1,3-DIARYLTRIAZENIDO COMPOUNDS OF ALUMINUM

Reaction of AIH((i)Bu)2 With 1 and 2 equiv of 1,3-diphenyltriazene, (Ph)NNN(H)(Ph), yields Al((i)BU)2[N(Ph)-NN(Ph)] (1) and Al((i)Bu) [N(Ph)NN(Ph)]2 (2), respectively. Compound 2 undergoes ligand exchange in solution to give an equimolar mixture of 1 and Al[N(Ph)NN(Ph)]3. The reaction of Al((t)Bu)3 with(Ph)NNN(H)(Ph) gives Al((t)BU)2[N(Ph)NN(Ph)] (3) as the only product. Addition of 1 equiv of (Ph)NNN(H)(Ph) to AlMe2(BHT)-(OEt2) (BHT-H = 2,6-di-tert-butyl-4-methylphenol) allows for the isolation of AlMe(BHT) [N(Ph)NN(Ph)] (4); however, higher equivalents of (Ph)NNN(H)(Ph) yield only Al[N(Ph)NN(Ph)]3. The bis(triazenide) complex Al(BHT)[N(Ph)NN(Ph)]2 (5) is isolated from the reaction of (Ph)NNN(H)(Ph) with AlH2(BHT)(NMe3), while Al(BHT)2[N(Ph)NN(Ph)] (6) is formed from the reaction of (Ph)NNN(H)(Ph) with AlMe(BHT)2. AlthoUgh the reaction of 1 with H-2salen [N,N'-ethylenebis(salicylideneamine)] does not yield Al[N(Ph)NN(Ph)](salen) (8) but rather yields AI((i)Bu)(salen) (7), compound 8 may be isolated from interaction of (Ph)NNN(H)(Ph) with AlMe(salen). The reaction between AlMe3 and 3 equiv of substituted 1,3-diaryltriazenes, (Ar)NNN(H)(Ar), yields the 6-coordinate aluminum tris(1,3-diaryltriazenido) compounds, Al[N(Ar)NN(Ar)]3 [Ar = 2-MePh (9), 4-MePh (10) , 4-MeOPh (11), 4-FPh (12), 4-ClPh (13), 4-BrPh (14), C6F5 (15)]. The unsymmetrical diaryltriazene complex Al[N(Pb)NN(4-MeOPh)]3 (16) adopts a trans-meridional conformation. The spectroscopic characterization of the tris(triazenido) complexes is discussed with respect to the nature of the aryl substituents. The X-ray structures of 1, 6, AlMe(salen), 9,11, 13, (C6F5)NNN(H)(C6F5), and (2-MePh)NNN(H)(2-MePh).(2-MePh)NH2 have been determined. Crystallographic data for 1: monoclinic, P2(1)/c, a = 12.437(7) angstrom, b = 12.327(5) angstrom, c = 13.413(9) angstrom, beta = 98.29(5)-degrees, Z = 4, R = 0.059, R(w) = 0.07 1. Crystallographic data for 6: monoclinic, C2/c, a = 17.967(b) angstrom, b = 10.030(5) angstrom, c = 21.650(6) angstrom, beta = 99.99(2)-degrees, Z = 2, R = 0.086, R(w) = 0.090. Crystallographic data for AlMe(salen): monoclinic, P2(1)/n, a = 11.751(8) angstrom, b = 12.227(9) angstrom, c = 12.609 angstrom, beta = 98.52(6)-degrees, Z = 4, R = 0.082, R(w) = 0.082. Crystallographic data for 9: monoclinic, P2(1)/c, a = 11.392(3) angstrom, b = 11.418(3) angstrom, c = 31.227(9) angstrom, beta = 94.31(2)-degrees, Z = 4, R = 0.093, R(w) = 0.099. Crystallographic data for 11: tetragonal, I4(1)/a, a = 27.996(6) angstrom, c = 20.613(5) angstrom, z = 16, R = 0.076, R(w) = 0.077. Crystallographic data for 13: monoclinic, P2(1)/c, a = 8.746(3) angstrom, b = 18.754(4) angstrom, c = 22.985(5) angstrom, beta = 90.36(3)-degrees, Z = 4, R = 0.042, R(w) = 0.056. Crystallographic data for (C6F5)NNN(H)(C6F5): monoclinic, P2(1)/c, a = 10.027(4) angstrom, b = 9.909(4) angstrom, c = 12.998(4) angstrom, beta = 96.00(3)-degrees, Z = 4, R = 0.034, R(w) = 0.046. Crystallographic data for (2-MePh)NNN(H)(2-MePh)-(2-MePh)NH2): triCliniC, P1, a = 9.609(9) angstrom, b = 10.272(5) angstrom, c = 11.276(5) angstrom, alpha = 108.53(8)-degrees, beta = 114.90(7)-degrees, gamma = 90.88(7)-degrees, Z = 2, R = 0.070, R(w) = 0.070.