Two furopyridine complexes of nickel(II) isothiocyanate

Acta Crystallogr C. 2004 May;60(Pt 5):m227-30. doi: 10.1107/S0108270104007796. Epub 2004 Apr 30.

Abstract

Pyridine fused with a furan ring (fupy), and its dimethyl derivative, have been used for the first time as ligands to synthesize potentially new Werner clathrates. The extended aromatic system of pyridine-like ligands influences considerably the molecular structure of prepared nickel complexes. The molecular structure of tetrakis(furo[3,2-c]pyridine)bis(isothiocyanato)nickel(II) tetrahydrofuran (THF) solvate, [Ni(NCS)(2)(C(7)H(5)NO)(4)].C(4)H(8)O or [Ni(NCS)(2)(fupy)(4)].THF, (I), reveals a 'four-blade propeller' arrangement of ligands, with the angles between the fupy planes and the basal octahedron plane spanning the range 38.7-55.3 degrees. These angles are much larger (69.9-78.8 degrees ) in the centrosymmetric complex tetrakis(2,3-dimethylfuro[3,2-c]pyridine)bis(isothiocyanato)nickel(II) 6.6-hydrate, [Ni(NCS)(2)(C(9)H(9)NO)(4)].6.6H(2)O or [Ni(NCS)(2)(Me(2)fupy)(4)].6.6H(2)O, (II), in which crystallographically imposed inversion symmetry is present.