191980-41-3Relevant academic research and scientific papers
Metal complexes with disubstituted oxamidic ligands
Casellato,Guerriero,Tamburini,Vigato
, p. 1 - 9 (1997)
Three oxamidic ligands have been prepared by reaction of oxalyldichloride with the appropriate amine H2NC6H4P(C6H5) 2 (H2A), H2NC2H4(NC5H4) (H2B) and H2NC2H4SC6H5 (H2C). They have been characterized by elemental analyses, IR, NMR, mass spectrometry and for H2B by X-ray diffractometry. The crystals, grown from a tetrahydrofuran/diethylether solution, are monoclinic, space group P21/c, cell dimensions a = 9.503(4), b = 6.278(4), c = 13.083(5) A and β = 100.24(4)o with Z = 2. The asymmetric unit is half of the ligand molecule which shows an inversion centre between the C-C bond of the oxamidic group. The molecule is elongated in a three steps configuration. The reaction of H2A with trans-Pd(C6H5CN)2(Cl)2 forms the white mononuclear cis-Pd(A) and the yellow homodinuclear trans-Pd2(A) (Cl)2 complexes as confirmed by scanning electron microscopy (SEM) and EDX analyses and by an X-ray structure of Pd2(A) (Cl)2. The yellow crystals, grown from alcoholic solution, are monoclinic, space group P21/c, cell dimensions a = 10.335(5), b = 10.246(5), c = 16.480(6) A and β = 100.81(5)o with Z = 2; as for H2B crystals, the asymmetric unit is half of the whole molecule. A distorted square planar coordination around each metal ion is reached by the coordination of a phosphorus, an oxygen and a nitrogen atom of the ligand and a chlorine atom. H2B forms the homodinuclear nickel(II) and copper(II) complexes M(B)(X)2 (X = C1-, CH3COO-, ClO-4). Crystals of the dinuclear copper(II) complex Cu2(B) (Cl)2(dmso)2, grown from dimethylsulphoxide, are triclinic, space group P1, cell dimensions a = 8.352(5), b = 8.361(5), c = 9.959(4) A, α = 83.39(4) β = 85.49(3), γ = 75.38(5)o with Z = 1. Again the dinuclear entity shows a inversion centre between the two C-C bonds of the oxamide ligand. Each copper(II) ion has a distorted square pyramidal environment formed by two nitrogen atom and an oxygen atom of half oxamidic ligand, a chlorine atom and the oxygen atom of a dimethylsulphoxide molecule; the copper-copper distance is 5.28 A. An antiferromagnetic interaction was observed for the dinuclear copper(II) complexes. H2C does not form complexes when reacted with transition metal ions.
