Cationic tridium-perfluoroalkyl complexes with NH3 and PH3 ligands. Activation of carbon-fluorine bonds by H2S to give bis(trifluoromethyl)dithiametallacyclobutane and bis(trifluoromethyl)trithiametallacyclohexane complexes

摘要

The cationic fluoroalkyl(aqua) complexes [Ir(eta(5)-C5Me5)(PMe3)(R-F)(H2O)][BF4] (R-F = CF-(CF3)(2), CF2CF3) react with NH3 and PH3 to afford the corresponding ammonia and phosphine complexes [Ir(eta(5)-C5Me5)(PMe3)(R-F)L][BF4] (R-F = CF(CF3)(2), CF2CF3; L = NH3, PH3). No reaction of NH3 or PH3 with the fluoroalkyl ligand is observed. The molecular structure of [Ir(eta(5)-C5Me5)(PMe3){CF(CF3)(2)}(NH3)][BF4] has been determined and shows hydrogen-bonded interactions between the coordinated NH3 ligand and the BF4- counterion. The molecular structure of the phosphine complex [Ir(eta(5)-C5Me5)(PMe3){CF(CF3)(2)}PH3][B{C6H3(CF3)(2)}(4)] has also been determined. Close intramolecular contacts between the NH3 or PH3 ligands and the fluorocarbon ligand in these two complexes are interpreted as resulting from steric requirements rather than intramolecular hydrogen bonding. Dimethyl sulfide reacts similarly to afford [Ir(eta(5)-C5Me5)(PMe3)(R-F)(Me2S)][BF4] (R-F = CF(CF3)(2), CF2CF3). In contrast, H2S reacts with the secondary fluoroalkyl complex [Ir(eta(5)-C5Me5)(PMe3){CFCF3)(2)}(H2O][BF4] to give the sulfhydryl complex [Ir(eta(5)-C5Me5)(PMe3){CF(CF3)(2)}(SH)] and with [Ir(eta(5)-C5Me5)(PMe3)(CF2CF3)(H2O)][[BF4] to give carbon-fluorine bond activation with formation of a mixture of compounds containing two new classes of fluorinated ligands. The molecular structures of representatives of each class, the 2,3-dithiametallacyclobutane complex Ir(eta(5)-C5Me5)(PMe3)(syn-S2CHCF3)] and the 2,4,6-trithiametallacyclohexane complex [Ir(eta(5)-C5Me5)(PMe3)(anti,anti-S-3{CHCF3}(2))], have been determined. Both syn and anti stereoisomers of the dithiametallacyclobutane complex and all three stereoisomers (syn,syn, syn,anti, and anti,anti) of the trithiametallacyclohexane complex are observed in solution as products of the reaction, and their configurations have been confirmed by NOE experiments. [References: 82]