Synthesis and Characterization of New N-Alkylamino-3,5-diphenylpyrazole Ligands and Reactivity Toward PdII and PtII. Study of the cis–trans Isomerization

2010 ◽  
Vol 63 (2) ◽  
pp. 257 ◽  
Author(s):  
Gemma Aragay ◽  
Josefina Pons ◽  
Vicenç Branchadell ◽  
Jordi García-Antón ◽  
Xavier Solans ◽  
...  

In this paper, the synthesis and characterization of two new N-alkylaminopyrazole ligands, 1-[2-(ethylamino)ethyl]-3,5-diphenylpyrazole (dpea) and 1-[2-(octylamino)ethyl]-3,5-diphenylpyrazole (dpoa) are reported. The reaction of these ligands with [MCl2(CH3CN)2] (M = PdII, PtII) affords the following square planar complexes: cis-[MCl2(NN′)] (M = PdII: NN′ = dpea, 1; dpoa, 2; M = PtII: NN′ = dpea, 3; dpoa, 4). Reaction of [PdCl2(CH3CN)2] and dpea or dpoa in 1:2 M:NN′ molar ratio, in the presence of NaBF4, yields complexes [Pd(NN′)2](BF4)2 (NN′ = dpea, [5](BF4)2); dpoa, [6](BF4)2). The solid-state structures of complexes 1, 3, and [5](BF4)2 have been determined by single-crystal X-ray diffraction methods. In complexes 1 and 3, the dpea ligand is coordinated through the Npz and Namino atoms to the metallic centre, which completes its coordination with two chlorine atoms in a cis disposition. For complex [5](BF4)2, the crystal structure consists of cations involving a [Pd(Npz)2(Namino)2]2+ core with a cis disposition of the two dpea ligands in a square-planar geometry and BF4 – anions. Theoretical calculations were carried out to optimize the geometries of the cis and trans isomers of the [Pd(dpea)2]2+ cation and of the [Pd(dpea)2](BF4)2 complex. The results show that the trans isomer is the most stable for [Pd(dpea)2]2+, in contrast with the cis stereochemistry observed in the crystal structure of [Pd(dpea)2](BF4)2. The calculations also predict that in acetonitrile solution, the dissociation of this complex into the corresponding ions is thermodynamically favourable. The cis–trans isomerization process of [Pd(dpea)2]2+ in acetonitrile solution has been studied by NMR spectroscopy at different temperatures. These experimental results confirm that the trans isomer is the thermodynamically most stable form of the complexes [5](BF4)2 and [6](BF4)2.

Author(s):  
Hana Bashir Shawish ◽  
Mohd Jamil Maah ◽  
Siti Nadia Abdul Halim

Three nickel thiosemicarbazone mixed ligands complexes have been synthesized. Complexes with the formula [NiL(PPh3)]Cl, [Ni2L2(Phen)],[Ni2L2(Bpy)] (where L= 2,3,4-trihydroxybenzaldehydethiosemicarbazone, PPh3=Triphenylphosphine, Phen=1,10-phenanthroline, Bpy= 2,2 –Bipyridine)have been characterized by IR spectroscopy, as well as elemental analysis. The structure of [NiL (PPh3)]Cl has been determined by X-raycrystallography. The crystal structure of this complex shows that the Schiff base ligand functions as an N,O,S chelating anion to the phosphine –coordinated nickel(II) atom, which exists as a distorted square – planar geometry.


2015 ◽  
Vol 70 (9) ◽  
pp. 649-658 ◽  
Author(s):  
Teresa S. Ortner ◽  
Michael Schauperl ◽  
Klaus Wurst ◽  
Thomas S. Hofer ◽  
Hubert Huppertz

AbstractThe potassium pentaborate KB5O7(OH)2 reported herein crystallizes in the monoclinic space group P21/c (no. 14) with the lattice parameters a = 904.8(2), b = 753.2(2), c = 1214.9(5) pm, β = 117.16(2)°, and V = 0.73663(5) nm3 (Z = 4). It is a disordered structural variant of an already known compound with the same composition (a = 766.90(3), b = 904.45(3), c = 1223.04(4) pm, β = 119.132(2)°, and V = 0.74101(5) nm3 (Z = 4)) reported by Wu in 2011. The disorder of the potassium cation in the single crystal structure determination of KB5O7(OH)2 presented here leads to a remarkably elongated a axis and a corresponding reduction of the length of the b axis in comparison to the ordered compound. The disordered variant was obtained through a hydrothermal synthesis from KNO3, B2O3, and Ce(NO3)3·6H2O with a molar ratio of 1:1:0.07.


