Browse
Submit Data
Databases
API
Help

Dataset Information

30 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Tuning the Sensitivity of Fluorescent Porphyrin Dimers to Viscosity and Temperature.

ABSTRACT: Conjugated porphyrin dimers have emerged as versatile viscosity-sensitive fluorophores that are suitable for quantitative measurements of microscopic viscosity by ratiometric and fluorescence lifetime-based methods, in a concentration-independent manner. Here, we investigate the effect of extended conjugation in a porphyrin-dimer structure on their ability to sense viscosity and temperature. We show that the sensitivity of the fluorescence lifetime to temperature is a unique property of only a few porphyrin dimers.

SUBMITTER: Vysniauskas A

PROVIDER: S-EPMC5575558 | biostudies-literature | 2017 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Tuning the Sensitivity of Fluorescent Porphyrin Dimers to Viscosity and Temperature.

Vyšniauskas Aurimas A Ding Dong D Qurashi Maryam M Boczarow Igor I Balaz Milan M Anderson Harry L HL Kuimova Marina K MK

Chemistry (Weinheim an der Bergstrasse, Germany) 20170613 46

Conjugated porphyrin dimers have emerged as versatile viscosity-sensitive fluorophores that are suitable for quantitative measurements of microscopic viscosity by ratiometric and fluorescence lifetime-based methods, in a concentration-independent manner. Here, we investigate the effect of extended conjugation in a porphyrin-dimer structure on their ability to sense viscosity and temperature. We show that the sensitivity of the fluorescence lifetime to temperature is a unique property of only a f ...[more]

PMID: 28480989

Similar Datasets

Bio-inspired cofacial Fe porphyrin dimers for efficient electrocatalytic CO2 to CO conversion: Overpotential tuning by substituents at the porphyrin rings.

Project description:Efficient reduction of CO2 into useful carbon resources particularly CO is an essential reaction for developing alternate sources of fuels and for reducing the greenhouse effect of CO2. The binuclear Ni, Fe-containing carbon monoxide dehydrogenase (CODHs) efficiently catalyzes the reduction of CO2 to CO. The location of Ni and Fe at proper positions allows their cooperation for CO2 to CO conversion through a push-pull mechanism. Bio-inspired from CODHs, we used several cofacial porphyrin dimers with different substituents as suitable ligands for holding two Fe ions with suitable Fe-Fe separation distance to efficiently and selectively promote CO2 to CO conversion with high turnover frequencies, TOFs. The substituents on the porphyrin rings greatly affect the catalysis process. By introducing electron-withdrawing/-donating groups, e.g. electron-withdrawing perfluorophenyl, at all meso positions of the porphyrin rings, the catalysis overpotential, ? was minimized by ?0.3?V compared to that obtained by introducing electron-donating mesityl groups. The Fe porphyrin dimers among reported catalysts are the most efficient ones for CO2 to CO conversion. Control experiments indicate that the high performance of the current CO2 to CO conversion catalysts is due to the presence of binuclear Fe centers at suitable Fe-Fe separation distance.

| S-EPMC4834491 | biostudies-literature

Unravelling the effect of temperature on viscosity-sensitive fluorescent molecular rotors.

Project description:Viscosity and temperature variations in the microscopic world are of paramount importance for diffusion and reactions. Consequently, a plethora of fluorescent probes have evolved over the years to enable fluorescent imaging of both parameters in biological cells. However, the simultaneous effect of both temperature and viscosity on the photophysical behavior of fluorophores is rarely considered, yet unavoidable variations in temperature can lead to significant errors in the readout of viscosity and vice versa. Here we examine the effect of temperature on the photophysical behavior of three classes of viscosity-sensitive fluorophores termed 'molecular rotors'. For each of the fluorophores we decouple the effect of temperature from the effect of viscosity. In the case of the conjugated porphyrin dimer, we demonstrate that, uniquely, simultaneous dual-mode lifetime and intensity measurements of this fluorophore can be used for measuring both viscosity and temperature concurrently.

| S-EPMC5520772 | biostudies-literature

Tuning the Circumference of Six-Porphyrin Nanorings.

