vinh Lam Nguyen. "The Microwave Rotational Electric Resonance (RER) Spectrum of Benzothiazole." Molecules 28, no. 8 (2023): 3419. http://dx.doi.org/10.3390/molecules28083419.

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The microwave spectra of benzothiazole were measured in the frequency range 2–26.5 GHz using a pulsed molecular jet Fourier transform microwave spectrometer. Hyperfine splittings arising from the quadrupole coupling of the 14N nucleus were fully resolved and analyzed simultaneously with the rotational frequencies. In total, 194 and 92 hyperfine components of the main species and the 34S isotopologue, respectively, were measured and fitted to measurement accuracy using a semi-rigid rotor model supplemented by a Hamiltonian accounting for the 14N nuclear quadrupole coupling effect. Highly accura

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40

Chan, Tek Long, and Zuowei Xie. "Synthesis, structure and aromaticity of carborane-fused carbo- and heterocycles." Chemical Science 9, no. 8 (2018): 2284–89. http://dx.doi.org/10.1039/c7sc04722c.

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The results of molecular structures, NMR data, and NICS (nucleus-independent chemical shift) and ISE (isomerization stabilization energy) values as well as molecular orbital analyses clearly suggest the presence of considerable aromatic character in the exo five-membered ring of carborane-fused carbo- and heterocycles and considerable conjugation between a 3-D carborane and a fused 2-D π-ring system.

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41

AbuSalim, Deyaa I., and Timothy D. Lash. "Aromatic Character and Relative Stability of Pyrazoloporphyrin Tautomers and Related Protonated Species: Insights into How Pyrazole Changes the Properties of Carbaporphyrinoid Systems." Molecules 28, no. 6 (2023): 2854. http://dx.doi.org/10.3390/molecules28062854.

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Pyrazoloporphyrins (PzPs), which are porphyrin analogues incorporating a pyrazole subunit, are examples of carbaporphyrin-type structures with a carbon atom within the macrocyclic cavity. DFT calculations were used to assess a series of 17 PzP tautomers, nine monoprotonated species and four related diprotonated PzP dications. The geometries of the structures were optimized using M06-2X/6-311++G(d,p), and the relative stabilities computed with the cc-PVTZ functional. Nucleus independent chemical shifts, both NICS(0) and NICS(1)zz, were calculated, and the anisotropy of the induced current densi

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42

Maria and Khurshid Ayub. "Aromaticities of Five Membered Heterocycles through Dimethyldihydropyrenes Probe by Magnetic and Geometric Criteria." Journal of Chemistry 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/456961.

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Aromaticities of five membered heterocycles, containing up to three heteroatoms, are quantified through the dimethyldihydropyrene (DHP) probe. Bond fixation caused by the fusion of heterocycles to the dimethyldihydropyrene nucleus (DHPN) was measured by changes in the1H NMR chemical shifts (magnetic) and bond lengths alterations (structural criterion). Chemical shifts of dihydropyrenes were calculated at GIAO HF/6-31G(d)//B3LYP/6-31+G(d). For1H NMR chemical shift analysis, two nonaromatic reference models are studied. Among the studied heterocycles, pyrazole and triazole are about 80–85% aroma

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43

Neelima, Gupta, та K. Bansal R. "Effect of introducing σ2,λ.3-phosphorus in indolizine nucleus: a theoretical study". Journal of Indian Chemical Society Vol. 80, Nov 2003 (2003): 997–1003. https://doi.org/10.5281/zenodo.5839655.

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Department of Chemistry, University of Rajasthan, Jaipur-302 004, India <em>E-mail : </em>niilima@sancharnet.in; rajbns@sify.com <em>Manuscript received / September 2003</em> Ab <em>initio</em> quantum chemical calculations of the indolizine, aza-, diaza- and triazaindolizines and their various possible mono phospha-analogues obtained by replacement of one =CH— in the five membered ring by <em>sp</em><sup>2</sup>-phosphorus (in all 20 systems : A-T) have been carried out at the B3LYP/6-311G** hybrid density functional level of theory. Thus different parameters of the molecular geometries

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Mathis, Amanda M., Jacqueline L. Holman, Lisa M. Sturk, et al. "Accumulation and Intracellular Distribution of Antitrypanosomal Diamidine Compounds DB75 and DB820 in African Trypanosomes." Antimicrobial Agents and Chemotherapy 50, no. 6 (2006): 2185–91. http://dx.doi.org/10.1128/aac.00192-06.

