Topological Approach To The Chemistry Of Conjugated Molecules (lecture Notes In Chemistry)

"The second step is to determine constitution, Le. which atoms are bonded to which and by what types of bond. The result is ex­ pressed by a planar graph (or the corresponding connectivity mat­ rix) •••• In constitutional formulae, the atoms are represented by letters and the bonds by lines. They describe the topology of the molecule." VLADIMIR PRELOG, Nobel Lecture, December l2;h 1975. In the present notes we describe the topological approach to the che­ mistry of conjugated molecules using graph-theoretical concepts. Con­ jugatedstructures may be conveniently studied using planar and connec­ ted graphs because they reflect in the simple way the connectivity of their pi-centers. Connectivity is important topological property of a molecule which allows a conceptual qualitative understanding, via a non­ numerical analysis, of many chemical phenomena or at least that part of phenomenon which depends on topology. This would not be possible sole­ ly by means of numerical (molecular orbital) analysis. "The second step is to determine constitution, Le. which atoms are bonded to which and by what types of bond. The result is exƯ pressed by a planar graph (or the corresponding connectivity matƯ rix) " " In constitutional formulae, the atoms are represented by letters and the bonds by lines. They describe the topology of the molecule." VLADIMIR PRELOG, Nobel Lecture, December l2;h 1975. In the present notes we describe the topological approach to the cheƯ mistry of conjugated molecules using graph-theoretical concepts. ConƯ jugatedstructures may be conveniently studied using planar and connecƯ ted graphs because they reflect in the simple way the connectivity of their pi-centers. Connectivity is important topological property of a molecule which allows a conceptual qualitative understanding, via a nonƯ numerical analysis, of many chemical phenomena or at least that part of phenomenon which depends on topology. This would not be possible soleƯ ly by means of numerical (molecular orbital) analysis Front Matter....Pages I-IX Introduction....Pages 1-3 Graphs in Chemistry....Pages 4-47 Total pi-Electron Energy....Pages 48-78 Resonance Energy....Pages 79-94 Reactivity of Conjugated Structures....Pages 95-113 Conclusions....Pages 114-114 Literature....Pages 115-120 Back Matter....Pages 121-123