Potassium S2N-heteroscorpionates: structure and iridaboratrane formation

The potassium salts of the new S2N-heteroscorpionate ligand hydrobis(methimazolyl)(3,5-dimethylpyrazolyl)borate [HB(mt)(2)(pz(3,5-Me))](-) and its known analogue hydrobis(methimazolyl)(pyrazolyl) borate [HB(mt)(2)(pz)](-) (prepared from KTp' or KTp and methimazole, Hmt), and the adduct KTp.Hmt have polymeric structures in the solid state (the first a ladder and the other two chains). The iridaboratranes [IrHLL'{B(mt)(2)X}] (X= pz(3,5-Me) or pz), prepared from the heteroscorpionate anion and [{Ir(cod)(mu-Cl)}(2)] (LL' = cod), subsequent carbonylation [LL' = (CO)(2)] and then reaction with phosphine [LL' = (CO)(PR3), R = Ph or Cy], have a pendant pyrazolyl ring and a bicyclo-[3.3.0] cage formed by an S-2-bound B(mt)(2) fragment. The binuclear species [(cod)HIr{mu-B(mt)(3)}IrCl(cod)], the only isolated product of the reaction of KTm with [{Ir(cod)(mu-Cl)}(2)], also has an S-2-bound iridaboratrane unit but with the third mt ring linked to square planar iridium(I).