Nanoscale aggregates of porphyrin: red-shifted absorption, enhanced absorbance and phototherapeutic activity

2021 ◽  
Author(s):  
Qihang Wu ◽  
Rui Xia ◽  
Chaonan Li ◽  
Yite Li ◽  
Tingting Sun ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Photophysical Properties ◽  
Nanoscale Aggregates ◽  
Supramolecular Aggregation

Supramolecular aggregation of fluorophores will result in a variable absorption spectrum, which is beneficial for tunning the photophysical properties and improving their functionalities. Herein, ordered aggregates of liposoluble porphyrin molecules...

scholarly journals Luminescent Tetranuclear Gold(I) Dibenzo[g,p]chrysene Derivatives: Effect of the Environment on Photophysical Properties

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 949 ◽  
Author(s):  
Francisco J. Caparrós ◽  
Mani Outis ◽  
Yongsik Jung ◽  
Hyeonho Choi ◽  
João Carlos Lima ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
High Resolution ◽  
Quantum Yield ◽  
31P Nmr ◽  
High Resolution Mass Spectrometry ◽  
Photophysical Properties ◽  
Emission Spectra ◽  
Intermolecular Contacts ◽  
Supramolecular Aggregation ◽  
Resolution Mass

A new 2,7,10,15-tetraethynyldibenzo[g,p]chrysene ligand (1) and two tetranuclear gold(I) derivatives containing PPh3 (3) and PMe3 (4) phosphines were synthesized and characterized by 1H and 31P NMR, IR spectroscopy, and high-resolution mass spectrometry. The compounds were studied in order to analyze the effect of the introduction of gold(I) on the supramolecular aggregation and photophysical properties. Absorption and emission spectra displayed broad bands due to the establishment of π π interactions as an indication of intermolecular contacts and the formation of aggregates. A decrease of the recorded quantum yield (QY) of the gold(I) derivatives was observed compared to the uncomplexed ligand. The introduction of the complexes into poly methyl methacrylate (PMMA) and Zeonex 480R matrixes was analyzed, and an increase of the measured QY of 4 in Zeonex was observed. No phosphorescent emission was detected.

scholarly journals Carbonyl-to-Alkyne Electron Donation Effects in up to 10-nm-Long, Unimolecular Oligo(p-phenylene ethynylenes)

2021 ◽  
Vol 03 (02) ◽  
pp. 337-345
Author(s):  
Sinu C. Rajappan ◽  
Olav Vestrheim ◽  
Mona Sharafi ◽  
Jianing Li ◽  
Severin T. Schneebeli
Keyword(s):  
Absorption Spectrum ◽  
Exponential Growth ◽  
Photophysical Properties ◽  
Rotational Barrier ◽  
Carbonyl Groups ◽  
Conformational Disorder ◽  
Triple Bonds ◽  
Phenylene Ethynylenes ◽  
Electron Donation

We synthesized some of the longest unimolecular oligo(p-phenylene ethynylenes) (OPEs), which are fully substituted with electron-withdrawing ester groups. An iterative convergent/divergent (a.k.a. iterative exponential growth – IEG) strategy based on Sonogashira couplings was utilized to access these sequence-defined macromolecules with up to 16 repeating units and 32 ester substituents. The carbonyl groups of the ester substituents interact with the triple bonds of the OPEs, leading to (i) unusual, angled triple bonds with increased rotational barrier, (ii) enhanced conformational disorder, and (iii) associated broadening of the UV/Vis absorption spectrum. Our results demonstrate that fully air-stable, unimolecular OPEs with ester groups can readily be accessed with IEG chemistry, providing new macromolecular backbones with unique geometrical, conformational, and photophysical properties.

scholarly journals FLUORESCENCE AND RED SHIFT OF THE PHOTOPHYSICAL PROPERTIES FROM PROTONATED SMALL MOLECULE

2020 ◽  
Vol 5 (1) ◽  
pp. 25-29
Author(s):  
Zakarias Seba Ngara
Keyword(s):  
Absorption Spectrum ◽  
Small Molecule ◽  
Energy Gap ◽  
Photophysical Properties ◽  
Photonic Devices ◽  
Red Shift ◽  
Direct Excitation ◽  
Develop Sensor ◽  
Color Emission ◽  
Film State

In this work, the fluorescence (FL) and bathochromic of the photophysical properties from protonated small molecule in cast film state have been investigated. To realize these purposes, the material of 4’,4’’’’-(1,4-phenylene bis (2,2’:6’,2”-terpyridine) (Phtpy) as a small molecule and  camphorsulfonic acid (CSA) as an acid for protonation was selected. For Phtpy, its maxima absorption is 300 nm and no FL color emission. After CSA solution was added in chlorofom solution of Phtpy, the absorption spectrum of protonated Phtpy is broaden to longer wavelength with two new peaks appear at around 350 and 370 nm. Upon direct excitation at wavelength of 300 nm, the range of FL spectrum of original and protonated Phtpy is from 320 to 580 nm and from 370 to 580 with their maxima FL intensities at 360 and 460 nm. Interestingly, protonated Phtpy emits blue FL color emission. In addition, energy gap of protonated Phtpy is smaller than that of pristine Phtpy. Finally, the FL  and remarkable red shift of absorption and FL spectra of protonated Phtpy will pave the way to develop sensor and other photonic devices with high performances in the ultaviolet region.

scholarly journals Sampling the protonation states: the pH-dependent UV absorption spectrum of a polypeptide dyad

2018 ◽  
Vol 20 (36) ◽  
pp. 23252-23261 ◽  
Author(s):  
Elisa Pieri ◽  
Vincent Ledentu ◽  
Miquel Huix-Rotllant ◽  
Nicolas Ferré
Keyword(s):  
Absorption Spectrum ◽  
Photophysical Properties ◽  
Uv Absorption ◽  
Ph Dependent ◽  
Uv Absorption Spectrum

When a chromophore interacts with several titratable molecular sites, the modeling of its photophysical properties requires to take into account all their probable protonation states.

