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Cai-Rong Zhang, Xing-Yu Li, Yu-Lin Shen, Youzhi Wu, Zi-Jiang Liu, Hongshan Chen
Novel dye sensitizers are highly expected in the development of dye-sensitized solar cells (DSSCs) since dye sensitizers can significantly affect the power conversion efficiency (PCE). Here, the molecular docking strategy is applied to design panchromatic dye sensitizers for DSSCs in order to improve light-harvesting efficiency covering the full solar spectrum. Considering the broad absorption bands of tetraanthracenylporphyrins (TAnPs) and tetraazuleneporphyrins (TAzPs), based upon porphyrin dye sensitizer YD2-o-C8, the panchromatic dye sensitizers coded as H2(TAnP)-α, H2(TAzP)-γ, H2(TAzP)-ε, and H2(TAzP)-δ are designed by the substitution of the porphyrin-ring in YD2-o-C8 with TAnPs and TAzPs moieties at different positions...
March 20, 2017: Journal of Physical Chemistry. A
Sankar Prasad Rath, Pritam Mondal, Sabyasachi Sarkar
Three cyclic zinc(II) bisporphyrins (CB) with highly flexible linkers are employed as artificial molecular containers that efficiently encapsulate/coordinate various aromatic aldehydes within their cavities. Interestingly, the arrangements of the guests and their reactivity inside the molecular clefts are significantly influenced by the cavity size. In presence of polycyclic aromatic aldehydes such as 3-formylperylene as a guest, the cyclic bisporphyrin host having smaller cavity (CB1) forms 1:1 sandwich complex...
March 20, 2017: Chemistry: a European Journal
Yani Chen, Guy Royal, Emmanuel Flahaut, Saioa Cobo, Vincent Bouchiat, Laëtitia Marty, Nedjma Bendiab
Carbon nanotube-chromophore hybrids are promising building blocks in order to obtain a controlled electro-optical transduction effect at the single nano-object level. In this work, a strong spectral selectivity of the electronic and the phononic response of a chromophore-coated single nanotube transistor is observed for which standard photogating cannot account. This paper investigates how light irradiation strongly modifies the coupling between molecules and nanotube within the hybrid by means of combined Raman diffusion and electron transport measurements...
March 17, 2017: Advanced Materials
Ranjana Gupta, Xiao-Xi Li, Kyung-Bin Cho, Mian Guo, Yong-Min Lee, Yong Wang, Shunichi Fukuzumi, Wonwoo Nam
The rate constants of the C=C epoxidation and the C-H hydroxylation (i.e., allylic C-H bond activation) in the oxidation of cyclohexene by a high-valent iron(IV)-oxo porphyrin π-cation radical complex, [(TMP(•+))Fe(IV)(O)(Cl)] (1, TMP = meso-tetramesitylporphyrin dianion), were determined at various temperatures by analyzing the overall rate constants and the products obtained in the cyclohexene oxidation by 1, leading us to conclude that the reaction pathway changes from the C=C epoxidation to the C-H hydroxylation by decreasing reaction temperature...
March 16, 2017: Journal of Physical Chemistry Letters
Lien Hong Tran, Sunyo Jung
We examined the effects of light quality on growth characteristics and porphyrin biosynthesis of rice seedlings grown under different wavelengths from light emitting diodes (LEDs). After 10 days of exposure to various wavelengths of LEDs, leaf area and shoot biomass were greater in seedlings grown under white and blue LEDs than those of green and red LEDs. Both green and red LED treatments drastically decreased levels of protoporphyrin IX (Proto IX) and Mg-porphyrins compared to those of white LED, while levels of Mg-Proto IX monomethyl ester and protochlorophyllide under blue LED were decreased by 21% and 49%, respectively...
March 16, 2017: International Journal of Molecular Sciences
Jie Yu, Ying-Ming Zhang, Pei-Yu Li, Yu Liu
A novel supramolecular assembly was constructed by the noncovalent complexation of hexa-cata-hexabenzocoronene modified permethyl-β-cyclodextrins with tetrasodium tetraphenylporphyrintetrasulfonate in water, exhibiting highly efficient excited energy transfer behaviors and a promising DNA photocleavage ability.
March 16, 2017: Chemical Communications: Chem Comm
Kaustuv Mittra, Asmita Singha, Abhishek Dey
The reaction of Fe(III) porphyrin complexes bearing distal hydrogen bonding residues with sulfide/hydrosulfide is kinetically monitored to reveal the presence of an intermediate and a kH/kD of 3.0. This intermediate is trapped at low temperatures and investigated with resonance Raman and electron paramagnetic resonance spectroscopy. The results, corroborated by density functional theory calculations, indicate that this species is a six-coordinate low spin hydrosulfide bound ferric porphyrin. The homolytic cleavage of the Fe(III)-SH bond resulting in the formation of a ferrous porphyrin and hydrosulfide radical (trapped with 5,5-dimethyl-1-pyrrilone-N-oxide) is found to be the overall rate-determining step of the reaction...
