Chandan Adhikary

Tridentate (NNO) Schiff-base copper(II) complex: synthesis, crystal structure, and magnetic study

A new azido adduct of a tridentate Schiff-base copper(II) complex has been synthesized and characterized structurally and magnetically. X-ray single crystal structure analysis reveals that the asymmetric unit of [Cu2(L)2(µ1,1-N3)2][Cu(L)(N3)] (1) [HL = 1-(N-ortho-hydroxyacetophenimine)-2,2-diethyl-aminoethane] has two independent moieties. One of these forms a dimer, containing end-on azido bridges, with its center of inversion related equivalents. The complex crystallizes in monoclinic space group P21/c with a = 10.112(2), b = 31.938(4), c = 9.718(2) Å and β = 95.00(2)°. Variable temperature magnetic susceptibility data show antiferromagnetic interactions between copper(II) centers.

Synthesis, X-ray crystal structure and magnetic study of a μ 1,5-dca bridged ferromagnetic dimeric copper(II) complex

Reaction of Cu(NO3)2 · 3H2O, 1-(N-salicyalideneimine)-2-(N,N-dimethyl)-aminoethane (HL1), LiClO4, and sodium dicyanamide (Nadca) in aqueous medium affords a dimeric complex [Cu2(L1)2 (μ1, 5-dca)](ClO4) (1). Single crystal X-ray analysis reveals that 1 is dinuclear with copper(II) ions bridged by a single dicyanamide group in end-to-end fashion. The coordination environment around copper(II) is square planar. Two nitrogens and oxygen of the tridentate Schiff-base ligand (HL1) occupy three coordination sites of the square plane while the remaining site is occupied by the nitrogen of a terminal nitrile of the bridging dca. The nitrogen of the other terminal nitrile group of the μ1,5-dca ligand connects a neighboring [CuL1] unit to yield [Cu2(L1)2(μ1,5-dca)](ClO4) (1). Variable temperature magnetic susceptibility measurements show that the magnetic interaction is ferromagnetic (J = 1.93 cm−1). The results of a magnetic model are in good agreement with the experimental data.

Synthesis, characterisation and X-ray structure of an azido adduct of a tridentate (NNO) Schiff base nickel(II) complex

The tridentate Schiff base 1-(N-salicylideneimino)-2-(N,N-diethyl-aminoethane (HL), derived from the condensation of salicylaldehyde with N,N-diethylethylenediamine, reacted with nickel(II) nitrate and azide to give a mononuclear complex of formula [Ni(L)(N3)], where HL = Et2N(CH2)2NCHC6H4(OH). The complex was characterized by spectroscopic and X-ray crystallographic methods. Coordination around nickel(II) is square planar. The molecular and supramolecular structure of the complex is discussed.