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Journal articles on the topic 'Heterocyclic ions'

Author: Grafiati

Published: 24 April 2022

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1

Li, Chongyang, Yongli Huang, Chang Q. Sun, and Lei Zhang. "Acidic Stabilization of the Dual-Aromatic Heterocyclic Anions." Catalysts 11, no. 7 (June 24, 2021): 766. http://dx.doi.org/10.3390/catal11070766.

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Recently, we discovered that the delocalization of nitrogen lone-pair electrons (NLPEs) in five-membered nitrogen heterocycles created a second σ-aromaticity in addition to the prototypical π-aromaticity. Such dual-aromatic compounds, such as the pentazole anion, were proved to have distinct chemistry in comparison to traditional π-aromatics, such as benzene, and were surprisingly unstable, susceptible to electrophilic attack, and relatively difficult to obtain. The dual-aromatics are basic in nature, but prefer not to be protonated when confronting more than three hydronium/ammonium ions, which violates common sense understanding of acid−base neutralization for a reason that is unclear. Here, we carried out 63 test simulations to explore the stability and reactivity of three basic heterocycle anions (pentazole anion N5¯, tetrazole anion N4C1H1¯, and 1,2,4-triazole anion N3C2H2¯) in four types of solvents (acidic ions, H3O+ and NH4+, polar organics, THF, and neutral organics, benzene) with different acidities and concentrations. By quantum mechanical calculations of the electron density, atomistic structure, interatomic interactions, molecular orbital, magnetic shielding, and energetics, we confirmed the presence of dual aromaticity in the heterocyclic anions, and discovered their reactivity to be a competition between their basicity and dual aromaticity. Interestingly, when the acidic ions H3O+/NH4+ are three times more in number than the basic heterocyclic anions, the anions turn to violate acid−base neutralization and remain unprotonated, and the surrounding acidic ions start to show a significant stabilization effect on the studied heterocyclic anions. This work brings new knowledge to nitrogen aromatics and the finding is expected to be adaptable for other pnictogen five-membered ring systems.

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2

Schmid, Dirk, Denis Bubrin, Daniela Förster, Martin Nieger, Eric Roeben, Sabine Strobel, and Dietrich Gudat. "Unsymmetrically substituted N-heterocyclic phosphenium ions." Comptes Rendus Chimie 13, no. 8-9 (August 2010): 998–1005. http://dx.doi.org/10.1016/j.crci.2010.04.020.

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3

Frisch, Philipp, and Shigeyoshi Inoue. "NHC-stabilized silyl-substituted silyliumylidene ions." Dalton Transactions 48, no. 28 (2019): 10403–6. http://dx.doi.org/10.1039/c9dt02010a.

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4

Estrada, Jess, and Vincent Lavallo. "Fusing Dicarbollide Ions with N‐Heterocyclic Carbenes." Angewandte Chemie International Edition 56, no. 33 (August 7, 2017): 9906–9. http://dx.doi.org/10.1002/anie.201705857.

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5

Estrada, Jess, and Vincent Lavallo. "Fusing Dicarbollide Ions with N‐Heterocyclic Carbenes." Angewandte Chemie 129, no. 33 (July 17, 2017): 10038–41. http://dx.doi.org/10.1002/ange.201705857.

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6

Sousa, Rui P. C. L., Raquel C. R. Gonçalves, Susana P. G. Costa, Rita B. Figueira, and Maria Manuela M. Raposo. "Heterocyclic Aldehydes Based on Thieno[3,2-b]thiophene Core: Synthesis and Preliminary Studies as Ion Optical Chemosensors." Cells 3, no. 1 (November 13, 2020): 88. http://dx.doi.org/10.3390/ecsoc-24-08092.

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Heterocyclic aldehydes show a variety of optical properties and the versatility of their reactivity allows them to yield a wide range of more complex compounds, with application in areas such as medicinal, materials and supramolecular chemistry. The biological and environmental relevance of certain molecules and ions turns them into targets for the design of molecular recognition systems. Recently, heterocyclic aldehydes have been reported in the literature as ion chemosensors. Following the group’s work on optical chemosensors, for the detection and quantification of ions and molecules with environmental and medicinal relevance, this work reports the synthesis and characterization of two heterocyclic aldehydes based on the thieno[3,2-b]thiophene core, by Suzuki coupling, as well as the synthesis of the corresponding precursors. Preliminary chemosensory studies for the synthesized heterocyclic aldehydes in the presence of selected cations were also performed, in solution, in order to determine their potential application as optical chemosensors.

