@article {3742, title = {On the conformational analysis and photochemical reactivity of 1,6-cyclodecanedione}, journal = {Molecular Crystals and Liquid Crystals Science and Technology Section a-Molecular Crystals and Liquid Crystals}, volume = {276}, year = {1996}, note = {ISI Document Delivery No.: UJ432Times Cited: 0Cited Reference Count: 2712th International Conference on the Chemistry of the Organic Solid State (ICCOSS XII)JUL 09-14, 1995MATSUYAMA, JAPANMinist Educ, Japan, Ehime Univ, Chem Soc Japan, Soc Synthet Organ Chem, Japan}, pages = {A289-A298}, type = {Proceedings Paper}, abstract = {Photolysis of 1,5-cyclodecanedione, both in the crystalline state and in solution, fails to lead to any Norrish/Yang type II products despite the fact that the conformation of the molecule in the solid state is nearly ideal for hydrogen atom abstraction. Based on X-ray crystal structure and molecular modeling studies, it is argued that gamma-hydrogen abstraction does occur in the solid state, but that closure of the resulting 1,4-biradical is slower than reverse hydrogen atom transfer owing to difficulty in forming the expected 8-membered ring-containing photoproduct. In solution, on the other hand, molecular mechanics calculations indicate that the lack of photoreactivity of 1,5-cyclodecanedione stems from the fact that this molecule exists nearly exclusively in a conformation for which gamma-hydrogen abstraction is sterically impossible.}, keywords = {ABSTRACTION, C-H...O, II REACTIONS, KETONES, MOLECULAR MECHANICS METHODOLOGY}, isbn = {1058-725X}, url = {://A1996UJ43200083}, author = {Lewis, T. J. and Rettig, S. J. and Sauers, R. R. and Scheffer, J. R. and Trotter, J. and Wu, C. H.} }