Rare-earth metal ethylene and ethyne complexes.

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.