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7

Frisch, Philipp, and Shigeyoshi Inoue. "Coinage metal complexes of NHC-stabilized silyliumylidene ions." Chemical Communications 54, no. 97 (2018): 13658–61. http://dx.doi.org/10.1039/c8cc07754a.

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8

Valdés-Martı́nez, Jesús, James H. Alstrum-Acevedo, Rubén A. Toscano, Simón Hernández-Ortega, Georgina Espinosa-Pérez, Douglas X. West, and Brian Helfrich. "Tetrachlorocuprate(II) salts of heterocyclic aminoguanidonium (guanylhydrazonium) ions." Polyhedron 21, no. 4 (March 2002): 409–16. http://dx.doi.org/10.1016/s0277-5387(01)01006-3.

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9

Someya, Chika I., Shigeyoshi Inoue, Carsten Präsang, Elisabeth Irran, and Matthias Driess. "Formation of N-heterocyclic, donor-stabilized borenium ions." Chemical Communications 47, no. 23 (2011): 6599. http://dx.doi.org/10.1039/c1cc11789k.

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10

Novak, Michael, Lulu Xu, and Rebecca A. Wolf. "Nitrenium Ions from Food-Derived Heterocyclic Arylamine Mutagens." Journal of the American Chemical Society 120, no. 7 (February 1998): 1643–44. http://dx.doi.org/10.1021/ja974222h.

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11

Johnson, MD, CA Mcintosh, and VC Reinsborough. "Binding of Nitrogen Heterocyclic Ligands and Tetraphenyl-Substituted Ions by β-Cyclodextrins." Australian Journal of Chemistry 47, no. 1 (1994): 187. http://dx.doi.org/10.1071/ch9940187.

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Binding constants obtained spectrofluorometrically are reported for β- cyclodextrin (substituted and unsubstituted ) inclusion of several commonly used nitrogen heterocyclic ligands and tetraphenyl-substituted ions.

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12

Tracz, Andrzej, Anna Gawin, Michał Bieniek, Tomasz K. Olszewski, and Krzysztof Skowerski. "Ammonium NHC-tagged olefin metathesis catalysts – influence of counter-ions on catalytic activity." New Journal of Chemistry 42, no. 11 (2018): 8609–14. http://dx.doi.org/10.1039/c8nj00614h.

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Ruthenium-based catalysts bearing quaternary ammonium groups in their N-heterocyclic carbene (NHC) fragments and different counter-ions were synthesised and tested in various olefin metathesis transformations.

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13

Fontana, Nicolò, Noel Angel Espinosa-Jalapa, Michael Seidl, and Jonathan O. Bauer. "Hidden silylium-type reactivity of a siloxane-based phosphonium–hydroborate ion pair." Chemical Communications 58, no. 13 (2022): 2144–47. http://dx.doi.org/10.1039/d1cc07016a.

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14

Reeske, Gregor, Clint R. Hoberg, and Alan H. Cowley. "One-Step Redox Route to N-Heterocyclic Phosphenium Ions." Inorganic Chemistry 46, no. 10 (May 2007): 4358. http://dx.doi.org/10.1021/ic700556q.

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15

Reeske, Gregor, and Alan H. Cowley. "One-Step Redox Route to N-Heterocyclic Phosphenium Ions." Inorganic Chemistry 46, no. 4 (February 2007): 1426–30. http://dx.doi.org/10.1021/ic061956z.

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16

Xu, Shujun, Kunpeng Song, Tao Li, and Bien Tan. "Palladium catalyst coordinated in knitting N-heterocyclic carbene porous polymers for efficient Suzuki–Miyaura coupling reactions." Journal of Materials Chemistry A 3, no. 3 (2015): 1272–78. http://dx.doi.org/10.1039/c4ta05265j.

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Microporous polymers were synthesised using external cross-linked N-heterocyclic carbene and benzene. These materials can serve as ligands to bind metal ions and demonstrated high catalytic activity for efficient Suzuki–Miyaura coupling reactions.

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17

Ríos, María-Camila, Néstor-Fabián Bravo, Christian-Camilo Sánchez, and Jaime Portilla. "Chemosensors based on N-heterocyclic dyes: advances in sensing highly toxic ions such as CN⁻ and Hg²⁺." RSC Advances 11, no. 54 (2021): 34206–34. http://dx.doi.org/10.1039/d1ra06567j.

