Influence of free and chelating phosphine on the NiS 2P 2 planar chromophore. Synthesis and single crystal structure determination of bis(triphenylphosphine) ( N, N′-iminodiethylenebis(phthalimide)-dithiocarbamato)nickel(II) perchlorate, methanol and water solvate and [1,2-bis(diphenylphosphino- k. P, P′)ethane]-( N, N′-iminodiethylenebis(phthalimide)dithiocarbamato)nickel(II) tetraphenylborate water solvate

Abstract

Syntheses and crystal structures of [Ni(padtc) (PPh 3) 2]ClO 4∗dCH 3OH∗dH 2O ( 1) and [Ni(padtc)(dppe)] BPh 4∗dH 2O (2) (padtc = N, N′-iminodiethylenebis(phthalimide)dithiocarbamate, dppe = 1,2-bis(diphenylphosphino)ethane) are reported. Crystal parameters: complex 1, space group P2/n, a = 26.388(3), b = 12.862(4), c = 17.815(2) A ̊ , β = 106.03(3)°, V = 5811.3(2) a ̊ A 3, Z = 4, R = 0.067 for 4150 reflections with I>2 σ( I); complex 2, space group P2 1/c, a = 19.722(2), b = 34.931(3), c = 20.373(3) A ̊ , β = 114.54(3)°, V = 12767.4(4) A ̊ 3, Z = 8, R = 0.069 for 12 012 reflections with I>2 σ( I). The bulky dithiocarbamate padtc is an umbrella shaped molecule flanking the NiS 2P 2 chromophore. Complex 2 is a molecule with the chelating phosphine dppe. Both the complexes have planar NiS 2P 2 chromophores in keeping with the observed diamagnetism. A relatively short NiP distance is observed in the dppe complex 2. The chelating dppe forces the NiS distances to be symmetric (2.200(2), 2.204(2) Å) unlike PPh 3 which induces asymmetry (2.227(3), 2.198(2) Å). Shortening of the thioureide CN bonds (1.307(10) Å in 1, 1.323(7) Å in 2, 1.359(3) Å in free padtc −) in the complexes is a clear indication of the localisation of the nitrogen electrons between C and N. Thioureide stretching bands in Ni(padtc) 2, [Ni(padtc)(PPh 3) 2] + and [Ni(padtc)(dppe)] + occur at 1494, 1509 and 1512 cm −1, respectively, in keeping with the significant reduction in CN bond distances.