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The Hill system (or Hill notation) is a system of writing empirical chemical formulae, molecular chemical formulae and components of a condensed formula such that the number of carbon atoms in a molecule is indicated first, the number of hydrogen atoms next, and then the number of all other chemical elements subsequently, in alphabetical order ...
Computer models of CB[5], CB[6], and CB[7]. Top row is the view into the cavity and the bottom is the side view. In host–guest chemistry, cucurbiturils are macrocyclic molecules made of glycoluril (=C 4 H 2 N 4 O 2 =) monomers linked by methylene bridges (−CH 2 −).
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 for conversion back into two-dimensional drawings or three-dimensional models of the molecules.
The finite group notation used is: Z n: cyclic group of order n, D n: dihedral group isomorphic to the symmetry group of an n–sided regular polygon, S n: symmetric group on n letters, and A n: alternating group on n letters. The character tables then follow for all groups.
The Leatherface program [11] is a general purpose molecule editor which allows automated modification of a number of substructural features of molecules in databases, including protonation state, hydrogen count, formal charge, isotopic weight and bond order. The molecular editing rules used by Leatherface are defined in SMARTS.
Skeletal structural formula of Vitamin B 12.Many organic molecules are too complicated to be specified by a molecular formula.. The structural formula of a chemical compound is a graphic representation of the molecular structure (determined by structural chemistry methods), showing how the atoms are connected to one another. [1]
One can subdivide chemical compounds into two main groups: molecules, which includes most organic, polyatomic gases, and organometallic compounds, and nonmolecular species, which includes most purely inorganic compounds. The structures of many reagents are often misunderstood because simplified formulas are presented in reaction schemes whereas ...
The η-notation is encountered in many coordination compounds: Side-on bonding of molecules containing σ-bonds like H 2: W(CO) 3 (P i Pr 3) 2 (η 2-H 2) [8] [9] Side-on bonded ligands containing multiple bonded atoms, e.g. ethylene in Zeise's salt or with fullerene, which is bonded through donation of the π-bonding electrons: K[PtCl 3 (η 2-C ...