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This review considers the most recent advances in sensing highly toxic ions such as CN− and Hg2+. Specifically, probes bearing N-heterocyclic compounds for their proven versatility for applications in the development of chemosensors are analyzed.

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18

Padwa, A. "Application of cascade processes toward heterocyclic synthesis." Pure and Applied Chemistry 75, no. 1 (January 1, 2003): 47–62. http://dx.doi.org/10.1351/pac200375010047.

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The reactions of N-acyliminium ions with tethered π-bonds are among the most important methods for preparing complex nitrogen-containing heterocycles. Pummerer-based cyclizations are also finding widespread application in both carbo- and heterocyclic syntheses. As part of a program concerned with new methods for alkaloid synthesis, we became interested in using a linked Pummerer/N-acyliminium ion cyclization sequence since we felt that this combination offers unique opportunities for the assemblage of complex target molecules. A synthetic method that combines transformations of different reaction types significantly broadens the scope of such procedures in synthetic chemistry. α-Thiocarbocations generated from the Pummerer reaction of β-phenylsulfinylmethyl-α,β-unsaturated amides can be intercepted by the adjacent amido group to produce transient amino- substituted furans, which undergo subsequent Diels-Alder cycloadditions. Using this domino amido-Pummerer/Diels-Alder cascade, we were able to assemble novel polycyclic systems in a single operation. The key step in the process involves the generation of a reactive N-acyliminium ion by fragmentation of an amino-substituted [4+2] cycloadduct. The successful synthesis of a number of alkaloids by this sequence of reactions reveals the usefulness and importance of this unique domino cascade.

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19

Suárez, Margarita, Enrique E. Maroto, Salvatore Filippone, Nazario Martín, and Roberto Martínez-Álvarez. "Competitive retro-cycloaddition reactions in heterocyclic fullerene bis-adducts ions: selective removal of the heterocyclic moieties." Rapid Communications in Mass Spectrometry 29, no. 6 (February 10, 2015): 497–504. http://dx.doi.org/10.1002/rcm.7131.

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20

Malinowska, Katarzyna, Ingo-Peter Lorenz, Beata Sadowska, and Paulina Mucha. "Metal Ion Complexes with Pyrazoles, Aziridines and Diaziridines – Synthesis and Biological Activity." Current Medicinal Chemistry 26, no. 4 (April 1, 2019): 648–63. http://dx.doi.org/10.2174/0929867325666180221124447.

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Heterocyclic compounds containing nitrogen ions, like pyrazoles, aziridines, diaziridines and their metal ion complexes with Cu(II), Zn(II) and Ru(III) and others exhibit a wide range of biological activity, including mainly anti-inflammatory, antioxidant, anticancer, and antimicrobial properties. Biological significance of these molecules and thus their potential use in medicine has driven growing interest into their coordination chemistry. A knowledge of the relationship between the structure of chemical compounds and their activity is needed for the synthesis of the preparations possessing the most beneficial features. The choice of interposed substituents may improve biocidal and antitumor action, reduce the toxicity of the initial substance, or even completely eliminate its adverse effects for healthy tissues. The main aim of this review paper is to present the current state of knowledge concerning the synthesis and biological activity of complexes with small heterocyclic ligands containing transition metal ions.

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21

Bobyleva, M. S., N. S. Kulikov, and S. I. Bobrovskii. "Mass spectrometry and structure of heterocyclic ions by collisional activation." Chemistry of Heterocyclic Compounds 25, no. 3 (March 1989): 274–79. http://dx.doi.org/10.1007/bf00472384.

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22

Imran, Muhammad, Andreas Mix, Beate Neumann, Hans-Georg Stammler, Uwe Monkowius, Petra Gründlinger, and Norbert W. Mitzel. "Hemi- and holo-directed lead(ii) complexes in a soft ligand environment." Dalton Transactions 44, no. 3 (2015): 924–37. http://dx.doi.org/10.1039/c4dt01406e.

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Structures and stereochemical activity of the lone pairs at the lead ion were investigated by synthetic, spectroscopic and structural studies of ten lead(ii) complexes with heterocyclic soft ligands. The majority of the complexes exhibited a hemi-directed environment around the lead ions.

