Yale University Organic Chemistry Course, Lecture 2
Course
ORGANIC CHEMISTRY
This is the first semester in a two-semester introductory course focused on current theories of structure and mechanism in organic chemistry, their historical development, and their basis in experimental observation. The course is open to freshmen with excellent preparation in chemistry and physics, and it aims to develop both taste for original science and intellectual skills necessary for creative research.
LECTURE 2: «Force Laws, Lewis Structures and Resonance»
Professor McBride begins by following Newton’s admonition to search for the force law that describes chemical bonding. Neither direct (Hooke’s Law) nor inverse (Coulomb, Gravity) dependence on distance will do – a composite like the Morse potential is needed. G. N. Lewis devised a «cubic-octet» theory based on the newly discovered electron, and developed it into a shared pair model to explain bonding. After discussing Lewis-dot notation and formal charge, Professor McBride shows that in some «single-minimum» cases the Lewis formalism is inadequate and salvaging it required introducing the confusing concept of «resonance.»
{$ noItemsMessage $}