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Facile redox-induced aromatic-antiaromatic interconversions were accomplished by using β-tetracyano-21,23-dithiaporphyrin (CN4 S2 Por). Introduced cyano groups not only increased the reduction potential of the porphyrin core but also stabilized the antiaromatic isophlorin (CN4 S2 Iph) by π conjugation. The reduction of CN4 S2 Por with hydrazine in polar solvents quantitatively affords CN4 S2 Iph, even under ambient conditions. CN4 S2 Iph retains a nearly planar conformation and exhibits considerable antiaromaticity. Aerobic oxidation of CN4 S2 Iph to CN4 S2 Por occurs in nonpolar solvents. This study was conducted to contribute to the understanding of the structure-antiaromaticity relationship.

Single-crystal X-ray crystallographic analyses of two kinds of [tetraarylporphyrin]22+/[polyoxomatalate]4− (POM, SV2W10O40) complexes showed that the porphyrin and POM make three-dimensional polymeric structures, and no discrete molecular structure of [porphyrin]2[POM] units was identified. Although the two components (porphyrin and POM) can be dissociated in solution, thin films made by casting the solution partially retained the crystallographic structure, as judged from the reflection spectra and X-ray powder diffraction. A thin film of the complex between electrodes with a gap of 2 μm showed good conductivity, whereas the porphyrin and POM components separately measured under the same conditions were insulating. The I–V curves of the complex showed negative differential resistance (NDR), which can be explained by (1) conduction switching at a certain bias voltage and (2) the slow response of the conductance switching in the voltage scan time range. The increased conduction at a higher bias voltage was confirmed by AC impedance spectrometry. This is a new proposal for a mechanism of NDR phenomena.

This work mainly reports the observation of novel supramolecular structures of TbIII-5,15-bisdodecylporphyrin (BDP, C12P) double-decker complexes on the surfaces of single-walled carbon nanotubes (SWNTs) performed by scanning tunneling microscopy under an ultra-high vacuum and low temperature, atomic force microscopy, scanning electron microscopy coupled with energy dispersive spectroscopy, and ultraviolet-visible spectroscopy. The molecules formed a well-ordered self-assembled helix-shaped array with regular periodicity on the tube surface. Additionally, some magnetic properties of the BDP-molecule as well as the resulting BDP-SWNT composites were investigated by superconducting quantum interference measurements. The molecule exhibits single-molecule magnetic (SMM) properties and the composite's magnetization increases almost linearly with decreasing temperature which is possibly due to the coupling between porphyrin molecules and SWNTs. Consequently, this may enable the development of more advanced spintronic devices based on porphyrin-nanocarbon composites.

In this study, supramolecular structures of metalloporphyrin derivatives, i.e., Zn, Co, and Ni on a single-walled carbon nanotube (SWNT) surface have been investigated using microscopic and spectroscopic measurements as well as density functional theory calculations, to identify the effect of metalation on the supramolecular structures of porphyrins on a curved carbon surface (SWNT). By changing the central metal incorporated inside the porphyrin ring, different supramolecular structures can be observed on the SWNT surface using scanning tunneling microscopy, which displays the effect of different metal centers on the supramolecular structure. Although predicting or understanding supramolecular structures on the SWNT surfaces is still a big challenge, this study will serve as a helpful key point for further understanding, building new supramolecular architectures on SWNT surfaces and designing novel molecular architectonics of porphyrin/SWNTs-based devices.

Copper- and nickel-porphyrin complexes show extremely weak axial coordination ability without any electron-withdrawing groups. Herein, we report axial ligation on CuII- and NiII-porphyrins in a highly rigid cofacial porphyrin dimer with a bidentate ligand, 1,4-diazabicyclo[2.2.2]octane (DABCO). To the best of our knowledge, this is the first report on the use of CuII- and NiII-porphyrins for coordination-induced guest binding of porphyrin-based host molecules without the help of other metal ions. The high rigidity of the dimer induces guest binding through the cooperative effect of weak axial ligation. The results showed that CuII- and ZnII-complexes bind one DABCO molecule inside their cavities, whereas the NiII-complex binds two additional DABCO molecules outside to form a stable 6-coordinate paramagnetic NiII-complexes.

