Photoeffects in thin-film molecular-level chromophore-quencher assemblies. 1. Physical characterization

Journal Article · Wed Jan 11 23:00:00 EST 1989 · Journal of Physical Chemistry; (USA)

DOI:https://doi.org/10.1021/j100338a060· OSTI ID:5447016

Surridge, N A; McClanahan, S F; Hupp, J T; Danielson, E; Gould, S; Meyer, T J ^[1]

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1. Univ. of North Carolina, Chapel Hill (USA)

Molecular-level chromophore-quencher assemblies have been prepared in precast chlorosulfonated polystyrene ((-CH{sub 2}CH(p-C{sub 6}H{sub 4}SO{sub 2}Cl)){sub x}-; PS-SO{sub 2}Cl) films by (1) exposing the intact film to solutions containing the chromophore ((bpy){sub 2}Ru(5-NH{sub 2}phen))(PF{sub 6}){sub 2} (bpy is 2,2{prime}-bipyridine; 5-NH{sub 2}phen is 5-amino-1,10-phenanthroline) which becomes chemically bond through sulfonamide bond formation, (2) partially hydrolyzing a portion of the remaining -SO{sub 2}Cl sites to -SO{sub 3}- sites and exposing the resulting films to acetonitrile solutions containing the electron-transfer quencher paraquat (PQ{sup 2+}) and the reductive scavenger triethanolamine (N(C{sub 2}H{sub 4}OH){sub 3}). The photophysical properties of the chromophore-based metal-to-ligand charge-transfer excited state have been investigated by lifetime and visible absorption and emission spectra. Although similar to related monomers, excited-state decay in the films is nonexponential. The dynamics of excited-state quenching by PQ{sup 2+} following pulsed laser excitation show that the chromophore occupies three different chemical sites within the films. At one site, which accounts for {approx}50% of the emitted light and appears to be located near ion channels created by hydrolysis, quenching is rapid, K{sub SV} {approx} 6.8 {times} 10{sup 4} M{sup {minus}1}. A second site exists that undergoes relatively slow quenching, K{sub SV} {approx} 3 {times} 10{sup 3} M{sup {minus}1}, and then only with added (NEt{sub 4})(ClO{sub 4}). A third site is present that is not quenched.

• DOE Contract Number: AS05-78ER06034
• OSTI ID: 5447016
• Journal Information: Journal of Physical Chemistry; (USA), Journal Name: Journal of Physical Chemistry; (USA) Vol. 93:1; ISSN 0022-3654; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400500* -- Photochemistry
CHEMICAL REACTIONS
DATA
ELECTRON TRANSFER
ENERGY LEVELS
EXCITED STATES
EXPERIMENTAL DATA
INFORMATION
MATERIALS
NUMERICAL DATA
ORGANIC CHLORINE COMPOUNDS
ORGANIC COMPOUNDS
ORGANIC HALOGEN COMPOUNDS
ORGANIC POLYMERS
ORGANIC SULFUR COMPOUNDS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHOTOCHEMICAL REACTIONS
PLASTICS
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
SYNTHETIC MATERIALS