Boron—nitrogen

There is the possibility of building up an extensive systematic chemistry of compounds containing boron-nitrogen bonds, analogous to the chemistry of carbon-carbon bonds but the reactivity of the B—bond is much greater than that of the C—C bond, so that we get physical, but not chemical, resemblances between analogous compounds. 

Thousands of compounds of the actinide elements have been prepared, and the properties of some of the important binary compounds are summarized in Table 8 (13,17,18,22). The binary compounds with carbon, boron, nitrogen, siUcon, and sulfur are not included these are of interest, however, because of their stabiUty at high temperatures. A large number of ternary compounds, including numerous oxyhaUdes, and more compHcated compounds have been synthesized and characterized. These include many intermediate (nonstoichiometric) oxides, and besides the nitrates, sulfates, peroxides, and carbonates, compounds such as phosphates, arsenates, cyanides, cyanates, thiocyanates, selenocyanates, sulfites, selenates, selenites, teUurates, tellurites, selenides, and teUurides. 

A new class of boron—nitrogen compounds was reported in 1975 when the first iminoborane having two-coordinate boron,... 

Boron-nitrogen heterocycles [4,5-diethyl-2,2,3-trimethyl-l-(<9-tnfluoro-methyl)phenyl-2,5-dihydro-l(-)-],2,5-azasilaboroles and -azastannaboroles] are formed in good yields The products demonstrate atropoisomensm due to the hmdered rotation about the N-aryl bond [113] (equation 88)... 

Other reactions adapted from asymmetric aldol reactions suffer in comparison from the fact that (probably due to the strength of the boron-nitrogen bond) boron-mediated processes generally yield the intermediate 2-halo-3-aminoester products rather than aziridine products directly [51]. 

Borazine, B3N3Hft, a compound that has been called inorganic benzene because of its similar hexagonal structure (but with alternating B and N atoms in place of C atoms), is the basis of a large class of boron—nitrogen compounds. Write its Lewis structure and predict the composition of the hybrid orbitals used by each B and N atom. 

Color colorless to yellow if pure, brown if doped with boron, nitrogen or aluininum X-ray Density (g/cm3) 3.214 Melting Point 2545°C at 1 atm. 2830°C at 35 atm. 

Interstitial Solid Solutions Interstitial solid solutions involve occupation of a site by introduced ions or atoms, which is normally empty in the crystal structure, and no ions or atoms are left out. Many metals form interstitial solid solutions in which small atoms (e.g., hydrogen, carbon, boron, nitrogen) enter empty interstitial sites within the host structure of the metal. Palladium metal is well known for its ability to absorb an enormous volume of hydrogen gas, and the product hydride is an interstitial sohd solution of formula PdH, 0 0.7, in which hydrogen atoms occupy... 

The ring compound MeAlNDipp 366a 73a (Fig. 11) is an analog of bora-zine, (HBNH)3 and its derivatives, which are in turn isoelectronic and isostructural with benzene. While this family of boron-nitrogen rings is... 

There is great interest in developing molecular precursors for boron-nitrogen polymers and boron nitride solid state materials, and one general procedure is described in this report. Combinations of B-trichloroborazene and hexamethyldisilazane lead to formation of a gel which, upon thermolysis, gives hexagonal boron nitride. The BN has been characterized by infrared spectroscopy, x-ray powder diffraction and transmission electron microscopy. 

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