Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

Özçelik, Serdar

doi:10.1016/s0022-2313(01)00243-5

Cited by 13 publications

(6 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Intersystem crossing, triplet formation and related deactivation channels of the first excited singlet state, i.e. the fluorescent state of cyanines are not very effective and have very low quantum yields [24][25][26][27][28][29][30][31][32]. Photoisomerisation and internal conversions leading to picosecond fluorescence lifetimes are considered as the main non-radiative deactivation pathways for cyanines [31,32].…”

Section: Resultsmentioning

confidence: 99%

Optical transition rates of a meso-substituted thiacarbocyanine in methanol-in-oil reverse micelles

Özçelik

Atay

2005

Journal of Luminescence

Self Cite

View full text Add to dashboard Cite

We report the photophysical properties of 3,3 0 -diethyl-5,5 0 -dichloro-9-phenylthiacarbocyanine (DDPT) in methanolin-oil (m/o) reverse micellar systems which form methanol droplets stabilized with anionic surfactant aerosol-OT (AOT) in n-heptane. The fluorescence quantum yield of DDPT is enhanced by a factor of 17 in the methanol droplet in comparison with bulk methanol. The fluorescence lifetimes of DDPT in m/o reverse micelles are prolonged up to 2.2 ns with increasing molar ratio of methanol to surfactant (w 0 =[MeOH]/[AOT]), whereas the fluorescence lifetime of DDPT in bulk methanol is 75 ps. The non-radiative rate constants of DDPT in the droplets are decreased by a factor of 40, resulting in a remarkable enhancement in quantum yields, indicating that internal motions of DDPT in the droplets are significantly reduced due to strong electrostatic interactions between the positively charged DDPT and the negatively charged sulfonate head-groups of AOT and the spatial confinement induced by the reverse micellar structure. r

show abstract

Section: Resultsmentioning

confidence: 99%

Optical transition rates of a meso-substituted thiacarbocyanine in methanol-in-oil reverse micelles

Özçelik

Atay

2005

Journal of Luminescence

Self Cite

View full text Add to dashboard Cite

show abstract

“…These findings are in agreement with the reported solvatochromism observed for TTBC monomer in various solvents. 30 It is confirmed that TTBC molecules were molecularly dispersed in PVA solution, and the spinning solution was initially free of aggregates.…”

Section: ■ Results and Discussionmentioning

confidence: 87%

Hierarchial Coassembly of a Cyanine Dye in Poly(vinyl alcohol) Fibrous Films by Electrospinning

et al. 2013

Self Cite

View full text Add to dashboard Cite

We report molecular aggregate formation of TTBC (1,1′,3,3′-tetraethyl-5,5′,6,6′-tetrachlorobenzimidazolocarbocyanine) in submicrometer-sized PVA (poly-(vinyl alcohol)) fibers by electrospinning. The formation of the molecular aggregate is examined by solution and instrumental parameters of electrospinning. The precursor solution of PVA/TTBC, in the range of 0.016−0.065 wt % is subjected to electrospinning under an electrical field ranging from 0.95 to 1.81 kV cm −1 . Both randomly deposited and uniaxially aligned fibers are achieved by using two parallelpositioned metal strips as counter electrode. Photoluminescence and polarized Fourier transform infrared spectroscopies are employed to determine spectral properties of the fibers. H-aggregates are formed within the electrospun fibers, regardless of their alignment, and H-and J-type aggregates coexist in the alternative spin-coated and the cast films. A strongly polarized photoluminescence emission is observed in the direction of uniaxially aligned fibers as a result of the orientation of the H-aggregates along the fiber axis. We demonstrate that electrospinning is a process capable of forming and orienting TTBC aggregates during the structural development of the polymer/dye nanofibers. These fibrous films may potentially find applications in optics and electronics. ■ INTRODUCTIONMolecular aggregates of dyes have attracted remarkable interest because they exhibit collective optical/excitonic properties with various functions. The strong coupling of transition dipoles of the constituent dye molecules which have internal molecular arrangement within the aggregate leads to delocalized excitonic states over a few to several molecules and, accordingly, the enhancement of the optical properties. 1 The aggregation patterns of the dye molecules exhibit red shift (J-type) and blue shift (H-type) in absorption bands. 2,3 TTBC is a twodimensional planar molecule that can form secondary interactions, yielding intriguing supramolecular structure. This cyanine dye undergoes both H-and J-type aggregation by shortrange noncovalent interactions, such as dipole−dipole interactions, π−π stacking, and hydrogen bonding. Aggregation is driven mainly by the presence of a strong transition dipole moment formed by conjugated π-electrons of the polymethine backbone of cyanine dyes. 4 The construction of sophisticated molecular dye assemblies and highly ordered dye aggregates plays a significant role in designing smart materials because their optical properties show alteration depending on the structural organization of the dyes. 5 The understanding of internal organization and controlling the mesoscopic morphology of cyanine aggregates has provided a powerful way of developing techniques for fabrication of functional structures designed for specific purposes. To date, a number of approaches have been demonstrated to form and align the aggregates, such as magnetic field, 6−9 vertical spin coating, 10−12 Langmuir−Blodgett films, 13,14 adsorption on a single crystal surface, 15,16 ...

show abstract

“…The simulated absorption and fluorescence spectrum of TTBC will be compared with the experimental spectra reported by Özçelik [18]. This versatile organic dye is an important biological molecular probe; it is envisioned that the knowledge gained from our work here may benefit the use and development of the optical and spectroscopic properties of this and similar dyes.…”

Section: Introductionmentioning

confidence: 90%

“…An experimental fluorescence maximum appears at 528 nm with a shoulder located at 560 nm in methanol; however, the bathochromic shift with solvent polarity was not observed. The dual emission was suggested experimentally only in glycerol where a double exponential decay was detected [18]. However there is no experimental evidence of a charge transfer state for that dye.…”

Section: Homo-1 Lumo+1mentioning

confidence: 99%

See 1 more Smart Citation

A computational study on the excited state properties of a cationic cyanine dye: TTBC

Karaca

Elmaci

2011

Computational and Theoretical Chemistry

View full text Add to dashboard Cite

a b s t r a c tThe ground and excited state behaviors of a biologically important mitochondria selective dye, 5,5 0 ,6,6 0 -tetrachloro-1,1 0 ,3,3 0 -tetraethyl-benzimidazolo carbocyanine (TTBC), were investigated in order to give useful information related to the enhancement of its electronic and optical properties. DFT and TDDFT levels of theory with different functionals and basis sets were used. The results obtained by using PBEPBE/6-31+G(d,p)/C-PCM are in good agreement with the experiments. The potential energy surface sections of TTBC were explored and the geometry optimized in the first excited state, S 1 , to analyze the fluorescence spectrum of the dye. There are two distinct minima on the S 1 surface, one located near the ground state geometry and an energetically favorable twisted geometry, having a charge transfer character. The observation of similar ground and excited state dipoles as well as solvent-independent fluorescence and absorption wavelengths reveals that there is no competition between the two minima; the emission is dominantly coming from the more planar configuration.

show abstract

Steady state and picosecond time-resolved photophysics of a benzimidazolocarbocyanine dye

Cited by 13 publications

References 43 publications

Optical transition rates of a meso-substituted thiacarbocyanine in methanol-in-oil reverse micelles

Optical transition rates of a meso-substituted thiacarbocyanine in methanol-in-oil reverse micelles

Hierarchial Coassembly of a Cyanine Dye in Poly(vinyl alcohol) Fibrous Films by Electrospinning

A computational study on the excited state properties of a cationic cyanine dye: TTBC

Contact Info

Product

Resources

About