Synthesis, crystal structure, and properties of the adduct of bis(O,O′-diisopropyl dithiophosphato) nickel(II) with pyridine [Ni(i-Pr2dtp)2(py)2]

A new adduct bis(pyridine)-bis(O,O'-diisopropyl dithiophosphato-S,S') nickel(II), [Ni(i-Pr(2)dtp)(2)(py)(2)] (dtp = dithiophosphate, py = pyridine) has been obtained by recrystallization from CH3COCH3. The crystal and molecular structure of the title complex has been determined by X-ray crystallography. It crystallizes in the monoclinic system, space group P2(1)/c, with lattice parameters a = 6.4890(13) Angstrom, b = 16.386(3) Angstrom, c = 14.830(3) Angstrom, beta = 99.74(3)degrees, V = 1554.1(5) Angstrom(3), and Z = 2. The crystal structure consists of discrete molecules of [Ni(i-Pr(2)dtp)(2)(py)(2)], which displays a slightly distorted octahedral geometry for the NiS4N2 chromophore. Two O,O'-diisopropyl dithiophosphate ions act as bidentate ligands with their S atoms coordinated to Ni atom. Each forms a four-membered chelate ring in the equatorial plane. The N atoms from two pyridine ligands are axially coordinated to the Ni atom. The Ni-S bond distances are 2.4492(8) Angstrom and 2.5711(9) Angstrom, and the Ni-N bond distances are 2.127(3) Angstrom. Thermal analyses show that the thermal decomposition of this adduct is so unstable that loss of two pyridine ligands begins at about 65degreesC. Electronic and IR spectra data is in agreement with the structural data.