Transition metal complexes with thiosemicarbazide-based ligands. Part 51. Square-planar nickel(II) complex with acetylacetone bis(S-n-propylisothiosemicarbazone) (L). Crystal and molecular structure of [Ni(L-H)]NCS and two isomorphic complexes [Ni(L-H)]I·EtOH and [Ni(L-H)]I·iPrOH

The template reaction of a warm methanolic solution of Ni(OAc)2·4H2O, S-n-propylisothiosemicarbazide hydroiodide and acetylacetone yielded the needle- like, brown, diamagnetic complex [Ni(L–H)]I·MeOH, and in the presence of an excess of NH 4NCS, brown, prismatic crystals of the complex [Ni(L–H)]NCS (1), both compounds involving the monoanionic form of the ligand, acetylacetone bis(S-n-propylisothiosemicarbazone), L. Slow recrystallization fromMeOH, EtOH, iPrOH and Me2CO gave the corresponding monosolvent complexes [Ni(L–H)]I·solvent, of which only those involving EtOH and iPrOH were suitable for structural analysis. The crystallographic parameters of [Ni(L–H)]I·EtOH (2) and [Ni(L–H)]I·iPrOH (3) are very similar to each other, showing their structures are isomorphic. The crystal structures of the title compounds consist of the independent ions: NCS-, or I-, and the chemically identical cation [Ni(L–H)]+, where L–H is the monoanion resulting from deprotonation of the acetylacetone moiety, a tetradentate N4 ligand forming a square-planar coordination around a Ni(II) ion. It was found that the isothiosemicarbazide fragment of the ligand has an imido form. The complex cations of the compounds [Ni(L–H)]NCS and [Ni(L–H)]I·EtOH exhibit significant difference only in the conformation of their propyl groups

Transition metal complexes with thiosemicarbazide-based ligands. Part 45. Synthesis, crystal and molecular structure of [2,6-diacetylpyridine bis(S-methylisothiosemicarbazonato)]diazide-iron(III)

The template reaction of a warm methanolic solution of FeCl3.6H2O, S-methylisothiosemicarbazidehydroiodide and 2,6-diacetylpyridine in the presence of LiOAc and NaN3 yielded the high-spin complex [Fe(HL)(N3)2], were HL is the monoanion of the ligand 2,6-diacetylpyridine bis(S-methylisothiosemicarbazone). X-Ray analysis of the complex showed its pentagonal-bipyramidal configuration, with pentadenate (N5) HL in the equatorial plane and two monodentate azide groups in the axial positions. Crystal data are: monoclinic, P21/c, a = 1.0263(2), b = 1.2525(2), c = 1.6660(3) nm, b = 98.94°, V = 2.1154 nm3, Z = 4, rx = 1.499 g cm-3, r0 = 1.48 g cm-3, F(000) = 984, m = 9.40 cm-3

Transition metal complexes with thiosemicarbazide-based ligands. Part46. Synthesis and physico-chemical characterization of mixed ligand cobalt(III)-complexes with salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine

Mixed ligand octahedral cobalt(III) complexes with the tridentate salicylaldehyde semi-, thiosemi- and isothiosemicarbazone and pyridine of general formula [CoIII(L11-3)(py)3]X (H2L1 = salicylaldehyde semicarbazone, X = [CoIICl3(py)]-, ClO4- . H2O, I- . 0.5 I2; H2L2 = salicylaldehyde thiosemicarbazone, X = [CoIICl3(py)]-, [CoIIBr3(py)]-, ClO4- . H2O, I3-; H2L3 = salicylaldehyde S-methylisothiosemicarbazone, X = [ CoIIBr3(py) ]-, ClO4- . H2O, BF4-) were synthesized. The tridentate coordination of all the three dianionic forms of the ligands involves the phenol oxygen, hydrazine nitrogen and the chalcogen (O or S) in case of salicylaldehyde semi-, thiosemicarbazone and the terminal nitrogen atom in the case of isothiosemicarbazone. For all the complexes, a meridial octahedral arrangement is proposed, which is a consequence of the planarity of the chelate ligand. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility, IR and electronic absorption spectra. The thermal decomposition of the complexes was investigated by thermogravimetry, coupled TG-MS measurements and DSC

Transition metal complexes with Girard reagent-based ligands. Part IV. Synthesis and characterization of pyridoxilidene Girard-T hydrazone complexes. Crystal structure of the copper(II) complex

