Iridium(III) Complex Containing a Unique Bifurcated Hydrogen Bond Interaction Involving Ir−H···H(N)···F−B atoms. Crystal and Molecular Structure of [IrH(η1-SC5H4NH)(η2-SC5H4N)(PPh3)2](BF4)·0.5C6H6

A synthetic route to a new iridium(III) complex containing a novel proton hydride bonding interaction has been established. fac -IrH 3 (PPh 3 ) 3 reacts with 2-mercaptopyridine HSpy (Spy = 2-SC 5 H 4 N) to give the known dihydride Ir(H) 2 (η 2 -Spy)(PPh 3 ) 2 8 . Ir(H) 2 (η 2 -Spy)(PPh 3 ) 2 reacts with HSpy . HBF 4 to give [IrH(η 1 -SC 5 H 4 NH)(η 2 -SC 5 H 4 N)(PPh 3 ) 2 ](BF 4 ) 9 which possesses a unique bifurcated hydrogen bonding interaction involving Ir−H···H(N)···F−B atoms with the distances of 2.0(1) Å for the H···H unit and of 2.0(1) Å for the F···H unit in the crystalline state. In solution the N−H···H−Ir interaction is maintained according to 1 H T 1 (min) and nOe measurements. Isotope shifts in the chemical shifts of the hydride and one phosphorus of 9 have been observed in 1 H and 31 P{ 1 H} NMR spectra of [IrH(η 1 -SC 5 H 4 ND)(η 2 -SC 5 H 4 N)(PPh 3 ) 2 ](BF 4 ), 9 - d 1, prepared by the reaction of 9 with MeOD or CF 3 CO 2 D. The crystal and molecular structure of [IrH(η 1 -SC 5 H 4 NH)(η 2 -SC 5 H 4 N)(PPh 3 ) 2 ](BF 4 )·0.5C 6 H 6 9 has been solved by X-ray analysis: monoclinic space group P 2 1 / c with a = 17.723(3) Å, b = 10.408(1) Å, c = 26.073(4) Å, β = 108.08(1)°, V = 4572.0(11) Å 3, and Z = 4. The known complex fac -IrH 3 (PPh 3 ) 3, 7, is made by a new and improved method by reacting mer -IrHCl 2 (PPh 3 ) 3 with NaOEt and H 2 (g). VT- 1 H NMR spectra (+90 to −80 °C) of the hydrides of 7 reveal that the J AA and J AX couplings change in the AA‘A‘‘XX‘X‘‘ pattern (A = 1 H, X = 31 P) but that the complex is not fluxional. The T 1 (min) value of 0.144 s for the hydrides of 7 at −60 °C (300 MHz) indicates that the shortest H-H distances are about 1.8 Å.