A5089647566- Porphyrin and Phthalocyanine Chemistry
- Molecular Junctions and Nanostructures
- Photochemistry and Electron Transfer Studies
- Luminescence and Fluorescent Materials
- Nonlinear Optical Materials Research
- Carbon Nanotubes in Composites
- Metal-Catalyzed Oxygenation Mechanisms
- Photosynthetic Processes and Mechanisms
- Conducting polymers and applications
- Synthesis and Properties of Aromatic Compounds
- Nonlinear Optical Materials Studies
- Spectroscopy and Quantum Chemical Studies
- Magnetism in coordination complexes
- Surface Chemistry and Catalysis
- Electrochemical Analysis and Applications
- Supramolecular Self-Assembly in Materials
- Photoreceptor and optogenetics research
- Photochromic and Fluorescence Chemistry
- Organic Electronics and Photovoltaics
- Mechanical and Optical Resonators
- Molecular Sensors and Ion Detection
- Metal complexes synthesis and properties
- Supramolecular Chemistry and Complexes
- Nanoplatforms for cancer theranostics
- Photodynamic Therapy Research Studies
Duke University
2016-2025
Center for Child and Family Health
2013-2023
San Francisco State University
2020
The Family Center
2014-2018
Durham Technical Community College
2014-2018
Duke Medical Center
2015
North Carolina State University
2015
University of North Carolina at Chapel Hill
2015
University of Pennsylvania
2002-2011
Temple University
2010
A new class of porphyrin-based chromophore systems has been prepared from ethyne-elaborated porphyrin synthons through the use metal-mediated cross-coupling methodologies. These feature chromophores wired together single ethynyl linkages. This type topological connectivity affords exceptional electronic interactions between which are manifest in their room temperature photophysics, optical spectroscopy, and electrochemistry; these spectroscopic signatures indicate that species model many...
We demonstrate that synthetic soft materials can extend the utility of natural vesicles, from predominantly hydrophilic reservoirs to functional colloidal carriers facilitate biomedical application large aqueous-insoluble compounds. Near-infrared (NIR)-emissive polymersomes (50-nm- 50-μm-diameter polymer vesicles) were generated through cooperative self assembly amphiphilic diblock copolymers and conjugated multi(porphyrin)-based NIR fluorophores (NIRFs). When compared with vesicles...
CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub> films with micrometer grains and microsecond carrier lifetimes are prepared through additive engineering.
A new class of chromophores has been fabricated that features both electron-releasing and electron-withdrawing groups fused via an intervening ethynyl moiety to the carbon framework a (porphinato)metal complex. These species possess large molecular first-order hyperpolarizabilities (β). We report herein synthesis, optical spectroscopy, hyper-Rayleigh scattering data used determine β values two archetypal members this exceptional nonlinear chromophores:...
Three supramolecular bischromophoric systems featuring zinc(II) and iron(III) porphyrins have been synthesized to evaluate the relative magnitudes of electronic coupling provided by hydrogen, σ, π bonds. Laser flash excitation generates highly reducing singlet excited state (porphinato)zinc chromophore that can subsequently be electron transfer quenched (porphinato)iron(III) chloride moiety. Measurement photoinduced rate constants enables a direct comparison how well these three types...
We have developed a controlled and highly reproducible method of making nanometer-spaced electrodes using electromigration in ambient lab conditions.This advance will make feasible single molecule measurements macromolecules with tertiary quaternary structures that do not survive the liquid-helium temperatures at which is typically performed.A second it yields gaps desired tunnelling resistance, as opposed to random formation temperatures.Nanogap occurs through three regimes: First evolves...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFacile elaboration of porphyrins via metal-mediated cross-couplingStephen G. DiMagno, Victor S. Y. Lin, and Michael J. TherienCite this: Org. Chem. 1993, 58, 22, 5983–5993Publication Date (Print):October 1, 1993Publication History Published online1 May 2002Published inissue 1 October 1993https://pubs.acs.org/doi/10.1021/jo00074a027https://doi.org/10.1021/jo00074a027research-articleACS PublicationsRequest reuse permissionsArticle...
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication the EditorNEXTBioresorbable Vesicles Formed through Spontaneous Self-Assembly of Amphiphilic Poly(ethylene oxide)-block-polycaprolactoneP. Peter Ghoroghchian, Guizhi Li, Dalia H. Levine, Kevin P. Davis, Frank S. Bates, Daniel A. Hammer, and Michael J. TherienView Author Information School Engineering Applied Science, Institute for Medicine Engineering, University Pennsylvania, 120 Hayden Hall, 3320 Smith Walk,...
We describe the theoretical basis for exceptionally large molecular first hyperpolarizabilities inherent to (5,15-diethynylporphinato)metal-bridged donor−acceptor (D−A) molecules. β values relevant hyper-Rayleigh experiments are calculated at 1.064 and 0.830 μm a complex with such structure, [5-((4'-(dimethylamino)phenyl)ethynyl)-15-((4''-nitrophenyl)ethynyl)-10,20-diphenylporphinato]zinc(II), 472 × 10-30 8152 cm5/esu, respectively. The 1 order of magnitude larger than that any other...
Abstract A new method for the regulation of photophysical properties highly conjugated porphyrin arrays is described. The absorptive and emissive signatures such supramolecular structures can be modulated to an impressive degree by of: i) extent steric interactions that define barrier rotation about bridge between chromophores, ii) magnitude ground state chromophore–chromophore electronic communication within supermolecule. power this approach illustrated straightforward synthesis as well...
