Addition of 1,3,4,5 tetramethylimidazol 2 ylidene (IMe4) to Ru(PPh3)3HCl (in the presence of H2) or Ru(PPh3)4H2 gave the all trans isomer of Ru(IMe4)2(PPh3)2H2, whereas 1,3 diethyl 4,5 dimethylimidazol 2 ylidene (IEt2Me2) reacted with Ru(PPh3)4H2 to form cis, cis, trans Ru(IEt2M…
