- One and two point binding of organic bases molecules by meso-nitro substituted Zn-octaethylporphyrins
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A study of complex formation of Zn-octaethylporphyrin and its mono-, di-, tri- and tetra-nitro meso-substituted derivatives towards propylamine, 1,3-diaminopropane, 2-(4-imidazolyl)-ethylamine and 1,4-diazabicyclo[2.2.2]octane was carried out by UV-vis titration method and 1H NMR. It has been determined that the nitro-substituted porphyrin receptors form with 1,3-diaminopropane and 2-(4-imidazolyl)-ethylamine 1:1 complexes with two points of binding. Individual contributions of a donor-acceptor interactions and a hydrogen bonding into a total energy of the complexes formation have been estimated. It has been shown that due to a good geometric match between the host-guest molecules the tetra-nitro substituted Zn-porphyrin has maximum binding ability towards the 1,3-diaminopropane, and the tri-nitro substituted Zn-porphyrin effectively binds the 2-(4-imidazolyl)-ethylamine.
- Mamardashvili, Galina M.,Kulikova, Olga M.,Maltseva, Olga V.,Koifman, Oscar I.,Mamardashvili, Nugzar Zh.
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- Evaluation of Octaethyl-7,17-dioxobacteriochlorin as a Ligand for Transition Metals
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The propensity of octaethyl-7,17-dioxobacteriochlorin toward the formation of transition metal complexes was evaluated. A variety of MII ions (M = Co, Ni, Cu, Zn, Pd, Ag, and Cd) and Fe(III) could be inserted using standard methodologies or, more often, using more forcing conditions. The stable products were spectroscopically characterized. The solid-state structures of the Ni(II), Cu(II), Pd(II), and Ag(II) complexes could also be determined by single crystal X-ray diffractometry, whereby the [7,17-dioxobacteriochlorinato] chromophore was found to be largely planar in all cases. The rate of Zn(II) insertion into octaethyl-7,17-dioxobacteriochlorin was less than half that into the corresponding 7-oxochlorin, which itself was about half the rate into the parent octaethylporphyrin. These rate differences reflect the relative decreased basicity of the β-oxo-substituted chromophores and possibly also their decreased conformational flexibility. We compare the basicity of the dioxobacteriochlorin to that of a range of related products of varying reduction state (porphyrin, chlorin, bacteriochlorin), an isomer, and the absence or presence of oxo-functionality, like oxochlorin, chlorin, oxobacteriochlorins, and bacteriochlorin, quantifying the effects of these macrocycle modifications. The work rationalizes earlier reports of the inability of tolyporphin A, a natural product possessing a 7,17-dioxobacteriochlorin chromophore, to form metal complexes and provide a more quantitative understanding of the degree of modulation that β-oxo groups have on the coordination properties of porphyrinoids.
- Brückner, Christian,Chaudhri, Nivedita,Li, Ruoshi,Schnable, David,Zeller, Matthias
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- Synthesis of porphyrinylamide and observation of N-methylation-induced trans-cis amide conformational alteration
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We synthesized porphyrinylamide 4b and its N-methylated derivative 5b. Direct N-methylation of porphyrinylamides 4 proved unsuccessful, so 5b was obtained via N-methylation of 5-aminoporphyrin 10 with potassium hexamethyldisilazide. The secondary amide 4b
- Matsumura, Mio,Tanatani, Aya,Kaneko, Tomoyo,Azumaya, Isao,Masu, Hyuma,Hashizume, Daisuke,Kagechika, Hiroyuki,Muranaka, Atsuya,Uchiyama, Masanobu
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- Coordination dimer based on zinc octaethylporphyrin and meso-pyridyl-substituted porphyrin
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New dimeric porphyrin was synthesized as a result of coordination interaction between 2,3,7,8,12,13,17,18-octaethylporphyrinatozinc(II) and 5-(3,5-di-tert-butylphenyl)-2,8,12,18-tetraethyl-3,7,13,17-tetramethyl-15- (pyridin-4-yl)porphyrin. The new compoun
- Guseva, L. Zh.,Pukhovskaya,Semeikin,Golubchikov
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- Spectrophotometric study of acid-base and complexing properties of 5,10,15-trinitro-2,3,7,8,12,13,17,18-octaethylporphyrin in acetonitrile
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Acid-base and complexing properties of 5,10,15-trinitro-2,3,7,8,12,13,17, 18-octaethylporphyrin have been studied by means of spectrophotometry in the acetonitrile/1,8-diazabicyclo[5.4.0]undec-7-ene, acetonitrile/perchloric acid, and acetonitrile/zinc ace