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23

Schütz, Markus, Yoshiteru Matsumoto, Aude Bouchet, Murat Öztürk, and Otto Dopfer. "Microsolvation of the pyrrole cation (Py+) with nonpolar and polar ligands: infrared spectra of Py+–Ln with L = Ar, N2, and H2O (n ≤ 3)." Physical Chemistry Chemical Physics 19, no. 5 (2017): 3970–86. http://dx.doi.org/10.1039/c6cp07251h.

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IR spectra and dispersion-corrected density functional calculations of pyrrole cluster ions with Ar, N₂, and H₂O reveal the competition between H-bonding and π-stacking motifs of this prototypical heterocyclic aromatic cation in a hydrophobic and hydrophilic solvent.

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24

Singh, Gurjaspreet, Diksha, Akshpreet Singh, Sanchita, Geetika Sharma, Shilpy, Pawan, Cristóbal Espinosa-Ruíz, and María Angeles Esteban. "Designing the recognition of Sn2+ ions and antioxidants: N-heterocyclic organosilatranes and their magnetic nanocomposites." New Journal of Chemistry 44, no. 16 (2020): 6238–50. http://dx.doi.org/10.1039/c9nj06363c.

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The present work involves synthesis of new series of N-heterocyclic unsymmetrical organosilatranes and the synthesized compounds were explored for the detection of Sn²⁺, cytotoxicity and antioxidant activity.

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25

HARRING, S. R., E. D. EDSTROM, and T. LIVINGHOUSE. "ChemInform Abstract: Episulfonium Ions and Episelenonium Ions. Versatile Heterocyclic Cations for the Synthesis of Natural Products." ChemInform 23, no. 50 (September 1, 2010): no. http://dx.doi.org/10.1002/chin.199250299.

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26

Yadav, Sangeeta, Rajesh Deka, Saravanan Raju, and Harkesh B. Singh. "Synthesis of N-heterocyclic nitrenium (NHN) ions and related donor systems: Coordination with d10-metal ions." Inorganica Chimica Acta 488 (March 2019): 269–77. http://dx.doi.org/10.1016/j.ica.2019.01.024.

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27

Gao, Yan, Jian Song, and Wei Wang. "Synthesis and Hg2+ Recognition of Novel Azobenzene Derivatives Bearing Heterocyclic Units." Journal of Chemical Research 36, no. 3 (March 2012): 146–48. http://dx.doi.org/10.3184/174751912x13297300856397.

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Four novel azobenzene derivatives, 4,4'-bis(CH2SAr)azobenzene (Ar = different heterocyclic units), have been prepared and characterised by IR, 1H NMR, 13C NMR, MS and elemental analysis. Their complexation properties to different heavy and transition metal ions have been studied by UV and fluorescence spectra. The compound 4,4'-bis(4,6-dimethyl-pyrimidine-2-ylmethylthio)azobenzene shows selective recognition of Hg2+.

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28

Ebenezer, Cheriyan, and Rajadurai Vijay Solomon. "Preorganization of N,O-hybrid phosphine oxide chelators for effective extraction of trivalent Am/Eu ions – a computational study." New Journal of Chemistry 46, no. 12 (2022): 5761–70. http://dx.doi.org/10.1039/d1nj06029e.

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29

Ochiai, Tatsumi, Tibor Szilvási, and Shigeyoshi Inoue. "Facile Access to Stable Silylium Ions Stabilized by N-Heterocyclic Imines." Molecules 21, no. 9 (August 30, 2016): 1155. http://dx.doi.org/10.3390/molecules21091155.

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30

Sheehan, Scott M., L. Scott Beall, and Albert Padwa. "π-Cyclization reactions of thio N-acyliminium ions for heterocyclic synthesis." Tetrahedron Letters 39, no. 27 (July 1998): 4761–64. http://dx.doi.org/10.1016/s0040-4039(98)00902-2.

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31

Perreault, H., L. Ramaley, F. M. Benoit, P. G. Sim, and R. K. Boyd. "Fragmentation reactions of doubly charged ions of nitrogenous heterocyclic aromatic compounds." Journal of Physical Chemistry 95, no. 13 (June 1991): 4989–98. http://dx.doi.org/10.1021/j100166a018.

