Complexes of Zn, Cd and Hg Halides with S and N Polydentate Schiff-Base. Metal Template Effect in the Synthesis of Analogous Oxygenated Base. Crystal Structure of [Zn(btsc)2Cl2] and [Cd(btsc)2Br2]

1991 ◽  
Vol 46 (6) ◽  
pp. 767-774 ◽  
Author(s):  
Pilar Souza ◽  
Luisa Sanz ◽  
Vicente Fernández ◽  
Agueda Arquero ◽  
Enrique Gutierrez ◽  
...  

Zinc, cadmiun and mercury dihalide react with 4-acetylpyridinthiosemicarbazone (4-aptsc) to give complexes with 1:1 and 2:1 ligand/metal stoichiometric ratios. These metals are effective templates for the Schiff-base condensation of 4-acetylpyridine with semicarbazide to give the complexes [M(4-apsc)X2] and [M(4-apsc)2X2] where M = Zn, Cd or Hg and X = Cl, Br or I. These compounds were characterized by elemental analyses, conductivities measurements, IR and 13C, 1H NMR spectra.The zinc chloride and bromide complexes of benzalthiosemicarbazone (btsc) have been prepared and characterized by X-ray measurements.The compounds Zn(btsc)2Cl2 and Cd(btsc)2Br2 are isostructural and crystallize in the space group P21/n. The crystal structure of the chlorine derivative has been resolved by single-crystal X-ray diffraction. The zinc centre is in a slightly distorted tetrahedral environment. There are intra and intermolecular hydrogen bonds.

2003 ◽  
Vol 58 (5) ◽  
pp. 389-394 ◽  
Author(s):  
Alexander A. Trifonov ◽  
Mikhail N. Bochkarev ◽  
Herbert Schumann ◽  
Sebastian Dechert

Racemic trans-2-(9(H)-fluoren-9-yl)cyclohexanol, C13H9-cyclo-C6H10-OH (1), reacts with two equivalents of potassium naphthalenide in THF to give the dipotassium salt [C13H8-cyclo-C6H10-O]- K2(THF) (2). Recrystallization of 2 from pyridine affords the solvent free salt [C13H8-cyclo-C6H10- O]K2 (3). The reactions of LaI3(THF)4 with one equivalent of 2 or of YbI2(THF)2 with equimolar amounts of 2 produce the alkoxolanthanum diiodide (C13H9-cyclo-C6H10-O)LaI2(DME)2 (4) and the ytterbium dialkoxide (C13H9-cyclo-C6H10-O)2Yb(THF)0.5(5), respectively. [(Me3Si)2N]3Y reacts with three equivalents of 1 with elimination of hexamethyldisilazane and formation of the yttrium trialkoxide (C13H9-cyclo-C6H10-O)3Y (6). The compounds 2 to 5 were characterized by elemental analyses, 1H NMR, 13C NMR and IR spectra. The molecular structure of 4 was determined by single crystal X-ray diffraction.


2014 ◽  
Vol 69 (11-12) ◽  
pp. 1061-1072 ◽  
Author(s):  
Ulf H. Strasser ◽  
Beate Neumann ◽  
Hans-Georg Stammler ◽  
Raphael J. F. Berger ◽  
Norbert W. Mitzela

