21. Preparation and reactions of dialkylaminoborazoles, and reaction of diethylaminoboron dichloride with primary amines

Gerrard, W.; Hudson, H. R.; Mooney, E.F.

doi:10.1039/jr9620000113

Cited by 25 publications

(20 citation statements)

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“…The thermal reactivity of (NEt 2 ) 3 B 3 N 3 H 3 (1) has been previously described by Gerrard et al [13], In accordance with their findings, diethylamine was evolved and characterized by its FTIR and 1 H NMR spectra showing that (1) oligomerizes via the formation of direct B-N bonds between two borazine rings ( Fig. 1).…”

mentioning

confidence: 56%

“…For these assignments, we used results of a current parallel study involving the formation of -N(R)-bridges between borazine rings [14], Therefore, it appears that the oligomerization of (NEt 2 ) 2 (NHPr')B 3 N 3 H 3 (2) proceeds mainly via the formation of B-N linked borazine rings (mechanism a). Concerning the oligomer derived from (NEt 2 )(NHPr') 2 B 3 N 3 H 3 (3), both 1 H and 13 C spectra are nearly the same as those of the oligomer derived from (2). The only noticeable difference in the case of (3) is that the signals characteristic of -NEt 2 groups are negligible showing that almost complete substitution of diethylamino groups took place during oligomerization.…”

Section: Hn Imentioning

confidence: 69%

“…11 B, 1 H, 13 C NMR spectra were recorded on a Bruker AM300 spectrometer at 96.28 MHz with Et 2 O.BF 3 as an external reference (positive values downfield), at 300 MHz and 75 MHz, respectively. The infrared spectra were obtained on an FTIR Nicolet Magna 550 spectrometer as KBr pellets.…”

Section: Methodsmentioning

confidence: 99%

“…were synthesised f o l l o w i n g procedures similar to those previously described in the literature for Btri(alkylamino)borazines [13]. In a typical experiment, triethylamine (120 mmol) was added to a solution of 2,4,6-trichloroborazine (TCB) (38 mmol) in toluene (130 ml).…”

Section: Synthesis and Characterisations Of Borazines The B-trisubstimentioning

confidence: 99%

“…This pattern is also observed on 1 H NMR spectra and the resulting overlapping of the signals limits integration ratio determination. On the other hand, 13 C NMR appeared as a more reliable spectroscopic technique for the understanding of the path leading to the oligomers.…”

mentioning

confidence: 99%

See 4 more Smart Citations

Thermal Oligomerization of Unsymmetrically B-Trisubstituted Borazines

Toury¹,

Miele²,

Cornu³

et al. 1999

Main Group Metal Chemistry

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mentioning

confidence: 56%

Section: Hn Imentioning

confidence: 69%

Section: Methodsmentioning

confidence: 99%

Section: Synthesis and Characterisations Of Borazines The B-trisubstimentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

Thermal Oligomerization of Unsymmetrically B-Trisubstituted Borazines

Toury¹,

Miele²,

Cornu³

et al. 1999

Main Group Metal Chemistry

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Boron Nitride Fibers Prepared from Symmetric and Asymmetric Alkylaminoborazines

Toury

Miele²,

Cornu

et al. 2002

Adv. Funct. Mater.

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The thermolysis of 2,4,6‐[(CH3)2N]3B3N3H3 (1), 2,4‐[(CH3)2N]2‐6‐(CH3HN)B3N3H3 (2), and 2‐[(CH3)2N]‐4,6‐(CH3HN)2B3‐N3H3 (3) led to polyborazines 4, 5, and 6 respectively. The polymers display direct B–N bonds between borazinic B3N3 rings and, in addition, a proportion of –N(CH3)– bridges for 5 and 6, as clearly underlined by 13C NMR spectroscopy. Melt‐spinning of these three polymeric precursors exemplified that their ease of processing increases in the order 4 < 5 < 6. Nevertheless, polyborazine filaments could be prepared from each of them and a subsequent thermal treatment up to 1800 °C resulted in the formation of crystalline hexagonal boron nitride fibers, which were characterized by X‐ray diffraction analysis, Fourier transform infrared (FTIR) spectroscopy, and Raman spectroscopy. Scanning electron microscopy (SEM) images showed that the ceramic fibers are circular and dense without major defects. The mechanical properties for 4‐derived fibers could not be measured because of their brittleness, whereas measurements on 5‐ and 6‐derived fibers gave tensile strength σR = 0.51 GPa, Young’s modulus E = 67 GPa, and σR = 0.69 GPa, E = 170 GPa, respectively. The improvement in mechanical properties for ceramic fibers prepared respectively from 4, 5, and 6 could be explained to a large extent by the improvement of the processing properties of the preceramic polymers. This evolution could be related to the increased ratio of bridging –N(CH3)– groups between the B3N3 rings within the polymers 4, 5, and 6 and therefore to the functionalities of the starting monomers 1, 2, and 3.

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