| Abstrakt: |
Reaction of FeCl3· 4 H2O with dttd2-, the dianion of 2,3,8,9-dibenzo-1.4,7,10-tetru-thiadecane, leads to the solvated [Fe(dttd)], which coordinates CO, PMe3and N3H4 yielding [Fe(CO)2dttd], [Fe(PMe3)2dttd], [Fe(CO)PMe3(dttd)], [Fe(N2H4)2dttd] and [Fe(N2H4)CO(dttd), respectively. With H2S and [Fe(dttd)] the Fe(III) complex (PPN)2[Fe2(S)2(dttd)2] is obtained. PPh3cannot be coordinated to [Fe(dttd)], whereas the reaction between [Fe(PPh3)(CO)3I2] and LiSC6H4SCH3yields [Fe(PPh3)CO(CH3SCeH4S)2] besides the major product [Fe(CO)2(CH3SCeH4S)2]. A PPh3complex can be obtained also with o-benzenedithiolate, C6H4S22-: Reacting [Fe(PPh3)(CO)3I3] with Li2S2C6H4yields the binuclear [Fe(PPh3)(CO)2C6H4S2]2. Oxidation of [Fe(N3H4)CO(dttd)] by various agents leads to [Fo(CO)dttd]2without evidence of formation of a N2complex intermediate. Nucleophilic attack of [Fe(CO)2(CH3SC6H4S)2] by lithium organyls as e.g. LiPh leads to the benzoylato complex [Li(THF)3][Fe(CO)(PhCO)(CH3SC6H4S)2]; the structures of the starting complex as well as of the adduct have been elucidated by X-ray structure determination. Nucleophilic attack of the corresponding [Fe(CO)2dttd] by LiPh occurs reversibly at the Fe center; by cleavage of a Fe-S bond [Fe(Ph)(CO)2dttd′]-is formed, where dttd′ is acting as a tridentate ligand. This result shows how the reactions of formally equivalent complexes like [Fe(CO)2(CH3SC6H4S)2] and [Fe(CO)2dttd] depend strongly upon the denticity of the sulfur ligands. The dependence upon the character of the nucleophilic agent is shown by the reaction of [Fe(CO)2dttd] with Li[BEt3H]; in this case again a CO ligand is attacked reversibly yielding the formyl complex [LiBEt3][Fe(HCO)CO(dttd)], the structure of which could be elucidated so far only spectroscopically as well as by elemental analysis. |
