Molecules

302 KiB

Open AccessArticle

Synthesis, Crystal Structure, Stacking Effect and Antibacterial Studies of a Novel Quaternary Copper (II) Complex with Quinolone

by Guangguo Wu, Guoping Wang, Xuchun Fu and Longguan Zhu

Molecules 2003, 8(2), 287-296; https://doi.org/10.3390/80200287 - 28 Feb 2003

Cited by 71 | Viewed by 11378

Abstract

The structural properties of a new copper (II) complex [Cu₂(cip)₂(bpy)₂(pip)]·6H₂O (bpy=2,2’-bipyridyl, cip=1-cyclopropyl-6-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, pip= piperazinyl anion), obtained during the synthesis of the copper complex with ciprofloxacin (cpf), has been investigated. The complex crystallizes in the [...] Read more.

The structural properties of a new copper (II) complex [Cu₂(cip)₂(bpy)₂(pip)]·6H₂O (bpy=2,2’-bipyridyl, cip=1-cyclopropyl-6-4-oxo-1,4-dihydroquinoline-3-carboxylic acid, pip= piperazinyl anion), obtained during the synthesis of the copper complex with ciprofloxacin (cpf), has been investigated. The complex crystallizes in the triclinic system, space group P-1. The cell dimensions are: a=6.874(2) Å, b= 10.761(3) Å, c= 17.969(5) Å, α =80.071(6)°, β= 85.253(6)°, γ=79.109(6)°，V=1284.5(6) Å3, and Z=2. The Cu (II) ion displays a five-coordinate square pyramidal coordination with two nitrogen donors from bpy, the 4-keto and 3-carboxylate oxygen donors of cip, and the third nitrogen atom of the pip anion occupying the fifth site. There is a stack effect between cip ring and bpy ring from another molecule, where the stacking distance is about 3.5 Å. The results of elemental analysis and FT-IR measurement are also included. Both ligand and complex were assayed against gram-positive and gram-negative bacteria by the doubling dilutions method. The complex shows the same minimal inhibitory concentration (MIC) against S. Aureus and E. Coli bacteria as the corresponding ligand. Full article

(This article belongs to the Special Issue Selected Papers from the International Symposium on Frontiers in Molecular Science (ISFMS 2002))

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57 KiB

Open AccessArticle

Synthesis and Biological Evaluation of Some New Coumarin Derivatives

by M. A. Al-Haiza, M. S. Mostafa and M. Y. El-Kady

Molecules 2003, 8(2), 275-286; https://doi.org/10.3390/80200275 - 28 Feb 2003

Cited by 162 | Viewed by 14830

Abstract

Pyrimidino[5`,4`-6,5]-,pyridino[3`,2`-6,5]- and pyrrolo[3`,2`-5,6]4H-pyrano-[3,2-c][1]benzopyran-6-one derivatives (5-7 and 10) could be obtained via reaction of 2-amino-4-(p-bromophenyl)-3-cyano(carboethoxy)-4H,5H-pyrano[3,2-c][1]benzopyran-5-ones (3a,b) with a variety of reagents. Alkylation of (3b) with either 2-furoyl chloride or chloroacetyl chloride gave the 2-N-substituted derivatives (9a,b). Benzofurano[3,2-b]4H-pyran derivative (12) was also prepared. The antimicrobial [...] Read more.

Pyrimidino[5`,4`-6,5]-,pyridino[3`,2`-6,5]- and pyrrolo[3`,2`-5,6]4H-pyrano-[3,2-c][1]benzopyran-6-one derivatives (5-7 and 10) could be obtained via reaction of 2-amino-4-(p-bromophenyl)-3-cyano(carboethoxy)-4H,5H-pyrano[3,2-c][1]benzopyran-5-ones (3a,b) with a variety of reagents. Alkylation of (3b) with either 2-furoyl chloride or chloroacetyl chloride gave the 2-N-substituted derivatives (9a,b). Benzofurano[3,2-b]4H-pyran derivative (12) was also prepared. The antimicrobial activity of the prepared compounds was tested. Full article

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102 KiB

Open AccessArticle

Crystal Structure of N,N,N’,N’-tetra-[(3,5-dimethyl-1-pyrazolyl) methyl]-para-phenylenediamine

by Maria Daoudi, Najib Ben Larbi, Driss Benjelloun, Abdelali Kerbal, Jean Pierre Launay, Jacques Bonvoisin, Joël Jaud, Mostafa Mimouni and Taibi Ben-Hadda

Molecules 2003, 8(2), 269-274; https://doi.org/10.3390/80200269 - 28 Feb 2003

Cited by 20 | Viewed by 9914

Abstract

The title compound, molecular formula C₃₀H₄₀N₁₀, crystallizes and exhibits a cisoidal conformation around a central p-phenylenediamine ring suggesting that this bis-tripodal ligand is highly flexible and could be accommodated by many and original metal coordinations. All four [...] Read more.