Compound 5,15-diphenyl porphyrin (DPP) has been synthesized and inserted with different kind of metal (Fe, Cu and Zn). Synthesis of DPP has been carried out through three stages reaction using pyrrole and benzaldehyde as starting materials. Identification of synthesized compounds of 5-phenyl dipyrromethane (DPM) and 5, 15-diphenyl porphyrin (DPP) was confirmed with H-NMR. Three different metals were then inserted into the cavity of DPP. Optical spectra of Cu, Fe, Zn-DPP was then investigated and compared with free-base DPP using UV/Vis spectrophotometer. The result showed that the yield reaction of DPM reached about 41.77% and DPP reached about 21.80%. Based on the spectra investigation of metal-DPP, it showed that DPP had different Soret and Q band when each Cu (II), Fe (II), Zn (II) was inserted into DPP. Moreover, Zn-DPP has Q band at to the rightest shifting than Cu-DPP or Fe-DPP which means it has the least excitation energy among them. Therefore, Zn-DPP has the more potential to be utilized for application such as DSSC.

The original single-molecule rectifier proposed by Aviram and Ratner is based on a donor-σ-acceptor structure, in which σ functions as the insulator to disconnect the π electronic systems of the two parts. However, there have been no reports on experimentally demonstrated highly efficient single-molecule rectifiers based on this mechanism. In this paper, we demonstrate single-molecule rectifiers with perpendicularly connected metal porphyrin-imide dyads. Our proposed molecule rectifiers use hydroxyl groups at both ends as weak anchoring groups. Measurements of the single-molecule current-voltage characteristics of these molecules clearly show that the rectification ratio reached a high value of 14 on average. Moreover, the ratio could be tuned by changing the central metal in the porphyrin core. All of these features can be explained by the energy-level shift of the molecular orbital using a model with three electronic parts.

Molecular structures for three oxidation forms (anion, radical, and cation) of terbium(III) bis(porphyrinato) double-decker complexes have been systematically studied. We found that the redox state controls the azimuthal rotation angle (φ) between the two porphyrin macrocycles. For [TbIII (tpp)2 ]n (tpp: tetraphenylporphyrinato, n=-1, 0, and +1), φ decreases at each stage of the oxidation process. The decrease in φ is due to the higher steric repulsion between the phenyl rings on the porphyrin macrocycle and the β hydrogen atoms on the other porphyrin macrocycle, which results from the shorter interfacial distance between the two porphyrin macrocycles. Conversely, φ=45° for both [TbIII (oep)2 ]-1 and [TbIII (oep)2 ]0 (oep: octaethylporphyrinato), but φ=36° for [TbIII (oep)2 ]+1 . Theoretical calculations suggest that the smaller azimuthal rotation angle of the cation form is due to the electronic interaction in the doubly oxidized ligand system.

Single molecule conductance (SMC) of a series of porphyrin derivatives, whose porphyrin units are connected through a phenylene bridge that have one or two thiolate end groups, was measured by a scanning tunneling microscopic break junction (STM-BJ) technique. The observed conductance values were analyzed by partial transmission probabilities (Ti) for the molecular parts using the equation G=G0∏iNTi . Unique combination of Ti was obtained, which indicates the validity of this analysis. By the analysis, the free-base porphyrin ring interacting with the gold electrode was found to show a greater transmission probability Tpor-Au than that of the bridge between thiolate and the gold electrode (TS-Au).

