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  2. Bond length - Wikipedia

    en.wikipedia.org/wiki/Bond_length

    The existence of a very long C–C bond length of up to 290 pm is claimed in a dimer of two tetracyanoethylene dianions, although this concerns a 2-electron-4-center bond. [4] [5] This type of bonding has also been observed in neutral phenalenyl dimers. The bond lengths of these so-called "pancake bonds" [6] are up to 305 pm.

  3. Metallic bonding - Wikipedia

    en.wikipedia.org/wiki/Metallic_bonding

    t. e. Metallic bonding is a type of chemical bonding that arises from the electrostatic attractive force between conduction electrons (in the form of an electron cloud of delocalized electrons) and positively charged metal ions. It may be described as the sharing of free electrons among a structure of positively charged ions (cations).

  4. Atomic spacing - Wikipedia

    en.wikipedia.org/wiki/Atomic_spacing

    In solid materials, the atomic spacing is described by the bond lengths of its atoms. In ordered solids, the atomic spacing between two bonded atoms is generally around a few ångströms (Å), which is on the order of 10 −10 meters (see Lattice constant). However, in very low density gases (for example, in outer space) the average distance ...

  5. Crystal structure - Wikipedia

    en.wikipedia.org/wiki/Crystal_structure

    Crystal structure of table salt (sodium in purple, chlorine in green) In crystallography, crystal structure is a description of ordered arrangement of atoms, ions, or molecules in a crystalline material. [1] Ordered structures occur from intrinsic nature of constituent particles to form symmetric patterns that repeat along the principal ...

  6. Hydrogen bond - Wikipedia

    en.wikipedia.org/wiki/Hydrogen_bond

    A symmetric hydrogen bond is a special type of hydrogen bond in which the proton is spaced exactly halfway between two identical atoms. The strength of the bond to each of those atoms is equal. It is an example of a three-center four-electron bond. This type of bond is much stronger than a "normal" hydrogen bond.

  7. Quadruple bond - Wikipedia

    en.wikipedia.org/wiki/Quadruple_bond

    A quadruple bond is a type of chemical bond between two atoms involving eight electrons. This bond is an extension of the more familiar types of covalent bonds: double bonds and triple bonds. [1] Stable quadruple bonds are most common among the transition metals in the middle of the d-block, such as rhenium, tungsten, technetium, molybdenum and ...

  8. Bond valence method - Wikipedia

    en.wikipedia.org/wiki/Bond_valence_method

    The bond valence method or mean method (or bond valence sum) (not to be mistaken for the valence bond theory in quantum chemistry) is a popular method in coordination chemistry to estimate the oxidation states of atoms. It is derived from the bond valence model, which is a simple yet robust model for validating chemical structures with ...

  9. Metal–metal bond - Wikipedia

    en.wikipedia.org/wiki/Metalmetal_bond

    An example of a metalmetal bond is found in dimanganese decacarbonyl, Mn 2 (CO) 10. As confirmed by X-ray crystallography, a pair of Mn(CO) 5 units are linked by a bond between the Mn atoms. The Mn-Mn distance (290 pm) is short. [3] Mn 2 (CO) 10 is a simple and clear case of a metal-metal bond because no other atoms tie the two Mn atoms ...