Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies.

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Research Abstract Details 

Research Abstract Table of Contents

Jump to the:

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Abstract Text:

Francis D'Souza,Mohamed E El-Khouly,Suresh Gadde,Amy L McCarty,Paul A Karr,Melvin E Zandler,Yasuyaki Araki,Osamu Ito,

Spectroscopic, redox, and electron transfer reactions of a self-assembled donor-acceptor dyad formed by axial coordination of magnesium meso-tetraphenylporphyrin (MgTPP) and fulleropyrrolidine appended with an imidazole coordinating ligand (C(60)Im) were investigated. Spectroscopic studies revealed the formation of a 1:1 C(60)Im:MgTPP supramolecular complex, and the anticipated 1:2 complex could not be observed because of the needed large amounts of the axial coordinating ligand. The formation constant, K(1), for the 1:1 complex was found to be (1.5 +/- 0.3) x 10(4) M(-1), suggesting fairly stable complex formation. The geometric and electronic structures of the dyads were probed by ab initio B3LYP/3-21G() methods. The majority of the highest occupied frontier molecular orbital (HOMO) was found to be located on the MgTPP entity, while the lowest unoccupied molecular orbital (LUMO) was on the fullerene entity, suggesting that the charge-separated state of the supramolecular complex is C(60)Im(*-):MgTPP(*+). Redox titrations involving MgTPP and C(60)Im allowed accurate determination of the oxidation and reduction potentials of the donor and acceptor entities in the supramolecular complex. These studies revealed more difficult oxidation, by about 100 mV, for MgTPP in the pentacoordinated C(60)Im:MgTPP compared to pristine MgTPP in o-dichlorobenzene. A total of six one-electron redox processes corresponding to the oxidation and reduction of the zinc porphyrin ring and the reduction of fullerene entities was observed within the accessible potential window of the solvent. The excited state events were monitored by both steady state and time-resolved emission as well as transient absorption techniques. In o-dichlorobenzene, upon coordination of C(60)Im to MgTPP, the main quenching pathway involved electron transfer from the singlet excited MgTPP to the C(60)Im moiety. The rate of forward electron transfer, k(CS), calculated from the picosecond time-resolved emission studies was found to be 1.1 x 10(10) s(-1) with a quantum yield, Phi(CS), of 0.99, indicating fast and efficient charge separation. The rate of charge recombination, k(CR), evaluated from nanosecond transient absorption studies, was found to be 8.3 x 10(7) s(-1). A comparison between k(CS) and k(CR) suggested an excellent opportunity to utilize the charge-separated state for further electron-mediating processes.

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Publishing Authors By Initials

F D'Souza,ME El-Khouly,S Gadde,AL McCarty,PA Karr,ME Zandler,Y Araki,O Ito,

For similar abstracts research abstracts see: abstracts research

PUBMED ID PMID:

MEDLINE DATE:

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Journal Published:

PUBLICATION TYPE: Research Support, Non-U.S. Gov

Journal: The journal of physical chemistry. B

VOLUME: 109

Page Numbers: 10107-14

Journal Abbreviation:

ISSN: 1520-6106

DAY: 26

MONTH: May

YEAR: 2005

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Information

Number of References:

LANGUAGE: eng

NlmUniqueID: 101157530

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Keywords Mesh Terms:

KEYWORDS:

MESH TERMS:

Chemical & Substance for Abstract: Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies. Information

Substance Name:

Registry Number:

Grant and Affiliation Information for Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies.

AFFILIATION: Department of Chemistry, Wichita State University, 1845 Fairmount, Wichita, Kansas 67260-0051, USA. Francis.DSouza@wichita.edu

Country: United States

AGENCY:

GRANT:

ACRONYM:

MEDLINETA: J Phys Chem B

REFSOURCE:

DATABASENAME:

ACCESSION NUMBER:

Number Hits: 0

Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies Related Publications

• A molecular phylogeny of the genus Echinococcus inferred from complete mitochondrial genomes.
• A soft X-ray (80-1500 eV) grazing-incidence monochromator with varied-line-spacing plane gratings at PF-BL-11A.
• Activity of anti-Porphyromonas gingivalis egg yolk antibody against gingipains in vitro.
• Bacterial, fungal and yeast contamination in six brands of irreversible hydrocolloid impression materials.
• Biomimetic coating of an apatite layer on poly(L-lactic acid); improvement of adhesive strength of the coating.
• Bone metabolism and formation of mice bred in a 2 G environment.
• Bootstrap significance test of synchronous spike events--a case study of oscillatory spike trains.
• Cervical spine loads and intervertebral motions during whiplash.
• Design of a Holographically Recorded Plane Grating with a Varied Line Spacing for a Soft X-ray Grazing-Incidence Monochromator.
• Editorial comment: factor that influence serum prostate-specific antigen levels in terms of maintaining quality within a PSA screening system.
• Endoglucanases from Paenibacillus spp. form a new clan in glycoside hydrolase family 5.
• Excess tyrosine stimulates eumelanin and pheomelanin synthesis in cultured slaty melanocytes from neonatal mouse epidermis.
• Impairment of endothelium-dependent relaxation of aortas and pulmonary arteries from spontaneously hyperlipidemic mice (Apodemus sylvaticus).
• In vitro antimicrobial activity of different gutta-percha points and calcium hydroxide pastes.
• In vitro antimicrobial activity of endodontic sealers, MTA-based cements and Portland cement.
• Intestinal cestodes.
• Involvement of MCP-1 in tubulointerstitial fibrosis through massive proteinuria in anti-GBM nephritis induced in WKY rats.
• Less-oxidative hemodialysis solution rendered by cathode-side application of electrolyzed water.
• Management of patients with normal-pressure hydrocephalus by using lumboperitoneal shunt system with the Codman Hakim programmable valve.
• Mid-term effects of steroid therapy on childhood-onset IgA nephropathy.
• Numerical Calculations of Heating Patterns around a Coaxial-Slot Antenna for Microwave Hyperthermia - Aiming at Treatment of Brain Tumor and Bile Duct Carcinoma-.
• Protection of estrogens against the progression of chronic liver disease.
• Recent outcome of Graves' disease patients with papillary thyroid cancer.
• Runt-related transcription factor 3 expression in human oral squamous cell carcinomas; implication for tumor progression and prognosis.
• SecY alterations that impair membrane protein folding and generate a membrane stress.
• Self-assembled via axial coordination magnesium porphyrin-imidazole appended fullerene dyad: spectroscopic, electrochemical, computational, and photochemical studies.
• Strain differences in the diabetogenic activity of streptozotocin in mice.
• Structure and function of the PB1 domain, a protein interaction module conserved in animals, fungi, amoebas, and plants.
• [Detection of Cysticercus bovis in a calf injected intravenously with taenia saginata hexacanth]
• [Rabies virus in naturally infected bats in the State of São Paulo, Southeastern Brazil]