- Ivanova,Nam, Dao Tkhe,Chizhova,Mamardashvili
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- Influence of substituents structure and their electronic effects on acid-base and complexing properties of 5,10,15,20-tetranitro-2,3,7,8,12,13,17, 18-octaethylporphyrin
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5,10,15,20-Tetranitro-2,3,7,8,12,13,17,18-octaethylporphyrin has been prepared, and its acid-basic properties have been studied in acetonitrile by titration with 1,8-diazabicyclo [5.4.0]undec-7-ene and perchloric acid. The substituted porphyrin ability to
- Ivanova,Chizhova,Pukhovskaya,Mamardashvili
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- Zinc porphyrin-anthraquinonylimidazole supramolecular dyads
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In this work, the synthesis and spectroscopic characterization of new zinc porphyrin-anthraquinone dyads is proposed. In particular, electron donor units based on zinc meso-tetraphenylporphyrin (ZnTPP) and zinc octaethylporphyrin (ZnOEP) have been coupled
- Sabuzi, Federica,Coletti, Alessia,Conte, Valeria,Floris, Barbara,Galloni, Pierluca
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p. 850 - 859
(2020/01/21)
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- Enthalpy—entropy compensation upon metal ion coordination with porphyrins: generalization for the free bases and doubly deprotonated macrocycles
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Enthalpy—entropy compensation upon the coordination of zinc ions by porphyrins with various structural organizations of peripheral substitution in solutions at 298 K was studied. The same compensation temperature Tc was found for both free base
- Ivanova, Yu. B.,Koifman, O. I.,Kruk, M. M.,Pukhovskaya, S. G.
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p. 1072 - 1075
(2020/07/25)
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- The effect of chemical modification of the macrocycle on the complex formation between porphyrins and metal salts in organic solvents
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The complex formation of β-octaethylporphyrin, β-octaethyl-meso-monophenylporphyrin, β-octaethyl-meso-tetraphenylporphyrin, meso-diphenylporphyrin, meso-triphenylporphyrin, and meso-tetraphenylporphyrin with Zn(II), Cu(II), Co(II), and Mn(II) acetates and chlorides in dimethylformamide, dimethylsulfoxide, pyridine, acetic acid, and a chloroform–methanol 1 : 1 mixture has been studied by means of spectrophotometry. The observed regulations are in line with the concept of chemical reactivity of the N–H bonds in porphyrins of different complexity.
- Maltceva,Mamardashvili, N. Zh.
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p. 1175 - 1183
(2017/08/08)
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- Dimeric and Trimeric Supramolecular Systems Formed by Donor?Acceptor Interactions of ZnII, MnIII, and SnIV Porphyrin Complexes
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The paper presents the methods of synthesis of dimeric and trimeric compounds formed by donor–acceptor interactions of ZnII, MnIII, and SnIV porphyrin complexes. The structure of the porphyrin ensembles was determined by
- Kuvshinova,Gornukhina,Semeikin,Golubchikov
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p. 3071 - 3078
(2018/02/21)
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- Unusual conformational preference of an aromatic secondary urea: Solvent-dependent open-closed conformational switching of N,N′- bis(porphyrinyl)urea
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N,N'-Bis(2,3,7,8,12,13,17,18-octaethylporphyrin-5-yl)urea (3) exhibits cis-trans conformational switching depending on the solvent properties, and can adopt the cofacial porphyrin dimer structure under certain conditions. The conformational preference can
- Matsumura, Mio,Tanatani, Aya,Azumaya, Isao,Masu, Hyuma,Hashizume, Daisuke,Kagechika, Hiroyuki,Muranaka, Atsuya,Uchiyama, Masanobu
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supporting information
p. 2290 - 2292
(2013/07/05)
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- Effect of the porphyrin structure on the kinetics of complex formation with zinc dipyrromethene in dimethylformamide
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The kinetics of complex formation of zinc dipyrromethene with tetraphenylporphyrin, octaethylporphyrin, and 5,15-dipentyl-2,3,7,8,12,13,17,18- octamethylporphine at 368-420 K have been studied. The kinetic parameters (k app, k v) of
