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The structure-property relationships in a series of meso-tetraphenylporphyrins modified by annulations of the pyrrole ring with either benzo or naphtho substituents are studied. Direction of this research includes modification of the structure of the annulated porphyrin by adding various functional groups to the benzo and/or naphtho region for maintaining solubility in the absence of the meso-phenyl groups.

The metal dependent electron donor or electron acceptor properties of the microscale four-leaf clover-shaped structures formed by self-assembly of anionic and cationic porphyrin are reported. The results demonstrated that clovers derived from anionic Zn porphyrins (electron donors) and cationic Sn porphyrins (electron acceptors) are photoconductors, but when the metals are reversed in the two porphyrins, the resulting clovers are insulators.

The studies have shown that Zn(II) porphyrin in Zn(II)cytochrome c (Zn cyt c) is a fluorescence resonance energy transfer (FRET) donor to an Alexa660 dye acceptor. The energy transfer efficiency is dependent on the distance between the two fluorophores and Zn(II) porphyrin is an effective energy donor for measuring molecular-scale distances by FRET.

M13 viruses chemically grafted with zinc porphyrins as scaffolds were utilized to assemble molecular pigments into a one-dimensional light-harvesting antenna. The M13 viruses with further genetic engineering could be applied to coassemble other functional materials with pigments to find potential use in photochemical devices.

A series of zinc porphyrin arrays consisting of a meso-meso linked porphyrin dimer, a meta-phenylene linked dimer, gable-like tetramers consisting of the meso-meso linked dimers bridged by a meta-phenylene linker, and a dodecameric ring composed of the alternating dimeric pattern and intramolecular hole hopping between the porphyrin moieties are analyzed by using electron paramagnetic resonance (EPR) spectroscopy. The results have shown that hole hopping is rapid even though the meta-phenyl bridges and direct meso-meso linkages have not provided optimal electronic coupling between the porphyrins within these multiporphyrin arrays.

Efficient performance requires well-controlled segregation of electron donor and acceptor moieties, which is achieved by using block copolymers of tetraphenylporphinatozinc(II) (donor) and [C.sub.60] fullerene (acceptor) using living ring-opening metathesis polymerization (ROMP). Thin films of the self-assembled nanophase-segregated copolymers have displayed high charge carrier mobilities and electrical conductivities as well as highly repeatable photocurrent switching with rapid ON/OFF responses upon white light irradiation.

Zn-Zn porphyrin dimers are incorporated into thin dye-sensitized solar cells (DSSCs) to boost their light harvesting efficiency. The improved light harvesting ability coupled to enhanced DSSC performance has shown the potential of 3-D light harvesting arrays as next generation light harvesters for artificial solar energy conversion systems.

The functionalization of single-walled carbon nanotubes (SWNTs) with zinc porphyrins (ZnP) using mild conditions to produce a series of SWNTs-ZnP electron donor-acceptor conjugates is described. The different absorption cross sections throughout the visible part of the solar spectrum are important in increasing the overall light-harvesting features.

An elegant method of self-assembly for modification of a Ti[O.sub.2] surface via use of coordinating ligands followed by immobilization of variety of sensitizers and a dyad is reported. The current-voltage performance of the photoelectrochemical cell could be improved significantly through the utilization of the zinc porphyrin-ferrocene dyad markedly and an electron transfer-hole migration mechanism.

Interfacial electron-cation recombination in zinc-tetra (4-carboxyphenyl) porphyrin (ZnTCPP)/Ti[O.sub.2] nanoparticle system is explored at the single-molecule level by recording and analyzing photon-to-photon pair times of the ZnTCPP fluorescence. The results have shown that the fluctuations of the interfacial electron transfer (ET) activity have modulated the ET cycles as well as the interfacial electron-cation recombination dynamics.

A molecular system in solution where the variation of excitation energy influenced the product distribution of a two-step electron transfer is reported. The results obtained opened pathways for possibilities of state selective electron transfer for reaction control.

A Zn(II) amidinium porphyrin is the excited-state electron donor (D) to a naphthalene diimide acceptor (A) appended with either a carboxylate or sulfonate functionality. The analysis of the proton-coupled electron transfer (PCET) kinetics ascertained from transient absorption and transient emission spectroscopy has disclosed that the ionized interface is affected by the local solvent environment, thus establishing that the initial static configuration of the proton interface is a critical determinant in the kinetics of PCET.

Sonogashira coupling is used for preparing a chromophore in which zinc porphyrin donors are linked through their meso positions by ethynyl bridges to a bis(indolinylidenemethyl) squaraine core. The chromophore has displayed a two-photon absorption spectrum characterized by a peak cross section of 11000 GM and has also displayed a large cross section of >780 GM over a photon-wavelength window.

A myoglobin (Mb) triple mutant (D44K/D60K/E85K, Mb(+6)) substituted with Zn-deuteroporphyrin is prepared and cytochrome [b.sub.5] (cyt [b.sub.5]) binding and electron transfer (ET) quenching of the [super 3]ZnMb(+6) triplet state is monitored. The mutations have created the conversion from 'Dynamic Docking' (DD) to simple docking 'simple docking' (SD) energy landscapes.

