1263-63-4Relevant academic research and scientific papers
Development of the sensitizer for generating higher-energy photons under diluted condition via the triplet-triplet annihilation-supported upconversion
Tanaka, Kazuo,Ohashi, Wataru,Inafuku, Kenichi,Shiotsu, Shohei,Chujo, Yoshiki
, (2020)
It was previously reported that photon upconversion can occur in the solution containing anthracene and the Pt complex of octaethylporphyrin (PtOEP) via the triplet-triplet annihilation process. In this study, by employing the modified Pt complex of the dual anthracene-tethered porphyrin, DA-PtP as a sensitizer, it is demonstrated that shorter-wavelength light can be generated under diluted condition. We synthesized DA-PtP and compared upconversion properties by changing the type of sensitizers. Accordingly, it was shown that the photon upconversion proceeded with the xenon lamp (540 nm) in the presence of DA-PtP. Furthermore, it was found that the emission band in the shorter wavelength light in the near UV region was observed from the solution containing DA-PtP even under diluted condition. From the mechanistic investigation, it was proposed that the anthracene moieties in DA-PtP might inhibit to form agglomeration with the free anthracene. As a result, reabsorption of the higher-energy light generated from upconversion could be suppressed.
A simple, catalytic H2-hydrogenation method for the synthesis of fine chemicals; hydrogenation of protoporphyrin IX dimethyl ester
Rebou?as, Júlio S.,James, Brian R.
, p. 5119 - 5122 (2006)
A conceptually simple H2-hydrogenation protocol is introduced for the high-yield preparation of a natural product derivative. Protoporphyrin IX dimethyl ester is hydrogenated to the mesoporphyrin analogue in N,N-dimethylacetamide under H2 (1 atm) at 80 °C within 30 min. The reaction is catalyzed by commercial RuCl3, without the need for the use of phosphine- and/or carbene-based ligands.
A convenient hydrogenation method for the synthesis of metallo- mesoporphyrin IX dimethyl esters via self-catalyzed CoCl2-NaBh 4 reagent system
Xu, Shichao,Hu, Bingcheng,Hu, Tianjing,Wang, Huan,Huang, Xiuyou,Lou, Xingkun,Liu, Zuliang
, p. 2461 - 2465 (2012)
A convenient protocol has been developed for the hydrogenation of metallo-protoporphyrin IX dimethyl esters (MPPDMEs) to their mesoporphyrin analogues using CoCl2-NaBH4 reagent system. Metallo-porphyrin complexes were found to perform as self-catalysts in this procedure. This method provides several advantages such as safe and simple procedure, short reaction time, high yields and low cost. Copyright
Protonation-deprotonation equilibria in tetrapyrroles Part 4: Mono- and diprotonations of deutero-, hemato-, meso-, and protoporphyrin IX dimethyl esters in methanolic hydrochloric acid
Hynninen, Paavo H.
, p. 385 - 395 (2015/05/20)
The N-protonations in the deutero, hemato, meso and protoporphyrin IX dimethyl esters (DME) were investigated by spectrophotometric titrations using HCl as the acid and methanol as the solvent. Two spectroscopically different protonated species were observed for each porphyrin DME in addition to the neutral form. These were assigned to the N-protonated monocation and dication. There were no difficulties encountered in observing the monocation formation in the HCl-MeOH system. Very sharp isosbestic points were characteristic of each protonation stage. The pK3 values for the porphyrins in the above order were 3.23, 4.70, 2.93 and 3.37; the pK4 values were 2.48, 2.62, 2.41 and 2.64, respectively. For all porphyrins studied, no further spectral changes were observed after the dication was completely formed. This was interpreted as indicating that the formation of more highly protonated species is not possible in fullydelocalized porphyrins possessing the 18 π-electron [18]diazaannulene delocalization pathway. When the titration was performed on the free dicarboxylic acid porphyrins, aggregation obscured the first protonation step and no clear monocation spectrum could be distinguished. However, also in that case the titration ended up to a UVvis spectrum typical of the dication and the effect of aggregation on the pK4 values was negligible. The UVvis spectrometric parameters are given for the neutral forms and for the protonated species of the porphyrin DMEs. The results are discussed in terms of the NH tautomerization connected to the π-electron delocalization pathway (aromaticity), which tends to hinder outofplane distortions in the porphyrin plane, and in terms of solvation and counterion stabilization of the protonated forms.
The Preparation of Analogues of the Ether-Linked Dimer and Oligomer Components of Hematoporphyrin Derivative
Byrne, Christopher J.,Ward, David A.
, p. 411 - 426 (2007/10/02)
The preparation of ether-linked porphyrin dimers and oligomers which are analogues of those present in the anticancer drugs hematoporphyrin derivative and Photofrin IIR is described.These materials are prepared from the appropriately substituted porphyrins containing a 1-hydroxyethyl or a vinyl side chain through an intermediate 1-bromoethyl derivative.Ether-linked porphyrin dimers with ethyl, formyl, hydroxymethyl and 1-alkoxyethyl side chains were prepared, together with trimers and tetramers containing ethyl side chains.Some of the spectroscopic and biological properties of these compounds are discussed.
