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 ‐(η 4 ‐C 6 H 4 S 2 )] ( 6 ) and [Cp*Ir‐ p ‐(η 4 ‐C 6 H 4 S 2 )] ( 7 ) were rationally synthesized and fully characterized for the first time including the X‐ray molecular structure of [Cp*Ir‐ p ‐(η 4 ‐C 6 H 4 S 2 )] ( 7 ). Our strategic approach involves the preparation of the halogenated 1,2‐ and 1,4‐dichloro arene π complexes [Cp*Ir‐ o ‐(η 6 ‐C 6 H 4 Cl 2 )][BF 4 ] 2 ( 4 ) and [Cp*Ir‐ p ‐(η 6 ‐C 6 H 4 Cl 2 )][BF 4 ] 2 ( 5 ), which are the key molecules for 6 and 7 . Subsequent treatment of 4 and 5 with NaSH and halogen displacement provides the target thioquinonoid π complexes 6 and 7 in 88 % and 95 % yields respectively. Further, the coordination chemistry of the o ‐dithiobenzoquinone iridium complex [Cp*Ir‐ o ‐(η 4 ‐C 6 H 4 S 2 )] ( 6 ) was studied by treating 6 with [(bpy)PtCl 2 ] in the presence of AgOTf, which provided the novel platinum complex [Pt(bpy){Cp*Ir‐ o ‐(η 4 ‐C 6 H 4 S 2 )}][OTf] 2 ( 10 ) in 91 % yield. The X‐ray molecular structure of 10 is reported and shows as outstanding features the formation of 1D supramolecular assembly, which results from π–π ( d = 3.484 Å; d = 3.669 Å) and Pt ··· Pt ( d = 3.574 Å) interactions between individual subunits.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)