meso-(2-Benzimidazolyl)-substituted BODIPYs: Synthesis, structures and spectroscopic properties

2020 ◽  
Vol 24 (01n03) ◽  
pp. 230-237
Author(s):  
Hu Gao ◽  
Chenhong Li ◽  
Zhen Shen
Keyword(s):  
Quantum Yield ◽  
Spectroscopic Properties ◽  
Crystallographic Analysis ◽  
Membered Ring ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Nir Dyes ◽  
Nir Fluorescence ◽  
Yield Formula ◽  
Post Modification

A series of meso-(2-benzimidazolyl)-substituted boron dipyrromethene (BODIPY) derivatives 3a–3c and 4 have been synthesized and characterized. The absorption and fluorescence bands of 3a are bathochromically shifted by 36 nm and 61 nm, respectively, compared with those of the meso-phenyl BODIPY in toluene. More importantly, the fluorescence quantum yields of these meso-(2-benzimidazolyl)-substituted BODIPYs (up to 0.45 in toluene) are much higher than those of the previously reported meso-heterocyclic BODIPYs. X-ray crystallographic analysis of the single crystal structure of 3a revealed that the dihedral angle of meso-benzimidazolyl ring and indacene plane (40.47[Formula: see text] ) is smaller compared with that of the meso-tolyl substituted BODIPY (61.4[Formula: see text] ). Replacement of the six-membered ring with a five-membered ring, as well as the absence of hydrogen at the imino-nitrogen, generated the reduced repulsion and the hydrogen bonding interaction. The increased planarity not only provided the substantial delocalization of [Formula: see text] electrons and red shifted the absorption and emission bands but also enhanced the fluorescence quantum yield by reducing free rotation induced nonradiative deactivation pathway. Furthermore, 3,5-distyryl coupled BODIPY 4 exhibits a NIR fluorescence band at 712 nm with moderate quantum yield ([Formula: see text] [Formula: see text] 0.3) in nonpolar and polar solvents, which indicate that meso-(2-benzimidazolyl) BODIPY acts as a good candidate for post modification toward NIR dyes for biological applications.

scholarly journals The Effect of Varying Short-Chain Alkyl Substitution on the Molar Absorptivity and Quantum Yield of Cyanine Dyes

2011 ◽  
Vol 6 ◽  
pp. ACI.S6568 ◽  
Author(s):  
Gala Chapman ◽  
Maged Henary ◽  
Gabor Patonay
Keyword(s):  
Quantum Yield ◽  
Alkyl Chain ◽  
Cyanine Dyes ◽  
Spectroscopic Properties ◽  
Molar Absorptivity ◽  
Alkyl Chain Length ◽  
Short Chain ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Alkyl Substitution

The effect of varying short-chain alkyl substitution of the indole nitrogens on the spectroscopic properties of cyanine dyes was examined. Molar absorptivities and fluorescence quantum yields were determined for a set of pentamethine dyes and a set of heptamethine dyes for which the substitution of the indole nitrogen was varied. For both sets of dyes, increasing alkyl chain length resulted in no significant change in quantum yield or molar absorptivity. These results may be useful in designing new cyanine dyes for analytical applications and predicting their spectroscopic properties.

Comparison of Fluorescence-to-Phosphorescence Quantum Yield Ratios in Solid-Matrix Luminescence as a Function of Temperature

1993 ◽  
Vol 47 (3) ◽  
pp. 283-286 ◽  
Author(s):  
R. J. Hurtubise ◽  
S. M. Ramasamy
Keyword(s):  
Quantum Yield ◽  
Singlet State ◽  
Yield Ratio ◽  
Solid Matrix ◽  
Quantum Yields ◽  
Phosphorescence Lifetime ◽  
Fundamental Parameters ◽  
Fluorescence Quantum Yields ◽  
Photophysical Parameters ◽  
Phosphorescence Quantum Yield

An equation that relates the ratio of fluorescence to phosphorescence quantum yields as function of temperature to basic photophysical parameters is considered. The quantum yields were obtained from three compounds on three different solid matrices. Fluorescence quantum yields did not change much with temperature, while phosphorescence quantum yields changed more substantially with temperature. For some of the systems considered, it was possible to show that, as the temperature was lowered, the quantum yield ratio was only a function of the phosphorescence lifetime of the phosphor. However, with other systems, the quantum yield ratio was dependent on both the rate constant of intersystem crossing from the singlet state to the triplet state and the phosphorescence lifetime. The equation discussed is important in defining the fundamental parameters that cause the luminescence quantum yield ratio to change as temperature is lowered.