The monoligand complexes of the formula M(HPLGT)(NCS)(2) (M = Cu(II), Zn(II)) in which the ligand tridentate ONO pyridoxilidene Girard-T hydrazone, [H(3)PLGT]Cl(2) center dot 2H(2)O, was coordinated in neutral doubly deprotonated form were synthesized. Also, the first complexes with the ligand coordinated in triply deprotonated monoanionic form of the formula [Cu(PLGT)N(3)] and [Co(PLGT)(NO(2))(2)NH(3)] center dot 3H(2)O are reported. The single crystal X-ray analysis of [Cu(HPLGT)(NCS)(2)] showed that Cu(II) is placed in a square-pyramidal surrounding consisting of one tridentate Schiff base and one NCS group in the basal plane and the other NCS group in the apical position. Intermolecular hydrogen bonds leading to centrosymmetrical dimerization of these complexes were discussed. In the reaction of Girard-T and Hacac in the presence of CuCl(2), a mixture of single crystal complexes of the composition [Cu(3,5-Me(2)pz)(2)Cl(2)](2) and [Cu(acac)(2)] center dot 2[Cu(3,5-Me(2)pz)(2)Cl(2)] was obtained and X-ray analysis of the latter one was reported

{4-[(Carbamimidoylhydrazono)methyl-kappa N-2(1),N-4]-5-hydroxymethyl-2-methylpyridinium-3-olate-kappa O}(methanol-kappa O)copper(II) dinitrate

The title compound, [Cu(C9H13N5O2)(CH4O)](NO3)(2), consists of square-planar cationic complex units where the Cu-II centre is coordinated by an N, N, O-tridentate pyridoxal aminoguanidine Schiff base adduct and a methanol molecule. The tridentate ligand is a zwitterion exhibiting an almost planar conformation. The dihedral angles between the mean planes of the pyridoxal ring and the six-and five-membered chelate rings are all less than 2.0 degrees. The charge on the complex cation is neutralized by two nitrate counter-ions. Extensive N -H center dot center dot center dot O and C -H center dot center dot center dot O hydrogen bonding connects these ionic species and leads to the formation of layers. The pyridoxal hydroxy groups are the only fragments that deviate significantly from the flat layer structure; these groups are involved in O-H center dot center dot center dot O hydrogen bonding, connecting the layers into a three-dimensional crystal structure

Transition metal complexes with thiosemicarbazide-based ligands. Part LVI: Nickel(II) complex with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone and unusually deformed coordination geometry

Synthesis of a new nickel(II) complex, [Ni(Ph(2)PzTSC-H)(2)] with 1,3-diphenylpyrazole-4-carboxaldehyde thiosemicarbazone (Ph(2)PzTSC), is described. The compounds have been characterized by elemental and thermal analysis, molar conductivity and spectral (UV-Vis, IR, H-1 NMR, and C-13 NMR) measurements. In the case of complex the magnetic measurement has been also performed. Crystal and molecular structures of both the free ligand and the complex have been determined by single crystal X-ray analysis. It was found that the ligand coordinates in a bidentate NS fashion, in its deprotonated thioenolato form. The cis-square-planar geometry of the complex is significantly distorted tetrahedrally. The Cambridge Structural Database (CSD) study has been performed to obtain geometrical and structural informations on similar nickel(II) complexes in order to compare structural data. (c) 2007 Elsevier Ltd. All rights reserved

Transition metal complexes with Girard reagent-based ligands. Part III. Synthesis and characterization of salicylaldehyde Girard-T hydrazone complexes. Crystal structure of ligand and two isostructural copper(II) complexes

The ligand, salicylaldehyde Girard-T hydrazonium chloride, [H(2)SalGT]Cl (1), and two complexes [Cu(HSalGT)X-2]center dot H2O (X = Br(2); Cl(3)) were synthesized and their crystal structures were determined by single-crystal X-ray analysis. In the two isostructural complexes, the Cu(II) is located in a square-pyramidal environment, with the chelating ligand and one halogen atom in the basal plane and the second halogen in the apical position. The most apparent structural difference between the 1 and its complexes 2 and 3 is the orientation of the N(CH3)(3) group: in 1, it is practically coplanar to the rest of the molecule, while in 2 and 3 it is oriented to the side of the axially bonded halogen, which can be explained by the C-H center dot center dot center dot X intramolecular interactions. The compounds were characterized by elemental analysis, molar conductivity, magnetic susceptibility and electronic absorption spectra

Transition metal complexes with Girard reagent-based ligands. Part V. Synthesis, characterization and crystal structure of pentagonal-bipyramidal manganese(II) complex with 2,6-diacetylpyridine bis(Girard-T hydrazone)

The article describes the synthesis and crystal structure of the Mn(II) complex with 2,6-diacetylpyridine bis (Girard-T hydrazone), (H(2)dap(GT)(2))(2+), of the formula [Mn(H(2)dap(GT)(2))(NCS)(2)](NCS)(2)center dot MeOH. The complex has a pentagonal-bipyramidal coordination geometry, with pentadentate N(3)O(2) ligand in the equatorial plane and two isothiocyanato groups in the axial positions. Both the ligand and the complex are characterized by their FT-IR spectra and thermal data. (C) 2010 Elsevier B.V. All rights reserved