ChemInform Abstract: 2,4,6‐Tri‐tert.‐butylphenyl‐Substituted Iminoboranes.

Abstract

212ChemInform Abstract Thermal elimination of fluorotrimethylsilane from the boranes (III) results, in the case of (IIIa) and (IIIb), in formation of the expected iminoboranes (IVa) (space group P21/c, Z=4) and (IVb). However, the analogous iminoborane from (IIIc) rearranges to give the benzoborolane derivative (V). The iminoborane (IVc) can be obtained by the two-step reaction starting from (VI). The tri-tert.-butylphenyl-substituted iminoboranes (IV) are thermally stable at temp. of more than 200 rc C, although they are reactive. (IVa) and (IVb) form corresponding benzoborolanes of the type (V) at 350 and 250 rc C, respectively. The H acidic compounds HX (VIII) are readily added to (IVb) to give the iminoboranes (IX). The N-aryl iminoborane (XII) is also thermally stable such as (IV).

Quasi-Isomeric Gallium Amides and Imides GaNR2 and RGaNR (R = Organic Group): Reactions of the Digallene, Ar‘GaGaAr‘ (Ar‘ = C6H3-2,6-(C6H3-2,6-Pri2)2) with Unsaturated Nitrogen Compounds

“…It contains the shortest known Ga-N distance of 1.701(3) Å in a stable molecular species as well as trans-bent N-Ga-C (148.2(2)°) and C-N-Ga (141.7(3)°) arrays. The trans-bending in 2 is in sharp contrast to the geometry of the lighter iminoboranes, Bu t BNBu t , 22 (Me 3 Si) 3 SiBNBu t , 23 Mes*BNBu t , 20 and Mes*NBN-(SiMe 3 )Bu t , 24 which feature linear RBNR′ arrangements and B-N distances in the range 1.22-1.26 Å. Calculations for HBNH support triple B-N bonding and afford a B-N bond strength of 88 kcal‚mol -1 , which is comparable to the strength of the C-C triple bond (94 kcal‚mol -1 ) in acetylene.…”

“…Chemistry of Aluminium, Gallium, Indium Monomeric imides are of interest because they have formal group 13 element-nitrogen triple bonds. Such compounds had been known only for BN species, [20][21][22][23][24] but in a preliminary report we showed that, with use of the bulky terphenyl substituents, the first heavier group 13 element monomeric imides Ar′MNAr # (M ) In or Ga) could be synthesized by reaction of Ar′MMAr′ (Ar′ ) C 6 H 3 -2,6-(C 6 H 3 -2,6-Pr i 2 ) 2 ) or C 6 H 3 -2,6(Xyl-4-Bu t ) 2 with N 3 Ar # (Ar # ) C 6 H 3 -2,6-(C 6 H 2 -2,6-Me 2 -4-Bu t ) 2 ). 25 These compounds had short Ga-N and In-N bond lengths, but they had trans-bent structures that were indicative of weakened M-N bonding.…”