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32

TURECEK, F. "ChemInform Abstract: Stereochemical Effects in the Fragmentation Processes of Heterocyclic Ions." ChemInform 26, no. 23 (August 17, 2010): no. http://dx.doi.org/10.1002/chin.199523312.

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33

Li, Chuan, Chenglong Deng, Baojing Zhao, Min Wang, Man Zhang, and Zhiming Zhou. "A Zwitterionic Compound with Heterocyclic Ions as Promising Heat‐Resistant Explosive." Propellants, Explosives, Pyrotechnics 45, no. 4 (April 2020): 531–35. http://dx.doi.org/10.1002/prep.201900415.

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34

Jovanovic, Vladislava, K. Babic-Samardzija, and Sofija Sovilj. "The effect of heterocyclic S,S’-ligands on the electrochemical properties of some cobalt(III) complexes in acid." Journal of the Serbian Chemical Society 70, no. 1 (2005): 51–61. http://dx.doi.org/10.2298/jsc0501051j.

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Eight mixed-ligand cobalt(III) complexes with the macrocyclic amine 1,4,8,11-tetraazacyclotetradecane (cyclam) and a heterocyclic dithiocarbamate (Rdtc-)i.e., morpholine-(Morphdtc), thiomorpholine- (Timdtc), piperazine-(Pzdtc), N-methylpiperazine-(Mepzdtc), piperidine- (Pipdtc), 2-, 3- or 4-methylpiperidine-(2-, 3- and 4-Mepipdtc) carbodithionato-S,S ions, of the general formula [Co(cyclam)Rdtc](ClO4)2, were investigated in deoxygenated 0.1 MHClO4 solutions. Cyclic voltammetry data at a glassy carbon (GC) electrode demonstrate a redox reaction of cobalt(III) from the complexes at potentials strongly influenced by the presence of different heterocyclic Rdtc- ligands. In this respect, the complexes were separated into two groups: the first, with a heteroatom O, S or N in the heterocyclic ring, and the second, with a methyl group on the piperidine ring of the Rdtc- ligand. Anodic polarization of an Fe electrode in the presence of the complexes shows their influence not only on the dissolution of iron but also on the hydrogen evolution reactions and on this basis complexes the complexes could be divided into the same two groups. It was found that the weaker the inhibiting effect of the free heterocyclic amines is, the significantly higher is the efficiency of the corresponding complexes.

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35

Jo, Minyoung, Jingbai Li, Alina Dragulescu-Andrasi, Andrey Yu Rogachev, and Michael Shatruk. "Incorporation of coinage metal–NHC complexes into heptaphosphide clusters." Dalton Transactions 49, no. 37 (2020): 12955–59. http://dx.doi.org/10.1039/d0dt03119d.

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A Me₃Si-protected P₇ cage reacts with N-heterocyclic-carbene complexes of coinage metals to yield a mononuclear Cu(i) complex featuring a Cu(η⁴-P₇) core and a trinuclear Au(i) complex with linearly coordinated metal ions attached to the P₇ cluster.

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36

Bierbaum, V. M. "Laboratory Studies of Ion Chemistry in the Interstellar Medium." Proceedings of the International Astronomical Union 9, S297 (May 2013): 258–64. http://dx.doi.org/10.1017/s1743921313015962.

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AbstractStudies of gas phase ion-neutral reactions provide insight into many areas of astrochemistry, including the elusive characterization of the Diffuse Interstellar Bands (DIBs). This presentation gives an overview of our experimental studies of several classes of positive and negative ions, using the flowing afterglow-selected ion flow tube and a newly modified ion trap. Earlier studies of carbon chain anions and polycyclic aromatic hydrocarbon (PAH) cations, both of which have been suggested as carriers of the DIBs, are described. More recent work including isomeric PAHs, nitrogen-containing PAHs, negative ions of PAHs, and negative ions of 5-membered heterocyclic rings are discussed. Finally, the study of quantitative thermochemistry by coupling our results with data from Photoelectron Spectroscopy is described.

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37

Stapf, Manuel, Wilhelm Seichter, and Edwin Weber. "Synthesis and UV/Vis analysis of amino acid-derived bisurea-type receptors involving anion complexation." Zeitschrift für Naturforschung B 70, no. 6 (June 1, 2015): 409–19. http://dx.doi.org/10.1515/znb-2015-0017.

