Tetra 4-sulfonatophenyl Porphyrin Research Articles

Intercalated cobalt porphyrin between layered double hydroxide nanosheets as an efficient and recyclable catalyst for aerobic epoxidation of alkenes

Anionic cobalt tetrasulfonatophenyl porphyrin (CoTPPS) intercalated NiAl LDH has been prepared through the exfoliation/restacking route. The obtained hybrids were characterized by XRD, SEM, TEM, IR, UV–Vis and TG-DSC. The volume ratio between the metalloporphyrin solution and LDH nanosheets suspension on the structure of restacking products was investigated and CoTPPS/Ni-Al LDH3.0 was found to exhibit the highest crystallinity. The interlayer spacing determined by XRD shows that CoTPPS was intercalated into the hyroxylated layers of LDH by a perpendicular orientation. The catalytic performance of the obtained hybrid material was investigated in the green epoxidation of various alkenes with oxygen as oxidant and isobutyaldehyde as co-reagent. The immobilized Co porphyrin demonstrated great application potential in oxidative catalysis, exhibiting exceptional stability and catalytic activity in oxidation of various alkenes.

Phase Acrobatics: The Influence of Excitonic Resonance and Gold Nonresonant Background on Heterodyne-Detected Vibrational Sum Frequency Generation Emission.

We show how heterodyne-detected vibrational sum frequency generation (HD-VSFG) spectroscopy can discriminate between the excitonic and monomeric properties of a helical, nanotube molecular aggregate by monitoring the phase of the VSFG emission associated with different polarization configurations. By keeping track of the "phase acrobatics" associated with the added phase of the nonresonant SFG emission of gold as well as that of the double-resonance conditions achieved when the SF frequency is resonant with an electronic exciton transition, we discover that for aggregates of tetra(sulfonatophenyl)porphyrin (TSPP) the PPP-polarized spectra exhibit double-resonance conditions while SSP-polarized spectra exhibit resonance only with the ground-state vibration. Along with observed shifts in the vibrational frequency, intensity differences, and sign flips in the imaginary second-order susceptibility, χs,Im(2), we conclude that PPP-polarized HD-VSFG spectra reflect the delocalized, excitonic nature of the molecular aggregate, while the SSP-polarized HD-VSFG spectra measure the localized, monomeric nature of the molecular subunits. It is implied from this study that HD-VSFG spectroscopy can be uniquely utilized to measure the excitonic and monomeric properties associated with molecular assemblies for a single sample.

Structure-Function Correlation of Photoactive Ionic pi-Conjugated Binary Porphyrin Assemblies

ABSTRACTWe present the first detailed structure-function study of a photoconducting ionic porphyrin supermolecular assembly, fabricated from tetra(N-methyl-4-pyridyl)porphyrin (TMPyP) and tetra(4-sulfonatophenyl)porphyrin (TSPP) in a 1:1 stoichiometric ratio. Rod like crystals large enough for single crystal diffraction studies were grown by utilizing a nucleation and growth model described in our previous work. The unit cell of the TMPyP:TSPP crystals is monoclinic P21/c and the cell constants are a = 8.3049(11) Å, b = 16.413(2) Å, c = 29.185(3) Å, β = 92.477(9)°. These crystals have smooth well defined facets and their internal structure consists of highly organized molecular columns of alternating porphyrin cations and anions that are stacked face to face. For the first time crystal morphology (habit) of an ionic porphyrin solid is predicted by using the crystal structure data and applying attachment energy (AE) model. The predicted habit is in good agreement with the experimental structural morphology observed in AFM and SEM images of the TMPyP:TSPP crystalline solid. The TMPyP:TSPP crystals are non-conducting in the dark and are photoconducting. The photoconductive response is significantly faster with excitation in the Q-band (Red) than with excitation in the Soret band (blue). DFT calculations were performed to determine their electronic band structure and density of states. The TMPyP:TSPP crystalline system is a useful model structure that combine the elements of molecular organization and morphology along with theory and correlate them with electronic and optical electronic properties.

