SYNTHESIS, X-RAY CRYSTAL-STRUCTURE AND MAGNETIC CHARACTERIZATION OF THE FIRST NI3S4N3 NICKEL THIOLATE CLUSTER

The tridentate N,O,S-ligand (RS)-2-[(2-mercapto-1-methylamino)ethyl]phenol (rac-1) was prepared from ortho-hydroxy-chloroacetophenone in three steps. When this ligand was treated with nickel(II) acetate, the novel ''Ni3S4N3'' cluster rac-3 was obtained. The X-ray crystal structure of rac-3 unambiguously revealed the pseudo-C-3 symmetric structure of this novel nickel cluster, which is made up by three nickel ions, one sulfide sulfur atom, and three homochiral ligand molecules, each contributing one thiolate sulfur atom and one amine nitrogen atom to the Ligation of the metal ions. According to NMR-spectroscopic results, this highly symmetric structure is maintained in solution. The magnetic studies revealed diamagnetic behavior in the solid state, although antiferromagnetic interaction bf the metal centers cannot absolutely be excluded.