Synthesis and characterization of ruthenium(II) complexes of the NNS-donor Schiff-base derived from 2-methyl-2-(2-pyridyl)benzothiazoline

2-Methyl-2-(2-pyridyl)benzothiazoline undergoes ring opening to the corresponding Schiff base (L) on reaction with [Ru(PPh3)(3)Cl-2], giving a five-coordinate Ru-II complex [Ru(PPh3)(L)Cl] (1). Reaction of (1) with an excess of 1-methylimidazole (1-Meimz) or 2-methylimidazole (2-Meimz) gave [Ru(PPh3)L(1-Meimz)(2)]ClO4 and [Ru(PPh3)L(2-Meimz)]ClO4, respectively, whilst reaction with excess 2,2'-bipyridine (bipy) or 1,10-phenanthroline (phen) gave [Ru(PPh3)(L)(N-N)]Cl [N-N=bipy (4) or phen (5)]. The compounds have been characterized using i.r., u.v.-vis., H-1-n.m.r. spectroscopy and by physico-chemical methods. A square pyramidal structure is proposed for these pentacoordinate complexes.