The chemistry and the stereochemistry of poly(n-alkyliminoalanes)

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

“…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.…”

“…The four shorter Al-Al edges are each bridged by a N atom, and every N atom is connected to another Al atom by a CH 2 group. Moreover every N atom À178.1 (2,6-Me 2 C 6 H 3 )N{Si(t-Bu)Me 2 }AlF 2 ÁTHF [14] À175.0 (n-Bu 4 N) 2 (PhPO 3 AlF 2 ) 2 [17] À180.0 (n-Bu 4 N) 2 (t-BuPO 3 AlF 2 ) 2 [17] À179.5 (n-Bu 4 N)(RMeAlF 2 ) (R ¼ Me) [18] À154.8 (n-Bu 4 N)(RMeAlF 2 ) (R ¼ (Me 3 Si) 3 C) [18] À145.9 (Me 4 N)(i-Bu 2 AlF 2 ) [19] À149.4 (Ph 4 P)(i-Bu 2 AlF 2 ) [19] À151.7 (1-AdCH 2 NAl) 7 [15], (n-Bu 4 N) 2 (PhPO 3 -AlF 2 ) 2 (1.659 Å ), (n-Bu 4 N) 2 (t-BuPO 3 AlF 2 ) 2 (1.666 Å ) [17]). A comparison of the 19 F NMR shifts of compounds having only terminal Al-F bonds is given in Table 4.…”

“…Al-N rings and clusters have been reviewed recently [5]. There are a few reports on aluminum imides (RNAlH) n (n ¼ 4, 6 or 8) [6][7][8] containing hydridic hydrogens bound to aluminum atoms. Compounds of composition (RNAlH) 7 with Al-H bonds are not known.…”

“…However, neither yields nor further reactivity were reported. Furthermore, only the preparation, NMR spectra and the mass spectrum of (EtAlNMe) 7 were mentioned [10,11], and based on these limited data alone it was thought to be an octamer. Nevertheless, the unambiguous geometry of this species has never been reported.…”

“…However, no chemistry on aggregates containing only terminal Al-F bonds is known so far. Herein we report an efficient synthetic route involving the reaction of RCN (R ¼ 1-adamantyl) with an excess of AlH 3 ÁNMe 3 in boiling toluene to form the first (RCH 2 NAlH) 7 (1) compound containing Al-H bonds, and the fluorination of the Al 7 N 7 and Al 4 C 4 N 4 cores to get the first two aggregates (RCH 2 NAl) 7 -F 2.26 H 4.74 (2) and (t-BuNCH 2 AlF) 4 (3) containing only terminal Al-F bonds.…”