T-shaped molecular geometryIn chemistry, T-shaped molecular geometry describes the structures of some molecules where a central atom has three ligands. Ordinarily, three-coordinated compounds adopt trigonal planar or pyramidal geometries. Examples of T-shaped molecules are the halogen trifluorides, such as ClF3. According to VSEPR theory, T-shaped geometry results when three ligands and two lone pairs of electrons are bonded to the central atom, written in AXE notation as AX3E2.
Square antiprismIn geometry, the square antiprism is the second in an infinite family of antiprisms formed by an even-numbered sequence of triangle sides closed by two polygon caps. It is also known as an anticube. If all its faces are regular, it is a semiregular polyhedron or uniform polyhedron. A nonuniform D4-symmetric variant is the cell of the noble square antiprismatic 72-cell. When eight points are distributed on the surface of a sphere with the aim of maximising the distance between them in some sense, the resulting shape corresponds to a square antiprism rather than a cube.
Bent's ruleIn chemistry, Bent's rule describes and explains the relationship between the orbital hybridization of central atoms in molecules and the electronegativities of substituents. The rule was stated by Henry A. Bent as follows: Atomic s character concentrates in orbitals directed toward electropositive substituents. The chemical structure of a molecule is intimately related to its properties and reactivity. Valence bond theory proposes that molecular structures are due to covalent bonds between the atoms and that each bond consists of two overlapping and typically hybridised atomic orbitals.
Xenon difluorideXenon difluoride is a powerful fluorinating agent with the chemical formula XeF2, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with water vapor, but is otherwise stable in storage. Xenon difluoride is a dense, colourless crystalline solid. It has a nauseating odour and low vapor pressure. Xenon difluoride is a linear molecule with an Xe–F bond length of 197.73pm in the vapor stage, and 200 pm in the solid phase.
Bicapped trigonal prismatic molecular geometryIn chemistry, the bicapped trigonal prismatic molecular geometry describes the shape of compounds where eight atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a biaugmented triangular prism. This shape has C2v symmetry and is one of the three common shapes for octacoordinate transition metal complexes, along with the square antiprism and the dodecahedron. It is very similar to the square antiprismatic molecular geometry, and there is some dispute over the specific geometry exhibited by certain molecules.
Ball-and-stick modelIn chemistry, the ball-and-stick model is a molecular model of a chemical substance which displays both the three-dimensional position of the atoms and the bonds between them. The atoms are typically represented by spheres, connected by rods which represent the bonds. Double and triple bonds are usually represented by two or three curved rods, respectively, or alternately by correctly positioned sticks for the sigma and pi bonds.
Dioxygen difluorideDioxygen difluoride is a compound of fluorine and oxygen with the molecular formula O2F2. It can exist as an orange-colored solid which melts into a red liquid at . It is an extremely strong oxidant and decomposes into oxygen and fluorine even at at a rate of 4% per dayits lifetime at room temperature is thus extremely short. Dioxygen difluoride reacts vigorously with nearly every chemical it encounters (including ordinary ice) leading to its onomatopoeic nickname FOOF (a play on its chemical structure and its explosive tendencies).
Capped octahedral molecular geometryIn chemistry, the capped octahedral molecular geometry describes the shape of compounds where seven atoms or groups of atoms or ligands are arranged around a central atom defining the vertices of a gyroelongated triangular pyramid. This shape has C3v symmetry and is one of the three common shapes for heptacoordinate transition metal complexes, along with the pentagonal bipyramid and the capped trigonal prism. Examples of the capped octahedral molecular geometry are the heptafluoromolybdate (MoF7−) and the heptafluorotungstate (WF7−) ions.
Sulfur hexafluorideSulfur hexafluoride or sulphur hexafluoride (British spelling) is an inorganic compound with the formula SF6. It is a colorless, odorless, non-flammable, and non-toxic gas. SF6 has an octahedral geometry, consisting of six fluorine atoms attached to a central sulfur atom. It is a hypervalent molecule. Typical for a nonpolar gas, SF6 is poorly soluble in water but quite soluble in nonpolar organic solvents. It has a density of 6.12 g/L at sea level conditions, considerably higher than the density of air (1.
Pentagonal bipyramidal molecular geometryIn chemistry, a pentagonal bipyramid is a molecular geometry with one atom at the centre with seven ligands at the corners of a pentagonal bipyramid. A perfect pentagonal bipyramid belongs to the molecular point group D5h. The pentagonal bipyramid is a case where bond angles surrounding an atom are not identical (see also trigonal bipyramidal molecular geometry). This is one of the three common shapes for heptacoordinate transition metal complexes, along with the capped octahedron and the capped trigonal prism.
