Reactions of AlH₃·NMe₃ with Nitriles:  Structural Characterization and Substitution Reactions of Hexameric Aluminum Imides

Abstract

The reaction of AlH(3).NMe(3) with RCN proceeds with the evolution of trimethylamine and affords (HAINCH(2)R)(6) (R = Ph (1), p-MeC(6)H(4) (2), p-CF(3)C(6)H(4) (3)). Compounds 1 and 3 are characterized by single-crystal structural analysis. Compound 1 reacts with Me(3)SiBr as well as with PhC[triple bond]CH to give (XAINCH(2)Ph)(6) (X = Br (4), PhC[triple bond]C (5)). Structural data and other characterization data of compounds 4 and 5 show that all the hydridic hydrogen atoms in 1 have been replaced by bromine atoms and PhC[triple bond]C groups, respectively. Compounds 1-5 are potential precursors for the preparation of aluminum nitride. Crystals of 1 are rhombohedral, space group R3 macro, with a = 15.7457(13) A, b = 15.7457(13) A, c = 14.949(2) A, V = 3209.8(5) A(3), and Z = 3. Crystals of 3.(3)/(4)C(7)H(8) are triclinic, space group P1 macro, with a = 17.527(11) A, b = 18.894(12) A, c = 19.246(15) A, alpha = 96.11(7) degrees, beta = 102.23(4) degrees, gamma = 106.79(3) degrees, V = 5867(7) A(3), and Z = 4. Compound 4 crystallizes in the monoclinic space group P2(1)/c, with a = 14.175(4) A, b = 16.678(5) A, c = 10.731(3) A, beta = 106.82(2) degrees, V = 2428.6(11) A(3), and Z = 2. Compound 5. C(7)H(8) crystallizes in the monoclinic space group C2/c, with a = 25.842(5) A, b = 15.443(3) A, c = 20.699(4) A, beta = 105.88(3) degrees, V = 7945(3) A(3), and Z = 4.

Synthesis and structural characterization of an unusual heptameric aluminum imide and the surface fluorination products of the Al7N7 and Al4C4N4 cores

“…of Me 3 SnF in refluxing toluene to afford compound 2 (Scheme 1). For the synthesis of 1 we followed the procedure for the preparation of hexameric aluminum imides (RCH 2 NAlH) 6 with various R groups (R ¼ Ph, p-MeC 6 H 4 , p-CF 3 C 6 H 4 ) [22].…”

“…In the 27 Al NMR spectra of 1 and 2 no resonances were detected due to the quadrupole moment of aluminum. In the case of the hexameric aluminum imide (RCH 2 NAlH) 6 (R ¼ Ph, p-MeC 6 H 4 , p-CF 3 C 6 H 4 ) [22], there is just a single resonance in the 1 H NMR spectrum at about 4.2 ppm for the CH 2 group connecting the R group and nitrogen atom, whereas in compounds 1 and 2 there are three and six singlets respectively ranging from 2.76 to 3.08 ppm due to the different environmentally arranged hydrogen atoms. The increase of singlets for the CH 2 group going from 1 to 2 is due to the partially fluorinated Al-H groups resulting in a more differentiated environment.…”

“…15.305 (3) 15.216 (3) 13.447(2) c (Å ) 20.996 (4) 21.059 (4) 17.086 (3) a (8) 82.71 (3) 82.75 (3) 908 b (8) 75.80 (3) 75.89 (3) 91.094 (14) g (8) 75.50 (3) 75.38 (3) Table 2 Selected bond distances (Å ) and bond angles (8) [7] 1.917-1.932 1.923 (4-C 6 H 4 FNAlMe) 4 [24] 1.922-1.951 1.934 (PhNAlPh) 4 [25] 1.900-1.930 1.914 (n-PrNAlH) 6 [8] 1.884-1.972 1.913 (p-CF 3 C 6 H 4 CH 2 NAlH) 6 [22] 1.880-1.980 1.919 (PhCH 2 NAlH) 6 [22] 1.886-1.974 1.918 (PhNAlMe) 6 [26] 1. Compound 2 was prepared from 1 using Me 3 SnF as a fluorinating agent.…”

“…Single crystals of 2 were determined from the crude mixture in toluene. The X-ray analysis of compound 2 shows that the occupancy of F(1), F(2) and F (3) is 53% respectively, while the other four fluorine atoms F(20), F(21), F (22) and F(23) have each an occupancy of 17%. The remainder is non-replaced hydrogen.…”

Synthesis and electrochemical behavior of the ferrocenyl units assembled on imidoalane and carbaalane clusters

“…Solvents were purified according to conventional procedures and were freshly distilled prior to use. Compounds 4 [14,15], 5 [16,17], 8 [13,18], ferrocenylnitrile [19], ferrocenylacetylene [20,21] and AIH 3 ' NMe3 [22] were prepared as described in the literature. IR spectra were recorded on a Bio-Rad Digilab FTS7 spectrometer.…”