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AbstractSixteen new bisurea compounds incorporating versatile proteinogenic amino acids as well as nipecotic acid have been synthesized via addition reaction to aryl diisocyanates. The products were analytically characterized and their ability for anion recognition was studied by UV/Vis spectroscopy. In the presence of fluoride, acetate or dihydrogenphosphate ions, hyperchromic and bathochromic peak shifts were determined. By way of contrast, bromide, iodide, or hydrogensulfate ions cause no significant change of absorbance. The special effect of heterocyclic derivatives was explained by molecular modeling calculations. In addition, the crystal structure of the byproduct dimethyl N,N′-(1,4-phenylene)dicarbamate is discussed.

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38

Adiraju, Venkata A. K., Muhammed Yousufuddin, and H. V. Rasika Dias. "Copper(i), silver(i) and gold(i) complexes of N-heterocyclic carbene-phosphinidene." Dalton Transactions 44, no. 10 (2015): 4449–54. http://dx.doi.org/10.1039/c4dt03285c.

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39

Altmann, Philipp J., Michael Ehrenreich, and Alexander Pöthig. "A hybrid imidazolylidene/imidazolium nickel NHC complex: an isolated intermediate." Acta Crystallographica Section C Structural Chemistry 73, no. 11 (October 6, 2017): 880–84. http://dx.doi.org/10.1107/s2053229617013250.

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Macrocyclic ligand systems with a variety of (different) donor sites oftentimes give rise to very exciting and unexpected multinuclear metal complexes. We report herein the structure of a trinuclear mixed imidazolylidene/imidazolium nickel N-heterocyclic carbene (NHC) complex, namely di-μ-chlorido-bis{μ-calix[2]imidazolium[2]imidazolylidene[2]pyrazolate}trinickel(II) tetrakis(hexafluoridophosphate) acetonitrile tetrasolvate, [Ni3(C24H24N12)2Cl2](PF6)4·4CH3CN or [Ni3(L Me)2Cl2](PF6)4·4CH3CN, that can be understood as a trapped reaction intermediate during the synthesis of the respective [Ni2 L Me](PF6)2 product. The structure not only contains protonated next to deprotonated imidazole heterocycles, but also Ni2+ ions with fundamentally different coordination modes within one molecule. Two of the three metal atoms are coordinated in a square-pyramidal fashion by half a ligand molecule and one chloride ligand, whereas the third Ni2+ ion is bound octahedrally by four pyrazolate moieties and two chloride anions.

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40

Callaway, Wyeth B., Jacqueline M. Veauthier, and Jonathan L. Sessler. "Schiff-base porphyrin and expanded porphyrin analogs." Journal of Porphyrins and Phthalocyanines 08, no. 01 (January 2004): 1–25. http://dx.doi.org/10.1142/s1088424604000027.

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In recent years, the field of porphyrin chemistry has expanded to include several new analogs of the original four pyrrole, carbon-bridged systems. This review traces the development of one such class of new macrocycles, namely Schiff-base porphyrin analogs. The review's focus is on the synthesis and properties of these new Schiff-base macrocycles that for ease of division have been divided into four classes: systems with two pyrrole rings, systems with three pyrrole or heterocyclic rings, systems with four pyrrole or heterocyclic rings, and systems with five or more pyrrole or heterocyclic rings. In addition to the role of metal ions as templating agents in the synthesis of these complexes, the rich coordination chemistry of several of the macrocycles is also discussed. X-ray crystallography has played an important role in determining the structures of many of these Schiff-base porphyrin analogs and many of the available structures have been incorporated into this review. Aromaticity of the macrocycles is discussed and has been evaluated from available electronic and NMR spectra. Finally, several potential applications of these molecules are discussed, briefly.

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41

Haslinger, Simone, Gerhard Laus, Volker Kahlenberg, Klaus Wurst, Thomas Bechtold, Stefan Vergeiner, and Herwig Schottenberger. "2-Azidoimidazolium Ions Captured by N-Heterocyclic Carbenes: Azole-Substituted Triazatrimethine Cyanines." Crystals 6, no. 4 (April 8, 2016): 40. http://dx.doi.org/10.3390/cryst6040040.

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42

Filatova, Elena G., Oksana V. Lebedeva, Yury N. Pozhidaev, and Alexey A. Konovalenko. "Natural Aluminosilicates Modified with Heterocyclic Amines for Extraction of Nickel(II) Ions." Journal of Physics: Conference Series 1172 (March 2019): 012045. http://dx.doi.org/10.1088/1742-6596/1172/1/012045.

