The Question a)If manganese reacts with CO and PH3 ligands to form a stable, tricarbonyl 5 coordinate complex, what manganese oxidation state and charge for the complex can be expected? Why? b)If the complex is diamagnetic how is manganese hybridized and what is the geometry of the complex? c)The stability of this complex should increase if PH3 Ligands are replaced with PF3 ligands. Why? What I know For part a the complex should be called tricarbonyldiphosphinemanganese(II?) It is a Mn surrounded by 3 CO and 2 PH3 and the C's and P's are bonded to the Mn. For Part A) I think the oxidation state should be 2 but only because that is what Mn normally is. For Part B) My guess is sp3d hybridized with a trigonal bipyramidal shape. I only say this because that is the shape and hybridization of a molcule w/ 5 atoms bonded to it. Is there anything different that needs to be done when considering coordination complexes? For Part C) I really don't know why PF3 ligands would make it more stable, my only guess would be that F is much more electronegative so would stabilize the electron density better. Thanks for any help.