CRYSTAL STRUCTURES OF AZIDO OR THIOCYANATO-COORDINATED NICKEL(II) COMPLEXES WITH TRIDENTATE SCHIFF BASES
A new azido-coordinated nickel(II) complex [NiL <sup>1</sup>(N <sub>3</sub>)] (1) and a new thiocyanato-coordinated nickel(II) complex [NiL <sup>2</sup>(NCS)] (2), where L <sup>1</sup> and L <sup>2</sup> are the monoanionic forms of Schiff bases 2-[(2-isopropylaminoethylimino)methyl]-6-methylphenol and 2-[(2-dimethlaminoethylimino)methyl]-6-methylphenol respectively, are prepared and structurally characterized by elemental analysis, IR spectra, and single crystal X-ray crystallography. Complex 1 crystallizes in the triclinic space group <i>P</i>-1 with unit cell dimensions <i>a</i> = 8.812(2) Å, <i>b</i> = 9.433(3) Å, <i>c</i> = 9.488(2) Å, α = 81.933(2)°, β = 69.925(2)°, γ = 84.591(2)°, <i>V</i> = 732.5(3) Å <sup>3</sup>, <i>Z</i> = 2, <i>R</i> <sub>1</sub> = 0.0291, and <i>wR</i> <sub>2</sub> = 0.0734. Complex 2 crystallizes in the monoclinic space group <i>P</i>2 <sub>1</sub>/ <i>n</i> with unit cell dimensions <i>a</i> = 7.4497(4) Å, <i>b</i> = 6.1933(3) Å, <i>c</i> = 31.5126(18) Å, β = 92.484(2)°, <i>V</i> = 1452.57(13) Å <sup>3</sup>, <i>Z</i> = 4, <i>R</i> <sub>1</sub> = 0.0307, and <i>wR</i> <sub>2</sub> = 0.0668. The Ni atom in each of the complexes is coordinated by three donor atoms of the Schiff base ligand and by one N atom of the azide or thiocyanate ligand, forming a square planar geometry. The azide and thiocyanate anions readily coordinate to the complexes as secondary ligands.