Crown ether complexation of p-block metal halides: synthesis and structural characterisation of [InI2(dibenzo-24-crown-8)(H2O)][InI4], [(SnBr4)(2)(dibenzo-24-crown-8)]center dot MeCN, [(SbCl3)(2)(dibenzo-24-crown-8)]center dot MeCN, [(BiCl3)(2)(dibenzo-24-crown-8)]center dot MeCN and [(SbBr3)(2)(dibenzo-24-crown-8)]

The reactions of the large crown ether 6,7,9,10,12, 13,20,21,23,24,26,27-do decahydrodibenzo[b,n][1,4,7,10,13,16, 19,22]octaoxycyclotetracosine (dibenz o-24-crown-8) with p-block metal halides have been studied, leading to the isolation and structural characterisation of [InI2(dibenzo-24-crown-8)(H2O) ][InI4] (I), [(SnBr4)(2)(dibenzo-24-crown-8)]. MeCN (II), [(SbCl3)(2)(diben to-24-crown-8)] (III), [(BiCl3)(2)(dibenzo-24-crown-(8))]. MeCN (IV) and [( SbBr3)(2)(dibenzo-24-crown-8)]. MeCN (V). Compound I was isolated as colour less block crystals; crystals are triclinic, space group P (1) over bar, Z = 2, R = 0.0372. The structure consists of [InI2(dibenzo-24-crown-8)(H2O)]( +) cations and [InI4](-) anions. For the cation, the threaded near-linear I nI2+ unit (In-I 2.6977(5), 2.6919(5) A) is located off-centre within the ca vity and is bonded to four ring oxygen atoms (In-O-crown 2.344(4)-2.560(4) Angstrom) and a single water molecule (In-O-water 2.271(4) Angstrom). The l atter forms intracavity hydrogen bonds of the type M-OH2...O-crown to two m ore of the oxygen atoms of the crown (O-water...O-crown 2.89, 2.94 Angstrom ). Compound II was isolated as orange block crystals, crystals are monoclin ic, space group I2/m, Z = 2, R = 0.0391. The structure features the two met al centres in exocyclic locations each bound to two oxygens of the ring (Sn -O-crown 2.262(3) Angstrom). The metal geometry is distorted octahedral (Sn -Br 2.5235(7), 2.5187(6) Angstrom). Compound III was isolated as colourless block crystals; crystals are monoclinic, space group C2/c, Z = 4, R = 0.03 11. The two SbCl3 moieties (Sb-Cl 2.3807(8), 2.3874(8), 2.4015(9) Angstrom) are coordinated to opposite sides of the crown which adopts a sigmoidal co nformation to create two O-5 donor cavities. Each Sb(III) centre is bound t o five oxygens of the ring (Sb-O-crown 2.852(2)-3.153(2) Angstrom). Crystal s of IV are monoclinic, space group C2/c, Z = 4, R = 0.0325. The structure is directly similar to that of III with two BiCl3 units (Bi-Cl 2.5034(12), 2.5054(13), 2.5389(12) Angstrom) coordinated to opposite sides of the ring which exhibits a sigmoidal conformation. Each Bi(III) centre is bonded to f ive crown oxygen atoms (Bi-O-crown 2.733(3)-3.221(4) Angstrom). Compound V crystallises in the triclinic space group P (1) over bar, Z = 2, R = 0.0693 . The two SbBr3 groups are located on opposite sides of the ring (Sb-Br 2.5 268(15), 2.5478(15), 2.5558(14) Angstrom) and each one is bound to four of the ring oxygen atoms (Sb-O-crown 2.893(7)-3.183(8) Angstrom). (C) 2000 Els evier Science S.A. All rights reserved.