Browsing by Author "RIECKHOFF, KE"

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DOUBLE FLUORESCENCE LIFETIMES OF METAL-FREE PHTHALOCYANINE IN A MIXED-SOLVENT SHPOLSKII MATRIX AT 4.2K
(1989-08-20)
CHEN, WH
;
RIECKHOFF, KE
;
VOIGT, EM
;
THEWALT, MLW
;
電子物理學系
ELECTRONIC-SPECTRA AND PHOTOCHEMICAL TRANSFORMATION OF TERTIARY BUTYLPHTHALOCYANINE IN SHPOLSKII MATRICES
(1991)
CHEN, WH
;
HU, YY
;
RIECKHOFF, KE
;
VOIGT, EM
;
電子物理學系
Electronic spectral properties of tertiary butylphthalocyanine (TBH2Pc) in a 4.2 K n-hexadecane (C-16) matrix were investigated. A clear doublet in the 0-0 fluorescence region was recorded, representing a approximately 20 cm-1 Stokes shift due to a different proton geometry (molecular tautomerism) in the centre of the molecule. Photochemical interconversion between the tautomers was studied by the intensity variation of fluorescence bands as a function of time. The transformation saturated in several tens to two hundreds of milliseconds under our pumping conditions. Similar investigations of the complex in solid n-octadecane (C18) were also carried out on a less detailed scale. The results were compared with those for free base phthalocyanine (H2Pc) in a mixed solvent matrix of alpha-chloronaphthalene (alpha-ClN) and n-octane (C-8).
ELECTRONIC-SPECTRA AND ZEEMAN EFFECT OF RUTHENIUM PHTHALOCYANINE IN SHPOLSKII MATRICES
(1989-10-10)
CHEN, WH
;
HUANG, TH
;
RIECKHOFF, KE
;
VOIGT, EM
;
光電工程學系
PHOTOCHEMICAL TRANSFORMATION OF METAL-FREE PHTHALOCYANINE IN A SHPOLSKII MATRIX
(1990)
CHEN, WH
;
RIECKHOFF, KE
;
VOIGT, EM
;
電子物理學系
;
Department of Electrophysics
TAUTOMERIC RELAXATION RATES IN THE GROUND-STATE OF TETRA-4-TERTIARY BUTYLPHTHALOCYANINE IN SHPOLSKII MATRICES
(1994-04-01)
CHEN, WH
;
GAO, J
;
RIECKHOFF, KE
;
VOIGT, EM
;
電子物理學系
We report experimental results of the ground state proton tunneling rate constant k in the absence of radiation to be from 0.03 to 0.35 s-1 at temperatures from 4.2 to 77 K for tetra-4-tertiary butylphthalocyanine tautomers embedded in hexadecane matrices. While a detailed microscopic description of the exact transfer mechanism is not possible from the data obtained so far, we present a model based on a new type of potential barrier and use the semiclassical WKB approximation to calculate transmission data compatible with experiment.