March 15, 2017: Inorganic Chemistry
Hyun-Suk Park, Sang-Beom Han, Da-Hee Kwak, Gyu-Ho Lee, In-Ae Choi, Do-Hyoung Kim, Kyeng-Bae Ma, Min-Cheol Kim, Kyung-Won Park
To develop doped carbon nanostructures as non-precious metal cathode catalysts, we synthesize the nanocomposites using SBA-15 and 5,10,15,20-tetrakis(4-methoxyphenyl)-porphyrin-Fe(III) chloride with different ratios of amorphous MoS2 precursor. From various analyses, it was found that during the pyrolysis at 900 oC under an N2 atmosphere, the amorphous MoS2 precursor was decomposed into Mo and S, facilitating the formation of graphene sheet-like carbon with MoC and doping of sulfur in the carbon. Especially, in the case of Mo/S/C-10, most of the 10 wt% MoS2 precursor was decomposed, thus forming S-doped carbon which was grown on MoC phase without crystalline MoS2 phase...
March 15, 2017: ChemSusChem
Katharina Kulikov, Senada Nozinovic, Stephanie Kath-Schorr
An unusually thermostable G-quadruplex is formed by a sequence fragment of a naturally occurring ribozyme, the human CPEB3 ribozyme. Strong evidence is provided for the formation of a uniquely stable intermolecular G-quadruplex structure consisting of five tetrad layers using CD-spectroscopy, UV-melting curves, two-dimensional NMR spectroscopy and gel shift analysis. The cationic porphyrin TMPyP4 destabilizes the complex.
March 13, 2017: Chembiochem: a European Journal of Chemical Biology
Samuel de Visser, Xiao-Xi Li, Veronica Postils, Wei Sun, Abayomi Faponle, Miquel Sola, Yong Wang, Wonwoo Nam
The cytochromes P450 are versatile enzymes in human physiology that perform substrate hydroxylation reactions extremely efficient. In this work, we present results of a computational study on the reactivity patterns of Compound I, Compound II and protonated Compound II with model substrates and addresses the question, which of those is the most effective oxidant. All calculations, regardless of the substrate, implicate that Compound I is the superior oxidant of the three. However, Compound II and protonated Compound II are found to react with free energies of activation that are only a few kcal mol-1 higher in energy than those obtained with Compound I...
March 10, 2017: Chemistry: a European Journal
Jarmila Kralova, Michal Kolar, Michal Kahle, Jaroslav Truksa, Sandra Lettlova, Kamila Balusikova, Petr Bartunek
The development of drug resistance is a major problem which often occurs during anticancer chemotherapies. Photodynamic therapy (PDT) has been studied as an alternative treatment modality for drug-resistant tumors, however the question of resistance to PDT and potential cross-resistance with chemotherapy has yet to be fully answered. To investigate the mechanism of resistance to PDT, we developed an in vitro experimental model system in a mouse mammary carcinoma cell line 4T1. We used two ethylene glycol derivatives of tetraphenylporphyrin, and tetraphenylchlorin derivative, temoporfin, as photosensitizers (PS)...
March 15, 2017: Scientific Reports
Jie Hu, Ryan Allen, Sarah Rozinek, Lorenzo Brancaleon
When investigating the interaction between proteins and protoporphyrins in aqueous solution, one typically has to contend with the tendency of the latter to form polydispersed aggregates. The interference of aggregated protoporphyrins manifests, at least, at two levels: aggregates sequester the majority of the protoporphyrin molecules in solution and prevent their interaction with the proteins, but also their presence interferes with optical experiments such as absorption and fluorescence spectroscopy. In this study we present a protocol which uses dialysis and centrifugation to eliminate the aggregates and yield solutions dominated by non-covalent complexes of albumin (HSA) and protoporphyrins...
March 13, 2017: Photochemical & Photobiological Sciences
Subbiramaniyan Kubendhiran, Subramanian Sakthinathan, Shen-Ming Chen, P Tamizhdurai, K Shanthi, Chelladurai Karuppiah
Nitrobenzene (NB) is widely used in the manufacturing of different types of products and other aromatic chemicals. Moreover, it is highly toxic and environmental pollutant compound. Therefore, the detection of nitro aromatic compounds (NACs) has gained more attention in the field of sensor. This article describes the green reduction utilized to preparation of green reduced graphene oxide/nickel tetraphenyl porphyrin (GRGO/Ni-TPP) nanocomposite modified electrode for the determination of nitrobenzene (NB). The GRGO was prepared by environmentally friendly method and using caffeic acid (CA) as a reducing agent...
