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  2. Furan - Wikipedia

    en.wikipedia.org/wiki/Furan

    Furan is a heterocyclic organic compound, consisting of a five-membered aromatic ring with four carbon atoms and one oxygen atom. Chemical compounds containing such rings are also referred to as furans. Furan is a colorless, flammable, highly volatile liquid with a boiling point close to room temperature.

  3. Thiophene - Wikipedia

    en.wikipedia.org/wiki/Thiophene

    Thiophene is considered to be aromatic, although theoretical calculations suggest that the degree of aromaticity is less than that of benzene. The "electron pairs" on sulfur are significantly delocalized in the pi electron system. As a consequence of its aromaticity, thiophene does not exhibit the properties seen for conventional sulfides. For ...

  4. Heterocyclic compound - Wikipedia

    en.wikipedia.org/wiki/Heterocyclic_compound

    Included are pyridine, thiophene, pyrrole, and furan. Another large class of organic heterocycles refers to those fused to benzene rings. For example, the fused benzene derivatives of pyridine, thiophene, pyrrole, and furan are quinoline, benzothiophene, indole, and benzofuran, respectively. The fusion of two benzene rings gives rise to a third ...

  5. Thiol - Wikipedia

    en.wikipedia.org/wiki/Thiol

    With metal ions, thiolates behave as ligands to form transition metal thiolate complexes. The term mercaptan is derived from the Latin mercurium captans (capturing mercury) [7] because the thiolate group bonds so strongly with mercury compounds. According to hard/soft acid/base (HSAB) theory, sulfur is a relatively soft (polarizable) atom. This ...

  6. Pyrrole - Wikipedia

    en.wikipedia.org/wiki/Pyrrole

    Pyrrole has a nutty odor. Pyrrole is a 5-membered aromatic heterocycle, like furan and thiophene. Unlike furan and thiophene, it has a dipole in which the positive end lies on the side of the heteroatom, with a dipole moment of 1.58 D. In CDCl 3, it has chemical shifts at 6.68 (H2, H5) and 6.22 (H3, H4).

  7. Spinel group - Wikipedia

    en.wikipedia.org/wiki/Spinel_group

    In this case, a three-fold rotoinversion with axis in the 111 direction is centred on the point (0, 0, 0) (where there is no ion) and can also be centred on the B ion at (1/2, 1/2, 1/2), and in fact every B ion is the centre of a three-fold rotoinversion (point group D 3d). Under this space group the two A positions are equivalent.

  8. Crystal field theory - Wikipedia

    en.wikipedia.org/wiki/Crystal_field_theory

    the nature of the metal ion. the metal's oxidation state. A higher oxidation state leads to a larger splitting relative to the spherical field. the arrangement of the ligands around the metal ion. the coordination number of the metal (i.e. tetrahedral, octahedral...) the nature of the ligands surrounding the metal ion.

  9. Organosulfur chemistry - Wikipedia

    en.wikipedia.org/wiki/Organosulfur_chemistry

    The resonance stabilization of thiophene is 29 kcal/mol (121 kJ/mol) compared to 20 kcal/mol (84 kJ/mol) for the oxygen analogue furan. The reason for this difference is the higher electronegativity for oxygen drawing away electrons to itself at the expense of the aromatic ring current.