CHEMISTRY OF C-TRIMETHYLSILYL-SUBSTITUTED HETEROCARBORANES .20. SYNTHETIC AND STRUCTURAL STUDIES ON SANDWICH LN(III) CARBORANE CLUSTERS .2.(LN(III)=SM, GD, DY, HO, ER)

The room-temperature reactions of i(TMEDA)]-1-Li(TMEADA)-2,3-(SiMe(3)) (2)-2,3-C2B4H4 with anhydrous LnCl(3) (Ln = Sm, Gd, Dy, Ho, Er), in mo lar ratios of 2:1 in dry benzene (C6H6), produced the sandwich paramag netic species -[(mu-H)(3)Li(TMEADA)]-1,1'-commo-Ln(2,3-C2B4H4)2] (Ln = Sm (1), Gd (2), Dy (3), Ho (4), Er (5)) in yields of 65%, 88%, 71%, 9 0%, and 93%, respectively. The compounds were characterized by IR spec troscopy, magnetic susceptibility measurements, and single-crystal X-r ay diffraction studies. Compounds 2 and 3 were further characterized b y EPR spectroscopy, and compound 1 was also characterized by H-1, C-13 , B-11, and Li-7 NMR spectroscopy. All compounds are bent-sandwich com plexes in which a Ln(III) atom is coordinated to two carborane ligands and two chloride ions. The room-temperature magnetic susceptibilities of 1-4 were found to be 1.1, 7.3, 9.4, and 10.1 mu(B) per metal atom, respectively.