Synergy and translation of allogenic bone marrow stem cells after photodynamic treatment of rheumatoid arthritis with tetra sulfonatophenyl porphyrin and TiO2 nanowhiskers

Rheumatoid arthritis (RA) etiology and amelioration remains a challenge in modern therapeutics. Herein, we explored the synergistic effect of allogenic bone marrow stem cell (BMSC) translation and photodynamic treatment of RA with tetra sulfonatophenyl porphyrin (TSPP) and TiO2 nanocomposites as a new strategy for RA theranostics. The translation of BMSCs with miRNAs into infected joints in long bones post-photodynamic therapy is helpful for treating and understanding RA pathophysiology. We observed that allogenic BMSC translation combined with TSPP-TiO2 nanocomposites can significantly (p < 0.01) lower the concentrations of serum biomarkers (tumor necrosis factor-α and interleukin-17) in a collagen induced arthritis (CIA) murine model, both in vitro and in vivo, as well as improve other parameters such as arthritis score, BMSC count, complete blood count, and numbers of platelets, red blood cells, and white blood cells. Moreover, a fluorescent TSPP in the feet or long bones and X-ray bioimaging of RA joints revealed the clinical efficacy of BMSCs combined with TSPP-TiO2 nanocomposites. Microarray data analysis illustrated that rno-mir-375-3p and rno-mir-196b-3p were up-regulated by approximately 100-fold in the BMSCs of ameliorated RA post-photodynamic therapy with TSPP-TiO2 nanocomposites. Our study not only suggests a new approach for RA theranostics, but also helps in understanding RA pathophysiology.

Surface-Enhanced Raman Spectra of Tetra(4-Sulfonatophenyl)Porphyrin on the Surface of Plasmonic Silver Films

Absorption and Raman spectra of the tetra(4-sulfonatophenyl)porphyrin (TSPP) zwitterion in aqueous solutions under conditions at which porphyrin nanotubes (PNT) form (pH 1) are presented. TSPP was immobilized on the surface of plasmonic silver films (PSF) via quick transfer of a suspension of the molecules into a solution at pH 5 and onto the film surface in order to avoid degrading the film. Images of PNT and spheroidal TSPP aggregates on the PSF surface were visualized using confocal microscopy. Spatially resolved surface-enhanced Raman spectra (SERS) of these objects were recorded. Differences in SERS of PNT and TSPP globular aggregates are discussed based on quantum-chemical calculations of TSPP vibrational spectra. Vibrational bands sensitive to the tube–spherulite transition are found.

Optoelectronic Properties of Metal-Free Binary Porphyrin Nanostructures

Nanostructures fabricated from tetrapyridylphenyl porphyrin (TPyP) and tetrasulfonatophenyl porphyrin (TSPP) in a 1:1 ratio are conducting and also photoconducting. I-V curves for the nanorods (in a vacuum environment) were collected in the dark and with (405, 473, and 633 nm) illumination. These wavelengths fall within the absorption spectrum of the porphyrin solid and allow determination of an action spectrum. With illumination, the nanorods show a sharp increase in conductivity followed by a slow increase in conductivity over time until a saturation photocurrent is reached. Once the light is off, the current decays slowly over time. This is referred to as persistent photoconductivity. The TPyP:TSPP nanorods exhibit an increase in photo-conductivity with an applied positive gate voltage and a decrease with an applied negative gate voltage, consistent with the electrons acting as the primary mobile charge carrier. Quantification of the persistent photoconductive behavior and a model for electron transport through the nanostructures will be presented.

Facile assembly for fast construction of intercalation hybrids of layered double hydroxides with anionic metalloporphyrin.

