• Title/Summary/Keyword: Porphyrins

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Synthesis and Spectral properties of meso-porphyrin (meso-Porphyrin의 합성과 분광특성)

  • Lee, Bum-Hoon;Jaung, Jae-Yun
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10b
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    • pp.100-103
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    • 2003
  • The basic structure of porphyrin consists of four pyrrole units linked by four methine bridges. It reveals that the cyclic 16-atom is the preferred cyclic system for n-electron delocalization since this pathway exhibits the highest degree of bond equalization. Scheme 1 (a) shows the 16-center system is the chromogen of the porphyrins, which allows 18-electron delocalization that could produce aromatic characteristics (1,2). (omitted)

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Chromatographic Techniques for the Isolation and Purification of Metalloporphyrins from Crude Asphalts (크로마토그래피를 이용한 아스팔트로 부터 금속 포르피린의 분리및 정제)

  • Woo Ki Chae
    • Journal of the Korean Chemical Society
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    • v.28 no.6
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    • pp.393-398
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    • 1984
  • Porphyrin-rich materials were obtained from some crude asphalts by gel permeation chromatography and silica gel chromatography. After extraction of each chromatographic fractions through alumina with pyridine, more concentrated metalloporphyrins were obtained. Demetallation of metalloporphyrins was possible without destroying porphyrin ring to provide different type of metal free porphyrins.

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Time-Resolved Resonance Raman Spectroscopic Study on Metallotetraphenylporphyrins: Effects of Metal Sizes

  • 정새채;김동호;조대원;윤민중
    • Bulletin of the Korean Chemical Society
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    • v.20 no.6
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    • pp.657-662
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    • 1999
  • The variation of Jahn-Teller(J-T) distortion imposed on various metallo- tetraphenylporphyrins(MTPPS;M=ZnⅡ,PdⅡ,PtⅡ,and RhⅢ) has been investigated by time-resolved resonance Raman spectroscopy. B1g and B2g modes of the triplet(π,π*) states for the heavy-metal porphyrins exhibit the enhancement of their intensities compared with those of 3ZnⅢTPP, while the enhancement of phenyl internal mode is reduced. These results suggest that the J-T distortion becomes manifest as the metal size increases, and consequently the porphyrin-to-phenyl ring charge transfer in the excited triplet state is inhibited.

Theoretical Analysis on Molecular Magnetic Properties of N-Confused Porphyrins and Its Derivatives

  • Wei, Wei;Bai, Fu-Quan;Xia, Bao-Hui;Zhang, Hong-Xing
    • Bulletin of the Korean Chemical Society
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    • v.33 no.9
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    • pp.2937-2942
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    • 2012
  • We have theoretically investigated the magnetic properties of N-confused porphyrin (NCP), tetraphenyl-N-confused porphyrin (TPNCP) and their substituted derivatives with O, S and Se heteroatoms (2ONCP, 2STPNCP, 2SeNCP, 2OTPNCP, etc.) by using DFT method. In the minimum energy structures of the 2OTPNCP, the two couples opposite phenyl substitutes are staggered. In the case of TPNCP, 2STPNCP and 2SeTPNCP, two phenyls being respectively close to or opposite to N-confused pyrrole are found to be pointed the same direction, whilst others are in the opposite direction. Based on the equilibrium structures, the $^1H$ chemical shifts and nucleus-independent chemical shifts (NICS) are calculated in this paper. The ${\pi}$ current density being induced by the tridimensional perpendicular magnetic field transmits the inner section of the pyrrole segments for NCP and TPNCP. As for their substituted derivatives with O, S and Se atoms, the current path passes through the outer section of the two heterorings. The NICS values at the ring critical points of the heterorings are much lower (in absolute value) than those of which is at the center of an isolated pyrrole molecule. The $^1H$ NMR for ${\beta}H$ atoms of the heterorings decreases from O, S to with Se.

Photochemical Property and Photodynamic Activity of Tetrakis(2-naphthyl) Porphyrin Phosphorus(V) Complex

  • Hirakawa, Kazutaka;Aoki, Shunsuke;Ueda, Hiroyuki;Ouyang, Dongyan;Okazaki, Shigetoshi
    • Rapid Communication in Photoscience
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    • v.4 no.2
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    • pp.37-40
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    • 2015
  • To examine the photosensitized biomolecules damaging activity, dimethoxyP(V)tetrakis(2-naphthyl)porphyrin (NP) and dimethoxyP(V)tetraphenylporphyrin (PP) were synthesized. The naphthyl moiety of NP hardly deactivated the photoexcited P(V)porphyrin ring in ethanol. In aqueous solution, the naphthyl moiety showed the quenching effect on the photoexcited porphyrin ring, possibly through electron transfer and self-quenching by a molecular association. Binding interaction between human serum albumin (HSA), a water soluble protein, and these porphyrins could be confirmed by the absorption spectral change. The apparent association constant of NP was larger than that of PP. It is explained by that more hydrophobic NP can easily bind into the hydrophobic pockets of HSA. The photoexcited PP effectively induced damage of the tryptophan residue of HSA, through electron transfer-mediated oxidation and singlet oxygen generation. NP also induced HSA damage during photo-irradiation and the contributions of the electron transfer and singlet oxygen mechanisms were speculated. The electron transfer-mediated mechanism to the photosensitized protein damage should be advantageous for photodynamic therapy in hypoxic condition. The quantum yield of the HSA photodamage by PP was significantly larger than that of NP. The quenching effect of the naphthyl moiety is considered to suppress the photosensitized protein damage. In conclusion, the naphthalene substitution to the P(V)porphyrins can enhance the binding interaction with hydrophobic biomacromolecules such as protein, however, this substitution may reduce the photodynamic effect of P(V)porphyrin ring in aqueous media.

