Electron rich of M:dihydride Electron poor of M:dihydrogen complex Explain: Mo(CO):(PMe3)H2 dihydride(两个分离的H山 Mo(CO)2(PMe3)3(H2)dihydrogen complex Electron rich of M: dihydride Electron poor of M: dihydrogen complex Explain: Mo(CO)3 (PMe3 )H2 dihydride ( 两个分离的H) Mo(CO)2 (PMe3 )3 (H2 ) dihydrogen complex