Supermesityl‐stabilisierte Iminoborane

Abstract

Amino‐imino‐borane R′(SiMe3)N–B≡N–R:IIc (R′ = CHMe2), IId (R′= CMe3) und IIe (R′ = SiMe3) mit R = 2,4,6‐Tri‐t‐butylphenyl‐ wurden aus den entsprechenden Fluorbis(amino)boranen Ic–e durch HF‐Eliminierung mit t‐Butyllithium (IIc, IId) bzw. Lithiumbis(trimethylislyl)amid (IIe) erhalten. IIc–e sind thermisch stabil und bei Raumtemperatur unbegrenzt haltbar. Die Umsetzungen der Fluorbis(amino)borane Ia (R′ = Me), Ib(R′ = CH2Me) und Ie (R′ = SiMe3) mit t‐ Butyllithium führen zur Abspaltung von LiF und HN(SiMe3)R′, wobei sich in allen Fällen des B‐t‐butyl‐substituierte Iminoboran III bildet. Die Verbindungen sind elementaranalytisch und spektroskopisch (MS, IR, NMR) charakterisiert. Eine Röntgenstrukturanalyse wurde von IId durchgeführt.

Synthesis of 5‐Aminotetrazole‐1 N‐oxide and Its Azo Derivative: A Key Step in the Development of New Energetic Materials

“…133 pm5, 9). Nevertheless, they are comparable to the formal single bonds in a supermesityl‐substituted aminoiminoborine16 [139.2(5) pm] and in a bis(trimethyl)silylaminodisilylamino‐substituted fluoroborane17 [143.4(1) and 144.2(1) pm]. According to Paetzold, who suggested a value of 141 pm as a typical R 2 BNR 2 bond length, we have to classify the BN bonds in 7 , 9 , 10 and 11 likewise 2…”

“…The longest is found in 11 [137.1(2) pm], whereas the sterically least affected 9 shows the shortest BF bond [135.8(3) pm]. The halide–boron bond lengths can be compared to the related cases in the tetrasilyl‐substituted aminofluoroborane16 [137.1(1) pm] and also to the maximum in the histogram of reported BF single bonds (136 pm) with a tricoordinate boron atom 18…”

First Trichloroaluminum Adducts of Silyliminoborenes

“…This tendency is comparable to the bonding situation in the adducts of carboaminoiminoborenes with gallium and indium trichloride [9] (131.7(4)/134.4(4) pm; 131.2(2)/134.5(2) pm) or pentacarbonyl chromium [10] (129.5(6)/136.8(6) pm) [11]. The alane coordination of the imine nitrogen lone pair prevents the formation of an aminoiminoborine (N-B≡N) in which different B-N bond lengths suggest formal single and triple B-N bonds (139.2(5) vs. 125.3(5) pm) [12].…”

Interplay of donor–acceptor interactions in stabilizing boron nitride compounds: insights from theory

“…Despite the planar nature of the B 2 N 2 rings, the intraring B-N distances within the bis-adducts (ImMe 2 ) 2 ÁB 2 N 2 , (ImMe 2 CH 2 ) 2 ÁB 2 N 2 , and (Me 3 PCH 2 ) 2 ÁB 2 N 2 all lie within a narrow range of 1.440 to 1.448 Å and suggest the absence of strong B-N p-bonding. To compare, iminoboranes (RBRNR 0 ) have B-N triple bond lengths in the range of 1.23 to 1.26 Å, [83][84][85][86] while the diborylamide anion [Mes 2 BQNQBMes 2 ] À (Mes = 2,4,6-Me 3 C 6 H 2 ), which has significant BQN double bond character, has B-N lengths of 1.343(5) and 1.348(5) Å. 87 The central B 3 N 3 units in each complex adopt nearly planar arrangements with intraring B-N bond lengths that are typical for short B-N single bonds (1.404 to 1.436 Å).…”