Preparation of Hydride‐Ethylene Complexes of Osmium

Ethylene complexes [OsH(η 2 ‐CH 2 =CH 2 )L 4 ] Y ( 1 , 2 ) [L = PPh(OEt) 2 , P(OEt) 3 ; Y = OTf, BPh 4 ] were prepared by reacting the dihydride OsH 2 L 4 first with methyl triflate CH 3 OTf and then with ethylene (1 atm). Alternatively, the compound [OsH(η 2 ‐CH 2 =CH 2 ){PPh(OEt) 2 } 4 ]OTf was prepared by allowing the dinitrogen derivative [OsH(N 2 ){PPh(OEt) 2 } 4 ]OTf to react with ethylene. Acrylonitrile CH 2 =C(H)CN reacts with OsH(OTf)L 4 [L = P(OEt) 3 ] to give the complex [OsH{κ 1 ‐NCC(H)=CH 2 }{P(OEt) 3 } 4 ]BPh 4 ( 3 ). The complexes were characterized spectroscopically (IR and 1 H, 13 C, 31 P NMR) and by X‐ray crystal structure determination of the [OsH(η 2 ‐CH 2 =CH 2 ){PPh(OEt) 2 } 4 ]BPh 4 derivative.