Synthesis and Characterization of (Pentafluorophenyl)amino-Based Amino- and Iminometallanes. Crystal Structures of (MeAlNC6F5)4 and NHC6F5Ga(MesGa)3(.mu.3-NC6F5)4 (Mes = 2,4,6-Me3C6H2)

Abstract

The novel compounds (MeAINC&)4 1, Mes2AlNHC& 2, Mes2GaNHC& 3, and NHC&Ga(MesGa)3@3-NC&)4 4 of group 13 have been prepared in high yields by the reaction of Me3A1, MessAl, and Mes3Ga with pentafluoroaniline, respectively. 1-4 have been fully characterized by elemental analysis, IR, NMR, and mass spectrometry. The crystal structures of 1 and 4 have been determined. 1- OShexane crystallizes in the space group Pi, a = 1594.1(5) pm, b = 1643.0(5) pm, c = 1777.0(6) pm, a = 66.81(1)", p = 63.77(1)", y = 64.16-(l)', V = 3.639(2) nm3, Z = 4, and R = 0.0507 (wR2 = 0.1294); 4 crystallizes in the space group C2/c, a = 4532.4(1) pm, b = 1207.7(4) pm, c = 2246.2(5) pm, a = y = 90°, p = 91.92(3), V = 12.288(6) nm3, Z = 8, and R = 0.0576 (wR2 = 0.1 172). The structure of 1 displays an almost perfect cube with alternating aluminum and nitrogen atoms. In contrast 4 consists of a distorted cube. 4 is the first example of an amino-substituted iminogallane containing a heterocubane structure. According to a modified Schomaker-Stevenson equation a bond order of 1 can be attributed to the exocyclic Ga(2)-N(5) bond length, whereas the Ga-N distances within the core have bond orders of 213.