Interaction Of Sbcl52- And Thioether Groups At The Open Coordination Sites Of Platinum(Ii) Diimine Complexes

In the solid-state, the approximately square planar cation in orange crystals of [Pt(NO(2)phen)(ttcn)](PF6)(2) (NO(2)phen = 5-nitro-1, 10-phenanthroline; ttcn = 1,4,7-trithiacyclononane) has a short apical Pt center dot center dot center dot S(ttcn) distance (2.9415(15) angstrom). In acetonitrile solution, the electronic spectrum shows a long-wavelength absorption band (412 nm; 2200 M-1 cm(-1)), consistent with the notion that the axial Pt center dot center dot center dot S(ftcn) interactions stabilize states having metal-to-ligand charge-transfer (MLCT) character. Reaction with the hexachloroantimonate(V) salt of tris(4-bromophenyl)aminium (TBPA(+)) results in complex redox chemistry, involving the platinum complex, SbCl52- and TBPA(+). In the case of Pt(bpy)(ttcn)(2+), orange-yellow crystals of [Pt(bpy)-(ttcn)](2)(Sb4Cl16) were isolated from the reaction, whereas the reaction With Pt(NO(2)phen)(ttcn)(2+) consistently yielded red crystals of [Pt(NO(2)phen)(ttcn)](SbCl5)center dot 2CH(3)CN, In the latter case, the geometry of the cation, including the apical Pt center dot center dot center dot S(ftcn distance (2.9390(12) angstrom), is very similar to that of the PF6- salt. However, the basal plane of each square pyramidal SbCl52- opposes the nearly parallel coordination plane of an adjacent Pt(NO(2)phen)(ttcn)(2+) complex, resulting in an unusually short intermolecular Pt center dot center dot center dot Sb distance of 3.4259(3) angstrom. The longest wavelength maximum in the diffuse reflectance spectrum and the solid-state emission maximum are shifted by similar to 1200 cm(-1) and similar to 700 cm(-1), respectively, to the red of those of the PF6- salt, consistent With perturbation of the complex's electronic structure because of the Pt center dot center dot center dot Sb interaction.