scholarly journals Theoretical and Experimental Investigations of Large Stokes Shift Fluorophores Based on a Quinoline Scaffold

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2488
Author(s):  
Barbara Czaplińska ◽  
Katarzyna Malarz ◽  
Anna Mrozek-Wilczkiewicz ◽  
Aneta Slodek ◽  
Mateusz Korzec ◽  
...  
Keyword(s):  
Theoretical Calculations ◽  
Stokes Shift ◽  
Visible Region ◽  
Spectroscopic Properties ◽  
Cellular Membrane ◽  
Structural Features ◽  
Quantum Yields ◽  
Experimental Investigations ◽  
Case Scenario ◽  
Fluorescence Quantum Yields

A series of novel styrylquinolines with the benzylidene imine moiety were synthesized and spectroscopically characterized for their applicability in cellular staining. The spectroscopic study revealed absorption in the ultraviolet–visible region (360–380 nm) and emission that covered the blue-green range of the light (above 500 nm). The fluorescence quantum yields were also determined, which amounted to 0.079 in the best-case scenario. The structural features that are behind these values are also discussed. An analysis of the spectroscopic properties and the theoretical calculations indicated the charge-transfer character of an emission, which was additionally evaluated using the Lippert–Mataga equation. Changes in geometry in the ground and excited states, which had a significant influence on the emission process, are also discussed. Additionally, the capability of the newly synthesized compounds for cellular staining was also investigated. These small molecules could effectively penetrate through the cellular membrane. Analyses of the images that were obtained with several of the tested styrylquinolines indicated their accumulation in organelles such as the mitochondria and the endoplasmic reticulum.

Ground- and Excited-State Absorption Spectra of 9-Acetoxy-10(4´-Acetoxy)phenylanthracenes

1986 ◽  
Vol 41 (10) ◽  
pp. 1200-1209
Author(s):  
Janina R. Heldt
Keyword(s):  
Mirror Symmetry ◽  
Energy Levels ◽  
Bathochromic Shift ◽  
Heavy Atom ◽  
Excited State Absorption ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Ring Molecules ◽  
Meso Position

The ground-(S0) and excited -(S1 and T1) state spectra of seven derivatives o f 9-acetoxy- 10(4´-acetoxy)phenylanthracene were determined in the region 50000 - 15000 cm -1 (200 - 660 nm). Comparison of these spectra to the unsubstituted molecule (anthracene) indicates the presence o f bathochromic shift and the steric effect. The substituents cause changes of positions of the energy levels (bigger shifts are noticed for low lying states) and also changes of the absorption intensities of some transitions. The steric hindrances between the phenyl-substituents and the anthracene skeleton are more pronounced if the - OAc(- Me) group or a heavy atom is introduced at position 2´o f the phenyl ring. Molecules possessing such substituents at the meso-position exhibit spectroscopic properties characteristic for a plane molecule in the S0 and S1 states; they show a better preservation of the mirror symmetry between the absorption and fluorescence spectra, lower Stokes shifts and the destabilization energies and bigger fluorescence quantum yields.

Photophysicochemical properties and photodynamic therapy activity of chloroindium(III) tetraarylporphyrins and their gold nanoparticle conjugates

2019 ◽  
Vol 23 (01n02) ◽  
pp. 34-45 ◽  
Author(s):  
Rodah C. Soy ◽  
Balaji Babu ◽  
David O. Oluwole ◽  
Njemuwa Nwaji ◽  
James Oyim ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Quantum Yield ◽  
Singlet Oxygen ◽  
Dose Range ◽  
Heavy Atom ◽  
Therapeutic Window ◽  
Quantum Yields ◽  
Yield Values ◽  
Yield Formula