This work reports confirmation of the experimental assignment of the absolute-handedness chirality of single-walled carbon nanotubes (SWNTs). This was achieved by applying the scanning tunneling microscopy (STM) imaging technique to a supramolecular composite consisting of a metalized porphyrin derivative (nickel-5,15-bisdodecylporphyrin [Ni-BDP]) affixed to the surfaces of chiral-concentrated SWNTs (with right-handed helix P- and left-handed helix M-). On the basis of the handedness chirality, different chiral supramolecular structures of Ni-BDP were observed on the surfaces of the two SWNT enantiomers. The incorporation of a metal center into the porphyrin ring did not significantly affect the SWNT absolute-handedness chirality assignment, the large pi-system porphyrin ring being the crucial factor. These findings will effectively pave the way towards the clear selective synthesis, separation, chemistry, and applications of SWNT enantiomers.

Three tobacco types (Burley, Flue Cured, and Oriental) and eight cigarette brands were unequivocally identified using an electronic nose formed by only three sensors based on a single novel conducting polymer (PF-BTB) doped with different porphyrins (H2TPP, H2TPFP, and H2BTBOP). The synthesis and characterization of the polymer are also discussed. Small changes in the porphyrin structure caused significant changes in the electrical conductance response patterns of the sensors upon exposure to complex chemical matrixes, representing a novel approach for tuning the selectivity of chemiresistive sensors for e-nose application. This e-nose is fast, cheap, reliable, can be easily operated, and could be a valuable tool for border agents fighting cigarette smuggling around the world, helping them prevent losses of millions in tax revenues and sales.

Porphyrin derivatives are potential candidates as constituents of functional molecular devices because their electronic levels can be rationally manipulated by chemical modification. In this work, we deposit a porphyrin molecule with a hydroxyphenyl side group on Au(111), which is designed and synthesized as a basic unit for functional single molecule devices, and observe the bonding structure and electronic states with scanning tunneling microscopy (STM). The molecule changes configuration from a monomer to a cluster to a monolayer as the coverage increases, ruled by the H-bonding interaction through the hydroxyphenyl group and the steric repulsion by the isopentoxy groups. The highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) localized in the porphyrin macrocycle are observed at −1.1 and +1.1 eV, respectively, with respect to the Fermi level. We also deposit a para-phenylene-bridged porphyrin array on the surface using the electrospray method, and observe the local density of states along the array., Accepted 03 Sep 2015

This work uncovers the application of porphyrin dimers for the use in electroanalysis, such as potentiometric determination of ions. It also puts in question a current perception of an occurrence of the super-Nernstian response, as a result of the possible dimerization of single porphyrins within an ion-selective membrane. To study that, four various porphyrin dimers were used as ionophores, namely, freebase-freebase, Zn-Zn, Zn-freebase, and freebase-Zn. Since the Zn-freebase and freebase-Zn porphyrin dimers carried both anion- and cation-sensitive porphyrin units, their application in ISEs was utilized in both anion- and cation-sensitive sensors. With respect to the lipophilic salt added, both porphyrins dimers were found anion- and cation-sensitive. This allowed using a single molecule as novel type of versatile ionophore (anion- and cation-selective), simply by varying the membrane composition. All anion-sensitive sensors were perchlorate-sensitive, while the cation-selective sensors were silver-sensitive. The selectivity of the sensors depended primarily on the porphyrin dimers in the ion-selective membrane. Furthermore, the selectivity of cation-sensitive dimer based sensors was found significantly superior to the ones measured for the single porphyrin unit based sensors (precursors of the porphyrin dimers). Thus, the dimerization of single porphyrins may actually be a factor to increase or modulate porphyrin selectivity. Moreover, in the case of cation-sensitive sensors, the selectivity vastly depended on the order of porphyrin units in the dimer. This opens a new approach of regulating and adjusting sensitivity and selectivity of the sensor through the application of complex porphyrin systems with more than one porphyrin units with mix sensitive porphyrins.

