The general structure of a tetrahedral molecule, with the central atom labelled pink.

In a tetrahedral molecular geometry a central atom is located at the center with four substituents located at the corners of a tetrahedron. The bond angles are cos^-1(-1/3) ≈ 109.5°. When all four substituents are the same and it is a perfect tetrahedron then it belongs to point group T_d. This molecular geometry is found for saturated compounds of carbon and silicon. Some other molecules and ions with this particular geometry include the xenon tetroxide molecule XeO₄, the perchlorate ion ClO₄^-, the sulfate ion SO₄^2-, the phosphate ion PO₄^3- and tetrakis(triphenylphosphine)palladium(0). My feeble attempt at drawing methane in terms of structure File links The following pages link to this file: Orbital hybridisation Categories: GFDL images ... “Atomic” redirects here. ... In organic chemistry, a substituent is an atom or group of atoms substituted in place of a hydrogen atom on the parent chain of a hydrocarbon. ... A tetrahedron (plural: tetrahedra) is a polyhedron composed of four triangular faces, three of which meet at each vertex. ... Geometry of the water molecule Molecules have fixed equilibrium geometries--bond lengths and angles--that are dictated by the laws of quantum mechanics. ... In mathematics, point group is a group of geometric symmetries (isometries) leaving a point fixed. ... Geometry of the water molecule Molecular geometry or molecular structure is the three dimensional arrangement of the atoms that constitute a molecule, inferred from the spectroscopic studies of the compound. ... Look up Saturation in Wiktionary, the free dictionary. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number silicon, Si, 14 Chemical series metalloids Group, Period, Block 14, 3, p Appearance as coarse powder, dark gray with bluish tinge Atomic mass 28. ... Xenon tetroxide (molecular formula XeO4) is a yellow crystalline solid that is stable below -35. ... Perchlorates are the salts derived from perchloric acid (HClO4). ... In inorganic chemistry, a sulfate (IUPAC-recommended spelling; also sulphate in British English) is a salt of sulfuric acid. ... Above is a ball-and-stick model of the inorganic hydrogenphosphate anion (HPO42−). Colour coding: P (orange); O (red); H (white). ... Tetrakis(triphenylphosphine)palladium(0) is the chemical compound Pd[P(C6H5)3]4, often abbreviated Pd(PPh3)4, or even PdP4. ...

Inverted tetrahedral geometry

Geometrical constraints in a molecule may cause a severe distortion of a tetrahedral geometry towards an inverted one. In inverted carbon for instance all 4 substituents are now on the same side ^[1].

organic molecules displaying inverted carbon are tetrahedranes and propellanes. The penalty usually is increase in strain energy for the molecule resulting in increased reactivity. Tetrahedrane is a hypothetical hydrocarbon with chemical formula C4H4 and a tetrahedral structure. ... In a molecule, strain energy is released when the constituent atoms are allowed to rearrange themselves in a chemical reaction or a change of chemical conformation in a way that: angle strain, torsional strain, ring strain and/or steric strain, Allylic strain, and pentane interference are reduced [1] . For example...

Note that inversion also takes place in so-called Walden inversion and nitrogen inversion but with different meanings. In chemistry Walden inversion is the inversion of configuration of a chiral centre in a molecule in a chemical reaction. ... In chemistry, a nitrogen compound like ammonia in a trigonal pyramid geometry undergoes rapid nitrogen inversion whereby the molecule turns inside out. ...

Planarization

A tetrahedron can also be distorted by increasing the angle between the two opposite bonds (again by force) resulting in the extreme case in complete flattening. For carbon this phenomenon can be observed in a class of compounds called the fenestranes. A fenestrane in organic chemistry is a type of chemical compound with a central quaternary carbon atom which serves as a common vertex for four fused carbocycles [1]. They can be regarded as spiro compounds twice over. ...

See also

• The other molecular geometries are collected according to the AXE method.

In chemistry, The AXE method is commonly used in formatting molecules to fit the VSEPR model that aims to explain molecular geometry. ...

References

1. ^ Inverted geometries at carbon Kenneth B. Wiberg Acc. Chem. Res.; 1984; 17(11) pp 379 - 386; DOI:10.1021/ar00107a001

Accounts of Chemical Research (usually abbreviated as ) is a peer-reviewed scientific journal, published since 1968 by the American Chemical Society. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ...

External links

• Further reading
• Further reading