Synthesis and the Effect of Anions on the Spectroscopy and Electrochemistry of Mono(dimethyl sulfoxide)-Ligated Cobalt Corroles.

A new series of cobalt A-triarylcorroles were synthesized and the compounds examined as to their electrochemical and spectroscopic properties in CHCl or dimethyl sulfoxide (DMSO) containing 10 different anions added to the solution in the form of tetrabutylammonium salts. The investigated anions were PF, BF, HSO, ClO, Br, I, Cl, OAc, F, OTs, and CN, all but three of which were found to facilitate reduction of the cobalt corrole in dilute CHCl solutions, as determined by a combination of UV-vis spectroscopy and spectroelectrochemistry. The synthesized corroles are represented as (Ar)CorCo(DMSO), where Ar is a -phenyl group containing one of 10 different electron-donating or -withdrawing substituents.

Spectral, Electrochemical, and ESR Characterization of Manganese Tetraarylporphyrins Containing Four β,β'-Pyrrole Fused Butano and Benzo Groups in Nonaqueous Media.

Two series of β,β'-pyrrole butano- and benzo-substituted mangenese(III) tetraarylporphyrins were synthesized and characterized with regard to their spectral and electrochemical properties. The investigated compounds have the general formula butano(Ar)PorMnCl and benzo(Ar)PorMnCl, where Por is the dianion of the porphyrin and Ar is a p-CHPh, Ph or p-ClPh group on each of the four meso-positions of the macrocycle. Each manganese(III) butano- or benzoporphyrin was examined in CHCl and/or pyridine containing 0.

Ligand Noninnocence in Cobalt Dipyrrin-Bisphenols: Spectroscopic, Electrochemical, and Theoretical Insights Indicating an Emerging Analogy with Corroles.

Three cobalt dipyrrin-bisphenol (DPPCo) complexes with different meso-aryl groups (pentafluorophenyl, phenyl, and mesityl) were synthesized and characterized based on their electrochemistry and spectroscopic properties in nonaqueous media. Each DPPCo undergoes multiple oxidations and reductions with the potentials, reversibility, and number of processes depending on the specific solution conditions, the specific macrocyclic substituents, and the type and number of axially coordinated ligands on the central cobalt ion. Theoretical calculations of the compounds with different coordination numbers are given in the current study in order to elucidate the cobalt-ion oxidation state and the innocence or noninnocence of the macrocyclic ligand as a function of the changes in the solvent properties and degree of axial coordination.

Synthesis and Electrochemical Characterization of Acetylacetone (acac) and Ethyl Acetate (EA) Appended β-Trisubstituted Push-Pull Porphyrins: Formation of Electronically Communicating Porphyrin Dimers.

Two new families of "push-pull" tetraphenylporphyrins with one acetylacetone (acac) or ethyl acetate (EA) moiety at a β-pyrrole position of the macrocycle and two Br or Ph substituents at the antipodal β-positions were synthesized and structurally, spectroscopically, and electrochemically characterized. The examined porphyrins are represented as MTPP(R)acac and MTPP(R)EA (where R = Br or Ph and M = H, Co, Ni, Cu, or Zn). NiTPP(Br)acac exhibits an extremely nonplanar conformation (Δ24 = 0.

β-Functionalized trans-A2B2 push-pull tetrabenzoporphyrins.

A series of β-functionalized trans-A2B2 tetrabenzoporphyrins have been successfully designed and synthesized through newly developed regioselective bromination chemistry of porphyrins and a Pd(0) catalyzed three-step-one pot reaction. These benzoporphyrins exhibit unique patterns of UV-Vis absorptions and emissions.

Electrochemistry of Bis(pyridine)cobalt (Nitrophenyl)corroles in Nonaqueous Media.

A series of bis(pyridine)cobalt corroles with one or three nitrophenyl groups on the meso positions of the corrole macrocycle were synthesized and characterized as to their electrochemical and spectroscopic properties in dichloromethane, benzonitrile, and pyridine. The potentials for each electrode reaction were measured by cyclic voltammetry and the electron-transfer mechanisms evaluated by analysis of the electrochemical data combined with UV-visible spectra of the neutral, electroreduced, and electroxidized forms of the corroles. The proposed electronic configurations of the initial compounds and the prevailing redox reactions involving the electroactive central cobalt ion, the electroactive conjugated macrocycle, and the electroactive meso-nitrophenyl groups are all discussed in terms of solvent binding and the number of the nitrophenyl groups and other substituents on the meso-nitrophenyl rings of the compounds.

Synthesis, Characterization, and Electrochemistry of Open-Chain Pentapyrroles and Sapphyrins with Highly Electron-Withdrawing meso-Tetraaryl Substituents.

A series of open-chain pentapyrroles and sapphyrins with highly electron-withdrawing substituents (i.e., CN, CF , or CO Me) on the meso-phenyl rings was synthesized and characterized as to the spectral properties, protonation reactions, and electrochemistry in non-aqueous media.