2016 ◽  
Vol 15 (2) ◽  
pp. 17-32
Author(s):  
Rita Bhattacharjee

A series of palladium(II) halo complexes of the types[PdX2L2].nH2O {n = 0, X = Cl, L = L4and L6; X = Br, L = L3,L4, L5 and L6; n = 2, X = Cl, L = L3and L7, X = Br, L = L1};Pd2X4L2 {X = Cl, Br, L = L2 and L8} and Pd2X4L3 [X = Cl, L= L1; X = Br, L = L7] were prepared where L is 6-R-5,6-dihydrobenzoimidazo quinazoline (R-Diq; where R =phenyl: L1/furyl: L2/thiophenyl: L3/o- or phydroxyphenyl: L4, L5/o- or p-chlorophenyl: L6,L7/dimethylaminophenyl: L8and characterized byelemental analyses, molar conductivity measurements,TGA, infrared, electronic, NMR and mass spectraltechniques. Based on these studies, monomeric/dimericstructure with a square planar geometry around the metalion was proposed for these complexes. Anti-microbialactivity for some of the synthesized complexes wereinvestigated.Keywords: dihydrobenzoimidazoquinazoline, palladium(II),thermal analysis, mass spectra, biological activity.


2017 ◽  
Vol 13 (2) ◽  
pp. 1-15
Author(s):  
Rita Bhattacharjee Virupaiah Gayathri

A series of palladium(II) halo complexes of the types [PdX 2 L 2 ].nH 2 O {n = 0, X = Cl, L = L 2 , L 4 and L 5 ; X = Br, L = L 2 ; n = 1, X = Cl, L = L 1 and L 3 } and Pd 2 X 4 L 3 [X = Br, L = L 1 , L 3 , L 4   and L 5 ] were prepared where L is 6-R-5,6- dihydrobenzoimidazo quinazoline (R-Diq; where R = ethyl: L 1 / n or i-propyl: L 2 , L 3 / n or i-butyl: L 4 , L 5 ) and characterized by elemental analyses, conductivity measurements, TGA, infrared, electronic, NMR and mass spectral techniques. Based    on these studies monomeric/dimeric structure with a square planar geometry around the metal ion was proposed for all the complexes. Some of the complexes were investigated for anti-microbial activity.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
H. D. Juneja ◽  
Manisha Joshi ◽  
J. P. Kanfade

The oxaloyl carboxymethyl cellulose (OCMC) complexes of Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) metal ions have been synthesized and the coordination of OCMC in these complexes has been investigated through IR spectra, reflectance spectra, and thermal analysis. On the basis of spectral and thermal data an octahedral geometry was assigned to[Mn(II)OCMC(H2O)2]nand[Co(II)OCMC(H2O)2]n, square planar geometry was assigned to[Cu(II)OCMC]n, and tetrahedral geometry was assigned to[Ni(II)OCMC]nand[Zn(II)OCMC]nMetallic Gel complexes.


2009 ◽  
Vol 6 (4) ◽  
pp. 993-1002 ◽  
Author(s):  
A. Venkatchallam ◽  
R. G. Deshmukh ◽  
Dilip C. Sawant

Synthesis and characterization of 2-(hydroxyimino)-1-(phenyl propylidene) thiocarbonohydrazide (called ‘HPTCHOPD’) was studied. The synthesized compound having the molecular formula C10H13N5OS, where in isonitrosopropiophenone is reacted with thiocarbonohydrazide in presence of sodium acetate in ethanol-water mixture. The yield which is comprises effecting the reaction in the presence of sodium acetate. Also the present work report a process for producing metal complexes having the formula ML2and (ML)2Cl, wherein M is the divalent metal cation, like cobalt (Co+2), nickel (Ni+2) and copper (Cu+2). The compound HPTCHOPD is admixed with a basic divalent compound that is halide, mainly chloride of Co+2, Ni+2and Cu+2in presence of methanol-water mixture. The metal complexes so produced are characterized on the basis of spectral, elemental and magnetic analysis; reveal interesting geometries and bonding features. The data suggested square planar geometry for Co+2complex, a distorted tetrahedral/square planar-octahedral geometry for Ni+2complex and a bridged structure for Cu+2complex.


