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  2. Ammonia borane - Wikipedia

    en.wikipedia.org/wiki/Ammonia_borane

    The molecule adopts a structure similar to that of ethane, with which it is isoelectronic. The B−N distance is 1.58(2) Å. The B−H and N−H distances are 1.15 and 0.96 Å, respectively. Its similarity to ethane is tenuous since ammonia borane is a solid and ethane is a gas: their melting points differing by 284 °C.

  3. Boron trifluoride - Wikipedia

    en.wikipedia.org/wiki/Boron_trifluoride

    BF 3 is commonly referred to as "electron deficient," a description that is reinforced by its exothermic reactivity toward Lewis bases. In the boron trihalides, BX 3 , the length of the B–X bonds (1.30 Å) is shorter than would be expected for single bonds, [ 7 ] and this shortness may indicate stronger B–X π-bonding in the fluoride.

  4. Olefin metathesis - Wikipedia

    en.wikipedia.org/wiki/Olefin_metathesis

    The initial result was disappointing as reaction of CpTa(=CH−t−Bu)Cl 2 with ethylene yielded only a metallacyclopentane, not metathesis products: [44] But by tweaking this structure to a PR 3 Ta(CHt−bu)(Ot−bu) 2 Cl (replacing chloride by t-butoxide and a cyclopentadienyl by an organophosphine, metathesis was established with cis-2 ...

  5. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    [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.

  6. Ammonium fluoride - Wikipedia

    en.wikipedia.org/wiki/Ammonium_fluoride

    The reaction occurring is: NH 4 F + HF → NH 4 HF 2. Ammonium fluoride sublimes when heated—a property common among ammonium salts. In the sublimation, the salt decomposes to ammonia and hydrogen fluoride; the two gases can still recombine, i.e. the reaction is reversible: [NH 4]F ⇌ NH 3 + HF

  7. Tetrahedral molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Tetrahedral_molecular_geometry

    The bond angle for a symmetric tetrahedral molecule such as CH 4 may be calculated using the dot product of two vectors. As shown in the diagram at left, the molecule can be inscribed in a cube with the tetravalent atom (e.g. carbon) at the cube centre which is the origin of coordinates, O. The four monovalent atoms (e.g. hydrogens) are at four ...

  8. Crossover experiment (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Crossover_experiment...

    Crossover experiments allow for experimental study of a reaction mechanism. Mechanistic studies are of interest to theoretical and experimental chemists for a variety of reasons including prediction of stereochemical outcomes, optimization of reaction conditions for rate and selectivity, and design of improved catalysts for better turnover number, robustness, etc. [6] [7] Since a mechanism ...

  9. Molecular orbital diagram - Wikipedia

    en.wikipedia.org/wiki/Molecular_orbital_diagram

    MO diagram of dihydrogen Bond breaking in MO diagram. The smallest molecule, hydrogen gas exists as dihydrogen (H-H) with a single covalent bond between two hydrogen atoms. As each hydrogen atom has a single 1s atomic orbital for its electron, the bond forms by overlap of these two atomic orbitals. In the figure the two atomic orbitals are ...