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ABSTRACT The aromatic diamidine pentamidine has long been used to treat early-stage human African trypanosomiasis (HAT). Two analogs of pentamidine, DB75 and DB820, have been shown to be more potent and less toxic than pentamidine in murine models of trypanosomiasis. The diphenyl furan diamidine, DB75, is the active metabolite of the prodrug DB289, which is currently in phase III clinical trials as a new orally active candidate drug to treat first-stage HAT. The new aza analog, DB820, is the active diamidine of the prodrug DB844, currently undergoing preclinical evaluation as a new candidate t

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Guo, Ming Hui, and Xin Guan. "Effect of UV-Irradiation on Surface Color and Chemical Structure of Wood." Advanced Materials Research 113-116 (June 2010): 1624–28. http://dx.doi.org/10.4028/www.scientific.net/amr.113-116.1624.

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The changes of the surface colors and chemical constituents of Mongolian Scotch pine treated by UV light were investigated by spectrophotometer and FTIR followed by acid pretreatment. The results show that the changes of the surface colors are related to carbonyl, aromatic nucleus, arone, Ar-OH, paraquinones, ortho quinine and so on in the course of UV irradiation. Acid promotes photocycloaddition and plays a hyperchromic effect.

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Aihara, Jun-ichi. "Nucleus-independent chemical shifts and local aromaticities in large polycyclic aromatic hydrocarbons." Chemical Physics Letters 365, no. 1-2 (2002): 34–39. http://dx.doi.org/10.1016/s0009-2614(02)01415-x.

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Gadre, Shridhar R., and C. H. Suresh. "Electronic Perturbations of the Aromatic Nucleus: Hammett Constants and Electrostatic Potential Topography†." Journal of Organic Chemistry 62, no. 8 (1997): 2625–27. http://dx.doi.org/10.1021/jo961679l.

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K., H. Popat, S. Nimavat K., M. Thaker K., and S. Joshi H. "Synthesis and biological activities of some quinoxaline derivatives bearing aromatic halogen nucleus." Journal of Indian Chemical Society Vol. 80, July 2003 (2003): 709–10. https://doi.org/10.5281/zenodo.5835542.

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Department of Chemistry, Saurashtra University, RaJkot-360 005, India <em>E-mail</em> : drhsjoshi@yahoo.com               <em>Fax</em> : 91-281-578512 <em>Manuscript received 4 April 2002, revised 1 January 2003. accepted 21 March 2003</em> 1-Aryl-3-(3'-chlorophenyl)-2-propen-1-ones (1a-j) on reaction with bromine in acetic acid yielded 1-aryl-3-(3'-chlorophenyl)-2,3-dibromopropan-1-ones (2a-j). Reaction of 2a-j with <em>o</em>-phenylenediamine afforded the corresponding 2-(3'-chlorophenyl)-3-substituted benzylquinoxaline (3a-j). The synthesi

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Ruiz-Morales, Yosadara. "Aromaticity in pericondensed cyclopenta-fused polycyclic aromatic hydrocarbons determined by density functional theory nucleus-independent chemical shifts and the Y-rule — Implications in oil asphaltene stability." Canadian Journal of Chemistry 87, no. 10 (2009): 1280–95. http://dx.doi.org/10.1139/v09-052.

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The characterization of the stability of the fused aromatic region (FAR) in oil asphaltenes in terms of kinetic and thermodynamic stability is primary. Such an understanding is important if we are to get the optimal use from the heavy fraction of any crude oil. The FAR region is composed of pericondensed cyclopenta-fused polycyclic aromatic hydrocarbon compounds (CPPAHs) with N, S, and O heteroatoms. The Clar model, which states that the most important representation of a PAH is one having the maximum number of disjoint π-sextets, depicted by inscribed circles, and a minimum number of fixed do

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Đorđević, Slađana, Dušan Ćoćić, Muntadar Al-Yassiri, Slavko Radenković, and Ralph Puchta. "Electronic structure and aromaticity of [12]infinitene: A DFT study." Kragujevac Journal of Science, no. 45 (2023): 29–40. http://dx.doi.org/10.5937/kgjsci2345029d.

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The electronic structure and aromaticity of the [12]infinitene molecule (1) and its formation via the Mallory reaction were studied using density functional theory (DFT). The examined reaction is based on a stepwise cyclization process. The nucleus-independent chemical shifts (NICS) were used to assess the aromatic character of the chemical species involved in the examined reactions. In addition, NICS-Scan, 2D and 3D multidimensional off-nucleus siso(r) magnetic shielding scans were also employed to examine the aromaticity of 1. It was found that the formation of 1 is an endothermal process, a

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