Cationic indium alkyl complexes incorporating aminotroponliminate ligands

The synthesis and structures of indium complexes incorporating the bidentate monoanionic ligand N,N'-diisopropylaminotroponiminate (Pr-i(2)-ATI) are described. The reaction of InCl3 with Li[Pr-i(2)-ATI] yields (Pr-i(2)-ATI)InCl2 (3), which is converted to (Pr-i(2)-ATI)InMe2 (4) by reaction with MeLi; 4 is also formed by the reaction of InMe3 with (Pr-i(2)-ATI)H. The reaction of 4 with [Ph3C] [B(C6F5)(4)] at 23 degreesC yields the diimine complex [{1,2-((NPr)-Pr-i)(2)-5-CPh3-cyclohepta-3,6-diene}InMe2] [B(C6F5)(4)] (5) via addition of Ph3C+ to the C5 carbon of 4. Thermolysis of 5 (75 degreesC) yields [(Pr-i(2)-ATI)InMe] [B(C6F5)(4)] (6) and Ph3CMe. 43 was isolated as the chlorobenzene solvate 6.PhCl. An X-ray diffraction study shows that there are two independent cations in the asymmetric unit of 6.PhCl. One cation (In(1)) is ion-paired with two B(C6F5)(4)(-) anions, while the second cation is complexed with two PhCl molecules and is disordered between two equally occupied positions (In(2) and In(3)). Dative In-ClPh bonding and PhCl/ATI pi-stacking interactions contribute to the PhCl coordination in 6.PhCl. The reaction of 4 with B(C6F5)(3) yields [(Pr-i(2)-ATI)InMe] [MeB(C6F5)(3)] (7), which decomposes slowly at 23 degreesC by C6F5- transfer reactions. The reaction of 4 with [HNMe2Ph] [B(C6F5)(4)] yields the labile amine adduct [(Pr-i(2)-ATI)In(Me)(NMe2Ph)][B(C6F5)(4)] (10).