Squaraine photophysics in polymer films

Journal Article · Thu Nov 03 04:00:00 EST 1994 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100095a043· OSTI ID:6735778

Scott, G W; Tran, K ^[1]

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1. Univ. of California, Riverside, CA (United States)

Absorption and emission spectra of four squaraine dyes-bis[4-(dimethylamino)phenyl]squaraine (H-Sq), bis-[4-(dimethylamino)-2-hydroxyphenyl]squaraine (HO-Sq), bis(trihydroxyphenyl)squaraine (3HO-Sq), and bis(azulyl)squaraine (Az-Sq)-are reported in dilute films of poly(methylmethacrylate) and polystyrene. Obtained for the first time are the fluorescence lifetimes of these dyes in these polymer films. Fluorescence lifetimes in liquid solutions are also reported. These emission kinetics combined with measurements of fluorescences quantum yields allow determination of radiative and nonradiative decay rate constants for three of the dyes. Comparison of determined radiative rate constants with those calculated from the absorption spectrum is consistent with the fluorescence originating from the absorbing species and state. The shortest lived fluorescence observed occurs for bis(trihydroxyphenyl)squaraine, and the short lifetime is attributed to either a rapid excited-state proton-transfer automerization or deprotonation. The S[sub 1] state of bis(azulyl)squaraine is nonfluorescent, presumably due to a rapid nonradiative decay similar to that which occurs in azulene. However, [open quotes]S[sub 2][close quotes] [yields] S[sub o] emission is observed for this azulyl-substituted squaraine. 47 refs., 6 figs., 2 tabs.

• OSTI ID: 6735778
• Journal Information: Journal of Physical Chemistry; (United States), Journal Name: Journal of Physical Chemistry; (United States) Vol. 98:44; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
400500 -- Photochemistry
661300 -- Other Aspects of Physical Science-- (1992-)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DECOMPOSITION
DOPED MATERIALS
DYES
EMISSION SPECTRA
ENERGY LEVELS
ESTERS
EXCITED STATES
FILMS
FLUORESCENCE
KINETICS
LUMINESCENCE
MATERIALS
OPTICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC POLYMERS
PETROCHEMICALS
PETROLEUM PRODUCTS
PHOTOCHEMICAL REACTIONS
PHYSICAL PROPERTIES
PLASTICS
PMMA
POLYACRYLATES
POLYMERS
POLYOLEFINS
POLYSTYRENE
POLYVINYLS
REACTION KINETICS
SPECTRA
SYNTHETIC MATERIALS