Trihalides of gallium, indium and thallium

AH (e4.), Friedel-Crafls iind Related Reactionji, Vol-s. 1-4, Interscience, New York, 1463. See especially Chap. I. Hislorical, by G. A. Oi.ah and R. E. A. Dear, and Chap. 2, Definition and scope by G. A. Olah. 

The thermochemistiy of the Group 13 trihalide complexes has been extensively studied and several stability sequences have been 

Regularities are more apparent when the acceptor atom remains constant and the attached groups are varied e.g., for all ligands so far studied the acceptor strength diminishes in the sequence 

It has also been found that halide-ion donors (such as X in A1X4 and GaX4 ) are more than 

TII3 is an intriguing compound which is isomorphous with NH4I3 and Csly (p. 836) it therefore contains the linear I3 ion and is a compound of Tl rather than Tl . It is obtained as black crystals by evaporating an equimolar solution of Til and I2 in concentrated aqueous HI. The formulation Tl (l3 ) rather than Tl (I )y is consistent with the standard reduction potentials °(T1 VT1 )1.26 V and °(il2/I )-(-0.54 V, 

---