BASE-FREE TRIS(TRIMETHYLSILYL)METHYL DERIVATIVES OF LITHIUM, ALUMINUM, GALLIUM, AND INDIUM

Ease-free LiR (R* = -C(SiMe3)(3)) has been prepared from R*Cl and Li- metal in toluene at 85-90 degrees C and used to synthesize the metalla nes RMMe2 with M = Al, Ga and In, respectively. The NMR (H-1, C-13, S i-29) and the vibrational spectra of these trisyl compounds have been discussed. AlCl3 and LiR(ratio 1:1) forms the metallate Li[R*AlCl3]. The triclinic unit cell (space group <P(1)over bar>) consists of a cen trosymmetric assoziate, formed by four Li[RAlCl3]-units with Al-Cl .. . Li bridges, two pairs of Li-atoms differing in their chlorine-coordi nation and two disordered toluene molecules, inserted in the crystal l attice (R-1/wR(2) = 0,0444/0,1072). The reaction of GaCl3 with LiR (1 :1) gives the unusual sesquichloride (RGa(Cl-1,Cl-33)Me-0,Me-67)(3) i n moderate yield. The X-ray structure determination shows a Ga3Cl3-ske leton with chairconformation and disordered, terminal gallium ligands (R-1/wR(2) = 0,0646/0,2270).