An oxovanadium(IV) complex containing a pentacoordinate Schiff-base ligand: synthesis and crystal and molecular structure of N,N′-(3,3′-dipropylamine)bis (3-methoxysalicylideneiminato)oxovanadium(IV) dihydrate

Abstract

Crystals ofN,N′-(3,3′-dipropylamine)bis(3-methoxysalicylideneiminato) oxovanadium(IV) dihydrate are monoclinic, space groupP2₁/n (No. 14) with four molecules in the unit cell of dimensionsa=8.667(4),b=20.617(4),c=12.744(3) Å,β=91.48(3)°. The structure was solved by the heavy-atom method and refined by block diagonal least-squares calculations with anisotropic thermal parameters for nonhydrogen atoms.R=0.038 for 1457 reflections withI>3σ(I). This structure is the first reported for an oxovanadium(IV) complex involving complexation of a pentacoordinate Schiff-base ligand. The coordination polyhedron is based on a distorted octahedron. Three nitrogen and one oxygen atom from the ligand form an equatorial plane around vanadium with V-N(1) 2.096(4), V-N(2) 2.180(4), V-N(3) 2.088(4), V-O(2) 1.961(3) Å, and octahedral coordination is completed by the vanadyl oxygen [V-O(1) 1.617(3) Å] and the remaining ligand oxygen [V-O(3) 2,098(3) Å]. The relatively long V-O(1) distance correlates well with the low value ofv(V=O) of 919 cm⁻¹. The molecules of the complex are linked by water molecules of crystallization to form infinite hydrogen-bonded chains parallel toa.