In this paper, a new composite sensor for e-nose application is described. A modification in the regular pair conductive polymer/Lewis acid dopant is proposed, replacing the acid by free-base or metallated porphyrins. Sensors doped with different porphyrin species, using the same conductive polymer, led to a huge variation in response to selected analytes. Two different arrays (doped with free-base and metallated porphyrins) using these sensors were able to identify four organic solvents, used as standard analytes: propanone, ethyl acetate, ethanol and toluene. Both of them could distinguish the tested vapours.

© 2016 The Chemical Society of Japan. A self-assembled monolayer of a mixture of radical 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP)TbIII doubledecker (TbIII(OEP)2) single-molecule magnets and alkoxylated dehydrobenzo[12]annulene (DBA) at the 1-phenyloctane/highly oriented pyrolytic graphite interface was investigated using scanning tunneling microscopy. The observations revealed that single TbIII(OEP)2 molecules were incorporated in the 2D pores of the honeycomb structure formed by a DBA derivative containing octyloxy chains. The number of TbIII(OEP)2 molecules coadsorbed in the porous DBA networks increased with increasing concentration of the TbIII(OEP)2 radical solution. ispartof: Chemistry Letters vol:45 issue:3 pages:286-288 status: published

Dendron-protected porphyrin polymers (Mn ∼ 43 000 g mol−1; Mw ∼ 111 000 g mol−1) were deposited using the Langmuir–Blodgett method on glass surfaces modified with N-phenyl-3-aminopropyltriethoxysilane. These deposited films were soaked in a solution of a fullerene derivative bearing a pyridinyl moiety. Topographical images of the surface obtained by atomic force microscopy showed that the height of the porphyrin polymers was 3.1 ± 0.5 nm as deposited, and clearly increased to 3.9 ± 0.3 nm upon soaking. The increase in height (about 0.8 nm) corresponded to the diameter of the fullerene, indicating that the pyridinyl moieties of the fullerene molecules bound to the zinc atoms of the porphyrin units. Porphyrin polymers having thiol groups at both ends bridging nano-gapped gold electrodes were fabricated on silicon chips. The chips were soaked in the fullerene derivative solution to make devices containing porphyrin polymers whose central zinc atoms were coordinated by the fullerene derivative. The current–voltage (I–V) characteristics of these devices were measured, and higher conductivity was observed during photoirradiation only when the devices contained both the porphyrin polymer and the fullerene derivative; no photo-response was observed when either component was absent.

Oligothiophenes and porphyrin oligomers were exploited as new molecules for the “molecular ruler” (MR) method in the form of simple molecular monolayers. When handled in air, oligothiophenes yielded extremely homogeneous nanogaps about 30 nm wide, while handling under N2 produced nanoscale gaps of around 10 nm between parent and daughter structures. The difference between these two results indicated that it was possible to control the width of this gap by varying the extent of oxidation of the oligothiophenes. Porphyrin oligomers also yielded nanogaps about 10 nm wide. Therefore, these two types of molecules are promising candidates for use in the MR methods.

Electrodes with a gap size of 15 ∼ 80 nm could be bridged by porphyrin molecular wires with 50 ∼ 300 nm length. The porphyrin units could be coordinated with Au nano-particles having pyridinyl moiety. The device with both the porphyrin and Au nano-particles showed photo-response characteristics while those without the Au nano-particles showed no response.

The electronic properties of a single-walled carbon nanotube/150mer of porphyrin polymer wire system were investigated. Current-voltage (I-V) curves were measured simultaneously along with topographic observations using point-contact current imaging atomic force microscopy. Symmetric I-V curves were obtained at bare single-walled carbon nanotubes but characteristic asymmetrical rectifying behavior was found at the single-walled carbon nanotube/1 50mer-porphyrin junctions. This finding is of key importance for the development of new nanoscale molecular electronic devices.