- Simonova,Zaitseva,Koifman
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p. 391 - 396
(2008/10/09)
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- Extra coordination properties of spatially distorted zinc porphyrins
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Two series of synthetic porphyrins with a progressively increasing degree of macrocycle deformation were studied. The equilibrium constants for the extra coordination of piperidine and N-methylimidazole by zinc complexes of spatially distorted porphyrins, octaethylporphyrin derivatives, and spatially hindered and planar analogs were determined. It was found that the steric distortion of the porphyrin nucleus destabilizes the extra complexes. Copyright
- Pukhovskaya,Guseva,Semeikin,Kuvshinova,Golubchikov
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p. 572 - 576
(2008/10/09)
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- Coordination of N-substituted porphyrins with simple and chelate zinc salts in DMSO
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The effect of peripheral substitution in the porphyrin macrocycle (H 2OEtP, H2TPP) of the nature of the N-substituent (X = Me, Ph) and of the anion in the salt solvate (A = Ac-, NO 3-, Acac-) on the complexation of the N-substituted porphyrins with zinc salts in DMSO is studied. The positions of the bands in the electronic absorption spectrum of the (A)M(N-X)P metal complex were found to depend only slightly on the nature of the A anion in the composition of the coordination sphere of the complex. An inhibition of coordination of the N-substituted H2TPP derivatives by zinc nitrate was discovered that is not typical of porphyrins proper. The type of hybridization of the substituted nitrogen atom in the porphyrin molecule is discussed. A mixed type of hybridization is suggested: the sp2- and p3-reforms in the ligands and an almost complete transition to the p3-form in the N-substituted metal complexes.
- Berezin,Zharnikova,Andrianov,Shatunov,Semeikin
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p. 325 - 332
(2008/10/08)
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- Distortion and aromatization factors on the complexing ability of tetrapyrrole macrocycles in acetonitrile
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The kinetics of complexation between porphyrins and zinc acetate in acetonitrile was studied for the porphyrins belonging to various structural groups, including aza-, benzo-, and distorted N- and multiply substituted macrocycles. The effects of the distortion, on the one hand, and the enhanced rigidity of a macrocycle, on the other, on the complexation process were considered. The coordination of the distorted porphyrins to metal salts is facilitated because of the disturbance of the steric component of the macrocyclic effect (MCE), whereas the complexation of the rigid macrocycles is facilitated because of the activation of the electronic component of MCE.
- Berezin,Bazlova,Malkova,Andrianov
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p. 295 - 299
(2008/10/08)
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- The lowest excited states of copper porphyrins
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Relaxation processes of excited copper porphyrins were studied with relevance to the structure of the substates of the lowest excited states.Lifetimes of luminescence at room temperature were determined as 17, 29, 69, and 105 ns for T(EtO)PPCu , TPPCu(TPP: 5,10,15,20-tetraphenylporphin), TFPPCu, and OEPCu(OEP: 2, 3, 7, 8,12,13,17,18 octaethylporphin ) in toluene, respectively.Emission intensities and lifetimes of OEPCu and TFPPCu measured as a function of temperature show a variation ascribed to a Boltzmann distribution between the lowest trip-doublet and -quartet with an energy gap of 300-00 cm -1 The anomalous temperature dependence for TPPCu and T( EtO) PPCu is explained by a larger energy gap and larger vibronic distortions in the excited state.The difference in behavior is attributed to the orbital nature of the triplet: a 1 e)>> for OEPCu and TFPPCu but a 2 e)>> for TPPCu and T(EtO)PPCu.The assumption of a low energy charge tl'ansfer state is not necessary for our analysis.
- Asano, Motoko,Kaizu, Youkoh,Kobayashi, Hiroshi
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p. 6567 - 6576
(2007/10/02)
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