Porphyrins as Photoredox Catalysts: Experimental and Theoretical Studies.

Metalloporphyrins not only are vital in biological systems but also are valuable catalysts in organic synthesis. On the other hand, catalytic properties of free base porphyrins have been less explored. They are mostly known as efficient photosensitizers for the generation of singlet oxygen via photoinduced energy transfer processes, but under light irradiation, they can also participate in electron transfer processes.

An aptamer-based quartz crystal microbalance biosensor for sensitive and selective detection of leukemia cells using silver-enhanced gold nanoparticle label.

An aptamer-based quartz crystal microbalance (QCM) biosensor was developed for the selective and sensitive detection of leukemia cells. In this strategy, aminophenylboronic acid-modified gold nanoparticles (APBA-AuNPs) which could bind to cell membrane were used for the labeling of cells followed by silver enhancement, through which significant signal amplification was achieved. Both the QCM and fluorescence microscopy results manifested the selectivity of the sensor designed.

Sensitive and visible detection of apoptotic cells on Annexin-V modified substrate using aminophenylboronic acid modified gold nanoparticles (APBA-GNPs) labeling.

A new strategy for sensitive detection of early stage apoptosis was proposed based on silver-enhanced gold nanoparticle (GNP) label method. Annexin-V modified substrate was constructed via layer-by-layer (LBL) method for specific capture of early stage apoptotic Jurkat cells. A new kind of aminophenylboronic acid modified gold nanoparticle (APBA-GNP) was synthesized and utilized for labeling cells, followed by silver enhancement.

Annexin-V modified QCM sensor for the label-free and sensitive detection of early stage apoptosis.

An easily-made Annexin-V modified quartz crystal microbalance (QCM) sensor was constructed for the quantitative detection of early stage apoptosis for the first time, achieving the goals of specific capture and sensitive detection of target cells in one step without the need for cell labelling.

Polymer nanocomposites with graphene-based hierarchical fillers as materials for multifunctional water treatment membranes.

Phase inversion of polymer casting mixtures filled with hierarchical functional nanostructures is proposed as a synthetic route for the design of multifunctional membranes. The study tested the hypothesis that by regulating the relative content of components representing different levels in the nanofiller hierarchy, the structure and additional functions of such membranes could be controlled separately. Exfoliated graphite nanoplatelets (xGnPs) decorated by Au nanoparticles (Au NPs), used as a model hierarchical nanofiller, were added to the casting mixture of polysulfone, N-Methyl-2-pyrrolidone and polyethylene glycol prior to forming the membrane by phase inversion.

Single-walled carbon nanotubes dispersed in aqueous media via non-covalent functionalization: effect of dispersant on the stability, cytotoxicity, and epigenetic toxicity of nanotube suspensions.

As the range of applications for carbon nanotubes (CNTs) rapidly expands, understanding the effect of CNTs on prokaryotic and eukaryotic cell systems has become an important research priority, especially in light of recent reports of the facile dispersion of CNTs in a variety of aqueous systems including natural water. In this study, single-walled carbon nanotubes (SWCNTs) were dispersed in water using a range of natural (gum arabic, amylose, Suwannee River natural organic matter) and synthetic (polyvinyl pyrrolidone, Triton X-100) dispersing agents (dispersants) that attach to the CNT surface non-covalently via different physiosorption mechanisms. The charge and the average effective hydrodynamic diameter of suspended SWCNTs as well as the concentration of exfoliated SWCNTs in the dispersion were found to remain relatively stable over a period of 4 weeks.

Interactions of aqueous NOM with nanoscale TiO2: implications for ceramic membrane filtration-ozonation hybrid process.

The combined effect of pH and calcium on the interactions of nonozonated and ozonated natural organic matter (NOM) with nanoscale TiO2 was investigated. The approach included characterization of TiO2 nanoparticles and NOM, extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) modeling of NOM-TiO2 and NOM-NOM interactions, batch study on the NOM adsorption onto TiO2 surface, and bench-scale study on the treatment of NOM-containing feed waters using a hybrid process that combines ozonation and ultrafiltration with a 5 kDa ceramic (TiO2 surface) membrane. It was demonstrated that depending on pH and TiO2 loading, the adsorption of NOM species is controlled by either the availability of divalent cations or by preozonation of NOM.

Stable colloidal dispersions of C60 fullerenes in water: evidence for genotoxicity.

Stable aqueous suspensions of colloidal C60 fullerenes free of toxic organic solvents were prepared by two methods: ethanol to water solvent exchange (EthOH/nC60 suspensions) and extended mixing in water (aqu/nC60 suspensions). The extended mixing method resulted in the formation of larger (dp approximately 178 nm) and less negatively charged (zeta approximately -13.5 mV) nC60 colloids than nC60 prepared by ethanol to water solvent exchange (dp approximately 122 nm, zeta approximately -31.