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[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
[31] [32] [33] Compressing boron above 160 GPa produces a boron phase with an as yet unknown structure, and this phase is a superconductor at temperatures below 6–12 K. [34] [35] Borospherene (fullerene-like B 40 molecules) and borophene (proposed graphene-like structure) were described in 2014.
Ball-and-stick model of the tetrahydroborate anion, [BH 4] −. Borohydride refers to the anion [B H 4] −, which is also called tetrahydridoborate, and its salts. [1] Borohydride or hydroborate is also the term used for compounds containing [BH 4−n X n] −, where n is an integer from 0 to 3, for example cyanoborohydride or cyanotrihydroborate [BH 3 (CN)] − and triethylborohydride or ...
As anticipated by its hydride clusters, boron forms a variety of stable compounds with formal oxidation state less than three. B 2 F 4 and B 4 Cl 4 are well characterized. [6] Ball-and-stick model of superconductor magnesium diboride. Boron atoms lie in hexagonal aromatic graphite-like layers, with a charge of −1 on each boron atom.
Various representations of bonding in borenium ions. [2]A borenium ion is an inorganic cation with the chemical formula [BR 2 L] +In this class of molecules, the electron-deficient boron center has two valence electrons involved in sigma bonding with two ligands, while the third ligand is a two-electron donor such that the overall charge of the complex is +1. [1]
The boron atom in BH 3 has 6 valence electrons. Consequently, it is a strong Lewis acid and reacts with any Lewis base ('L' in equation below) to form an adduct: [8] BH 3 + L → L—BH 3. in which the base donates its lone pair, forming a dative covalent bond. Such compounds are thermodynamically stable, but may be easily oxidised in air.
Some of the most studied examples of such Lewis acids are the boron trihalides and organoboranes: [9] BF 3 + F − → BF − 4. In this adduct, all four fluoride centres (or more accurately, ligands) are equivalent. BF 3 + OMe 2 → BF 3 OMe 2. Both BF 4 − and BF 3 OMe 2 are Lewis base adducts of boron trifluoride.
A borane is a compound with the formula BR x H y although examples include multi-boron derivatives. A large family of boron hydride clusters is also known. In addition to some applications in organic chemistry , the boranes have attracted much attention as they exhibit structures and bonding that differs strongly from the patterns seen in ...