When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. Lewis acids and bases - Wikipedia

    en.wikipedia.org/wiki/Lewis_acids_and_bases

    A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may ...

  3. Lewis structure - Wikipedia

    en.wikipedia.org/wiki/Lewis_structure

    Lewis structures – also called Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures (LEDs) – are diagrams that show the bonding between atoms of a molecule, as well as the lone pairs of electrons that may exist in the molecule. [1][2][3] A Lewis structure can be drawn for any covalently bonded ...

  4. Radical (chemistry) - Wikipedia

    en.wikipedia.org/wiki/Radical_(chemistry)

    Lewis dot structure of a Hydroxide ion compared to a hydroxyl radical. In chemistry, a radical, also known as a free radical, is an atom, molecule, or ion that has at least one unpaired valence electron. [1][2] With some exceptions, these unpaired electrons make radicals highly chemically reactive. Many radicals spontaneously dimerize.

  5. Adduct - Wikipedia

    en.wikipedia.org/wiki/Adduct

    A good example is the formation of adducts between the Lewis acid borane and the oxygen atom in the Lewis bases, tetrahydrofuran (THF): BH 3 ·O(CH 2) 4 or diethyl ether: BH 3 ·O(CH 3 CH 2) 2. Many Lewis acids and Lewis bases reacting in the gas phase or in non-aqueous solvents to form adducts have been examined in the ECW model . [ 3 ]

  6. Gilbert N. Lewis - Wikipedia

    en.wikipedia.org/wiki/Gilbert_N._Lewis

    Gilbert Newton Lewis ForMemRS [1] (October 23 [2][3][4] or October 25, 1875 – March 23, 1946) [1][5][6] was an American physical chemist and a dean of the college of chemistry at University of California, Berkeley. [3][7] Lewis was best known for his discovery of the covalent bond and his concept of electron pairs; his Lewis dot structures ...

  7. Frustrated Lewis pair - Wikipedia

    en.wikipedia.org/wiki/Frustrated_Lewis_pair

    Non-nucleophilic. Weak. v. t. e. A frustrated Lewis pair (FLP) is a compound or mixture containing a Lewis acid and a Lewis base that, because of steric hindrance, cannot combine to form a classical adduct. [1] Many kinds of FLPs have been devised, and many simple substrates exhibit activation. [2][3] The discovery that some FLPs split H 2[4 ...

  8. 1,5-Diazabicyclo (4.3.0)non-5-ene - Wikipedia

    en.wikipedia.org/wiki/1,5-Diazabicyclo(4.3.0)non...

    Infobox references. 1,5-Diazabicyclo [4.3.0]non-5-ene (DBN) is a chemical compound with the formula C 7 H 12 N 2. [1] It is an amidine base used in organic synthesis. A related compound with related functions is 1,8-diazabicyclo [5.4.0]undec-7-ene (DBU). The relatively complex nature of the formal names for DBU and DBN (hence the common use of ...

  9. Simplified Molecular Input Line Entry System - Wikipedia

    en.wikipedia.org/wiki/Simplified_Molecular_Input...

    SMILES generation algorithm for ciprofloxacin: break cycles, then write as branches off a main backbone. The Simplified Molecular Input Line Entry System (SMILES) is a specification in the form of a line notation for describing the structure of chemical species using short ASCII strings. SMILES strings can be imported by most molecule editors ...