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43

Ryashentseva, M. A., E. P. Belanova, K. I. Slovetskaya, and E. G. Aleshin. "Chromium oxide catalysts with low valence state ions for heterocyclic ring formation." Bulletin of the Academy of Sciences of the USSR Division of Chemical Science 35, no. 4 (April 1986): 710–12. http://dx.doi.org/10.1007/bf00954212.

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44

Laachir, Abdelhakim, Fouad Bentiss, Salaheddine Guesmi, Mohamed Saadi, and Lahcen El Ammari. "Crystal structure of bis(azido-κN)bis[2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole-κ2N2,N3]nickel(II)." Acta Crystallographica Section E Crystallographic Communications 71, no. 2 (January 14, 2015): m24—m25. http://dx.doi.org/10.1107/s2056989015000201.

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Reaction of 2,5-bis(pyridin-2-yl)-1,3,4-thiadiazole and sodium azide with nickel(II) triflate yielded the mononuclear title complex, [Ni(N3)2(C12H8N4S)2]. The NiIIion is located on a centre of symmetry and is octahedrally coordinated by four N atoms of the two bidentate heterocyclic ligands in the equatorial plane. The axial positions are occupied by the N atoms of two almost linear azide ions [N—N—N = 178.8 (2)°]. The thiadiazole and pyridine rings of the heterocyclic ligand are almost coplanar, with a maximum deviation from the mean plane of 0.0802 (9) Å. The cohesion of the crystal structure is ensured by π–π interactions between parallel pyridine rings of neighbouring molecules [centroid-to-centroid distance = 3.6413 (14) Å], leading to a layered arrangement of the molecules parallel to (001).

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45

Supuran, Claudiu T., Andrea Scozzafava, and Andrei Jitianu. "Carbonic Anhydrase Inhibitors. Part 541: Metal Complexes of Heterocyclic Sulfonamides: A New Class of Antiglaucoma Agents." Metal-Based Drugs 4, no. 6 (January 1, 1997): 307–15. http://dx.doi.org/10.1155/mbd.1997.307.

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Metal complexes of heterocyclic sulfonamides possessing carbonic anhydrase (CA) inhibitory properties were recently shown to be useful as intraocular pressure (IOP) lowering agents in experimental animals, and might be developed as a novel class of antiglaucoma drugs. Here we report the synthesis of a heterocyclic sulfonamide CA inhibitor and of the metal complexes containing main group metal ions, such as Be(II), Mg(II), Al(III), Zn(II), Cd(II) and Hg(II) and the new sulfonamide as well as 5-amino-1,3,4-thiadiazole-2-sulfonamide as ligands. The new complexes were characterized by standard physico-chemical procedures, and assayed as inhibitors of three CA isozymes, CA I, II and IV. Some of them (but not the parent sulfonamides) strongly lowered IOP in rabbits when administered as a 2% solution into the eye.

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Rajendran, Rajam, and Yoshiyuki Ohta. "Binding activity of Natto (a fermented food) and Bacillus natto isolates to mutagenic-carcinogenic heterocyclic amines." Canadian Journal of Microbiology 47, no. 10 (October 1, 2001): 935–42. http://dx.doi.org/10.1139/w01-094.

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The fermented food, whole meal Natto, viscous polymeric material from Natto, Natto bean, cooked soya bean, and 28 bacterial isolates from Natto were studied for their binding capacity to foodborne mutagenic-carcinogenic heterocyclic amines. The mutagenic heterocyclic amines used were Trp-P-1 (3-amino-1,4-dimethyl-5H-pyrido(4,3-b)indole); Trp-P-2 (3-amino-1-methyl-5H-pyrido(4,3-b)indole); Glu-P-1 (2-amino-6-methyldipyrido(1,2-a:3'2'-d)imidazole); PhIP (2-amino-1-methyl-6-phenylimidazo(4,5-b)pyridine); IQ (2-amino-3-methylimidazo(4,5-f)quinoline); MeIQ (2-amino-3,4-dimethylimidazo(4,5-f)quinoxaline); MeIQx (2-amino-3,8-dimethylimidazo(4,5-f)quinoxaline); and MeAαC (2-amino-3-methyl-9H-pyrido(2,3)indole). The lyophilized Natto and other fractions of Natto exhibited high binding activity towards Trp-P-1, Trp-P-2, PhIP, and MeAαC, while Glu-P-1, IQ, and MeIQ were not effectively bound. The binding capacity of bacterial isolates (Bacillus natto) were isolate-mutagen dependent. Heat treated lyophilized cells, cell wall, and cytoplasmic contents of the bacterial isolate with the highest binding capacity were analyzed for their ability to bind different heterocyclic amines. The results indicate the importance of the cell wall in binding to heterocyclic amines, whereas the cytoplasmic contents were less effective. Heat-treated cells were not much different from that of viable cells in their binding. The impact of different factors, such as pH, incubation time, metal ions, different concentrations of sodium chloride and alcohol, various enzymes, and acetylation of mutagens on binding of Trp-P-1 and IQ, were discussed. The significance of the present results is also discussed from the viewpoint that Natto, a fermented food, is able to scavenge dietary mutagenic heterocyclic amines through binding.Key words: fermented food, mutagens, heterocyclic amines, Natto, binding.

