2026-09-21T23:30:33Z https://www.ideals.illinois.edu/oai-pmh

oai:www.ideals.illinois.edu:2142/69725 2023-07-11 col_2142_5131 col_2142_11615 com_2142_5130 com_2142_9130 com_2142_8903

Thomas, Michele Moisio 2014-12-15T19:54:05Z 2014-12-15T19:54:05Z 10000-01-01 1981 1981 High pressure fluorescence studies from 0 - 10 kilobars have been performed on electron donor-acceptor (EDA) complexes of s-tetracyanobenzene (TCNB) with a series of aromatic hydrocarbons. Four solvents were used, 2,2,4,4,6,8,8-heptamethylnonane (HMN), methylcyclohexane (MCH), 2,6,10,14-tetramethylpentadecane (TMPD), and a mixture of MCH and HMN. A viscosity range from 0.006 to 10,000 poise was covered at two temperatures, 0(DEGREES)C and 25(DEGREES)C. As pressure (viscosity) increased the fluorescence spectrum shifted from one dominated by emission from the equilibrium (EQ) excited singlet state to one dominated by Franck-Condon (FC) singlet emission. Lifetime measurements for the complexes of o-xylene and p-xylene with TCNB yielded the two radiative rates (k(,EQ) and k(,FC)) as well as the rate of relaxation from FC to the EQ excited state (k(,RE)). k(,RE) was found to correlate well with viscosity and to be independent of temperature at constant viscosity, indicating that the relaxation process is diffusion controlled. Made available in DSpace on 2014-12-15T19:54:05Z (GMT). No. of bitstreams: 1 8203614.pdf: 1741810 bytes, checksum: 917f7c0843e41c2735aa05aec0757c41 (MD5) Previous issue date: 1981 Embargo set by: Seth Robbins for item 69891 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs U of I Only 64 p. Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1981. http://hdl.handle.net/2142/69725 (UMI)AAI8203614 Chemistry, Physical High Pressure Study of Viscosity Effects on the Luminescence of Some S-Tetracyanobenzene Eda Complexes text Chemical Engineering Chemical Engineering University of Illinois at Urbana-Champaign Dissertation Ph.D.