Project description:Most macrocycles are made from a simple repeat unit, resulting in high symmetry. Breaking this symmetry allows fine-tuning of the circumference, providing better control of the host-guest behavior and electronic structure. Here, we present the template-directed synthesis of two unsymmetrical cyclic porphyrin hexamers with both ethyne (C2) and butadiyne (C4) links, and we compare these nanorings with the symmetrical analogues with six ethyne or six butadiyne links. Inserting two extra carbon atoms into the smaller nanoring causes a spectacular change in binding behavior: the template affinity increases by a factor of 3 × 109, to a value of ca. 1038 M-1, and the mean effective molarity is ca. 830 M. In contrast, removing two carbon atoms from the largest nanoring results in almost no change in its template-affinity. The strain in these nanorings is 90-130 kJ mol-1, as estimated both from DFT calculation of homodesmotic reactions and from comparing template affinities of linear and cyclic oligomers. Breaking the symmetry has little effect on the absorption and fluorescence behavior of the nanorings: the low radiative rates that are characteristic of a circular delocalized S1 excited state are preserved in the low-symmetry macrocycles.

| S-EPMC6523998 | biostudies-literature

Self-Assembly of Covalently Linked Porphyrin Dimers at the Solid-Liquid Interface.

Project description:The synthesis and surface self-assembly behavior of two types of metal-porphyrin dimers is described. The first dimer type consists of two porphyrins linked via a rigid conjugated spacer, and the second type has an alkyne linker, which allows rotation of the porphyrin moieties with respect to each other. The conjugated dimers were equipped with two copper or two manganese centers, while the flexible dimers allowed a modular built-up that also made the incorporation of two different metal centers possible. The self-assembly of the new porphyrin dimers at a solid-liquid interface was investigated at the single-molecule scale using scanning tunneling microscopy (STM). All dimers formed monolayers, of which the stability and the internal degree of ordering of the molecules depended on the metal centers in the porphyrins. While in all monolayers the dimers were oriented coplanar with respect to the underlying surface ('face-on'), the flexible dimer containing a manganese and a copper center could be induced, via the application of a voltage pulse in the STM setup, to self-assemble into monolayers in which the porphyrin dimers adopted a non-common perpendicular ('edge-on') geometry with respect to the surface.

| S-EPMC6720350 | biostudies-literature

Macroscopically Anisotropic Structures Produced by Light-induced Solvothermal Assembly of Porphyrin Dimers.

Project description:Porphyrin-based molecules play an important role in natural biological systems such as photosynthetic antennae and haemoglobin. Recent organic chemistry provides artificial porphyrin-based molecules having unique electronic and optical properties, which leads to wide applications in material science. Here, we successfully produced many macroscopically anisotropic structures consisting of porphyrin dimers by light-induced solvothermal assembly with smooth evaporation in a confined volatile organic solvent. Light-induced fluid flow around a bubble on a gold nanofilm generated a sub-millimetre radial assembly of the tens-micrometre-sized petal-like structures. The optical properties of the petal-like structures depend on the relative angle between their growth direction and light polarisation, as confirmed by UV-visible extinction and the Raman scattering spectroscopy analyses, being dramatically different from those of structures obtained by natural drying. Thus, our findings pave the way to the production of structures and polycrystals with unique characteristics from various organic molecules.

| S-EPMC6056561 | biostudies-literature

Project description:The controlled delocalization of molecular excitons remains an important goal towards the application of organic chromophores in processes ranging from light-initiated chemical transformations to classical and quantum information processing. In this study, we present a methodology to couple optical and magnetic spectroscopic techniques and assess the delocalization of singlet and triplet excitons in model molecular chromophores. By comparing the steady-state and time-resolved optical spectra of Zn-porphyrin monomers and weakly coupled dimers, we show that we can use the identity of substituents bound at specific positions of the macromolecules' rings to control the inter-ring delocalization of singlet excitons stemming from their B states through acetylene bridges. While broadened steady-state absorption spectra suggest the presence of delocalized B state excitons in mesityl-substituted Zn-tetraphenyl porphyrin dimers (Zn2U-D), we confirm this conclusion by measuring an enhanced ultrafast non-radiative relaxation from these inter-ring excitonic states to lower lying electronic states relative to their monomer. In contrast to the delocalized nature of singlet excitons, we use time-resolved EPR and ENDOR spectroscopies to show that the triplet states of the Zn-porphyrin dimers remain localized on one of the two macrocyclic sub-units. We use the analysis of EPR and ENDOR measurements on unmetallated model porphyrin monomers and dimers to support this conclusion. The results of DFT calculations also support the interpretation of localized triplet states. These results demonstrate researchers cannot conclude triplet excitons delocalize in macromolecular based on the presence of spatially extended singlet excitons, which can help in the design of chromophores for application in spin conversion and information processing technologies.

