Cation-induced crown porphyrin dimers of oxovanadium(IV)

Thanabal, V.; Krishnan, V.

doi:10.1021/ic00140a006

Cited by 56 publications

(19 citation statements)

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“…2d-i Among the noncovalently linked porphyrin dimers, the dimers formed by cation (K + , NH 4 + , Cs + , Ba 2+ ) complexation of 5,10,15,20-tetrakis(benzo-15-crown-5)porphyrin (TCP) and their metal derivatives (MTCP), synthesized by Thanabal and Krishnan, are one of the attractive classes of compounds (Chart 1). 3,4 The structure of the dimers were deduced from the stoichiometry of the dimerization reaction and from ESR and ENDOR studies of the Cu(II) and VO(IV) metallated porphyrins. [3][4][5][6] The optical and emission properties of the cation-induced supramolecular dimers were found to be different from those of the monomeric entities.…”

Section: Introductionmentioning

confidence: 99%

Electrochemical, Spectral, and Computational Studies of Metalloporphyrin Dimers Formed by Cation Complexation of Crown Ether Cavities

et al. 2004

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The effect on the electrochemical oxidation and reduction potentials of 5,10,15,20-tetrakis(benzo-15-crown-5)porphyrin (TCP) and its metal derivatives (MTCP; M = Mg(II), VO(IV), Co(II), Ni(II), Cu(II), Zn(II), Pd(II), Ag(II)) upon potassium ion induced dimerization of the porphyrins was systematically performed in benzonitrile containing 0.1 M (TBA)ClO(4) by differential pulse voltammetry technique. The HOMO--LUMO energy level diagram constructed from the electrochemical data revealed destabilization of the HOMO level and stabilization of the LUMO level upon dimer formation while such a perturbation was larger for the HOMO level than the LUMO level. The geometry and electronic structure of a representative ZnTCP and its dimer, K(4)(ZnTCP)(2), were evaluated by the ab initio B3LYP method utilizing a mixed basis set of 3-21G(*) for Zn, K, O, and N and STO-3G for C and H. The inter-porphyrin ring distance of the dimer calculated from the optimized geometry agreed with the spectroscopically determined one, and the calculated HOMO and LUMO frontier orbitals revealed delocalization on both of the porphyrins rings. The metal-metal distances calculated from the triplet ESR spectra of the K(+) induced porphyrin dimers bearing paramagnetic metal ions in the cavity followed the trend Cu--Cu < VO--VO < Ag--Ag. However, the spectral shifts resulting from the exciton coupling of the interacting porphyrin pi-systems revealed no specific trend with respect to the metal ion in the porphyrin cavity. Additionally, linear trends in the electrochemically measured HOMO--LUMO gap and the energy corresponding to the most intense visible band of both MTCP and K(4)(MTCP)(2) were observed. A reduced HOMO--LUMO gap predicted for the dimer by B3LYP/(3-21G(), STO-3G) calculations was confirmed by the results of optical absorption and electrochemical studies.

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Section: Introductionmentioning

confidence: 99%

Electrochemical, Spectral, and Computational Studies of Metalloporphyrin Dimers Formed by Cation Complexation of Crown Ether Cavities

et al. 2004

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“…Tetrakis(iVtosylmonoazabenzo-15-crown-5)-and (N-benzylmonoazabenzo-15-crown-5)-substituted porphyrin derivatives 607 and 608 were synthesized by the reaction of pyrrole and the appropiate 4/-formyl-iV-substituted- tetrakis(benzo-15-crown-5) derivative 599 was synthesized by treating 4'-chlorocarbonyl-substituted benzo-15-crown-5 (S56) with a,a,a,a-tetrakis(m-aminobenzo)porphyrin. 283 Attachment of crown ether units onto the porphyrin ring greatly increases its solubility in many solvents, therefore, the properties of the crowns are easier to study. These compounds may act as catalysts in some reactions which require the simultaneous presence of both crown ether and porphyrin moieties.…”

Section: Introductionmentioning

confidence: 99%

“…Cations (K+, Cs+, Ba2+, and NH4+), which require two crown ether cavities for complexation, induced dimerization of the porphyrins. 279,283,288 The electrochemical redox and photophysical properties of these porphyrin complexes with metal cations were studied. Beer and co-workers289,290 reported cyclophane and cavitand-bridged tetrakis(benzo-15-crown-5) derivatives (Figure 17).…”

Section: Introductionmentioning

confidence: 99%

Bis- and Oligo(benzocrown ether)s

An¹,

Bradshaw²,

Izatt³

et al. 1994

Chem. Rev.

143

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“…The early research in understanding the chemistry of heme-containing proteins focused on synthesis and studies of porphyrin ligand systems. The coordination of porphyrin ligands and the photophysical properties of their metal complexes have been studied (Thanabal and Krishnan, 1982;Chandrashekar and Krishnan, 1982;Chandrashekar and Krishnan, 1981). Several modified porphyrins have been synthesized and studied for their chemical reactivity, structural diversity, aromaticity, anion receptor properties and their applications in photodynamic therapy (PDT) related to cancer treatment (Chandrashekar and Venkatraman, 2003;.…”

Section: Bioinorganic Chemistry Research In Indiamentioning

confidence: 99%

Bioinorganic Chemistry Research in India

Mugesh¹

2019

PINSA

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Nature uses metal ions and metal containing biomolecules for carrying out crucial cellular processes. They are mostly associated with the protein core, or found in cofactors such as porphyrins, or in protein-bound clusters. A few processes and reaction which involve the metals are respiration, photosynthesis, complex DNA synthesis and repair mechanisms, circulation, muscle contraction, etc. Bioinorganic chemistry deals with the study of metal ions and their importance in biological system. This article encompasses the progress and current status in the understanding of metalloenzymes and biomimetic inorganic chemistry, especially in India. The broad aspects of metals in medicine; use of metal containing nanoparticles and complexes for therapeutic and diagnostic purposes; the array of methodologies employed to understand and mimic the structure and function of metallobiomolecules; metal containing compounds in bioremediation etc. are discussed. Further, the significance and a future prospect of the bioinorganic chemistry research are elucidated briefly.

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Cation-induced crown porphyrin dimers of oxovanadium(IV)

Cited by 56 publications

References 0 publications

Electrochemical, Spectral, and Computational Studies of Metalloporphyrin Dimers Formed by Cation Complexation of Crown Ether Cavities

Electrochemical, Spectral, and Computational Studies of Metalloporphyrin Dimers Formed by Cation Complexation of Crown Ether Cavities

Bis- and Oligo(benzocrown ether)s

Bioinorganic Chemistry Research in India

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