om6b00891_si_002.cif (103.95 kB)
Formation of Dinuclear Iridium Complexes by NHC-Supported C–H Bond Activation
dataset
posted on 2017-01-30, 12:48 authored by Miguel A. Esteruelas, Ana M. López, Enrique Oñate, Ainhoa San-Torcuato, Jui-Yi Tsai, Chuanjun XiaThe formation of
dinuclear iridium complexes by NHC-supported aryl-CH
bond activation reactions is reported. Complex IrH5(PiPr3)2 (1) reacts with 1,3-bis(3-methylimidazolium)benzene
bis(tetrafluoroborate) ([C6H4(HImMe)2][BF4]2) to give the dinuclear species {[IrH2(PiPr3)2]2[μ-C6H2(ImMe)2]} (2), with a
core formed by five fused rings. Complex 1 also reacts
with 1,1′-diphenyl-3,3′-alkylenediimidazolium
dihalides ([(CH2)n(HImC6H5)2]X2; n = 2, 3, 4). The reactions lead to the dinuclear complexes {[IrH2(PiPr3)2]2[μ-(CH2)n(ImC6H4)2]} (n = 2 (3), 3 (4), 4 (5). These compounds can be described as
two six-coordinate d6-iridium dihydride metal fragments
containing an orthometalated phenylimidazolylidene, which are connected
through an alkylene linker. In contrast to the diimidazolium
salts, 1,1′-diphenyl-3,3′-methylenedibenzimidazolium
dibromide ([CH2(HBzImC6H5)2]Br2) reacts with 1 to give a 1:1 mixture
of the mononuclear complexes IrH2Br{κ-N-(HBzImC6H5)}(PiPr3)2 (6) and IrH2{κ2-C,C-(MeBzImC6H4)}(PiPr3)2 (7). The latter and
its analogous IrH2{κ2-C,C-(PhBzImC6H4)}(PiPr3)2 (8) can be also obtained,
as pure solids, by means of the reactions of 1 with 1-methyl-3-phenylbenzimidazolium
tetrafluoroborate and 1,3-diphenylbenzimidazolium chloride,
respectively.