PORPHYRINS. 24. IDENTIFICATION OF ISOMERIC MONOESTERS OF NATURAL PORPHYRINS BY PMR SPECTROSCOPY
Maravin, G.B.,Ponomarev, G.V.
, p. 637 - 642 (2007/10/02)
The monomethyl esters of mono(dimethylamides) and the bisdimethylamides of mesoporphyrin-IX, mesoporphyrin-III, and mesoporphyrin-XIII have been obtained, together with their zinc complexes.A relationship has been found between the chemical shifts of the signals for CONMe2 in the PMR spectra and the positions of the substituents in the porphyrin ring, enabling a correct assignment to be made for the first time of these signals to the groups in positions 132 and 172 of the porphyrin ring, to establish the structures of the isomeric monomethyl esters of mesoporphyrin-IX, and to develop a method identifying monoesters of natural porphyrins by converting them into the monoesters of the mono(dimethylamides) of mesoporphyrin-IX, followed by examination of their PMR spectra.
A FACILE PORPHYRIN ESTERIFICATION / ETHERIFICATION PROCEDURE
Byrne, Christopher J.,Ward, A. David
, p. 1421 - 1424 (2007/10/02)
Porphyrin carboxylic acids and 1-hydroxyethyl groups can be rapidly esterified and etherified using alcohol/trialkyl orthoformate/strong acid mixtures; addition of water to the reagent permits esterification only.
Porphyrin Sythesis through Tripyrrins: An Alternative Approach
Smith, Kevin M.,Craig, G. Wayne
, p. 4302 - 4306 (2007/10/02)
A new route for synthesis of unsymmetrically substituted porphyrins is described.The route follows the earlier approach through pyrromethanes, tripyrrin hydrobromides, and a,c-biladiene dihydrobromides, except that the pyrromethane intermediate is elongated in an initially "clockwise" direction to give a benzyl tripyrrincarboxylate.Various advantages over the tert-butyl tripyrrincarboxylates used in the earlier method (Scheme I) are discussed.The new route is demonstrated in the syntheses of five pure porphyrins required for other current studies.
Mechanism of a Novel Synthesis of Haemin c from Protohaemin and L-Cysteine. A Markownikoff-type Radical Addition Reaction
Kojo, Shosuke,Sano, Seiyo
, p. 2864 - 2870 (2007/10/02)
As a simulation of in vivo sulphide bond formation of c-type cytochromes, haemin c (4) was synthesized by the reaction of iron protoporphyrin IX with sodium borohydride in the presence of L-cysteine, oxygen, and cetyltrimethylammonium bromide (CTAB).When L-cysteine was omitted from the reaction mixture, mesohaemin (9) and haematohaemin (5) were obtained.The inhibitory effect of cyanide anion or carbon monoxide, as well as the inability of protoporphyrin (8) to serve in place of (3) in both reactions, indicated that the iron of (3) and oxygen were crucial in a primary process to give a common intermediate (11) for (4), (5), and (9).Trapping of (11) with oxygen indicated that it is the α-carbon radical of the 2- or 4-ethyl group derived from (3).The addition of deuterium (from sodium borodeuteride) to the β-carbon of the vinyl group of (3) and the resulting formation of (11) strongly suggested the intermediacy of a free hydrogen atom, which was generated in the reduction of (3) with sodium borohydride.The generation of a free hydrogen atom was also supported by a transfer experiment.
Studies of Spiro-chlorin Formation Using Porphyrin Amides
Smith, Kevin M.,Almeida, Jose A.P.Baptista de,Lewis, W. Michael
, p. 481 - 487 (2007/10/02)
Syntheses of 7-(3-ethoxycarbonylpropyl)-2,3,5-triethyl-1,4,6,8-tetramethylporphyrin (8) (via the MacDonald dipyrrylmethane route) and 2-(2-chloroethyl)-4-ethyl-6-methoxycarbonyl-7-(3-methoxycarbonylpropyl)-1,3,5,8-tetramethylporphyrin (22) (via the tripyrrene route) are described.The corresponding pyrrolidines of these compounds were cyclized in high yield to furnish the spiroimines (20 and 30 respectively), but attempts to hydrolyze these imines to the appropriate spiroketochlorins were largely unsuccessful.A small amount of the spiroketochlorin 9 (from 8) was obtained, and this was succesfully hydrogenated to give the dihydro derivative 21.The major problem in imine hydrolysis was observed to be reversion to the parent porphyrin through simple bond migration and spiro ring cleavage.A successfull transformation of protoporphyrin-IX dimethyl ester (31) into mesoporphyrin-IX dimethyl ester (32) using di-imide generated from dipotassium azodicarboxylate is discribed.
