Abstract
The paper presents a summary and extension of some of the recently published work on increased-valence theory. For four-electron three-centre bonding units, increased-valence structures 2 and 4 may be derived from the Lewis structures 1 and 3 by means of the one-electron delocalizations that are indicated in the latter structures. ▪ The three bonding electrons in each of the structures 2 and 4 occupy non-orthogonal two-centre bonding molecular orbitals, and the A atom contributes only one atomic orbital to the bonding scheme. It is demonstrated that the A-atom valence is able to exceed unity in each of these structures when the valence is calculated according to a Wiberg-type procedure. Increased-valence structures are used to illustrate how electronic reorganization may proceed for radical transfer, thermal decomposition and cycloaddition reactions that involve the 1,3-dipolar molecule N 2O, and gas-phase S N2 reactions. A relationship is established between increased-valence and approximate molecular orbital descriptions of hydrogen bonding.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
