Reaction of [fac-(CO)3(dppe)Mn(OH2)]BF4 with 13CO and conversion of the resulting tetracarbonyl to labeled isocyanato complexes

Abstract When 13 CO is bubbled into a CH 2 Cl 2 solution of [ fac -(CO) 3 (dppe)Mn(OH 2 )]BF 4 (dppe=Ph 2 PCH 2 CH 2 PPh 2 ), the aqua ligand is replaced by the CO to give the tetracarbonyl, [(CO) 3 ( 13 CO)(dppe)Mn]BF 4 ( 1 ) in which the labeled CO appears exclusively at the site originally occupied by the aqua ligand. Treatment of this aqua complex with NaN 3 leads to an approximate 50:50 mixture of isocyanates corresponding to attack, with equal probability, at either the labeled CO or its axial partner. Neither of the two CO groups trans to the P atoms in the tetracarbonyl are affected.