Porphyrin nanotubes are made by ionic self-assembly of two oppositely charged synthetic porphyrin molecules. The diameter the can be altered modifying structure one tectons. photocatalytically active, mechanically responsive to light, and composed J-aggregates that exhibit resonance light scattering.

Seeding and autocatalytic reduction of platinum salts in aqueous surfactant solution using ascorbic acid as the reductant leads to remarkable dendritic metal nanostructures. In micellar solutions, spherical nanostructures are obtained, smallest these nanodendrites resemble assemblies joined nanoparticles single crystals. With liposomes template, sheets form thin circular disks or solid foamlike nanomaterials can be made. Synthetic control over morphology nanodendrites, nanosheets,...

Porphyrins and related tetrapyrroles have been extensively studied because of their importance in biological processes they are often used the development artificial photosynthesis, catalysis, sensor systems. Challenges functional nanoscale porphyrin systems many, including need to organize porphyrins (e.g., facilitate such as energy- electron transfer) couple nanostructures other components catalytic elements conductors) produce multifunctional This article summarizes recent advances...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNonplanar distortion modes for highly substituted porphyrinsCraig J. Medforth, Mathias O. Senge, Kevin M. Smith, Laurie D. Sparks, and John A. ShelnuttCite this: Am. Chem. Soc. 1992, 114, 25, 9859–9869Publication Date (Print):December 1, 1992Publication History Published online1 May 2002Published inissue 1 December 1992https://pubs.acs.org/doi/10.1021/ja00051a019https://doi.org/10.1021/ja00051a019research-articleACS PublicationsRequest reuse...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNonplanar porphyrins. X-ray structures of (2,3,7,8,12,13,17,18-octaethyl- and -octamethyl-5,10,15,20-tetraphenylporphinato)zinc(II)Kathleen M. Barkigia, Dolores Berber, J. Fajer, Craig Medforth, Mark W. Renner, Kevin SmithCite this: Am. Chem. Soc. 1990, 112, 24, 8851–8857Publication Date (Print):November 1, 1990Publication History Published online1 May 2002Published inissue 1 November...

ADVERTISEMENT RETURN TO ISSUEPREVarticleNEXTRuffling in a Series of Nickel(II) meso-Tetrasubstituted Porphyrins as Model for the Conserved Ruffling Heme Cytochromes cW. Jentzen, M. C. Simpson, J. D. Hobbs, X. Song, T. Ema, N. Y. Nelson, Medforth, K. Smith, Veyrat, Mazzanti, R. Ramasseul, J.-C. Marchon, Takeuchi, W. A. Goddard, III, and ShelnuttCite this: Am. Chem. Soc. 1995, 117, 45, 11085–11097Publication Date (Print):November 1, 1995Publication History Published online1 November...

The view that the large red shifts seen in UV−visible absorption bands of peripherally crowded nonplanar porphyrins are result deformations macrocycle has recently been challenged by suggestion arise from substituent-induced changes bond lengths and angles, termed in-plane nuclear reorganization (IPNR). We have analyzed contributions to band a series nickel or zinc meso-tetraalkylporphyrins establish origins these ruffled porphyrins. Structures were obtained using molecular mechanics force...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetal dependence of the nonplanar distortion octaalkyltetraphenylporphyrinsL. D. Sparks, C. J. Medforth, M. S. Park, R. Chamberlain, Ondrias, O. Senge, K. Smith, and A. ShelnuttCite this: Am. Chem. Soc. 1993, 115, 2, 581–592Publication Date (Print):January 1, 1993Publication History Published online1 May 2002Published inissue 1 January 1993https://pubs.acs.org/doi/10.1021/ja00055a030https://doi.org/10.1021/ja00055a030research-articleACS...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRelationships between structural parameters and Raman frequencies for some planar nonplanar nickel(II) porphyrinsJ. A. Shelnutt, C. J. Medforth, M. D. Berber, K. Barkigia, SmithCite this: Am. Chem. Soc. 1991, 113, 11, 4077–4087Publication Date (Print):May 1, 1991Publication History Published online1 May 2002Published inissue 1 1991https://pubs.acs.org/doi/10.1021/ja00011a004https://doi.org/10.1021/ja00011a004research-articleACS PublicationsRequest...

Nanotubes prepared by the self-assembly of D-Phe-D-Phe molecules are investigated electron microscopy and Monte Carlo simulations; nanotubes appear to be porous capable forming novel peptide–nanotube platinum–nanoparticle composites.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotophysical Properties of Conformationally Distorted Metal-Free Porphyrins. Investigation into the Deactivation Mechanisms Lowest Excited Singlet StateSteve Gentemann, Craig J. Medforth, Timothy P. Forsyth, Daniel Nurco, Kevin M. Smith, Jack Fajer, and Dewey HoltenCite this: Am. Chem. Soc. 1994, 116, 16, 7363–7368Publication Date (Print):August 1, 1994Publication History Published online1 May 2002Published inissue 1 August...

Porphyrin nanotubes represent a new class of nanostructures for which the molecular building blocks can be altered to control their structural and functional properties. Nanotubes containing tin(IV) porphyrins are photocatalytically active reduce metal ions from aqueous solution. The is deposited selectively onto tube surfaces, producing novel composite that have potential applications as nanodevices. Two examples presented here with continuous gold wire in core ball at end coated platinum...