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Zhao, Liang Rong, Ping Shen, Xu Qin Zhan, Ming Xun Yan, and Chang Ying Yang. "A Highly Selective Chemosensor Probe for Ag⁺ in 50% THF/H₂O." Advanced Materials Research 718-720 (July 2013): 7–9. http://dx.doi.org/10.4028/www.scientific.net/amr.718-720.7.

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A highly selective chemosensor for Ag+ based on heterocyclic compound Diethyl 6-anilino-5H-2,3-dithia-5,7-diazacyclopenta (cd) indene-1,4-dicarboxylate (D1) was investigated. The deprotonation of N-H was observed easily in spectra of D1 (2.5×10-5 M) in 50% H2O/THF solution after NaOH addition, and the deprotonated D1 could interact with Ag+, resulted in the sharp decrease of deprotonated absorption. The addition of other metal ions would not produce an obvious change, which means quite extreme selectivity for Ag+ compared with other metal ions. The LOD of the method to detect Ag+ was 8.07×10-8 M. It is indicated that a novel high selective chemosensor for Ag+ was build up.

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Wu, Xiao-Na, Zhi-Hao You, and Yan-Kai Liu. "Different hybridized oxygen atoms controlled chemoselective formation of oxocarbenium ions: synthesis of chiral heterocyclic compounds." Organic & Biomolecular Chemistry 16, no. 35 (2018): 6507–20. http://dx.doi.org/10.1039/c8ob01743c.

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49

Ling, Irene, Alexandre N. Sobolev, and Colin L. Raston. "Functional heterocyclic molecular inclusion in p-sulfonatocalix[5]arene and lanthanide(iii) complexes." RSC Advances 6, no. 104 (2016): 102695–702. http://dx.doi.org/10.1039/c6ra23283c.

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p-Sulfonatocalix[5]arene either self-assemble in the presence of lanthanide ions into dense packed arrays of calixarenes or a grid-like arrangement comprising molecular capsules from adjacent bilayers, with the ‘molecular capsules’ confining small to large molecules.

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Stiborová, Marie, and Sylva Leblová. "Effect of heterocyclic compounds and 2-mercaptoethanol on rape alcohol dehydrogenase." Collection of Czechoslovak Chemical Communications 52, no. 8 (1987): 2107–13. http://dx.doi.org/10.1135/cccc19872107.

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Rape alcohol dehydrogenase (ADH) is inhibited by heterocyclic compounds with a five- to six-membered ring (imidazole, pyrazole, 4-methylpyrazole, 3-methylpyrazole, pyridine, nicotine amide) and by o-phenanthroline, a heterocyclic, polycyclic compound. Pyrazole and its derivatives, imidazole and pyridine, are competitive inhibitors with respect to ethanol. Nicotine amide and o-phenanthroline behave as mixed inhibitors (competitive – noncompetitive) with respect to the substrate. The addition of Zn2+-ions to the reaction medium interferes with the competition by o-phenanthroline. 4-Methylpyrazole and pyrazole are the strongest inhibitors of rape ADH. 2-Mercaptoethanol is an inhibitor of rape ADH which competes with ethanol and the coenzyme. The reversible inhibition by mercaptoethanol changes into the irreversible inactivation of the enzyme. The binding of inhibitors to the zinc atom present in the molecule of rape ADH and the localization of the metal in the enzyme protein have been studied.

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