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  2. Phosphonium - Wikipedia

    en.wikipedia.org/wiki/Phosphonium

    Phosphonium ion Structure of PH + 4, the parent phosphonium cation. In chemistry, the term phosphonium (more obscurely: phosphinium) describes polyatomic cations with the chemical formula PR + 4 (where R is a hydrogen or an alkyl, aryl, organyl or halogen group). These cations have tetrahedral structures.

  3. Allotropes of phosphorus - Wikipedia

    en.wikipedia.org/wiki/Allotropes_of_phosphorus

    It would appear that violet phosphorus is a polymer of high relative molecular mass, which on heating breaks down into P 2 molecules. On cooling, these would normally dimerize to give P 4 molecules (i.e. white phosphorus) but, in a vacuum , they link up again to form the polymeric violet allotrope.

  4. Chemical structure - Wikipedia

    en.wikipedia.org/wiki/Chemical_structure

    Phosphorus pentoxide chemical structure in 2D. A chemical structure of a molecule is a spatial arrangement of its atoms and their chemical bonds. Its determination includes a chemist's specifying the molecular geometry and, when feasible and necessary, the electronic structure of the target molecule or other solid.

  5. VSEPR theory - Wikipedia

    en.wikipedia.org/wiki/VSEPR_theory

    On the other hand, there are only three outer atoms. This is referred to as an AX 3 E type molecule because the lone pair is represented by an E. [1]: 410–417 By definition, the molecular shape or geometry describes the geometric arrangement of the atomic nuclei only, which is trigonal-pyramidal for NH 3. [1]: 410–417

  6. Square antiprismatic molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Square_antiprismatic...

    An example of a molecular species with square prismatic geometry (a slightly flattened cube) is octafluoroprotactinate(V), [PaF 8] 3–, as found in its sodium salt, Na 3 PaF 8. [6] While local cubic 8-coordination is common in ionic lattices (e.g., Ca 2+ in CaF 2 ), and some 8-coordinate actinide complexes are approximately cubic, there are no ...

  7. Trigonal pyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Trigonal_pyramidal...

    3, and the sulfite ion, SO 2− 3. In organic chemistry, molecules which have a trigonal pyramidal geometry are sometimes described as sp 3 hybridized. The AXE method for VSEPR theory states that the classification is AX 3 E 1. Phosphine, an example of a molecule with a trigonal pyramidal geometry.

  8. Trigonal bipyramidal molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Trigonal_bipyramidal...

    Finally, the triiodide ion (I − 3) is also based upon a trigonal bipyramid, but the actual molecular geometry is linear with terminal iodine atoms in the two axial positions only and the three equatorial positions occupied by lone pairs of electrons (AX 2 E 3); another example of this geometry is provided by xenon difluoride, XeF 2.

  9. Square planar molecular geometry - Wikipedia

    en.wikipedia.org/wiki/Square_planar_molecular...

    Structure of cisplatin, an example of a molecule with the square planar coordination geometry. In chemistry, the square planar molecular geometry describes the stereochemistry (spatial arrangement of atoms) that is adopted by certain chemical compounds. As the name suggests, molecules of this geometry have their atoms positioned at the corners.