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  • Molecules
  • They find that electron- acceptor molecules such as trinitrobenzene (TNB) form 1:1 adducts with the expanded porphyrins, which leads to changes in color and can produce columnar stacking and the formation of discotic mesophases. (sciencemag.org)
  • The abdomen of the fossil mosquito was shown to contain very high levels of iron, and mass spectrometry data provided a convincing identification of porphyrin molecules derived from the oxygen-carrying heme moiety of hemoglobin. (pnas.org)
  • Two rings of porphyrin molecules nestle together like carefully crafted Russian nesting dolls. (acs.org)
  • When purple bacteria harvest light, for example, energy cascades between rings of 9, 18, and 32 chlorophyll molecules that each bear a porphyrin group bound to a magnesium ion. (acs.org)
  • The porphyrin macrocycle provides a versatile platform upon which to build elaborate superstructures, and this feature coupled with a rich and well-developed synthetic chemistry has led to the synthesis of many elegant models of heme protein active sites and numerous porphyrin-based receptor molecules. (unt.edu)
  • One design feature which is not usually considered in the design of porphyrin-based receptor molecules is nonplanarity of the porphyrin ring, although there are a few systems such as the pyridine sensitive Venus Flytrap and the chirality-memory molecule which illustrate that nonplanar porphyrin-based receptors can display unique and interesting behavior. (unt.edu)
  • Density functional theory (DFT) was employed to investigate protonation, deuteration, and substitution effects on the vibrational spectra of porphyrin molecules. (intechopen.com)
  • zinc-porphyrins
  • The outer ring, made from 12 zinc-porphyrins, is tethered to the core by six Y-shaped ligands that bind to the zinc and aluminum centers. (acs.org)
  • But they found that the outer ring could be constructed by mixing chains of four zinc-porphyrins with the Y-shaped ligands and the inner ring. (acs.org)
  • beta-linked zinc porphyrins were then reported to show promising device performances with a benchmark efficiency of 7.1% reported in 2007. (rsc.org)
  • molecular
  • This would allow the achievement of porphyrin layers characterised by different chiroptical and molecular recognition properties. (hindawi.com)
  • The inner ring contains six aluminum-porphyrins, connected by dialkyne groups and supported by a scaffold of molecular spokes. (acs.org)
  • The best PSSC system exhibited a panchromatic feature for light harvesting covering the visible spectral region to 700 nm, giving opportunities to many other porphyrins , such as fused and dimeric porphyrins , with near-infrared absorption spectral features, together with the approach of molecular co-sensitization, to enhance the device performance of PSSC. (rsc.org)
  • A very simple and efficient singlet-oxygen-mediated oxidative system that uses solar radiation, molecular oxygen, and Merrifield-supported porphyrins is presented. (wiley.com)
  • Hydrogels prepared from high molecular mass PVA have a better sorption profile for porphyrins, and are better suited for the preparation of controlled release vehicles. (ad-astra.ro)
  • The connection is made between the normal-coordinate structural decomposition (NSD) and the vibronic molecular states and spectra of porphyrins. (unt.edu)
  • We report the discovery of intact porphyrins, the molecular fossils of chlorophylls, from 1,100-million-year-old marine black shales of the Taoudeni Basin (Mauritania), 600 million years older than previous findings. (pnas.org)
  • The polymerization, in the presence of a free-base porphyrin cored chain transfer agent (CTA-FBP), produced porphyrin star polymers with controlled molecular weights and narrow polydispersities for a number of monomers including N , N -dimethylacrylamide (DMA) and styrene (St). Well-defined amphiphilic star block copolymers, P-(PS-PDMA) 4 and P-(PDMA-PS) 4 (P: porphyrin), were also prepared and used for self-assembly studies. (hindawi.com)
  • chiral
  • Moreover, the variation of peripheral substituents of porphyrins, such as, for example, chiral appended functionalities, can result in the formation of porphyrin aggregates featuring high supramolecular chirality. (hindawi.com)
  • A novel porphyrin-based receptor molecule for chiral amine ligands is described in which nonplanarity of the porphyrin macrocycle is used to orient the ligand and to enhance porphyrin-ligand interactions. (unt.edu)
