Squaraine photophysics in polymer films

Journal Article · Thu Nov 03 00:00:00 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), Vol. 98:44; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

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