Counter-ion effects switch ligand binding from C-2 to C-5 in kinetic carbenes formed from an imidazolium salt and IrH₅(PPh₃)₂

Abstract

Changing the counter-anion in 2-pyridylmethyl imidazolium salts (Br, BF4, PF6, SbF6) causes their kinetic reaction products with IrH5(PPh3)2 to be switched from normal C-2 to abnormal C-5 binding.