  • Herein, they describe the design, synthesis, and characterization of a new kind of nonplanar porphyrin-based receptor molecule for chiral amines. (unt.edu)
  • characterization
  • Preparation and characterization of absolutely pure and stable nanoparticles of 5,10,15,20-meso-tetrakis phenyl porphyrin (TPP) and catalytically repute 5,10,15,20-meso-tetrakis pentaflurophenyl porphyrin (H 2 F 20 TPP) by improved 'reprecipitation method' is described. (springer.com)
  • photosynthesis
  • Without porphyrins and their relative compounds, life as we know it would be impossible and therefore the knowledge of these systems and their excited states is essential in understanding a wide variety of biological processes, including oxygen binding, electron transfer, catalysis and the initial photochemical step in photosynthesis. (springer.com)
  • atoms
  • Deuteration of N atoms at the porphyrin core is found to result not only in a red shift in the frequencies of the corresponding peaks below 1600 cm-1, but also to generate new Raman bands of frequencies in the range of 2565-2595 cm-1, resulting from N‐D bond stretching. (intechopen.com)
  • spectra
  • Expressions for the optical absorption spectra with vibrational structure are developed with these NSD-determined deformations as parameters, and the expressions are applied to the UV-visible absorption spectra porphyrins. (unt.edu)
  • In this chapter, we discuss IR and Raman spectra of protonated, deuterated, and meso ‐substituted parent porphyrin using density functional theory (DFT) to calculate the IR and Raman spectra, and, where possible, make comparison to experimental spectra. (intechopen.com)
  • harvest light
  • When I saw the structure, I immediately thought of the light-harvesting system in nature, in which multiple porphyrin arrays harvest light energy," says Makoto Fujita of the University of Tokyo, who has also developed concentric self-assembled structures. (acs.org)
  • nitrogen
  • The porphyrin nitrogen isotopes (δ 15 N por = 5.6-10.2‰) are heavier than in younger sedimentary sequences, and the isotopic offset between sedimentary bulk nitrogen and porphyrins (ε por = −5.1 to −0.5‰) points to cyanobacteria as dominant primary producers. (pnas.org)
  • functional
  • An imidazole-bearing zinc porphyrin ( P Zn ) has been designed for the selective detection of Au 3+ , and the porphyrin and gold complex ( P Zn ·Au 3+ ) can additionally be used to identify gold-binding functional groups such as cysteine residues and other mercaptans. (rsc.org)
  • The controlled organization of functional dyes, such as porphyrins, into polymer supramolecular systems has numerous potentially interesting material applications [ 1 ]. (hindawi.com)
  • Procedure
  • NSD is a procedure that provides a description of the distortion of a porphyrin from a D{sub 4h} symmetric reference structure in terms of equivalent displacements along the normal coordinates. (unt.edu)
  • small
  • Earlier this year, Anderson's team unveiled small tubes that contained a pair of six-porphyrin rings stacked on top of each other. (acs.org)
  • It's normal to have a small amount of porphyrins in your blood and other body fluids. (medlineplus.gov)
  • Mesotetra(4-carboxyphenyl)porphyrin (mTCPP) is a commercially available small molecule fluorophore and photosensitizer with four free carboxylic acid groups. (mdpi.com)
  • oxygen
  • Although metalloporphyrin polymers possess many interesting properties for applications, such as catalysis, light harvesting, oxygen transportation [ 3 - 17 ], and so on, other increasingly studied applications, such as sensors [ 18 ], prefer free-base porphyrin polymers. (hindawi.com)
  • metal ion
  • However, its use has been limited to metal ion (Zn(II) [ 16 ], Pd(II) [ 17 ]) coordinated porphyrin initiators and thus the production of metal complexed polymers. (hindawi.com)
  • core
  • Attempts to synthesize polymers containing free-base porphyrin using ATRP was unsuccessful, because Cu(II) (formed by the Cu(I) catalyst) will preferentially insert into the porphyrin core [ 14 , 16 ]. (hindawi.com)
  • Suggests
  • The similarity of results suggests that most if not all of the indicated porphyrin aggregate of the lunar sample probably was synthesized from rocket fuel during the landing of the lunar module. (sciencemag.org)