The title compound, molecular formula C₃₀H₄₀N₁₀, crystallizes and exhibits a cisoidal conformation around a central p-phenylenediamine ring suggesting that this bis-tripodal ligand is highly flexible and could be accommodated by many and original metal coordinations. All four five-membered pyrazole rings are identical. The molecule presents an inversion centre that coincides with the phenyl ring centre: pyrazole rings are two-by-two equivalent. The electrostatic spatial intramolecular repulsion between N4 and N5 is probably responsible for this general arrangement. These data emphasize the basic character of nitrogens N4 and N5. Full article

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30 KiB

Open AccessArticle

Synthesis of 2-(2-R1-Hydrazino)-5-(R2-benzyl)-2-thiazolines on the Basis of Meerweins Arylation Products of Allyl Isothiocyanate

by Volodymyr V. Karpyak, Mykola D. Obushak and Mykola I. Ganushchak

Molecules 2003, 8(2), 263-268; https://doi.org/10.3390/80200263 - 28 Feb 2003

Cited by 9 | Viewed by 7275

Abstract

3-Aryl-2-chloropropylisothiocyanates (1) are formed by interaction of arenediazonium chlorides with allyl isothiocyanate. Adducts 1 react with monoacylhydrazines to form 1-acyl-4-(3-aryl-2-chloropropyl)thiosemicarbazides (2a–d). Thiosemicarbazides 2a–d in the presence of bases selectively transform into 2-(2-R¹-hydrazino)-5-(R²-benzyl)-2-thiazolines (3a–d). Full article

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37 KiB

Open AccessArticle

Effect of Microwaves in the Chiral Switching Asymmetric Michael Reaction

by S. Narasimhan and S. Velmathi

Molecules 2003, 8(2), 256-262; https://doi.org/10.3390/80200256 - 28 Feb 2003

Cited by 11 | Viewed by 8300

Abstract

Highly enantioselective Michael reactions of malonates with cyclic enones are achieved in remarkably less time under microwave irradiation using newly developed heterobimetallic catalysts. Full article

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279 KiB

Open AccessArticle

Regioselective Ethanolamination and Ketalization of 3-Ph-2,4-diacetyl(diethoxycarbonyl)-5-hydroxy-5-methylcyclohexanones

by Adele P. Kriven'ko, Eleanor A. Kozlova, Alexander V. Grigor'ev and Vitaly V. Sorokin

Molecules 2003, 8(2), 251-255; https://doi.org/10.3390/80200251 - 28 Feb 2003

Cited by 7 | Viewed by 7935

Abstract

The reaction of 3-phenyl-2,4-diacetyl(diethoxycarbonyl)-5-hydroxy-5-methylcyclohexanones with ethanolamine and ethylene glycol proceeds regioselectively using the carbonyl group of the alicycle to produce the corresponding cyclohexenylethanolamines and dioxolanes. Full article

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76 KiB

Open AccessArticle

Synthesis and X-ray Crystal Structure of Meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-1,8-di-(1-methylnaphthalene)

by Robert I. Haines and Dean R. Hutchings

Molecules 2003, 8(2), 243-250; https://doi.org/10.3390/80200243 - 28 Feb 2003

Cited by 3 | Viewed by 8831

Abstract

The pendant-arm macrocycle, meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-1,8-di-(1-methylnaphthalene) has been synthesized and its single crystal structure determined. The molecule crystallizes in a primitive monoclinic cell, with the space group P2₁/_a (#14). The cell dimensions are a = 10.778(3)Å, b = 13.809(3) Å, c = [...] Read more.

The pendant-arm macrocycle, meso-5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradecane-1,8-di-(1-methylnaphthalene) has been synthesized and its single crystal structure determined. The molecule crystallizes in a primitive monoclinic cell, with the space group P2₁/_a (#14). The cell dimensions are a = 10.778(3)Å, b = 13.809(3) Å, c = 11.420(2) Å, = 102.49(2)°, volume = 1659.5(6) Å³. Full article

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322 KiB

Open AccessArticle

The 3-Attractor Water Model: Monte-Carlo Simulations with a New, Effective 2-Body Potential (BMW)

by Yuri G. Bushuev, Svetlana V. Davletbaeva and Francis Muguet

Molecules 2003, 8(2), 226-242; https://doi.org/10.3390/80200226 - 14 Feb 2003

Cited by 9 | Viewed by 11594

Abstract

According to the precepts of the 3-attractor (3-A) water model, effective 2-body water potentials should feature as local minima the bifurcated and inverted water dimers in addition to the well-known linear water dimer global minimum. In order to test the 3-A model, a [...] Read more.

According to the precepts of the 3-attractor (3-A) water model, effective 2-body water potentials should feature as local minima the bifurcated and inverted water dimers in addition to the well-known linear water dimer global minimum. In order to test the 3-A model, a new pair wise effective intermolecular rigid water potential has been designed. The new potential is part of new class of potentials called BMW (Bushuev-Muguet-Water) which is built by modifying existing empirical potentials. This version (BMW v. 0.1) has been designed by modifying the SPC/E empirical water potential. It is a preliminary version well suited for exploratory Monte-Carlo simulations. The shape of the potential energy surface (PES) around each local minima has been approximated with the help of Gaussian functions. Classical Monte Carlo simulations have been carried out for liquid water in the NPT ensemble for a very wide range of state parameters up to the supercritical water regime. Thermodynamic properties are reported. The radial distributions functions (RDFs) have been computed and are compared with the RDFs obtained from Neutron Scattering experimental data. Our preliminary Monte-Carlo simulations show that the seemingly unconventional hypotheses of the 3-A model are most plausible. The simulation has also uncovered a totally new role for 2-fold H-bonds. Full article

(This article belongs to the Special Issue Selected Papers from the International Symposium on Frontiers in Molecular Science (ISFMS 2002))

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