نتایج جستجو برای: expanded porphyrins

تعداد نتایج: 64232  

Journal: :Chemical communications 2015
Miriam de Torres Sergey Semin Ilya Razdolski Jialiang Xu Johannes A A W Elemans Theo Rasing Alan E Rowan Roeland J M Nolte

Zinc porphyrin dimers and trimers, in which the porphyrins are connected via a ruthenium metal core, exhibit large third-order nonlinear optical absorption coefficients and refractive indices. These properties are a result of the presence of multiple porphyrins, which lead to an extension of the π-conjugated system and the octupolar effect.

Journal: :Chemical communications 2014
Ram B Ambre Gao-Fong Chang Chen-Hsiung Hung

Zinc porphyrins possessing three p-carboxyphenyl anchoring groups with various substituents were prepared by a facile three-step route in good yields. Zn1NH3A with electron donating and anti-aggregation meso substituents has achieved the highest efficiency of 6.10%. These porphyrins with three p-carboxyphenyl groups are more stable toward photo-bleaching than their single anchoring group analogs.

2006
Masamichi Ikai Hisato Takeuchi Hisayoshi Fujikawa Yasunori Taga

Phosphorescent organic light-emitting diodes (OLEDs) have the great advantage of highlyefficient emission compared with conventional fluorescent OLEDs. Pt(II) porphyrins are among the most promising saturated red phosphorescent dyes, yet tuning of their properties by making structural modifications has only been attempted on a modest scale, despite the large structuraldiversity of synthetic por...

2006
Keiko KOMAGOE Keietsu TAMAGAKE Takashi KATSU

ers used in photodynamic therapy. Upon light irradiation, porphyrins produce singlet oxygen, which causes cytotoxic activity at specific subcellular sites, leading to cell death. The quantum yield of singlet oxygen depends on the porphyrin employed, being significantly lowered by dimerization or aggregation of the porphyrin. The aggregation of porphyrins also affects the transfer of electrons f...

Journal: :Analyst 2021

Porphyrins and phthalocyanines used to construct sensors for electroanalytical drug detection.

2014
Tatiana V. Esipova Sergei A. Vinogradov

Significant effort has been directed in recent years toward porphyrins with enhanced two-photon absorption (2PA). However, the properties of their triplet states, which are central to many applications, have rarely been examined in parallel. Here we report the synthesis of asymmetrically π-extended platinum(II) and palladium(II) porphyrins, whose 2PA into single-photon-absorbing states is enhan...

Journal: :Organic & biomolecular chemistry 2008
K Eszter Borbas Hooi Ling Kee Dewey Holten Jonathan S Lindsey

A broad range of applications requires access to porphyrins that are compact, water-soluble, and bioconjugatable. A symmetrically branched hydrocarbon chain ('swallowtail') bearing polar end groups imparts high (>10 mM) aqueous solubility upon incorporation at one of the meso positions of a trans-AB-porphyrin. Two such swallowtail-porphyrins (1a, 1b) equipped with a conjugatable group (carboxyl...

Journal: :Dalton transactions 2008
Ching-Yao Lin Yen-Chuan Chen Chi-Wen Yao Sung-Chou Huang Yi-Hui Cheng

Two series of free-base and manganese N-methyl-pyridylethynyl-5,15-biphenyl porphyrins were synthesized, and their UV-Visible, electrochemical and spectro-electrochemical properties were studied. Cyclic voltammetry experiments showed positive shifts in the reduction potentials and the UV-Visible spectra showed significant red-shifts in the absorption wavelengths of these porphyrins, indicating ...

Journal: :Chemical communications 2012
Karl Börjesson Jakob G Woller Elham Parsa Jerker Mårtensson Bo Albinsson

A binding pocket consisting of two zinc porphyrins self assembled by Watson-Crick base pairing is presented. The porphyrin binding pocket is located in the confined environment of a lipid membrane whereas the DNA is located in the water phase. Bidentate electron accepting ligands are shown to coordinate in-between the two porphyrins.

Journal: :The journal of physical chemistry. A 2015
Allyson M Buytendyk Jacob D Graham Julian Gould Kit H Bowen

The singly charged, parent anions of three transition metal, tetraphenyl porphyrins, M(TPP) [Fe(TPP), Mn(TPP), and Ni(TPP)], were studied by negative ion photoelectron spectroscopy. The observed (vertical) transitions from the ground state anions of these porphyrins to the various electronic states of their neutral counterparts were modeled by density functional theory computations. Our experim...

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