On Molecular Orbital Correlation Diagrams, the Occurrence of Möbius Systems in Cyclization Reactions, and Factors Controlling Ground- and Excited-State Reactions. I

1966 ◽  
Vol 88 (7) ◽  
pp. 1564-1565 ◽  
Author(s):  
Howard E. Zimmerman
Keyword(s):  
Excited State ◽  
Molecular Orbital ◽  
Cyclization Reactions ◽  
Orbital Correlation

Resolving the Quadruple Bonding Conundrum in C2 Using Insights Derived from Excited State Potential Energy Surfaces: A Molecular Orbital Perspective

2019 ◽  
Author(s):  
Ishita Bhattacharjee ◽  
Debashree Ghosh ◽  
Ankan Paul
Keyword(s):  
Excited State ◽  
Potential Energy ◽  
Molecular Orbital ◽  
High Spin ◽  
Potential Energy Surfaces ◽  
Valence Bond ◽  
Deep Minimum ◽  
State Potential ◽  
Energy Surfaces ◽  
Mo Theory

The question of quadruple bonding in C<sub>2</sub> has emerged as a hot button issue, with opinions sharply divided between the practitioners of Valence Bond (VB) and Molecular Orbital (MO) theory. Here, we have systematically studied the Potential Energy Curves (PECs) of low lying high spin sigma states of C<sub>2</sub>, N<sub>2</sub> and Be<sub>2</sub> and HC≡CH using several MO based techniques such as CASSCF, RASSCF and MRCI. The analyses of the PECs for the<sup> 2S+1</sup>Σ<sub>g/u</sub> (with 2S+1=1,3,5,7,9) states of C<sub>2</sub> and comparisons with those of relevant dimers and the respective wavefunctions were conducted. We contend that unlike in the case of N<sub>2</sub> and HC≡CH, the presence of a deep minimum in the <sup>7</sup>Σ state of C<sub>2</sub> and CN<sup>+</sup> suggest a latent quadruple bonding nature in these two dimers. Hence, we have struck a reconciliatory note between the MO and VB approaches. The evidence provided by us can be experimentally verified, thus providing the window so that the narrative can move beyond theoretical conjectures.

Interpretation of excited state Hartree–Fock analytic derivative anomalies for NO2 and HCO2 using the molecular orbital Hessian

1991 ◽  
Vol 95 (10) ◽  
pp. 7466-7478 ◽  
Author(s):  
Neil A. Burton ◽  
Yukio Yamaguchi ◽  
Ian L. Alberts ◽  
Henry F. Schaefer
Keyword(s):  
Excited State ◽  
Molecular Orbital ◽  
Hartree Fock

Decomposition Mechanism of 1,2-Dioxetane

1974 ◽  
Vol 52 (23) ◽  
pp. 3837-3843 ◽  
Author(s):  
Gene Barnett
Keyword(s):  
Thermal Decomposition ◽  
Molecular Orbital ◽  
Equilibrium Structure ◽  
Decomposition Mechanism ◽  
Correlation Diagram ◽  
Molecular Orbital Calculations ◽  
Temperature Dependent ◽  
Planar Configuration ◽  
Orbital Correlation

An orbital correlation diagram was constructed for the thermal decomposition of 1,2-dioxetane into products that allow chemiluminescence. A decomposition mechanism is proposed that gives a temperature dependent rupture of the OO bond, thus allowing ring twisting which is followed by the rupture of the CC bond. This mechanism is consistent with results of the thermochemical analysis for this type of reaction. The equilibrium structure of 1,2-dioxetane was determined from the molecular orbital calculations and gave a planar configuration for the COOC ring.

Sign in / Sign up

Export Citation Format

Share Document