Charge transport along zinc porphyrin-based molecular wires is simulated by considering both bandlike and hopping mechanisms. The increase in charge transfer integrals between monomer units and the reduction of the amount of energetic disorder along the molecular wire are the important factors used for determining the increase of the charge carrier mobility on formation of supramolecular ladderlike structures.

The tetratopic ligand 1,2,4,5-tetrakis(4-carboxyphenyl)benzene is used as a key building block for preparing a permanently microporous metal-organic framework with Lewis acidic (porphyrin)Zn struts (ZnPO-MOF). ZnPO-MOF has efficiently catalyzed acyl-transfer reactions by preconcentrating the substrates within its pores.

The deformation of polymersome is examined by loading polymerosomes with dye-labeled ferritin and P[Zn.sub.2]. The studies have shown synergy between ferritin and P[Zn.sub.2], which appears to be a general protein-polymer membrane phenomenon, as replacement of ferritin with bovine serum albumin or equine skeletal myoglobin has resulted in vesicles with similar asymmetric morphology.

The nanostructured multilayer of porphyrin/fullerene pairs obtained by codeposition of Zn-tetraphenyl-porphyrin (ZnTPP) and [C.sub.70] in ultrahigh-vacuum by powder sublimation is described. The studies have shown the existence of charge-transfer interactions between the electron-rich Zn-tetraphenyl-porphyrin (ZnTPP) and the electron-deficient fullerene.

Various synthetic routes are utilized to synthesize the tetrafunctionalized A[B.sub.3]-type porphyrin building blocks containing two different types of functional groups with [N.sub.4], [N.sub.3]O, [N.sub.3]S, and [N.sub.2][S.sub.2] porphyrin cores. The results from the studies on porphyrin tetrads and porphyrin pentads revealed that the monomeric porphyrin subunits in tetrads and pentads retained their individual characteristics features and exhibited weak interaction among the porphyrin subunits.

The naturally existing chlorophyll-a was used to prepare zinc 3-hydroxymethyl-protopyropheophorbide-d derivatives having carbonyl group(s) at the 13/15-, 13-, and 15-positions and lacking C=O group. The results revealed that both the presence of the C=O group and its situation at the 13-position were preferable for formation of the well-ordered J-aggregates.

The synthesis of three oligonaphthalenes with zinc porphyrin and free-base porphyrin moieties is described. The synthesis provides insight into the cascade energy transfer observed between the zinc and free-base porphyrins.

A back-gated silicon-on-insulator metal-oxide-semiconductor field effect transistor (SOI-MOSFET) transistor having a thin native layer of oxide on the top is used, upon which a single monolayer of zinc tetraarylporphyrin is deposited by using Langmuir-Blodgett (LB) methods. The transistor response to a few hundred attomoles of bound pyridine is detected, which when coupled with the ability to reset the device using light has shown that these systems can be used as sensors.

The application of an electron deficient zincated porphyrin tweezer as an effective host system for binding of 1,2-bisfunctional diols, amino alcohols, and diamines is demonstrated. The method is the first routine system, which addresses the absolute stereochemical determination of both threo and erythro compounds without the need for chemical derivatization.

Tetrakis(permethyl-[beta]-cyclodextrin)-modified zinc(II) porphyrin and tetra([beta]-cyclodextrin)-modified zinc(II) porphyrin are synthesized by click chemistry. The results have shown that the complexation strength of porphyrin with cyclodextrin is a vital factor to activate the potential binding sites of a molecular building block.

The experimental studies were conducted to determine the thermochemical properties of the compound, 5,10,15,20-tetrakis(4-methoxyphenyl)porphine zinc(II) (ZnTMPP). The results indicate that methoxyphenyl groups stabilize the porphine ring leading to stronger Zn-N bonding coordination.

A variety of directly linked porphyrin arrays is developed on the basis of the Ag(I)-promoted coupling reactions of Zn(II) 5,-15-diaryl porphyrin that gives a meso-meso-linked diporphyrin. The results demonstrate the competition in excitation energy transfer (EET) process that can be modulated by the choice of metalloporphyrin and by inference, its location in the array.

Research has been conducted on zinc porphyrins connected via intervening bis(dipyrrinato)metal complex. The authors describe the synthesis and characterization of triads composed of zinc porphyrins' linear array.

Comparison of bis(zinc porphyrin), ZnZn with zinc-freebase bis-porphyrin, Zn2H in CH2CI2 and CCl4 solvents is done to investigate the mechanism of supramolecular chirality induction in achiral ethane-bridged syn bis-porphyrins on interaction with chiral amines (L*). The system presented, possesses a high degree of chiroptical activity allowing the use of Zn2H for the determination of the absolute configuration of chiral ligands, by virtue of its one-point coordination property.

Studies done on quino-and isoquinoporphyrins, which are obtained, from commercially available 6-nitroquinoline and 5-nitroisoquinoline by using the Barton-Zard pyrrole synthesis and the MacDonald '3+1' methodology are presented. A zinc chelate of the isoquinoporphyrin system demonstrates a high degree of regioselective intermolecular interaction that may be of value in the development of molecular recognition studies.

Researchers have reported the binding of a chiral inducer which can ditopically interact with the concave porphyrins accompanying a preferential orientation would efficiently transfer the chirality through the complexation. The preliminary results suggest a new approach to the generation of chirality transfer control. The chiral inducer could be automatically removed from the bis(porphyrin)-containing cavity by the effector.