Synthesis, Structural Characterization, and Reactivity of Rare Earth Complexes Incorporating Lewis Base Appended nido-Carborane Anions of the C₂B₉ and C₂B₁₀ Systems

Reaction of 1-Me 2 NCH 2 CH 2 -1,2-C 2 B 10 H 11 ( 1 ) with excess Na metal in THF, followed by treatment with 1 equiv of YCl 3, afforded [ η 1: η 6 -(Me 2 NCH 2 CH 2 )C 2 B 10 H 11 ]YCl(THF) 3 ( 2 ), which contains a terminal Y−Cl bond. Recrystallization of 2 from MeCN/toluene gave [ η 1: η 6 -(Me 2 NCH 2 CH 2 )C 2 B 10 H 11 ]YCl(MeCN) 3 ·MeCN ( 3 ·MeCN). Treatment of 2 with 1 equiv of Cp‘ ‘Li in THF gave [ η 1: η 6 -(Me 2 NCH 2 CH 2 )C 2 B 10 H 11 ]YCp‘ ‘( μ -Cl)Li(THF) 2 ( 4 ). Interaction of 2 with AgBPh 4 or potassium phthalimide gave neutral carborane 1 and other unidentified species. Amine elimination reaction is an effective method for the production of half-sandwich lanthanacarborans. Treatment of 7-Me 2 NHCH 2 CH 2 -7,8-C 2 B 9 H 11 ( 5 ) with Ln[N(SiHMe 2 ) 2 ] 3 (THF) 2 or ClY[N(SiHMe 2 ) 2 ] 2 (THF) x afforded [ η 1: η 5 -(Me 2 NCH 2 CH 2 )C 2 B 9 H 10 ]Ln[N(SiHMe 2 ) 2 ](THF) 2 (Ln = Sm ( 6 ), Er ( 7 )) or [ η 1: η 5 -(Me 2 NCH 2 CH 2 )C 2 B 9 H 10 ]YCl(THF) 2 ( 8 ), respectively. Complex 8 was also prepared from an equimolar reaction of K 2 [Me 2 NCH 2 CH 2 C 2 B 9 H 10 ] with YCl 3 in THF. [ η 1: η 1: η 5 -(Me 2 NCH 2 CH 2 )(MeOCH 2 CH 2 )C 2 B 9 H 9 ]Y( μ -Cl) 2 K(THF) 2 ( 10 ) was prepared in a similar manner from the reaction of K 2 [(Me 2 NCH 2 CH 2 )(MeOCH 2 CH 2 )C 2 B 9 H 9 ] with YCl 3 . Complex 10 underwent partial hydrolysis to produce [YCl 2 (THF) 5 ][ nido -(Me 2 NCH 2 CH 2 )(MeOCH 2 CH 2 )C 2 B 9 H 10 ]·THF ( 11 ·THF). On the other hand, treatment of K 2 [(Me 2 NCH 2 CH 2 )(MeOCH 2 CH 2 )C 2 B 9 H 9 ] with 1 equiv of Cp‘ ‘ 2 LnI in THF afforded mixed-sandwich lanthanacarboranes [ η 1: η 1: η 5 -(Me 2 NCH 2 CH 2 )(MeOCH 2 CH 2 )C 2 B 9 H 9 ]LnCp‘ ‘ (Ln = Y ( 12 ), Er ( 13 )). Complex 12 was also prepared from an equimolar reaction of 10 with Cp‘ ‘Li in THF. All complexes were fully characterized by various spectroscopic techniques and elemental analyses. Complexes 3, 4, 6 − 8, and 11 − 13 were further confirmed by single-crystal X-ray analyses.