Synthesis, structural characterization, and reactivity of rare earth complexes incorporating Lewis base appended nido-carborane anions of the C2B9 and C2B10 systems

Reaction of l-Me2NCH2CH2-1,2-C2B10H11 (1) with excess Na metal in THF, followed by treatment with 1 equiv of YCl3, afforded [eta(1):eta(6)-(Me2NCH2CH2)C2B10H11]YCl(THF)(3) (2), which contains a terminal Y-Cl bond. Recrystallization of 2 from MeCN/toluene gave [eta(1):eta(6)-(Me-2-NCH2CH2)C2B10H11]YCl(MeCN)(3)center dot MeCN (3 center dot MeCN). Treatment of 2 with 1 equiv of Cp"Li in THF gave [eta(1):eta(6)-(Me2NCH2CH2)C2B10H11]YCp"(mu-Cl)Li(THF)(2) (4). Interaction of 2 with AgBPh4 or potassium phthalimide gave neutral carborane I and other unidentified species. Amine elimination reaction is an effective method for the production of half-sandwich lanthanacarborans. Treatment of 7-Me2NHCH2CH2-7,8-C2B9H11 (5) with Ln[N(SiHMe2)(2)](3)-(THF)(2) or ClY[N(SiHMe2)(2)](2)(THF)(x) afforded [eta(1):eta(5)-(Me2NCH2CH2)C2B9H10]Ln[N(SiHMe2)(2)]-(THF)(2) (Ln = Sm (6), Er (7)) or [eta(1):eta(5)-(Me2NCH2CH2)C2B9H10]YCl(THF)(2) (8), respectively. Complex 8 was also prepared from an equimolar reaction of K-2[Me2NCH2CH2C2B9H10] with YCl3 in THF. [eta(1):eta(1):eta(5)-(Me2NCH2CH2)(MeOCH2CH2)C2B9H9]Y(mu-Cl)(2)K(THF)(2) (10) was prepared in a similar manner from the reaction of K-2[(Me2NCH2CH2)(MeOCH2CH2)C2B9H9] with YCl3. Complex 10 underwent partial hydrolysis to produce [YCl2(THF)(5)][nido-(Me2NCH2CH2)(MeOCH2CH2)C2B9H10]center dot THF (11 center dot THF). On the other hand, treatment of K-2[(Me2NCH2CH2)(MeOCH2CH2)C2B9H9] with 1 equiv of CP"(2)LnI in THF afforded mixed-sandwich lanthanacarboranes [eta(1):eta(1):eta(5)-(Me2NCH2CH2)(MeOCH2CH2)C2B9H9]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.