Global Molecular Identification from Graphs. IV. Molecules with Four Closed p-Shell Atoms and beyond

• Published in: Croatica Chemica Acta Vol. 77; no. 1-2; p. 65
• Main Authors: J. Walters, Chris, Caviness, Ken, A. Hefferlin, Ray
• Format: Paper
• Language: English
• Published: Hrvatsko kemijsko društvo 31-05-2004
• Subjects: bonding; chemical space; data mining; graphs; Lewis diagrams; molecules with closed-shell atoms; octet rule; stoichiometric molecules
• ISSN: 0011-1643; 1334-417X

The identification of main-group molecules having atoms with closed valence p shells, i.e., having atoms with eight valence electrons, is continued into the realm of four-atom molecules. All possible covalently-bonded species, obtained from two independent computer programs, are shown. The method for generalizing to molecules in which some or all atoms have closed valence s shells, i.e., having atoms with two valence electrons, is recalled. A list of all prototype linear/bent four-atom molecules, with dative bonds in addition to covalent and/or van der Waals bonds, is presented (permutations having been culled out). A program code, lists of molecules based on other graphs, and lists of five- and covalently-bonded six-atom species, are available on the Web. For molecules derived from the two other four-vertex graphs, their vast numbers require extensive indexing schemes for the results to be useful. The paper concludes with some preliminary observations concerning the stabilities of four-atom molecules having atoms with closed shells.