Anionic manganese tetrasulfonatophenyl porphyrin (MnTSPP) has been intercalated into the interlamellar space of Mg-Al and Ni-Al layered double hydroxides (LDHs) through the exfoliation/restacking approach by using exfoliated LDH nanosheets and guest molecules as building blocks. The obtained hybrids were characterized by a variety of analytical techniques such as CHN analysis, XRD, FTIR, SEM, HRTEM, UV-vis spectroscopy and thermal analysis. Interlayer spacings determined from XRD patterns reveal a perpendicular orientation of the MnTSPP anions between the hyroxylated layers of both LDHs. The results of zeta potential measurements give information about the surface charge change of LDH nanoparticles associated with the spontaneous coassembly process. The catalytic performance of the heterogeneous catalysts MnTSPP/Mg-Al LDH2.0 and MnTSPP/Ni-Al LDH1.0 for the epoxidation of cyclohexene was investigated using molecular oxygen as an oxidant and isobutylaldehyde as a co-reductant. The intercalated hybrids appear to be promising catalysts owing to their good catalytic activity and selectivity.

Effect of Human and Bovine Serum Albumin on kinetic Chemiluminescence of Mn (III)-Tetrakis (4-Sulfonatophenyl) Porphyrin-Luminol-Hydrogen Peroxide System

The present work deals with an attempt to study the effect of human and bovine serum albumin on kinetic parameters of chemiluminescence of luminol-hydrogen peroxide system catalyzed by manganese tetrasulfonatophenyl porphyrin (MnTSPP). The investigated parameters involved pseudo-first-order rise and fall rate constant for the chemiluminescence burst, maximum level intensity, time to reach maximum intensity, total light yield, and values of the intensity at maximum CL which were evaluated by nonlinear least square program KINFIT. Because of interaction of metalloporphyrin with proteins, the CL parameters are drastically affected. The systems resulted in Stern-Volmer plots with k Q values of 3.17 × 105 and 3.7 × 105 M−1 in the quencher concentration range of 1.5 × 10−6 to 1.5 × 10−5 M for human serum albumin (HSA) and bovine serum albumin (BSA), respectively.

Cover Picture: Photocontrolled Release and Uptake of a Porphyrin Guest by Dithienylethene‐Tethered β‐Cyclodextrin Host Dimers (Chem. Eur. J. 5/2004)

The cover picture shows the reversible photocontrolled release and uptake of a tetrasulfonatophenyl porphyrin (TSPP) from a photoswitchable dithienylethene‐tethered β‐cyclodextrin dimer. The background displays the interplay of the two elements involved: light and water. The open flexible form of the dimer binds TSPP strongly in aqueous solution (orange structure). Irradiation of the complex with UV‐light (blue arrow) closes the dithienylethene tether of the β‐cyclodextrin dimer and hence places the two β‐cyclodextrin cavities further apart from each other (blue structure, top). The stability of this closed dimer–TSPP complex is significantly lower and TSPP is released from the dimer to the aqueous solution (blue structure, right). By irradiation with visible light (orange arrow) the dithienylethene tether can be completely converted back to the more flexible open form, allowing the dimer to once again strongly bind TSPP and leading to the uptake of TSPP from aqueous solution. This chemistry is described in more detail by J. Huskens, D. N. Reinhoudt, et al. on p. 1114ff.

A Spectroelectrochemical Investigation of the Reduction of the Water-Soluble MnTSPP: SERS Spectra of MnIITSPP

Electrochemical and surface spectroscopic techniques are used to investigate the reductive electrochemistry of the water-soluble manganese tetrasulfonatophenyl porphyrin. The electrocehmistry of MnTSPP at a Ag, Au, and Pt electrode and the normal Raman and surface-enhanced Raman scattering spectra of the two redox forms of MnTSPP were studied. Voltammetric studies indicate two reductive peaks at −0.45 and −0.85 V on an Ag electrode. Potential-dependent shifts in the 466 nm UV/vis absorbance band to 432 nm at −0.5 V on a gold minigrid electrode indicate that reduction of the porphyrin central metal from MnIII to MnII occurs at this potential. A 32 cm-1 downshift in the ν4 vibration from 1368 to 1336 cm-1 at −0.5 V is further evidence for the reduction of the metal from the MnIII to the MnII state. The reduction of the porphyrin macrocyclic ring to the radical anion is also observed at −0.8 V. The core-sensitive modes of aquo MnIIITSPP are in excellent agreement with that of a 6-coordinate species. Upon red...