March 3, 2017: Journal of Colloid and Interface Science
Xia Dong, Hongli Chen, Jingwen Qin, Chang Wei, Jie Liang, Tianjun Liu, Deling Kong, Feng Lv
Visualization of a drug delivery system could reveal the pharmacokinetic properties, which is essential for the design of a novel drug delivery system. In vivo optical imaging offers an advanced tool to monitor the drug release process and the therapeutic effect by the combination of fluorescence imaging and bioluminescence imaging. Multispectral fluorescence imaging can separate the drug and the carrier without interference. Herein, a dual fluorescent anti-tumor drug delivery system was monitored with the doxorubicin-loaded hydrogel to further explore the application of the porphyrin-incorporated hydrogel with four-arm PEG-PCL copolymer as a drug carrier, based on the beneficial fluorescence and good biocompatibility of the porphyrin incorporated hydrogel...
November 2017: Drug Delivery
Bapan Saha, Sk Asif Ikbal, Ana G Petrovic, Nina Berova, Sankar Prasad Rath
We report here the synthesis of a new chiral Zn(II) bisporphyrin tweezer in which two achiral Zn(II) porphyrin moieties are covalently linked by (1R,2R)-diphenylethylenediamine, which produces a strong chiral field around the porphyrin moieties. The chiral tweezer exhibits not only intensity modulation in UV-vis and CD exciton couplets but also a dramatic change, namely, the inversion in the sign of the interporphyrin helicity upon binding of achiral diamines of varying lengths. The stoichiometry-controlled formation of a 1:1 sandwich complex followed by a 1:2 open complex was realized with smaller achiral diamines (n: 2-5) at their low and high concentration regions, respectively, leading to two-step inversion of chirality...
March 10, 2017: Inorganic Chemistry
Wenbei Zhang, Tianlu Cui, Lingyun Yang, Chao Zhang, Ming Cai, Sai Sun, Yefeng Yao, Xiaodong Zhuang, Fan Zhang
Iron and nitrogen (Fe/N) co-doped porous carbons have already shown great potential as electrocatalysts for oxygen reduction reaction in alkaline media. However, it still remains a great challenge to finely integrate a hierarchical porous structure and Fe/N co-doping effect into one material at the same time. In this work, a rational design toward Fe/N-codoped hierarchical porous carbon spheres was developed by the formation of an iron-porphyrin-containing conjugated microporous polymer sphere with hollow structure (HCMP) through a silica sphere template directed condensation of pyrrole and 1,4-phthalaldehyde, then etched with NaOH, and treated with FeCl2...
February 28, 2017: Journal of Colloid and Interface Science
Maria A Castriciano, Denis Gentili, Andrea Romeo, Massimiliano Cavallini, Luigi Monsù Scolaro
Chirality is one of the most intriguing properties of matter related to a molecule's lack of mirror symmetry. The transmission of chirality from the molecular level up to the macroscopic scale has major implications in life sciences but it is also relevant for many chemical applications ranging from catalysis to spintronic. These technological applications require an accurate control of morphology, homogeneity and chiral handedness of thin films and nanostructures. We demonstrate a simple approach to specifically transfer chirality to the model supramolecular system of J aggregates of the protonated form of tetrakis(4-sulfonatophenyl)-porphyrin by utilizing a soft lithography technique...
March 9, 2017: Scientific Reports
Eugen Stulz
DNA is well-known as bearer of the genetic code. Since its structure elucidation nearly seven decades ago by Watson, Crick, Wilkins, and Franklin, much has been learned about its detailed structure, function, and genetic coding. The development of automated solid-phase synthesis, and with it the availability of synthetic DNA with any desired sequence in lengths of up to hundreds of bases in the best case, has contributed much to the advancement of the field of DNA research. In addition, classic organic synthesis has allowed introduction of a very large number of modifications in the DNA in a sequence specific manner, which have initially been targeted at altering the biological function of DNA...
March 8, 2017: Accounts of Chemical Research
Wanji Seo, David L White, Alexander Star
We report a facile chemical method for fabricating holey graphene by catalytic oxidation of highly ordered pyrolytic graphite (HOPG) using an Fe(III) porphyrin complex-based covalent organic framework (COF) as a bifunctional surface catalyst-template. We demonstrate regular hole formation after oxidation with H2O2 and NaOCl, COF removal, and HOPG exfoliation.
March 8, 2017: Chemistry: a European Journal
Hui Zhang, Yu-Hao Li, Yang Chen, Man-Man Wang, Xue-Sheng Wang, Xue-Bo Yin
Phototherapy shows some unique advantages in clinical application, such as remote controllability, improved selectivity, and low bio-toxicity, than chemotherapy. In order to improve the safety and therapeutic efficacy, imaging-guided therapy seems particularly important because it integrates visible information to speculate the distribution and metabolism of the probe. Here we prepare biocompatible core-shell nanocomposites for dual-modality imaging-guided photothermal and photodynamic dual-therapy by the in situ growth of porphyrin-metal organic framework (PMOF) on Fe3O4@C core...
March 8, 2017: Scientific Reports
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