| S-EPMC10829018 | biostudies-literature

Synthesis of Porphyrin and Bacteriochlorin Glycoconjugates through CuAAC Reaction Tuning.

Project description:Rapid and reproducible access to a series of unique porphyrin and bacteriochlorin glycoconjugates, including meso-glycosylated porphyrins and bacteriochlorins, and beta-glycosylated porphyrins, via copper catalyzed azide-alkyne 1,3-dipolar cycloaddition (CuAAC) is reported for the first time. The work presented highlights the system-dependent reaction conditions required for glycosylation to porphyrins and bacteriochlorins based on the unique electronic properties of each ring system. Attenuated reaction conditions were used to synthesize fifteen new glycosylated porphyrin and bacteriochlorin analogs in 74 - 99% yield, and were extended to solid support to produce the first oligo(amidoamine)-based porphyrin glycoconjugate. These compounds hold significant potential as next generation water soluble catalysts and photodynamic therapy/photodynamic inactivation (PDT/PDI) agents.

| S-EPMC7546392 | biostudies-literature

Singly and doubly ?-to-? platinum-bridged porphyrin dimers and their reductive eliminations.

Project description:2-Borylated porphyrins reacted with Pt(cod)Cl2 to give ?-to-? platinum-bridged porphyrin dimers, which were converted to ?-to-? directly linked porphyrin dimers through triphenylphosphine-mediated reductive elimination. Similar reactions of 2,18-diborylated Ni(ii)-porphyrin and Zn(ii)-porphyrin gave the corresponding doubly ?-to-? platinum-bridged porphyrin dimers. Treatment of the doubly ?-to-? platinum-bridged Ni(ii)-porphyrin dimer with triphenylphosphine caused a single reductive elimination to produce a Ni(ii)-porphyrin dimer possessing a ?-to-? platinum bridge and a ?-to-? direct C-C bond.

| S-EPMC6055090 | biostudies-other

Conformation of self-assembled porphyrin dimers in liposome vesicles by phase-modulation 2D fluorescence spectroscopy.

Project description:By applying a phase-modulation fluorescence approach to 2D electronic spectroscopy, we studied the conformation-dependent exciton coupling of a porphyrin dimer embedded in a phospholipid bilayer membrane. Our measurements specify the relative angle and separation between interacting electronic transition dipole moments and thus provide a detailed characterization of dimer conformation. Phase-modulation 2D fluorescence spectroscopy (PM-2D FS) produces 2D spectra with distinct optical features, similar to those obtained using 2D photon-echo spectroscopy. Specifically, we studied magnesium meso tetraphenylporphyrin dimers, which form in the amphiphilic regions of 1,2-distearoyl-sn-glycero-3-phosphocholine liposomes. Comparison between experimental and simulated spectra show that although a wide range of dimer conformations can be inferred by either the linear absorption spectrum or the 2D spectrum alone, consideration of both types of spectra constrain the possible structures to a "T-shaped" geometry. These experiments establish the PM-2D FS method as an effective approach to elucidate chromophore dimer conformation.

| S-EPMC3189026 | biostudies-literature

Porphyrin-Ryleneimide Hybrids: Tuning of Visible and Near-Infrared Absorption by Chromophore Desymmetrization.

Project description:Unsymmetrically fused porphyrins containing one or two naphthalimide subunits were prepared in modular syntheses relying on electron-rich and electron-poor pyrrole building blocks. These new chromophores show progressive changes in their electron-deficient character, while retaining comparably small optical and electrochemical band gaps. The intrinsic curvature and extended optical absorption of these systems make them of interest as mono- and difunctional components of multichromophoric assemblies.

| S-EPMC7506948 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data