New 10-membered inorganic heterocyclic diphosphanes, PhN(PX)(2){(-OC6H2((BU)-B-t)(2))(mu-S)(Bu-t)(2)C6H2O-)} (X = Cl, F). Synthesis and transition metal complexes (molybdenum(0), ruthenium(II), palladium(II), and platinum(II)) of heterocyclic diphosphanes. Crystal and molecular structures of the chloro derivative, PhN(PCl)(2)](-OC6H2(Bu)(2))(mu-S)(Bu-t)(2)C6H2O-)}, and ofa molybdenum(0) complex of the fluoro derivative, [Mo(CO)(3){eta(3)-PhN(PF)(2){(-OC6H2(Bu-t)(2))(mu-S)(Bu-t)(2)C6H2O-)}-kappa

Bis(dichlorophosphino)aniline, PhN(PCl2)(2), reacts with stoichiometric amo unts of 2,2 ' -thiobis(4,6-di-tert-butylphenol) to afford a 10-membered het erocycle, PhN(PCl)(2){(-OC6H2(' Bu)(2))(mu -S)((' Bu)(2)C6H2O-)} (1), in hi gh yield. The structure of the heterocycle has been determined by a single- crystal X-ray analysis. The 10-membered heterocycle 1 reacts with SbF3 to a fford the corresponding fluoro derivative 2 in good yield. The compounds 1 and 2 act as tridentate ligands with molybdenum carbonyl derivatives, formi ng complexes of the type [Mo(CO)(3)-{eta (3)-PhN(PX)(2){(-OC6H2(' Bu)(2))(m u -S)((' Bu)(2)C6H2O)}-kappaP,kappaP,kappaS}] (3 X = Cl, 4 X = F). A crysta l structure of the fluoro derivative 4 showed the facial tricarbonyl comple x comprising a relatively strain-free tetracyclic structure with molybdenum in an octahedral environment; the two phosphorus and the sulfur centers we re the donor atoms. Compound 2 readily reacts with Ru(M), Pd(II), and Pt(H) derivatives to form chelate complexes, demonstrating the eta (2) mode of c oordination.