Square porphyrin nanosheets with uniform thickness (7−12 nm) and aspect ratios up to 100 have been synthesized for the first time using a reprecipitation method. They retain photocatalytic activity of precursor molecules can be self-metallized Pt, Pd, Au. Their unique morphology, properties, large surface areas suggest potential applications in photo- electrocatalysis, sensing, as components optoelectronic nanodevices, solar energy capture conversion.

We apply first principles computational techniques to analyze the two-electron, multi-step, electrochemical reduction of CO2 CO in water using cobalt porphyrin as a catalyst. Density Functional Theory calculations with hybrid functionals and dielectric continuum solvation are used determine steps at which electrons added. This information is corroborated ab initio molecular dynamics simulations an explicit aqueous environment reveal critical role stabilizing key intermediate formed by bound...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystallographic and EXAFS studies of conformationally designed nonplanar nickel(II) porphyrinsKathleen M. Barkigia, Mark W. Renner, Lars R. Furenlid, Craig J. Medforth, Kevin Smith, Jack FajerCite this: Am. Chem. Soc. 1993, 115, 9, 3627–3635Publication Date (Print):May 1, 1993Publication History Published online1 May 2002Published inissue 1 1993https://pubs.acs.org/doi/10.1021/ja00062a029https://doi.org/10.1021/ja00062a029research-articleACS...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTConsequences of Oxidation in Nonplanar Porphyrins: Molecular Structure and Diamagnetism the .pi. Cation Radical Copper(II) OctaethyltetraphenylporphyrinMark W. Renner, Kathleen M. Barkigia, Yun Zhang, Craig J. Medforth, Kevin Smith, Jack FajerCite this: Am. Chem. Soc. 1994, 116, 19, 8582–8592Publication Date (Print):September 1, 1994Publication History Published online1 May 2002Published inissue 1 September...

The photophysical properties and their temperature dependence are reported for the sterically encumbered nonplanar zinc free base 2,3,5,7,8,10,12,13,15,17,18,20-dodecaphenylporphyrins (ZnDPP H2DPP), 2,3,7,8,12,13,17,18-octaethyl-5,10,15,20-tetraphenylporphyrins (ZnOETPP H2OETPP), complex of 5,10,15,20-tetra-tert-butylporphyrin (ZnT(t-Bu)P). Compared to planar 5,10,15,20-tetraphenylporphyrins (ZnTPP H2TPP), above compounds exhibit reduced lifetimes lowest excited singlet state, fluorescence...

The lifetime of the (dz2,dx2-y2) metal excited state nickel(II) 5,10,15,20-tetra-tert-butylporphyrin (NiT(t-Bu)P) exhibits an extraordinary dependence on solvent dielectric properties and temperature. At room temperature, excited-state deactivation time varies from 2 ps in highly polar solvents to about 50 ns nonpolar media. lifetimes increase several microseconds both near 80 K. In contrast, (d,d) nominally planar nickel porphyrins such as tetraphenylporphyrin (NiTPP) vary only weakly with...

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTConformational Flexibility in Dodecasubstituted PorphyrinsDaniel J. Nurco, Craig Medforth, Timothy P. Forsyth, Marilyn M. Olmstead, and Kevin SmithView Author Information Department of Chemistry University California Davis, 95616-5295 Cite this: Am. Chem. Soc. 1996, 118, 44, 10918–10919Publication Date (Web):November 6, 1996Publication History Received26 June 1996Published online6 November inissue 1 January...

Porphyrin nanofiber bundles (see figure) are synthesized by a novel phase-transfer ionic self-assembly technique, allowing the use of wide range water-insoluble porphyrin tectons. Their photocatalytic self-metallization with Pt, Au, Ag, or Pt–Au alloys result in unusual porphyrin–metal composite nanostructures potential applications catalysis, sensing, and solar hydrogen production.

Microscale four-leaf clover-shaped structures are formed by self-assembly of anionic and cationic porphyrins. Depending on the metal complexed in porphyrin macrocycle (Zn or Sn), cores either electron donors acceptors. All four combinations these two metals tetra(N-ethanol-4-pyridinium)porphyrin tetra(sulfonatophenyl)porphyrin result related cloverlike with similar crystalline packing indicated X-ray diffraction patterns. The clover morphology transforms as ionic strength temperature...

Tuning of the structures and electronic effects nanocrystals is great relevance to preparation specialized materials such as artificial enzymes. In this study, binary porphyrin have been prepared by ionic self-assembly oppositely charged Fe(III) Mn(III) porphyrins. The characterized SEM, XPS UV–vis spectroscopy tested biomimetic models catalase. heterometallic material [Mn/Fe], association MnTHPyP FeTSPP, showed highest activity for H2O2 dismutation reaction, 89–95 U·mg−1, over a pH range...

The effects of ruffling on the axial ligation properties a series nickel(II) tetra(alkyl)porphyrins have been investigated with UV−visible absorption spectroscopy, resonance Raman X-ray crystallography, classical molecular mechanics calculations, and normal-coordinate structural decomposition analysis. For modestly nonplanar porphyrins, porphyrin is found to cause decrease in binding affinity for pyrrolidine piperidine, mainly caused by constant addition first ligand; ligand completely...