Boron-containing Compounds

Based on the characterization and analysis of the worn surfaces, it has been proposed that the anti-wear mechanism consists of the prepared compound boron-containing thiophosphite derivative reacting with the steel surface during the friction process to generate a protective film mainly composed of phosphate, sulfide, sulfate, organic amine, and B2O3 (25). 

This compound, which contains atoms arranged tetrahedrally around the boron atom, can readily be isolated from a mixture of dimethyl ether and boron trichloride. On occasions a chlorine atom, in spite of its high election affinity, will donate an electron pair, an example being found in the dimerisation of gaseous monomeric aluminium chloride to give the more stable Al2Clg in which each aluminium has a tetrahedral configuration ... 

Boranes are typical species with electron-deficient bonds, where a chemical bond has more centers than electrons. The smallest molecule showing this property is diborane. Each of the two B-H-B bonds (shown in Figure 2-60a) contains only two electrons, while the molecular orbital extends over three atoms. A correct representation has to represent the delocalization of the two electrons over three atom centers as shown in Figure 2-60b. Figure 2-60c shows another type of electron-deficient bond. In boron cage compounds, boron-boron bonds share their electron pair with the unoccupied atom orbital of a third boron atom [86]. These types of bonds cannot be accommodated in a single VB model of two-electron/ two-centered bonds. 

Air-Stable boron-containing polymers can be prepared by the reaction of dicyano compounds with the / fZ-butylborane—trimethyl amine complex (449). 

Fluoride ion, and weak acids and bases do not interfere, but nitrate, nitrite, perchlorate, thiocyanate, chromate, chlorate, iodide, and bromide do. Since analysis of almost all boron-containing compounds requires a preliminary treatment which ultimately results in an aqueous boric acid sample, this procedure may be regarded as a gravimetric determination of boron. 

The chemistry of compounds which contain boron-boron bonds. R. J. Brotherton, Prog. Boron Chem., 1964,1,1-81 (189). 

Interactions between non-halogen-containing IIIB compounds and transition-metal complexes are found in 6.5.3. Most of these IIIB compounds are boron-containing heterocycles. A series of interesting sandwich compounds, including triple- and tetradecked complexes, are synthesized by methods in 6.5.2.1-6.5.3. 

Reactions between anionic species containing one or more group-IIIB elements (particularly boron) and complexes of transition-metal halides are used to produce an immense number of ionic boron-containing compounds. For this reason a strong selection factor must be made. 

There are many compounds that contain boron and hydrogen, and they are known collectively as the boron hydrides. Six boron hydrides were prepared by Alfred Stock in 1910-1930 by the addition of hydrochloric acid to magnesium boride that was produced in small amounts when B203 was reduced with magnesium. 

Niedenzu, K, and Dawson, J. W. (1965). Boron-Nitrogen Compounds. Academic Press, New York. An early introduction to boron-nitrogen compounds that contains a wealth of relevant information. 

Boryl nitronates (75-78), (217, 229-231) which have been poorly studied, are as a rule unstable. It should be noted that dimers (75) are crystalline compounds, which decompose in the solid state within a few days to give boron-containing heterocycles (79) (Scheme 3.74). 

Bis(dimesitylboryl)-2,2 -bithiophene (BMB-2T, 242) forms a stable amorphous glass and emits pure blue color with a high fluorescence QE of 86% in THF solution [270]. However, an OLED with ITO/m-MTDATA/TPD/BMB-2T/Mg Ag emits with a broad emission due to an exciplex with TPD. The exciplex can be prevented by insertion of a thin layer of 1,3,5-tris(biphenyl-4-yl)benzene (TBB) between TPD and BMB-2T, leading to a pure blue emission. It seems that the boron complex or boron-containing compounds easily form an exciplex with common HTMs. Other similar blue emitter materials also demonstrate such behavior. 

Hydroboration -oxidation was first reported by H.C. Brown in 1959. For his studies on boron containing organic compounds, Brown shared the 1979 Nobel prize in Chemistry with G. Wittig. 

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