Synthesis, performance and growth mechanism of silver nanoparticle coated SERS fiber probe

2019 ◽  
Vol 107 (3) ◽  
pp. 305
Author(s):  
Mengmei Geng ◽  
Yuting Long ◽  
Tongqing Liu ◽  
Zijuan Du ◽  
Hong Li ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Absorption Spectrum ◽  
Reaction Time ◽  
Growth Mechanism ◽  
Fiber Optic ◽  
Fiber Optic Probe ◽  
Visible Absorption ◽  
Fiber Probe ◽  
Surface Enhanced Raman ◽  
Optic Probe

Surface-enhanced Raman Scattering (SERS) fiber probe provides abundant interaction area between light and materials, permits detection within limited space and is especially useful for remote or in situ detection. A silver decorated SERS fiber optic probe was prepared by hydrothermal method. This method manages to accomplish the growth of silver nanoparticles and its adherence on fiber optic tip within one step, simplifying the synthetic procedure. The effects of reaction time on phase composition, surface plasmon resonance property and morphology were investigated by X-ray diffraction analysis (XRD), ultraviolet-visible absorption spectrum (UV-VIS absorption spectrum) and scanning electron microscope (SEM). The results showed that when reaction time is prolonged from 4–8 hours at 180 °C, crystals size and size distribution of silver nanoparticles increase. Furthermore, the morphology, crystal size and distribution density of silver nanoparticles evolve along with reaction time. A growth mechanism based on two factors, equilibrium between nucleation and growth, and the existence of PVP, is hypothesized. The SERS fiber probe can detect rhodamin 6G (R6G) at the concentration of 10−6 M. This SERS fiber probe exhibits promising potential in organic dye and pesticide residue detection.

Modeling of Short-Millimeter-Wave CMOS Transmission Line with Lossy Dielectrics with Specific Absorption Spectrum

2013 ◽  
Vol E96.C (10) ◽  
pp. 1311-1318 ◽  
Author(s):  
Kyoya TAKANO ◽  
Shuhei AMAKAWA ◽  
Kosuke KATAYAMA ◽  
Mizuki MOTOYOSHI ◽  
Minoru FUJISHIMA
Keyword(s):  
Absorption Spectrum ◽  
Transmission Line ◽  
Millimeter Wave ◽  
Specific Absorption ◽  
Lossy Dielectrics

Solvent Dependence of Structural Dynamics and Spin-flip Processes in 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (ortho-3CzBN)

2020 ◽  
Author(s):  
Masaki Saigo ◽  
Kiyoshi Miyata ◽  
Hajime Nakanotani ◽  
Chihaya Adachi ◽  
Ken Onda
Keyword(s):  
Dft Calculations ◽  
Excited States ◽  
Structural Changes ◽  
Photophysical Properties ◽  
Delayed Fluorescence ◽  
Time Resolved ◽  
Thermally Activated Delayed Fluorescence ◽  
Thermally Activated ◽  
Solvent Dependence ◽  
Acetonitrile Solutions

We have investigated the solvent-dependence of structural changes along with intersystem crossing of a thermally activated delayed fluorescence (TADF) molecule, 3,4,5-tri(9H-carbazole-9-yl)benzonitrile (o-3CzBN), in toluene, tetrahydrofuran, and acetonitrile solutions using time-resolved infrared (TR-IR) spectroscopy and DFT calculations. We found that the geometries of the S1 and T1 states are very similar in all solvents though the photophysical properties mostly depend on the solvent. In addition, the time-dependent DFT calculations based on these geometries suggested that the thermally activated delayed fluorescence process of o-3CzBN is governed more by the higher-lying excited states than by the structural changes in the excited states.<br>

Theoretical Framework of 1,3-Thiazolium-5-Thiolates Mesoionic Compounds: Exploring the Nature of Photophysical Properties and Molecular Nonlinearity

2020 ◽  
Author(s):  
Zeyu Liu ◽  
Shugui Hua ◽  
Tian Lu ◽  
Ziqi Tian
Keyword(s):  
Optical Properties ◽  
Rational Design ◽  
Rayleigh Scattering ◽  
Function Analysis ◽  
Theoretical Calculations ◽  
Photophysical Properties ◽  
Optical Nonlinearity ◽  
Nonlinear Properties ◽  
Photoelectric Performance ◽  
Wave Function Analysis

Inspired by a previous experimental study on the first-order hyperpolarizabilities of 1,3-thiazolium-5-thiolates mesoionic compounds using Hyper-Rayleigh scattering technique, we theoretically investigated the UV-Vis absorption spectra and every order polarizabilities of these mesoionic molecules. Based on the fact that the photophysical and nonlinear properties observed in the experiment can be perfectly replicated, our theoretical calculations explored the essential characteristics of the optical properties of the mesoionic compounds with different electron-donating groups at the level of electronic structures through various wave function analysis methods. The influence of the electron-donating ability of the donor on the optical properties of the molecules and the contribution of the mesoionic ring moiety to their optical nonlinearity are clarified, which have not been reported by any research so far. This work will help people understand the nature of optical properties of mesoionic-based molecules and provide guidance for the rational design of molecules with excellent photoelectric performance in the future.

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