Professor McBride uses a hexagonal "benzene" pattern and Franklin's X-ray pattern of DNA, to continue his discussion of X-ray crystallography by explaining how a diffraction pattern in "reciprocal space" relates to the distribution of electrons in molecules and to the repetition of molecules in a crystal lattice. He then uses electron difference density mapping to reveal bonds, and unshared electron pairs, and their shape, and to show that they are only one-twentieth as dense as would be expected for Lewis shared pairs. Anomalous difference density in the carbon-fluorine bond raises the course's second great question, "Compared to what?"
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.
As one of the world's great universities, Yale traces its roots back to the early 1640s when colonial clergyman sought to establish a school in order to continue the tradition of European education within the Americas. Yale has now grown to educate over 11,000 students from over 100 countries on a 310-acre campus in New Haven, Connecticut. Within the school's 260 buildings are over 2,000 undergraduate programs in 65 departments taught by a distinguished faculty. As Academic Earth's first partner school, Yale has been a leader within the space of OpenCourseWare by consistently delivering on its esteemed mission to expand access to educational materials for all who wish to learn.