The coordination complexes with 18 electrons around the metal center were discussed which included CO, allyl, and cyclopentadienyl ligands. Of course, 18-electron metal complexes live with numerous others as well. For each of the following ligands, find out the number of electrons that it donates to the metal center, assuming that the 18-electron rule is observed for all of the instance complexes. Show your electron-counting work.
cyclooctadiene ("cod") complex: Ni(cod)2
o-phenylene bis(dimethylarsine) ("diars") complex: Mo(CO)4 (diars)
2,2 '-bipyridine ("2,2' -bipy") complex: Ru(2,2'-bipy)2Cl2
4,4' -bipyridine ("4,4'-bipy") complex: [Ru(4,4'-bipy)4]1+
terpyridine ("terpy") complex: [Re(CO)3(terpy)]1+