COORDINATION OF THE NEW WEAKLY COORDINATING ANIONS AL(OCH(CF3)(2))(4)(-), AL(OC(CH3)(CF3)(2))(4)(-), AND AL(OC(PH)(CF3)(2))(4)(-) TO THE MONOVALENT METAL-IONS LI+ AND TL+

The structures of Li+ or Tl+ salts of three new fluoroalkoxide-contain ing aluminate anions were determined by X-ray crystallography. For LiA l(OC(Ph)(CF3)(2))(4), monoclinic, C2/c, a = 42.297(6), b = 10.641(1), c = 19.132(2) Angstrom, beta = 114.808(9), Z = 8, T = -100 degrees C, R = 0.052; for TiAl(OC(CH3)(CF3)(2))(4), monoclinic, P2(1)/c, a = 12.6 50(3), b = 9.970(2), c = 21.237(4) Angstrom, beta = 94.00(3)degrees, Z = 4, T = -100 degrees C, R = 0.073; for TiAl(OCH(CF3)(2))(4), monocli nic, P2(1)/n, a = 14.261(1), b = 9.8024(9), c = 16.911(2) Angstrom, be ta = 93.467(8), Z = 4, T = -130 degrees C, R = 0.053. The monatomic, m onovalent cations interact with their respective anions by means of M- O and M-F bonds. The Ti+ cations in TiAl(OCH(CF3)(2))(4) and TiAl(OC(C H3)(CF3)(2))(4) interact with three different aluminate anions. The Li + cation in LiAl(OC(Ph)(CF3)(2))(4) interacts with only one aluminate anion, forming a rare trigonal-prismatic LiO2F4 coordination unit. (C) 1998 Elsevier Science B.V.