Protonation of cationic hydride and alkyl complexes of Ir(III)

Article abstract of DOI:10.1016/0022-328X(92)80011-L

Reaction of HBF4*OEt2 with IrH2(MeCN)P3⁺ (1) (P = PMe2Ph) in the presence of MeCN gives rapid conversion to cis,mer-IrH(MeCN)2P3²⁺ and H2.The corresponding reaction with cis,mer-IrMe2(MeCN)P3⁺ is much slower, but gives the corresponding product, cis,mer-IrMe(MeCN)2P3²⁺.In the absence of added MeCN, HBF4*OEt2 transforms the dihydride cation 1 to equimolar cis,mer-IrH(MeCN)2P3²⁺ and IrH4P3⁺; 0.5 mol of acid suffices to effect this reaction.In the absence of added MeCN, the protonation of the dimethyl cation leads to the ether complex mer-IrMe(Et2O)(MeCN)P3²⁺ , which is subsequently scavenged by adventitious water to yield mer-IrMe(H2O)(MeCN)P3²⁺.The crystal structure of this aquo complex, as its BF4 salt, shows a chain of BF4^-/IrMe(H2O)(MeCN)P3²⁺ units held together by two hydrogen bonds to each water molecule.Crystallographic data for (BF4)2 (at -169 deg C): a = 10.709(3) Angstroem, b = 15.645(4), c = 10.481(2), β = 106.49(1) deg with Z = 2 in space group P<*>1.