Health & Environmental Research Online (HERO)


Print Feedback Export to File
7728642 
Journal Article 
SYNTHESIS, STRUCTURE, AND SPECTROSCOPIC CHARACTERIZATION OF UNASSOCIATED MONOAMIDO, DIAMIDO, AND TRIAMIDO DERIVATIVES OF ALUMINUM AND GALLIUM 
Brothers, PJ; Wehmschulte, RJ; Olmstead, MM; Ruhlandtsenge, K; Parkin, , SR; Power, PP 
1994 
1 
Organometallics
ISSN: 0276-7333
EISSN: 1520-6041 
13 
7 
2792-2799 
English 
WOS:A1994NW03700040 
As part of a study of the possible existence of π-interactions in Al-N or Ga-N bonds,the synthesis and spectroscopic and structural characterization of several unassociated amido derivatives of aluminum and gallium are described. The compounds Mes*GaCl{N(H)Ph}·0.25 (hexane), 1, Mes*2GaN(H)Ph, 2, MesAl{N(SiMe3)2}2, 3, Mes*Ga(NHPh)2, 4, and ClGa-{N(SiMe3)2}2, 5 (Mes = 2, 4, 6-Me3C6H2, Mes*= 2, 4, 6-t-Bu3C6H2) were synthesized by simple salt elimination procedures and characterized by 1H and 13C NMR and X-ray crystallography. In addition, the X-ray crystal structures of the previously reported triamido compounds Al{N(i- Pr)2}3, 6, and Ga{N(SiMe3)2}3, 7, are described. The Al-N and Ga-N distances in 1–7 fall within the narrow limits 1.790(4)–1.809(2) and 1.829(9)-1.874(4) Å, respectively, which are within the previously known range for bonds between three-coordinate nitrogen and three-coordinate aluminum or gallium. Dynamic behavior in the 1H and 13C NMR spectra of 2 and 3 was also observed,with a barrier near 11 kcal mol-1 being estimated in both molecules. The structural and dynamic NMR data suggest that any π-interactions in the M-N bonds are rather weak and are of the order of 10 kcal mol-1. Crystal data at 130 K with Mo Kα (4, 6, 7, λ = 0.710 73 Å) or Cu Kα (1–3, 5, λ = 1.541 78 Å) radiation: (1) C25.5H38.5ClGaN, a = 9.421(2) Å, b = 14.413(2) Å, c = 18.967(3) Å, α = 87.88(2)°, ß = 79.22(2)°, γ = 80.66(2)°, triclinic, space group. P1, Z = 4, R = 0.083 for 3867 (I > 3σ(I)) reflections; (2) C42H64GaN, a = 9.945(2) Å, b = 11.245(2) Å, c = 17.825(2) Å, α = 87.28(2)°, β = 85.73(2)°, γ = 79.25(2)°, space group PĪ, Z = 2, R = 0.054 for 4155 (I > 2σ(I)) reflections; (3) C21H47AIN2Si4, a = 13.403(3) Å, b = 16.651(2) Å, c = 26.061(5) Å, β = 91.46(2)°, monoclinic, space group C2/c, Z = 8, R = 0.035 for 2992 (I >2 σ(I)) reflections; (4) C30H30GaN2, a =20.346(4) Å, b = 11.696(3) Å, c = 13.565(3) Å, β = 123.17(2)°, monoclinic, space group C2/c, Z =4, R = 0.066 for 1707 (I > 3σ(I)) reflections; (5) C12H36ClGaN2Si4, a = 11.657(3) Å, b = 12.677(2) Å, c = 15.831(3) Å, orthorhombic, space group P212121, Z = 4, R = 0.040 for 2577 (I > 3σ (I)) reflections; (6) C18H42AlN3, a = 7.803(6) Å, b = 16.590(12) Å, c = 17.397(14) Å, α = 102.68(5), β = 90.67(5)°, γ = 96.67(5)°, triclinic, space group P1, Z = 4, R = 0.071 for 4311 (I > 2σ(I)) data; (7) C18H54GaN3Si6, a = 16.008(3) Å, c = 8.444(2) Å, trigonal, space group P31c, Z = 2, R= 0.059 for 718 (I > 3 σ(I)) reflections. © 1994, American Chemical Society. All rights reserved.