Containers diborane

The sulfur-containing diborane compounds 39 were considered of potential interest as reagents in metal-catalyzed diboration reactions <2000AXC440>. 

Finally, some electron rich, sulphur-containing species have been prepared as part of a study of potential molecular electronic materials containing diborane(4) compounds. In a... 

Aluminium tetrahydridoborate is a volatile liquid. It is the most volatile aluminium compound known. It is covalent and does not contain ions but has a hydrogen-bridge structure like that of diborane, i.e. each boron atom is attached to the aluminium by two hydrogen bridges ... 

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. 

Diborane reacts with ethylene oxide at —80° C to form diethoxyborane and a soHd polymer containing approximately eight ethylene oxide units per molecule (88). Potassium thiocyanate or thiourea react ia aqueous solution with ethylene oxide to give ethylene sulfide (89). 

In a 200-ml three-necked flask fitted with a dropping funnel (drying tube) is placed a solution of 13.4 g (0.12 mole) of 1-octene in 35 ml of THF. The flask is flushed with nitrogen and 3.7 ml of a 0.5 M solution of diborane (0.012 mole of hydride) in THF is added to carry out the hydroboration. (See Chapter 4, Section I regarding preparation of diborane in THF.) After 1 hour, 1.8 ml (0.1 mole) of water is added, followed by 4.4 g (0.06 mole) of methyl vinyl ketone, and the mixture is stirred for 1 hour at room temperature. The solvent is removed, and the residue is dissolved in ether, dried, and distilled. 2-Dodecanone has bp 119710 mm, 24571 atm. (The product contains 15 % of 5-methyl-2-undecane.) The reaction sequence can be applied successfully to a variety of olefins including cyclopentene, cyclohexene, and norbornene. 

Diborane reacts with ammonia to form an ionic compound (there are no other products). The cation and anion each contain one boron atom, (a) Predict the identity and formula of each ion. (b) Give the hybridization of each boron atom, (c) Identify the type of reaction that has occurred (redox, Lewis acid-base, or Bronsted acid-base). 

A modification of the rf discharge method, in which the BCI3 source is held at -78°C, yields B4CI4 containing a tetrahedron of linked B atoms. Reaction of B4CI4 with diborane leads to chlorohexaborane and chlorodecaborane clusters". 

My thesis was completed in 1938 and the results were published in 1939 Hydrides of Boron. XI. The Reaction of Diborane with Organic Compounds Containing a Carbonyl Group (3). 

Use of lumps of the solid aluminate, rather than its ethereal solution, and of peroxide-containing etherate [1], rather than the peroxide-free material specified [2], caused an explosion during the attempted preparation of diborane. 

The rhodium-catalyzed borylation of methyl C-H bonds is compatible with several moieties containing oxygen, nitrogen, and fluorine.154 For example, the reaction of pinacol acetal of 2-hexanone with bis(pinacolato)diborane (B2pin2) in the presence of Cp Rh(774-C6Me6) catalyst gives the alkylboronate ester in 74% yield (Equation (111)). The rhodium-catalyzed C-H activation and borylation occur at the least hindered and least electron-rich methyl group. 

Seven to eight millimoles of unreacted diborane(6) may be recovered from the trap at -196°, whereas pure l-methyldiborane(6) is contained in the trap at -140°. Transfer of this product from its trap should be carried out by distillation from a bath at -11 lu. The yield of l-methyldiborane(6) is 3 mmole, 20% of the theoretical value based on consumed diborane(6). 

---