TY - JOUR
T1 - Liquid Crystalline Solvents as Mechanistic Probes. IV. The Influence of Ordered Media on the Norrish Type II Photoprocesses in α‐Diketones
AU - Nerbonne, Jeanne M.
AU - Weiss, Richard G.
PY - 1979
Y1 - 1979
N2 - The Norrish II photoreactions of octane‐4,5‐dione (1) and 1,6‐diphenylhexane‐3,4‐dione (2) have been investigated at several temperatures and in isotropic and ordered (liquid crystalline) media. The sole photoproducts detected in all solvents are 1/1 diastereomeric mixtures of α‐hydroxycyclobutanones. The quantum yields for disappearance of 1 and 2 tend to decrease as the temperature increases in all media investigated. Whereas the quantum yield ratio for disappearance of 1 in cholesteric mesophases and hexane is greater than one, the ratio for disappearance of 2 is less than one. Possible explanations for these observations, based upon the influence of solvent order on solute conformational lability, are advanced.
AB - The Norrish II photoreactions of octane‐4,5‐dione (1) and 1,6‐diphenylhexane‐3,4‐dione (2) have been investigated at several temperatures and in isotropic and ordered (liquid crystalline) media. The sole photoproducts detected in all solvents are 1/1 diastereomeric mixtures of α‐hydroxycyclobutanones. The quantum yields for disappearance of 1 and 2 tend to decrease as the temperature increases in all media investigated. Whereas the quantum yield ratio for disappearance of 1 in cholesteric mesophases and hexane is greater than one, the ratio for disappearance of 2 is less than one. Possible explanations for these observations, based upon the influence of solvent order on solute conformational lability, are advanced.
UR - http://www.scopus.com/inward/record.url?scp=84985053392&partnerID=8YFLogxK
U2 - 10.1002/ijch.197900041
DO - 10.1002/ijch.197900041
M3 - Article
AN - SCOPUS:84985053392
SN - 0021-2148
VL - 18
SP - 266
EP - 271
JO - Israel Journal of Chemistry
JF - Israel Journal of Chemistry
IS - 3-4
ER -