| Abstrakt: |
Modes of formation as well as redox and substitution reactions of the 1,2-benzenedithiolate complexes [Mo(C6H4S2)3]n-(n = 0, 1, 2, (3)) are described. [MoCl4(THF)2] with neutral C6H4(SH)2gives the Mo(VI) complex [Mo(C6H4S2)3]; with C6H4S22-, however, the Mo(IV) complex [Mo(C6H4S2)3]2-can be isolated as the PPh4+or NR4+salt; in the course of the synthesis of (NMe4)2[Mo(C6H4S2)3] in MeOH/THF, the complex salt trans-(NMe4)2[Mo(C6H4S2)2(OCH3)2] is also obtained. Directly and controlled by pH, [Mo(VI)(C6H4S2)3] can be reduced by NaOH/MeOH to afford [Mo(V)(C6H4S2)3]-or [Mo(IV)(C6H4S2)3]2-. [Mo(VI)(C6H4S2)3] and (NMe4)2[Mo(IV)(C6H4S2)3] symproportionate in MeOH to yield (NMe4)[Mo(V)(C6H4S2)3] , which was isolated for the first time. When butyllithium reacts with [Mo(VI)(C6H4S2)3] in the molar ratio of 1:1, 2 :1 or 3:1, one obtains the Mo(V), Mo(IV) dithiolates or an orange complex, respectively. The latter is extremely H2O - as well as O2-sensitive; it is identified by its reactions with H2O , ROH, O2, alkyl halides and NO as well as by 1H NMR spectroscopy as a salt containing the [MO(H)(C6H4S2)3]3-anion. [Mo(H)(C6H4S2)3]3-is the first example of an exclusively sulfur coordinated metal hydride complex. With NO it reacts in several steps yielding first N2O and [Mo(IV)(C6H4S2)3]2-; subsequently the Mo(IV) complex is reductively nitrosylated by further NO yielding cis-[Mo(NO)2(C6H4S2)2]2-, which is isolated as NMe4+salt. |
