hydrogenchloride in benzene byproducts: [p-tolyl-NH=CH-NH-tolyl-p]Cl; HCl gas was bubbled through a benzene soln. of Rh-complex for 3 h; ppt. (amidinium chloride) was filtered off, washed with benzene and crystd. from MeOH/Et2O, (Rh(NBD)Cl)2 was obtained from the supernatant liquor;