Solution Nuclear Magnetic Resonance Spectral Characterization of Iron(II) Porphyrin Complexes of Weakly Coordinating Anions

  • Song, Byung-Ho;Park, Bong-Jin;Han, Chul-Hee
    • Bulletin of the Korean Chemical Society
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    • v.23 no.1
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    • pp.119-122
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    • 2002
  • Weakly coordinating anions show little affinity for binding to unfunctionalized iron(II) porphyrins. The electron-deficient 5, 10, 15, 20-tetrakis(pentafluorophenyl)porphinatoiron(II) compound is utilized in this study to demonstrate solution coordination by chloride, bromide and acetate ions. The binding strength of anions to the iron(II) porphyrin is reflected by a systematic change in pyrrole proton chemical shift in $^1H$ NMR spectra; the pyrrole resonance moves downfield when the ${\sigma}$-donor ability of anions is decreased.

Recyclable Porphyrin Catalyst with Core-shell Nanostructure

  • Choi, Bo-Gyu;Ko, Soo-Y.;Nam, Won-Woo;Jeong, Byeong-Moon
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1819-1822
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    • 2005
  • In the search for a simple preparation method of heterogeneous catalyst, the iron porphyrins were coordinated bonded to the surface of a polymeric core-shell nanosphere. The heterogeneous catalyst was characterized by FT-IR, scanning electron microscope, and UV-vis spectrophotometer. The iron porphyrin bound core-shell nanospheres was about 470 nm in diameter and their catalytic activity for cyclohexene oxidation was similar to a homogeneous iron porphyrin in a solvent composition range of 25-75% acetonitrile/water (v/v). In addition, they could be recovered by simple centrifugation and their catalytic activity was maintained more than the third cycle.

Mn(III)-, Fe(III)-porphyrin Catalyzed Oxidation of cycloolefins (Mn(III)-, Fe(III)-porphyrin 유도체를 촉매제로 한 시클로올레핀 화합물의 산화반응)

  • Na, Hun-Gil;Park, Yu-Chul
    • Journal of the Korean Applied Science and Technology
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    • v.15 no.2
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    • pp.41-48
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    • 1998
  • The catalytic oxidations of several cycloolefins in $CH_2Cl_2$ were been investigated using Mn(III)-, Fe(III)-porphyrin complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were $(p-CH_3O)TTP,\;(p-CH_3)TTP,$ TPP, (p-F)TPP, (p-Cl)TPP and $(F_{20})TPP$ (TPP = tetraphenylporphyrin), and olefins were cyclopentene, cyclohexene and cycloheptene. The substrate conversion yield was discussed according to the substituent effects of metalloporphyrin. The conversion yield of substrate by changing the substituent of TPP increased in the order of $p-CH_3O$ < $p-CH_3$ < H < p-F < p-Cl, which was consistent with the sequence of $4{\sigma}$ values of TPP. The conversion of cycloalkene followed the order of $C_5\;<\;C_6\;<\;C_7$.

Hydroxylation of Cycloalkanes Catalyzed by In(III)-, Tl(III)-Porphyrin (In(III)-, Tl(III)-porphyrin을 촉매제로 한 시클로알칸의 히드록시화 반응)

  • Na, Hun-Gil
    • Journal of the Korean Applied Science and Technology
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    • v.17 no.1
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    • pp.15-21
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    • 2000
  • The catalytic hydroxylation of several cycloalkanes in dichloromethane have been investigated using In(Ⅲ)-, Tl(Ⅲ)-porphyrin complexes as a catalyst and NaClO, $NaClO_{2}$, $H_{2}O_{2}$ as a terminal oxidant. Porphyrins were TPP and ($F_{20}$)TPP (TPP = tetraphenylporphyrin) and substrates were cyclopentane, cyclohexane, cycloheptane and cyclooctane. The substrate conversion yield was discussed according to the substituent effect and hinderance effect of metalloporphyrin and the radius effect of non-redox metal ion. The conversion yield of cycloalkane followed the order of $ C_{5} $ < $ C_{6}$ < $ C_{7}$ = $ C_{8}$. In this experimental condition $NaClO_2$ was rather efficient terminal oxidant than NaClO and $H_{2}O_{2}$.