Novel chloroindium(III) complexes of tetra(4-methylthiophenyl)porphyrin (2a) and tetra-2-thienylporphyrin (2b) dyes have been synthesized and characterized. The main goal of the project was to identify fully symmetric porphyrin dyes with Q-band regions that lie partially in the therapeutic window that are suitable for use in photodynamic therapy (PDT). 2a and 2b were found to have fluorescence quantum yield values [Formula: see text] 0.01 and moderately high singlet oxygen quantum yields (0.54−0.73) due to heavy atom effects associated with the sulfur and indium atoms. The dark toxicity and PDT activity against epithelial breast cancer cells (MCF-7) were investigated over a dose range of 3.0−40 [Formula: see text]g [Formula: see text] mL[Formula: see text]. The in vitro dark cytotoxicity of 2a is significantly lower than that of 2b at [Formula: see text] 40 [Formula: see text]g [Formula: see text] mL[Formula: see text]. 2a was conjugated with gold nanoparticles (AuNPs) to form a nanoconjugate (2a-AuNPs), which exhibited a higher singlet oxygen quantum yield ([Formula: see text] value and PDT activity than was observed for 2a alone. The results suggest that the AuNPs nanoconjugates of readily synthesized fully symmetric porphyrin dyes are potentially suitable for PDT applications, if meso-aryl substituents that provide scope for nanoparticle conjugation can be introduced that shift the Q bands into the therapeutic window.

Vibrational dependence of electronic nonradiative processes in the state of and

1984 ◽  
Vol 62 (12) ◽  
pp. 1361-1368 ◽  
Author(s):  
D. Winkoun ◽  
D. Chapoulard ◽  
G. Dujardin ◽  
S. Leach
Keyword(s):  
Vibrational Mode ◽  
Spectroscopic Properties ◽  
Quantum Yields ◽  
Electronic Relaxation ◽  
Matrix Elements ◽  
Relaxation Rates ◽  
Fluorescence Quantum Yields ◽  
Fluorescence Photon ◽  
Mode Selectivity ◽  
Nonradiative Processes

Vibrational mode selective, radiationless transitions have been sought in the [Formula: see text] states of [Formula: see text] and [Formula: see text] by determining the radiative kr(ν′) and nonradiative knr(ν′) rates of electronic relaxation of energy selected vibronic levels of these cations. The relaxation rates were derived from measurements of ion fluorescence quantum yields and lifetimes using a photoelectron-fluorescence photon delayed coincidence apparatus, described in the text, in which the ions are formed by direct photoionization. Mode selective behavior is confirmed for the ν1 and ν2 modes of the [Formula: see text] state of [Formula: see text], previously studied by a threshold photoelectron-fluorescence photon coincidence method in which photoion formation involved auto-ionization as well as direct photoionization. In the case of the ν3 and ν4 modes of [Formula: see text], knr(ν′) was found to depend only on the excess energy Eν′ in the [Formula: see text] state and not on the particular mode optically excited. The absence of mode selectivity in this cation could be due to very rapid vibrational redistribution, but more probably results from similar-valued nonradiative coupling matrix elements of vibronic levels involving ν3 and (or) ν4 modes for a given value of Eν′. This is shown to be consistent with the known spectroscopic properties of [Formula: see text].

scholarly journals Chiral Cyclic [n]Spirobifluorenylenes: Carbon Nanorings Consisting of Helically Arranged Quaterphenyl Rods Illustrating Partial Units of Woven Patterns

2020 ◽  
Author(s):  
Kaige Zhu, ◽  
Kosuke Kamochi ◽  
Takuya Kodama ◽  
Mamoru Tobisu ◽  
Toru Amaya
Keyword(s):  
Building Blocks ◽  
Spectroscopic Properties ◽  
Crystallographic Analysis ◽  
Quantum Yields ◽  
X Ray ◽  
New Family ◽  
Circularly Polarized Luminescence ◽  
Polarized Luminescence ◽  
Yamamoto Coupling ◽  
Carbon Nanorings

Chiral cyclic [n]spirobifluorenylenes consisting of helically arranged quaterphenyl rods, illustrating partial units of woven patterns, were designed and synthesized as a new family of carbon nanorings. The synthesis was accomplished by the Ni(0)-mediated Yamamoto-coupling of chiral spirobifluorene building blocks. The structures of the cyclic 3-, 4-, and 5-mers were determined by X-ray crystallographic analysis. These carbon nanorings exhibited a strong violet colored emission with high quantum yields in solution (95%, 93%, and 94% for 3-, 4-, and 5-mer, respectively). Other spectroscopic properties, including their chiroptical properties, were also investigated. The g-values for circularly polarized luminescence were found to be in the order of 10<sup>-3</sup>, where that of the 4-mer showed a relatively higher value 8.5 x 10<sup>-3</sup>. Characteristic spiroconjugation induced by multiple<br>3) bifluorenyl units, for example the even-odd effect of the number of units in the matching of the sign of the orbitals, were also indicated by DFT calculations.<br>