2009 ◽  
Vol 6 (1) ◽  
pp. 173-187
Author(s):  
Baghdad Science Journal

This work represents the preparation of the starting material, 3-chloro-2-oxo-1,4-dithiacyclohexane (S) using a new method. This material was reacted with, 4-phenylthiosemicarbazide to give (H3NS3) as a tetradentate ligand H3L. New complex of rhenium (V) with this ligand of the formula [ReO(L)] was prepared. New complexes of the general formula [M(HL)] of this ligand when reacted with some metal ions where: M = Ni(II), Cu(II), Cd(II), Zn(II), Hg(II) have been reported. The ligand and the complexes were characterized by infrared, ultraviolet–visible, mass, 1H nuclear magnetic resonance and atomic absorption spectroscopic techniques and by (HPLC), elemental analysis, and electrical conductivity. The proposed structure for H3L with Re (V) is square pyramidal, while Ni(II) complex was square planar geometry, and with the rest of metal ions are distorted tetrahedral.


2003 ◽  
Vol 68 (8-9) ◽  
pp. 641-647 ◽  
Author(s):  
Sandra Konstantinovic ◽  
Blaga Radovanovic ◽  
Zivojin Cakic ◽  
Vesna Vasic

Complexes of Co(II), Ni(II), Cu(II) and Zn(II) with 3-salicylidenehydrazono-2-indolinone were prepared. Their structure was established to be [MLCl].Cl by using elemental analysis and molar conductivity, as well as AA, FTIR, UV/VIS and 1H-NMR spectroscopic methods. The spectral studies indicated a square-planar geometry for the Ni(II) and Cu(II) complexes and a tetrahedral one for the Co(II) and Zn(II) complexes. The complexes were tested for antibacterial activity against Staphylococcus aureus, Enterococcus D, Proteus mirabilis, Escherichia coli, Bacillus anthracis, Pseudomonas aeruginosa and Candida albicans.


2020 ◽  
Vol 11 (4) ◽  
pp. 319-323
Author(s):  
Cemal Koray Ozer ◽  
Gun Binzet ◽  
Hakan Arslan

Herein, we describe the synthesis and characterization of bis(N-(diethylcarbamothioyl)cyclohexane carboxamido)copper(II) complex, cis-[Cu(L-κ2S,O)2], has been prepared by the reaction of N-(diethyl carbamothioyl)cyclohexanecarboxamide ligand with copper(II) acetate. The green colored crystals of the complex were obtained by slow evaporation of their dichloromethane:ethanol solution (2:1, v:v). The crystal structure of cis-[Cu(L-κ2S,O)2] was obtained by single-crystal X-ray diffraction. The crystal structure reveals an monoclinic C2 (no. 5) space group with cell parameters a = 14.848(3) Å, b = 10.543(2) Å, c = 10.511(2) Å, β = 123.84(3)°, V = 1366.7(7) Å3, Z = 2, T = 153(2) K, μ(MoKα) = 0.979 mm-1, Dcalc = 1.327 g/cm3, 4979 reflections measured (6.6° ≤ 2Θ ≤ 50.68°), 2243 unique (Rint = 0.0223, Rsigma = 0.0444) which were used in all calculations. The final R1 was 0.0225 (>2sigma(I)) and wR2 was 0.0490 (all data). The angular structural index parameter, τ4, is equal to 0.40, which confirms the distorted square planar geometry for the title compound. The puckering parameters (q2 = 0.015(3) Å, q3 = 0.576(3) Å, QT = 0.577(3) Å, θ = 1.6(3)° and φ = 20(11)°) of the title complex show that the cyclohexane ring adopts a chair conformation. The two ethyl groups of the diethyl amine group have anti-orientation with respect to one another. The crystal packing shows the molecules stacked in parallel sheets along [010], accompanied by C3-H3A···O1ⁱ (i -x, +y, 1-z) intermolecular contact.


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