scholarly journals Synthesis of mesomeric betaine compounds with imidazolium-enolate structure

2012 ◽  
Vol 8 ◽  
pp. 390-397 ◽  
Author(s):  
Nina Gonsior ◽  
Fabian Mohr ◽  
Helmut Ritter

The synthesis of a heterocyclic mesomeric betaine by quaternization reaction of 1-butylimidazole and tetrabromo-1,4-benzoquinone is presented. The structure was verified by means of X-ray single-crystal analysis, NMR and IR spectroscopy. Inclusion complexes of the heterocyclic mesomeric betaine with randomly methylated (1.8) β-cyclodextrin were investigated by UV–vis spectroscopy. Furthermore, the reaction conditions were applied to poly(vinylimidazole) and 1,4-bis(1H-imidazol-1-yl)butane to obtain functionalized polymer networks and condensate polymers, respectively.

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
Stergios Zanias ◽  
Giannis S. Papaefstathiou ◽  
Catherine P. Raptopoulou ◽  
Konstantinos T. Papazisis ◽  
Vasiliki Vala ◽  
...  

As part of our interest into the bioinorganic chemistry of gallium, gallium(III) complexes of the azole ligands 2,1,3-benzothiadiazole (btd), 1,2,3-benzotriazole (btaH), and 1-methyl-4,5-diphenylimidazole (L) have been isolated. Reaction of btaH or btd withGaBr3orGaCl3resulted in the mononuclear complexes[GaBr3(btaH)2](1) and[GaCl3(btd)2](2), respectively, while treatment ofGaCl3with L resulted in the anionic complex(LH)2[GaCl4](3). All three complexes were characterized by single-crystal X-ray crystallography and IR spectroscopy, while their antiproliferative activities were investigated against a series of human and mouse cancer cell lines.


2015 ◽  
Vol 70 (12) ◽  
pp. 851-856 ◽  
Author(s):  
Chun-Hua Dai ◽  
Fu-Lin Mao

AbstractThe tridentate N-donor ligand 2,6-di(2-oxazolyl)pyridine (L) reacts with AgClO4 and AgPF6 to yield two new complexes, {[Ag5(L)5](ClO4)5}n (1) and {[Ag5(L)5](PF6)5}n (2), which have been characterized by single-crystal and powder X-ray diffractions, IR spectroscopy, and elemental and thermogravimetric analyses. Complexes 1 and 2 are isotypic, displaying helical chain structures. The fluorescence properties of 1 and 2 were investigated.


Author(s):  
Marieta Muresan-Pop ◽  
Sergiu Macavei ◽  
Alexandru Turza ◽  
Gheorghe Borodi

Four new solvates of the anti-HIV compound etravirine [systematic name: 4-({6-amino-5-bromo-2-[(4-cyanophenyl)amino]pyrimidin-4-yl}oxy)-3,5-dimethylbenzonitrile, C20H15BrN6O] with dimethyl sulfoxide (C2H6OS, two distinct monosolvates), 1,4-dioxane (C4H8O2, the 0.75-solvate) and N,N-dimethylacetamide (C4H9NO, the monosolvate), which exhibit conversion to the same anhydrous etravirine phase upon desolvation, and a stable etravirinium oxalate salt {6-amino-5-bromo-4-(4-cyano-2,6-dimethylphenoxy)-2-[(4-cyanophenyl)amino]pyrimidin-1-ium hemioxalate, C20H16BrN6O+·0.5C2O4 2−} were obtained. The crystal structures were solved by single-crystal X-ray diffraction and analyzed by powder X-ray diffraction, and the intermolecular interactions were explored by Hirshfeld surface analysis. Lattice energies were evaluated using the atom–atom force field Coulomb–London–Pauli (AA CLP) approximation, which distributes the total energy as four separate contributions: Coulombic, polarization, dispersion and repulsion. The formation of the solvates and the oxalate salt was further characterized by thermal analysis and IR spectroscopy.


Synlett ◽  
2018 ◽  
Vol 30 (01) ◽  
pp. 54-58 ◽  
Author(s):  
Timothy Swager ◽  
Cagatay Dengiz ◽  
You-Chi Wu

We report the synthesis and characterization of iptycene–naphthazarin dyes by using a sequential Diels–Alder approach. The tautomerization of naphthazarin was used as the key step in the synthesis, with structures confirmed by single-crystal X-ray and NMR analysis. The systematic trends in electronic properties were investigated by UV/Vis spectroscopy. BF2 complexes of the dyes were prepared by reaction with BF3·OEt2 in CH2Cl2.