An extensive series of conjugated (porphinato)zinc(II)-based chromophores featuring nitrothiophenyl and nitrooligothiophenyl electron-accepting moieties has been synthesized using metal-catalyzed cross-coupling reactions involving [5-bromo-15-triisopropylsilylethynyl-10,20-diarylporphinato]zinc(II) an unusual electron-rich Suzuki-porphyrin synthon, [5-(4-dimethylaminophenylethynyl)-15-(4',4',5',5'-tetramethyl[1',3',2']dioxaborolan-2'-yl)-10,20-diarylporphinato]zinc(II), with appropriately...
We show that meso-to-meso ethyne-bridged (porphinato)zinc(II) oligomers (PZnn structures) define exceptional low band gap organic materials possess both large magnitude NIR S1 → S0 fluorescence quantum yields and substantial Sn absorptive cross-sections, tunable over a wide 850−1400 nm spectral window. These PZnn species (φf values) comparable to the highest reported for laser dyes in 750−900 regime; importantly, these emitters do not suffer from commonly cited tricarbocyanine dye drawbacks...
Amphiphilic, linear conjugated poly[p-{2,5-bis(3-propoxysulfonicacidsodiumsalt)}phenylene]ethynylene (PPES) efficiently disperses single-walled carbon nanotubes (SWNTs) under ultrasonication conditions into the aqueous phase. Vis-NIR absorption spectroscopy, atomic force microscopy (AFM), and transmission electron (TEM) demonstrate that these solubilized SWNTs are highly individualized. AFM TEM data reveal interaction of PPES with gives rise to a self-assembled superstructure in which...
Selective near-IR (NIR) excitation (780 nm) of the conjugated supermolecule ruthenium(II) [15-(4′-ethynyl-(2,2′;6′,2′′-terpyridinyl))-bis[(5,5′,-10,20-di(2′,6′-bis(3,3-dimethylbutoxy)phenyl)porphinato)zinc(II)]ethyne][4′-pyrrolidin-1-yl-2,2′;6′,2′′-terpyridine] bis(hexafluorophosphate) (Pyr1RuPZn2) in solutions containing N,N-bis(ethylpropyl)perylene-3,4,9,10-tetracarboxylicdiimide (PDI) or tetracene gives rise to a substantial anti-Stokes energy gain (PDI, 0.70 eV; tetracene, 0.86 eV)....
Metal nanoparticles (NPs) respond to electromagnetic waves by creating surface plasmons (SPs), which are localized, collective oscillations of conduction electrons on the NP surface. When interparticle distances small, SPs generated in neighboring NPs can couple one another, intense fields. The coupled particles then act as optical antennae capturing and refocusing light between them. Furthermore, a molecule linking such be affected these interactions well. Here, we show that using an...
De novo protein design provides a framework to test our understanding of function and build proteins with cofactors functions not found in nature. Here, we report the designed bind powerful photooxidants evaluation use these generate diffusible small-molecule reactive species. Because excited-state dynamics are influenced by hydration photooxidant's environment, it was important only binding site but also evaluate its dynamic properties. Thus, used computational conjunction molecular (MD)...
The photophysical properties of a series ethynyl-bridged (porphinato)zinc(II) oligomers have been investigated over the femtosecond and picosecond time scales using ultrafast magic angle polarized pump−probe spectroscopy. Bis[(2,2',-5,10,15,20-tetraphenylporphinato)zinc(II)]ethyne, bis[(5,5',-10,20-diphenylporphinato)zinc(II)]ethyne, 5,15-bis{[(5',-10',20'-diphenylporphinato)zinc(II)]ethynyl}[10,20-diphenylporphinato]zinc(II) exhibit rapid (≤150 fs) formation emitting state following Soret...
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSuzuki Porphyrins: New Synthons for the Fabrication of Porphyrin-Containing Supramolecular AssembliesAlison G. Hyslop, Matthew A. Kellett, Peter M. Iovine, and Michael J. TherienView Author Information Department Chemistry, University Pennsylvania, Philadelphia, Pennsylvania 19104-6323 Cite this: Am. Chem. Soc. 1998, 120, 48, 12676–12677Publication Date (Web):November 21, 1998Publication History Received9 July 1998Published online21 November...
We report the complete de novo design of a four-helix bundle protein that selectively binds nonbiological DPP−Fe(III) metalloporphyrin cofactor (DPP−Fe(III) = 5, 15-Di[(4-carboxymethyleneoxy)phenyl]porphinato iron(III)). A tetrameric, D2-symmetric backbone scaffold was constructed to encapsulate two units through bis(His) coordination. The sequence determined with aid statistical computational algorithm SCADS. 34-residue peptide chemically synthesized. UV−vis and CD spectroscopy,...
A new class of porphyrins in which intervening ethynyl moieties connect aryl groups to the porphyrin 5- and 15-positions is described. The synthesis optical spectroscopy five compounds are reported: [5,15-bis[(4'-dimethylaminophenyl)ethynyl]-10,20-diphenylporphinato]zinc(II), [5,15-bis[(4'-methoxyphenyl)ethynyl]-10,20-diphenylporphinato]zinc(II), [5,15-bis[(phenyl)ethynyl]-10,20-diphenylporphinato]zinc(II), [5,15-bis[(4'-fluorophenyl)ethynyl]-10,20-diphenylporphinato]zinc(II),...