ELECTRON-TRANSFER SERIES OF [M-2S2] TYPE . COMPLEXES DERIVED FROM O-MERCAPTOPHENOL 1-MERCAPTO-2-NAPHTHOL AND 1-HYDROXY-2-PYRIDINETHIONE

The existence of an electron-transfer series of the [M-O2S2]z type has been investigated. The results are compared with those found for the [M-O4]z and [M-S4]z series. Dianionic complexes M(mp)22~ (mp = o-mercaptolatophenolate) have been synthesized with Zn, Cu, Ni, Pd, and Co, and their electronic structures have been investigated. Polarographic studies show that each M(mp)22- except Zn(mp)22 can be oxidized to the corresponding M(mp)2; Ni(mp)2 and Co(mp)2 have been isolated. A related complex Ni(mn)2 (mn = 1-mercaptolato-2-naphtholate) has been prepared. Polarographic oxidation of Ni(mp)2 and Ni(mn)2 to the neutral complexes has been observed; Ni(mn)2~ also undergoes polarographic reduction to the dianion. These results indicate that the scope of the electron-transfer series for [Ni-O2S2]2 is as extensive as in the [Ni-S4]z case. The esr spectra of the spin doublet ions Ni(mp)2 and Ni(mn)2- reveal considerable g-tensor anisotropy (similar to that found for [Ni-S4]-). Co(mp)2- is monomeric with a triplet ground state. Polarographic oxidation of Co(mp)2~ in dichloromethane solutions proceeds with the production of the dimers Co2(mp)4~ and Co2(mp)4. Polarographic oxidation of Cu(pt)2 and Ni(pt)2 (which are isoelectronic with Cu(mp)22- and Ni(mp)22-) has been observed (pt = anion derived from 1-hydroxy-2-pyridinethione). © 1969, American Chemical Society. All rights reserved.