| An array of mono- and 1,2-disubstituted derivatives of the (eta)('2)-S(,2) and Se(,2) ligand systems have been prepared. The reactivity and distinctive ('1)H NMR spectroscopic behavior of complexes containing these ligands have been examined. The reactivity studies were extended to solid-state metal sulfides, particularly pyrite (FeS(,2)).;Attempted synthesis of the first (eta)('1) or (eta)('2)-SO ligand by sulfur-abstraction from complexes containing (eta)('2)-S(,2)O ligands was unsuccessful, but formation of {Ir(SeS)(dppe)(,2)}('+) was observed in the reaction of Ir(dppe)(,2)('+) and (CH(,3)C(,5)H(,4))(,2)Ti S(,x)Se(,5-x). A stabilized form of the SO unit, the O-methyl thioperoxide ligand, was observed in Ir((eta)('1)-SOCH(,3))(CH(,3)NC)(dppe)(,2)('2+) and produced by abstraction of the unsubstituted sulfur in {Ir(S(,2)OCH(,3))(dppe)(,2)}('2+) with CH(,3)NC.;Formation of pollutants, such as SO(,2), from the decomposition of pyrite has remained a major barrier to the increased use of coal as a fuel source. Desulfurization of pyrite with (n-C(,4)H(,9))(,3)P at 260(DEGREES)C produced an equilibrium mixture of FeS and Fe(,0.95)S and the corresponding phosphine sulfide: Partial desulfurization of an array of metal sulfides (MoS(,3), CoS(,2), Cu(,2)S) with organophosphines demonstrated this reaction's generality.;Catalytic desulfurization of pyrite with R(,3)P reagents was accomplished by addition of iron as a sulfur-receptor. An overall rate of (TURN)40 turnovers/hr and 85% conversion to Fe(,0.99)S was observed with an 100:1 ratio of FeS(,2) to (n-C(,4)H(,9))(,3)P at 300(DEGREES)C.;{Ir(S(,2)CH(,3))(dppe)(,2)}('2+) (dppe = Ph(,2)PCH(,2)CH(,2)PPh(,2)) is a potent chalcogen-transfer reagent towards nucleophiles (Ph(,3)P, CH(,3)NC, CN('-)) and several reaction pathways have been observed. The multistep reaction with 2 CH(,3)NC produced cis-{Ir(CH(,3)NC)(SCH(,3))(dppe)(,2)}('2+) and serves as a model for the Oxirane olefin epoxidation process. Organoperacids effect facile oxidation of {Ir(E(,2))(dppe)(,2)}('+) (E = S, Se) complexes to the (eta)('2)-S(,2)O, S(,2)O(,2), and Se(,2)O derivatives. Likewise, oxidation of (C(,5)H(,5))Nb(S(,2))Cl produced an (eta)('2)-S(,2)O ligand. The reaction of {Ir(S(,2)O(,x))(dppe)(,2)}('+) (x = 1,2) with CH(,3)OSO(,2)F formed the corresponding O-alkylated (eta)('2)-S(,2)O(,x)CH(,3) derivatives.;The stoichiometric organophosphine desulfurization reaction was applied to a dried sample of Illinois coal (2.0% FeS(,2)). Complete conversion of pyrite to pyrrhotite and 90% recovery of free organophosphine sulfide was accomplished. |
