Abstract
Guanidinate homometallic rare-earth ethyl complexes [LLn(μ(2)-η(1):η(2)-Et)(Et)](2) (Ln = Y(1-Y), Lu(1-Lu)) and heterobimetallic rare-earth ethyl complexes LLn(Et)(μ(2)-η(1):η(2)-Et)(μ(2)-η(1)-Et)(AlEt(2)) (Ln = Y(2-Y), Lu(2-Lu)) have been synthesized by the treatment of LLn(CH(2)C(6)H(4)NMe(2)-o)(2) (L = (PhCH(2))(2)NC(NC(6)H(3)(i)Pr(2)-2,6)(2)) with different equivalents of AlEt(3) in toluene at ambient temperature. Interestingly, the unprecedented rare-earth ethyne complex [LY(μ(2)-η(1)-Et)(2)(AlEt)](2)(μ(4)-η(1):η(1):η(2):η(2)-C(2)H(2)) (3-Y) containing a [C(2)H(2)](4-) unit was afforded from 2-Y. The formation mechanism study on 3-Y was carried out by DFT calculations. Furthermore, the nature of the bonding of 3-Y was also revealed by NBO analysis. The reactions of LLn(CH(2) C(6)H(4)NMe(2)-o)(2) (Ln = Y, Lu) with AlEt(3) (4 equiv.) in toluene at 50 °C produced firstly the non-Cp rare-earth ethylene complex LY(μ(3)-η(1):η(1):η(2)-C(2)H(4))[(μ(2)-η(1)-Et)(AlEt(2))(μ(2)-η(1)-Et)(2)(AlEt)] (4-Y), and the Y/Al ethyl complex LY[(μ(2)-η(1)-Et)(2)(AlEt(2))](2) (5-Y) as an intermediate of 4-Y was isolated from the reaction of LY(CH(2)C(6)H(4)NMe(2)-o)(2) with AlEt(3) (4 equiv.) in toluene at -10 °C.