Page 188 - Academic Press Encyclopedia of Physical Science and Technology 3rd Organic Chemistry
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                                           Organic Chemical Systems,



                                                                                            Theory






              Josef Michl

              University of Colorado



               I. Classical Bonding Theory
              II. Qualitative Molecular Orbital Model of Electronic
                 Structure
              III. Quantitative Aspects of Molecular Structure
              IV. Reaction Paths









              GLOSSARY                                            φ 1 and φ 2 is given by  φ 1 Hφ 2 dτ, where integration
                                                                  is over all space.
              Electron affinity Energy released when an electron is  Ionization potential Minimum energy that must be pro-
                brought from infinity and added to a molecule (it may  vided to a molecule in order to remove one of its elec-
                be negative if energy actually has to be provided).  trons to infinity.
              Electronegativity Measure of the tendency of an atom or  Ortho, meta, para Designation of relative positions of
                an orbital to attract and accommodate electron density.  two substituents on a benzene ring: located on adjacent
              Gradient of a surface The gradient at a point is a vector  ring carbons (ortho), on next-nearest-neighbor ring car-
                directed up the steepest slope of the surface at that  bons (meta), and on carbons across the ring from one
                point; its length is a measure of the slope.      another (para).
              Improper rotational axis of symmetry (of order n) A  Pauli principle A wave function describing the state of
                molecule is said to possess such an axis located in a  a system containing two or more electrons is antisym-
                particular direction if rotation by an angle 2π/n about  metric with respect to the exchange of all coordinates
                that direction, followed by mirroring in a plane perpen-  of any two electrons (i.e., is converted to minus itself
                dicular to the direction, converts the molecule back to  on such an exchange). One of the consequences is that
                itself.                                           two electrons of the same spin cannot reside in the same
              Inner-shell electrons Electrons in orbitals of energy  orbital.
                lower than that of the valence shell (closer to the
                nucleus).
              Interaction matrix element The interaction matrix ele-  THE THEORY of organic chemistry deals with the funda-
                ment of the Hamiltonian H between wave functions  mental concepts that underlie and unify the experimental



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