ortho- and para-thioquinonoid π-complexes:: First synthesis, reactivity, and crystal structure determination

Overcoming a long-standing challenge, the o- and p-dithiobenzoquinone iridium complexes [Cp*Ir-o-(eta(4)-C6H4S2)] (6) and [Cp*Ir-p-(eta(4)-C6H4S2)] (7) were rationally synthesized and fully characterized for the first time including the X-ray 14 molecular structure of [Cp*Ir-p-(eta(4)-C6H4S2)] (7). Our strategic approach involves the preparation of the halogenated 1,2- and 1,4-dichloro arene pi complexes [Cp*Ir-p-(eta(C6H4Cl2)-C-6)][BF4](2) (4) and [CP*Ir-p-(eta(C6H4Cl2)-C-6)][BF4](2) (5), which are the key molecules for 6 and 7. Subsequent treat ment of 4 and 5 with NaSH and halogen displacement provides the target thioquinonoid pi complexes 6 and 7 in 88 % and 95 % yields respectively. Further, the coordination chemistry of the o-dithiobenzoquinone iridium complex [Cp*Ir-o-(eta(4)- C6H4S2)] (6) was studied by treating 6 with [(bpy)PtCl2] in the presence of AgOTf, which provided the novel platinum complex [Pt(bpy)(Cp*Ir-o-(eta(4)-C6H4S2)}[OTf](2) (10) in 91% yield. The X-ray molecular structure of 10 is reported and shows as outstanding features the formation of 11) supramolecular assembly, which results from pi-pi (d = 3.484 angstrom; d = 3.669 angstrom) and Pt center dot center dot center dot Pt (d = 3.574 angstrom) interactions between individual subunits. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)