2020 ◽  
Author(s):  
Viktoria Leonhardt ◽  
Stefanie Fimmel ◽  
Ana-Maria Krause ◽  
Florian Beuerle

<div><div><div><p>A trigonal-bipyramidal covalent organic cage compound serves as an efficient host to form stable 1:1-complexes with C60 and C70. Fullerene encapsulation has been comprehensively studied by NMR and UV/Vis spectroscopy, mass spectrometry as well as single-crystal X-ray diffraction. Exohedral functionalization of encapsulated C60 via threefold Prato reaction revealed high selectivity for the symmetry-matched all-trans-3 addition pattern.</p></div></div></div>


2021 ◽  
Vol 68 (4) ◽  
pp. 1008-1015
Author(s):  
Yong Yuan ◽  
Xi-Kun Lu ◽  
Gao-Qi Zhou ◽  
Xiao-Yang Qiu

Three new copper(II) complexes, [Cu(LH)2]Br2 (1), [Cu(LH)2]NCS2 (2), and [Cu(LH)2](NO3)2 (3), where LH is the zwitterionic form of 2-bromo-6-((2-(isopropylamino)ethylimino)methyl)phenol (HL), were synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy. The structures of the complexes were further confirmed by single crystal X-ray structure determination. All compounds are mononuclear copper(II) complexes. The Cu atoms in the complexes are coordinated by two imino N and two phenolate O atoms from two LH ligands, forming square planar coordination. The compounds were assayed for their antimicrobial activities.


Author(s):  
Sergei V. Voitekhovich ◽  
Berthold Kersting ◽  
Oleg A. Ivashkevich

The dinuclear nickel(II) complex [Ni2LmClO4] + , where Lm represents a 24-membered macrocyclic hexaaza-dithiophenolate ligand, reacts with 5-(4-pyridyl)tetrazole (PyrCN4H) to give the dinuclear complex [Ni2Lm(PyrCN4)]+ . The new complex was both isolated as perchlorate or tetraphenylborate salts and characterised by elemental analysis and IR spectroscopy. The structure of [Ni2Lm(PyrCN4)]BPh4 ⋅ MeCN was determined by single crystal X-ray diffraction, showing that tetrazolate units are in a N2,N3-bridging mode to generate dioctahedral N3Ni(µ-S)2(µ-N4CPyr)NiN3 core.


2020 ◽  
Vol 1 (4) ◽  
pp. 22-25
Author(s):  
Azwan Morni

This study reports a green method for the synthesis of gold nanoparticles (AuNPs) using the aqueous extract of Salix aegyptiaca extract. The effects of gold salt concentration, extract concentration and extract quantity were investigated on nanoparticles synthesis. Novel methods of ideally synthesizing AuNPs are thus thought that are formed at ambient temperatures, neutral pH, low costs and environmentally friendly fashion. AuNPs were characterized with different techniques such as UV–vis spectroscopy, FT-IR spectroscopy, X-ray diffraction, and TEM. FT-IR spectroscopy revealed that gold nanoparticles were functionalized with biomolecules that have primary carbonyl group, -OH groups and other stabilizing functional groups. TEM experiments showed that these nanoparticles are formed with various shapes and X-ray diffraction pattern showed high purity and face centered cubic structure of AuNPs. For electrochemical properties of AuNPs, a modified glassy carbon electrode using AuNPs (AuNPs/GCE) was investigated. The results show that electronic transmission rate between the modified electrode and [Fe (CN)6]3-/4- increased.


2003 ◽  
Vol 58 (7) ◽  
pp. 698-703 ◽  
Author(s):  
Adel S. Girgis ◽  
I. S. Ahmed-Farag

Reaction of 6-arylmethylene-6,7,8,9-tetrahydro-5H-benzocyclo-hepten-5-ones (1) with malononitrile in the appropriate alcohol in the presence of sodium afforded the corresponding 2-alkoxy-4-aryl- 6,7-dihydro-5H-benzo[6,7]cyclohepta[1,2-b]pyridine-3-carbonitriles (2) and not their isomeric forms 2-alkoxy-4-aryl-6,7-dihydro-5H-benzo[3,4]-cyclohepta[1,2-c]pyridine-1-carbonitriles (3). The proposed structure was confirmed via independent synthesis of (2) through the reaction of 6,7,8,9- tetrahydro-5-benzocycloheptenone (4) with the appropriate ylidenemalononitriles 5 under the same reaction conditions. Single crystal X-ray diffraction proves the structures of 2a,b.


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