B&O

B&O may refer to:

Borate

Borates are the name for a large number of boron-containing oxyanions. The term "borates" may also refer to tetrahedral boron anions, or more loosely to chemical compounds which contain borate anions of either description. Larger borates are composed of trigonal planar BO₃ or tetrahedral BO₄ structural units, joined together via shared oxygen atoms and may be cyclic or linear in structure. Boron most often occurs in nature as borates, such as borate minerals and borosilicates.

Structures

The simplest borate anion, the orthoborate ion, BO₃³⁻ is known in the solid state, for example in Ca₃(BO₃)₂. In this it adopts a near trigonal planar structure. It is a structural analogue of the carbonate anion CO₃²⁻, with which it is isoelectronic. Simple bonding theories point to the trigonal planar structure. In terms of valence bond theory the bonds are formed by using sp²hybrid orbitals on boron. Some compounds termed orthoborates do not necessarily contain the trigonal planar ion, for example gadolinium orthoborate, GdBO₃ contains the polyborate (B₃O₉)⁹⁻ ion, whereas the high temperature form contains planar BO₃³⁻.

EMC 1800 hp B-B

Electro-Motive Corporation (later Electro-Motive Division, General Motors) produced five 1800 hp B-B experimental passenger train-hauling Diesel locomotives in 1935; two company-owned demonstrators, #511 and #512, the Baltimore and Ohio Railroad's #50, and two units for the Atchison, Topeka and Santa Fe Railway, Diesel Locomotive #1. In addition, two single power cars and two twin-unit power cars for the Chicago, Burlington and Quincy Railroad's Zephyr streamliners were built to fundamentally the same design, but clad in Budd Company streamlined stainless steel carbodies. These were #9904 Pegasus and #9905 Zephyrus for the Twin Zephyrs, and #9906A/B Silver King/Silver Queen and #9907A/B Silver Knight/Silver Princess for the Denver Zephyrs.

All were the mechanical ancestors to EMD's successful E-units, with identical pairs of 900 hp (670 kW) Winton 201-A Diesel engines, although they ran on AAR type B two-axle trucks instead of the A1A trucks of E-units. When delivered, the units were fitted with shrouding around their trucks, but this did not last long.

Boron trioxide

Boron trioxide (or diboron trioxide) is one of the oxides of boron. It is a white, glassy solid with the formula B₂O₃. It is almost always found as the vitreous (amorphous) form; however, it can be crystallized after extensive annealing (that is, under prolonged heat).

Glassy boron oxide (g-B₂O₃) is thought to be composed of boroxol rings which are six-membered rings composed of alternating 3-coordinate boron and 2-coordinate oxygen. Because of the difficulty of building disordered models at the correct density with a large number of boroxol rings, this view was initially controversial, but such models have recently been constructed and exhibit spectroscopic properties in excellent agreement with experiment. The rings are thought to make a few BO₃ triangles, but mostly link (polymerize) into ribbons and sheets. The crystalline form (α-B₂O₃) (see structure in the infobox) is exclusively composed of BO₃ triangles. This trigonal, quartz-like network undergoes a coesite-like transformation to monoclinic β-B₂O₃ at several gigapascals (9.5 GPa).

Boron suboxide

Boron suboxide (chemical formula B₆O) is a solid compound containing six boron atoms and one oxygen atom. Its structure is built of eight icosahedra at the apexes of the rhombohedral unit cell (space group R3-m). Each icosahedron is composed of twelve boron atoms. Two oxygen atoms are located in the interstices along the [111] rhombohedral direction. Due to its short interatomic bond lengths and strongly covalent character, B₆O displays a range of outstanding physical and chemical properties such as great hardness (close to that of rhenium diboride and boron nitride), low mass density, high thermal conductivity, high chemical inertness, and excellent wear resistance.

B₆O can be synthesized by reducing B₂O₃ with boron or by oxidation of boron with zinc oxide or other oxidants. These boron suboxide materials formed at or near ambient pressure are generally oxygen deficient (B₆O_x, x<0.9) and have poor crystallinity and very small grain size (less than 5 µm). High pressure applied during the synthesis of B₆O can significantly increase the crystallinity, oxygen stoichiometry, and crystal size of the products. Mixtures of boron and B₂O₃ powders were usually used as starting materials in the reported methods for B₆O synthesis.