New organobimetallic compounds containing catecholate and o-semiquinolate ligands

New organobimetallic compounds CatSn[CpM(CO)n]2 (2–4) were obtained by the insertion of CatSn(II) (1) into the metal–metal bond of [CpM(CO)n]2 (Cat – 3,6-di-tert-butylcatecholate dianion; M = Fe (2), n = 2; M = Mo (3), W (4), n = 3). The structure of CatSn[CpMo(CO)3]2 was determined by X-ray analysis. The oxidation of compounds 2–4 with silver(I) triflate was found to produce stable paramagnetic o-semiquinolate derivatives which keep both Sn–M bonds. New paramagnetic tin(IV) complexes were investigated by EPR spectroscopy.