Synthesis of the ligand N,N′-bis(2-tert-butylthiobenzenylidene)-diethylenetriamine;: its reactivity with nickel(II) salts

The synthesis of the Schiff base ligand N,N'-bis(2-tert-butylthiobenzenylidene)-diethylenetriamaine ((t)Bu(2)L1) and its reactivity with nickel(II) salts is described. Reaction of (t)Bu(2)L1 with nickel chloride results in two different complexes, depending on the temperature of the reaction mixture. The green paramagnetic five-coordinate complex [Ni((t)Bu(2)L1)Cl-2] forms on reaction at room temperature, whereas at reflux temperature the red diamagnetic [Ni(L1*)]Cl . H2O is formed. In the ligand L1* one of the imine groups is hydrolysed, and the protecting tert-butyl group of the remaining thiobenzylidene is lost, resulting in a new tetradentate N3S thiolato ligand. [Ni(L1*)]Cl . H2O crystallises in the monoclinic space group P2(1)/c, with Ni-N distances of 1.860(7), 1.941(8) and 1.914(7) Angstrom and a Ni-S distance of 2.131(3) Angstrom. (C) 1999 Elsevier Science S.A. All rights reserved.