Abstract 5,11,17,23-Tetrakis(trimethylsilylethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (1) was synthesised in two steps starting from 25,26,27,28-tetra-n-propoxycalix[4]arene, and the structure of 1 was determined by X-ray diffraction. Compound 1 was desilylated (K2CO3) to give 5,11,17,23- tetrakis(ethynyl)-25,26,27,28-tetra-n-propoxycalix[4]arene (2), which was tetra-aurated under basic conditions (NaOEt, THF) with a series of phosphane-gold chlorides (o-Tol3PAuCl, Ph3PAuCl, Ph2MePAuCl, PhMe2PAuCl, Me3PAuCl, Cy3PAuCl, t-Bu3PAuCl) to afford in good to excellent yields the tetra-aurated tetraethynylcalix[4]arene species 3-9 in one step [with phosphane ligands o-Tol3P (3), Ph3P (4), Ph2MeP (5), PhMe2P (6), Me3P (7), Cy3P (8), t-Bu3P (9)]. All compounds were characterised by 1H NMR and infrared spectroscopy, mass spectrometry and by elemental analyses, additionally 3, 4, 5, 8 and 9 by 13C{1H}, and 3-6, 8 and 9 by 31P{1H} NMR spectroscopy. The molecular structures of complexes 3 and 9 were determined by X-ray diffraction and show pinched-cone conformations, but neither intra- nor intermolecular attractive aurophilic Au···Au contacts. The acceptor ability of complexes 3 and 9 was investigated by complexation attempts with various phosphane-gold chlorides and xenon gas under pressure, but interactions could not be determined experimentally. The formation of a complex between xenon and gilded calix[4]arene could, however, be predicted for fluorine-substituted species and with very small phosphane ligands (PH3) on the basis of quantum-chemical calculations; the energy of formation is 9:6 kJ mol-1. The crystal structure of Ph2MePAuCl was also determined and shows Au···Au-bonded dimers.


2007 ◽  
Vol 62 (4) ◽  
pp. 495-500 ◽  
Author(s):  
Brajagopal Samanta ◽  
Joy Chakraborty ◽  
Shyamapada Shit ◽  
Stuart R. Batten ◽  
Paul Jensen ◽  
...  

The new complex Cu[L1]Cr2O7has been synthesised with the N,N′-bis(2-pyridylmethylene) butane-1,4-diamine Schiff base L1, [NC5H4CH=N(CH2)4N=CHC5H4N], and characterised with elemental analyses and different spectroscopic and electrochemical studies. The structure of the new complex has been established by single crystal X-ray diffraction. The complex crystallises in the monoclinic system with space group P21/c having cell parameters a = 14.7(5), b = 9.22(2), c = 16.2(5) Å , β = 116.9(1)°, and Z = 4. The Cr2O72− unit is bonded through one terminal oxygen donor end to the central Cu(II) chelated by the Schiff base ligand.


2013 ◽  
Vol 803 ◽  
pp. 80-84
Author(s):  
Yu Qi Liu ◽  
Yong Yang ◽  
Rui Yang ◽  
Xiao Jun Xu

A novel metalorganic coordination polymer, namely [Co3(bpd)5.5(NCS)6(NH3)]n2H2O (1) (bpd=1,4-bis (4-pyridyl)-2,3-diaza-1,3-butadiene), has been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray diffraction. Compound 1 presents 2D[3,4,-connected 3-nodal net with the point symbol (4268210)(4462)(8210). In addition, four identical 2D single nets is interlocked with each other in parallel, thus directly leading to the formation of a polycatenated layer (2D2D).


2021 ◽  
Author(s):  
SOUMYA SUNDAR MATI ◽  
Dr. SAUGATA KONAR ◽  
BOBY SAMAI

A zinc coordinated rare binuclear complex was synthesised and characterized by elemental analysis and single-crystal X-ray diffraction. Two mononuclear units formed by two Schiff base ligands 2-((2-(pyrimidin-2-yl)hydrazono)methyl)phenol (PHP) coordinated with...


2019 ◽  
Vol 25 (1) ◽  
pp. 66-72 ◽  
Author(s):  
Li Qiao ◽  
Peng-Peng Cai ◽  
Zhong-Hua Shen ◽  
Hong-Ke Wu ◽  
Cheng-Xia Tan ◽  
...  

AbstractTwo pyrazol-4-carboxamides, 3-(difluoromethyl)-N-(mesitylcarbamoyl)-1-methyl-1H-pyrazole-4-carboxa-mide (7a) and 3-(difluoromethyl)-N-((3,5-dimethylphenyl) carbamoyl)-1-methyl-1H-pyrazole-4-carboxamide (7b) were synthesized and their structures were confirmed by the aid of 1H NMR and HRMS analyses. The structure of the pyrazole-4-carboxamide, 7a was also determined by X-ray diffraction. The preliminary activity results demonstrate that these two compounds exhibit good inhibitory activity against Botrytis cinerea. Further docking results indicated that the key active group is difluoromethyl pyrazole moiety.


