TRANSITION-METAL COMPLEXES WITH SULFUR LIGANDS .62. HYDROGEN EVOLUTION UPON REACTION OF PROTONS WITH SULFUR-COORDINATED FE(II) COMPLEXES - INVESTIGATION OF THE H+, H2, AND H- INTERACTIONS WITH IRON 1,2-BENZENEDITHIOLATE COMPLEXES

In search for model systems of iron hydrogenases, we investigated the interaction of iron 1,2-benzenedithiolate complexes with H+, H-2, and H-. The reaction of [Fe(II)('S2')2]2- ('S2'2- = 1,2-benzenedithiolate(2-)) with H+ yielding [Fe(III)('S2')2]2- and H-2 was examined in detail. A mechanism is suggested. H-2 activation by [Fe('S2')2]n2- (n = 1, 2) was not observed. With an excess of NaBH4, [Fe(III)('S2')2]2(2-) and [Fe(IV)('S2')2(PMe3)2] are reduced to the corresponding [Fe(II)('S2')2]2- and [Fe(III)-('S2')2(PMe3)2]-, respectively; the reduction of [Fe(IV)('S2')2(PMe3)2] with n-BuLi and LiBEt3H yields [Fe(II)('S2')2]2-, and no hydride complexes are found even when an excess of LiBEt3H is used.