Computational design of ratiometric two-photon fluorescent Zn2+ probes based on quinoline and di-2-picolylamine moieties

2021 ◽  
Author(s):  
Zhe Shao ◽  
Wen-Ying Zhang ◽  
Ke Zhao
Keyword(s):  
Quantum Yield ◽  
Cross Sections ◽  
Fluorescence Quantum Yield ◽  
Density Functional ◽  
Computational Design ◽  
Photon Absorption ◽  
Quantum Yields ◽  
Fluorescence Quantum Yields ◽  
Two Photon ◽  
Before And After

Abstract To improve two-photon absorption (TPA) response of a newly synthesized probe, a series of ratiometric two-photon fluorescent Zn2+ sensors based on quinoline and DPA moieties have been designed. The one-photon absorption, TPA and emission properties of the experimental and designed probes before and after coordination with Zn2+ are investigated employing the density functional theory in combination with response functions. The design consists of two levels. In the first level of design, five probes are constructed through using several electron acceptors or donors to increase accepting or donating ability of the fluorophores. It shows that all the designed probes have stronger TPA intensities at longer wavelengths with respect to the experimental probe because of the increased intra-molecular charge transfer. Moreover, it is found that the probe 4 built by adding an acyl unit has the largest TPA cross section among the designed strictures due to the form of longer conjugated length and more linear backbone. One dimethylamino terminal attached along the skeleton can improve TPA intensity more efficiently than two side amino groups. Therefore, in the second level of design, a new probe 7 is formed by both an acyl unit and a dimethylamino terminal. It exhibits that the TPA cross sections of probe 7 and its zinc complex increase dramatically. Furthermore, the fluorescence quantum yields of the designed probes 4 and 7 are calculated in a new way, which makes use of the relation between the computed difference of dipole moment and the measured fluorescence quantum yield. The result shows that our design also improves the fluorescence quantum yield considerably. All in all, the designed probes 4 and 7 not only possess enhanced TPA intensities but also have large differences of emission wavelength upon Zn2+ coordination and strong fluorescence intensity, which demonstrates that they are potential ratiometric two-photon fluorescent probes.

Detection of biomacromolecules with fluorescent light-up probes

2006 ◽  
Vol 78 (12) ◽  
pp. 2325-2331 ◽  
Author(s):  
Katja Faulhaber ◽  
Anton Granzhan ◽  
Heiko Ihmels ◽  
Giampietro Viola
Keyword(s):  
Quantum Yield ◽  
Conformational Changes ◽  
Linear Dichroism ◽  
Quantum Yields ◽  
Fluorescent Light ◽  
Double Logarithmic Plot ◽  
Egg Albumin ◽  
Fluorescence Quantum Yields ◽  
Double Stranded Dna ◽  
Emission Quantum Yield

The emission properties of selected benzo[b]quinolizinium (acridizinium) derivatives in the presence of double-stranded DNA and proteins are presented. Spectrophotometric studies and linear dichroism (LD) spectroscopic experiments reveal that benzo[b]quinolizinium derivatives bind to DNA, mainly by intercalation. In contrast to the 9-aminobenzo[b]quinolizinium, which exhibits a moderate emission quantum yield in water, the 6-aminobenzo[b]quinolizinium ion as well as N-phenyl-9-aminobenzo[b]quinolizinium derivatives are almost nonfluorescent. The low intrinsic fluorescence quantum yields of the latter compounds are caused by conformational changes in the excited state, as shown by a linear double-logarithmic plot of the emission quantum yield vs. the solvent viscosity. Most notably, the fluorescence intensities of these dyes increase significantly by a factor of 10 to 50 upon addition of double-stranded DNA or proteins such as human serum albumin (HSA) or chicken egg albumin (CEA). Thus, these compounds exhibit ideal properties to be used as DNA- or protein-sensitive light-up probes.

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