Base-free tris(trimethylsilyl)methyl derivatives of lithium, aluminium, 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 metallanes R*MMe2 with M = Al, Ga and In, respectively. The NMR (H-1, C-13, Si-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 centrosymmetric assoziate, formed by four Li[R*AlCl3]-units with Al-Cl ... Li bridges, two pairs of Li-atoms differing in their chlorine-coordination and two disordered toluene molecules, inserted in the crystal lattice (R-1/wR(2) = 0,0444/0,1072). The reaction of GaCl3 with LiR* (1:1) gives the unusual sesquichloride (R*Ga(Cl-1,Cl-33)Me-0,Me-67)(3) in moderate yield. The X-ray structure determination shows a Ga3Cl3-skeleton with chairconformation and disordered, terminal gallium ligands (R-1/wR(2) = 0,0646/0,2270).