2002 ◽  
Vol 57 (11) ◽  
pp. 1191-1194 ◽  
Author(s):  
Chirantan Roy Choudhury ◽  
Subrata Kumar Dey ◽  
Sutapa Sen ◽  
Bappaditya Bag ◽  
Samiran Mitra ◽  
...  

The single pyrazine-bridged polymeric complex {[Ni(pyz)(H2O)4](NO3)2.2H2O}n has been synthesised and characterised by elemental analyses, IR and UV-vis spectra, and a single-crystal X-ray diffraction study. The coordination around the Ni centre is perfectly octahedral. The Ni(H2O)4 coordination planes are bridged by pyrazine ligands forming an infinite chain structure. Two nitrate anions and two water molecules exist in the lattice and are linked by intermolecular hydrogen bonds to the coordinated water molecules.


2007 ◽  
Vol 62 (3) ◽  
pp. 475-482 ◽  
Author(s):  
Karsten Schubert ◽  
Helmar Görls ◽  
Wolfgang Weigand

Starting from 4-bromoacetophenone 1, the 4-bromo-β -hydroxydithiocinnamic acid 2 and the 4-bromo-β -hydroxydithiocinnamic acid hexyl ester 3 were prepared using carbon disulfide and potassium-tert-butylate as a base. Acting as a ligand, the acid gives 1,1-ethenedithiolato complexes with (Ph3P)2Pt(II) (4a), (Et3P)2Pt(II) (4b), dppePt(II) (4c), (Ph3P)2Pd(II) (4d), dppePd(II) (4e), and dppeNi(II) (4f). In contrast to the acid, the deprotonated ester 3 forms a monoanionic bidentate ligand. [O,S] Complexes of Pt(II) (5a), Pd(II) (5b) and Ni(II) (5c) were obtained. All complexes have been fully characterised using 1H NMR, 13C NMR and 31P NMR spectroscopy, mass spectrometry, infrared spectroscopy and elemental analyses. The molecular structures of the complexes 4b and 5a - 5c were determined by X-ray diffraction analyses.


Crystals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 360 ◽  
Author(s):  
Yan Zhang ◽  
Zhao Yang ◽  
Shuaihua Zhang ◽  
Xingtong Zhou

A novel cocrystal of the potent H2 receptor antagonist famotidine (FMT) was synthesized with malonic acid (MAL) to enhance its solubility. The cocrystal structure was characterized by X-ray single crystal diffraction, and the asymmetry unit contains one FMT and one MAL connected via intermolecular hydrogen bonds. The crystal structure is monoclinic with a P21/n space group and unit cell parameters a = 7.0748 (3) Å, b = 26.6502 (9) Å, c = 9.9823 (4) Å, α = 90, β = 104.2228 (12), γ = 90, V = 1824.42 (12) Å3, and Z = 4. The cocrystal had unique thermal, spectroscopic, and powder X-ray diffraction (PXRD) properties that differed from FMT. The solubility of the famotidine-malonic acid cocrystal (FMT-MAL) was 4.2-fold higher than FMT; the FAM-MAL had no change in FMT stability at high temperature, high humidity, or with illumination.


2013 ◽  
Vol 634-638 ◽  
pp. 2592-2595
Author(s):  
Qing Wei Wang ◽  
Ting Feng Lu ◽  
Jia Guo ◽  
Xiu Mei Li

A new metal-organic complex FeII2FeIII2(cbba)4(L)6 (Hcbba = 2-(4΄-chlorine-benzoyl) benzoic acid, L = 3-(2-pyridyl)pyrazole) 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction, elemental analyses, TG and IR spectroscopy. The compound crystallizes in monoclinic, space group Cc with a = 17.729(5), b = 15.919(5), c = 33.650(5) Å, β = 92.058(5)°, V = 9491(4) Å3, C104H68Cl4Fe4N18O12, Mr = 2126.96, Dc = 1.489 g/cm3, μ(MoKα) = 0.786 mm1, F(000) = 4344, Z = 4, the final R = 0.0559 and wR = 0.1122 for 12093 observed reflections (I > 2(I)).


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