4-(S-Acetylthiomethyl)phenyl- and pyrenyl-functionalized π-conjugated porphyrin oligomers were synthesized. The distribution of the length of the oligomers could be controlled by changing the ratio of the starting porphyrin to the capping molecules. Oligomers from dimers to heptamers were isolated using size exclusion chromatography. The spectroscopic properties of these oligomers were measured to determine the influences of the number of porphyrin units and capping molecules on the absorption and emission spectra.

The fabrication of supramolecular porphyrin arrays on the surface of a mica substrate is demonstrated. The supramolecular structures are prepared at the air–water interface from a dilute solution of porphyrin dimer and bidentate ligand and then transferred to mica by using the conventional Langmuir–Blodgett method. Isolated wire-like structures and networks of structures are observed by atomic force microscopy. From the analysis of the height histogram and width, these structures are considered to be side-by-side arrangements of supramolecular chains of porphyrin dimer and bidentate ligand. By changing the ligand molecule, we demonstrate that the configuration of the supramolecular structure can be controlled.

Metalloporphyrin complexes with a photochromic axial ligand were synthesized and photoisomerization behavior of those complexes was investigated. In this study, 3,3′-azopyridine (AZP) was used as the axial ligand. We found that the structure of the axial-coordinated complexes depended on the center metal of porphyrin. When magnesium was employed as the center metal, a 1 : 1 coordinated complex was obtained. On the other hand, zinc or rhodium porphyrins formed the sandwich-bonded complexes. The photoisomerization behavior also depended on the center metal of the porphyrins, and the cis-to-trans “one-way” photoisomerization of the AZP axial ligand took place in the complexes of zinc and rhodium porphyrins. The one-way isomerization may be interpreted as the results of the photoinduced electron transfer from porphyrin to AZP.

Sub-micrometer long butadiyne-linked porphyrin wires were synthesized by oxidative coupling of diethynylporphyrin. The porphyrin wires were analyzed by analytical gel permeation chromatography, absorption spectroscopy and matrix-assisted laser desorption/ionization time of flight mass spectroscopy. Observations of the wire were performed by atomic force microscopy. Self-assembled structures of the wires were observed on highly oriented pyrolytic graphite. Self-assembling features of the porphyrin wires depended on the length of the porphyrin wires and the concentration of the depositing solution.

In the aim to prepare thick porphyrin molecular wires, which is visible by atomic force microscopy (AFM), even on the rough surfaces of nanogap electrodes fabricated by electron beam lithography, dendrimer protected porphyrins whose two meso-positions are substituted with ethynyl groups. The porphyrin monomer was reacted with palladium catalyst to make oligomers. Analyses of them with time-of-flight mass spectroscopy (TOF-MS), gel-permeation-chromatography (GPC) revealed that the oligomers were distributed up to 16 mer, whose molecular weight was about 38 000 Daltons.

Tetra-meso-substituted rhodium(III) porphyrins with axial ligand of molecular wire were synthesized for the first time to demonstrate the preparation of self-standing molecule for measuring a single electron conductivity using scanning tunneling microscope technique. The self-standing structure of molecular wire was confirmed by X-ray crystallographic analysis. Cyclic and pulse voltammograms of each compound were measured, and these results indicated that we can freely change the energy level of self-standing molecule and estimate it by using voltammetric measurement.

We report oxygen reduction reaction (ORR) activity in phenolsubstituted iron porphyrin dimer as a catalyst. Supported on carbon, the Fe(III)-porphyrin dimer (FeDOH/C) shows ~60 mV higher onset potential (OP) and ~50 mV higher half-wave potential (HWP) than those of unsubstituted monomer (FeM/C). Comparing these two catalysts with the phenol-substituted monomer catalyst (FeMOH/C), the origins of improvement in OP and HWP of FeDOH/C are attributed to its phenol group under an acidic condition and to the proximity of two iron active centers coordinated by four nitrogen ligands.

We have developed a new methodology that enables the synthesis of any sequence of metal porphyrin arrays starting from a common key molecule. Using this method, we prepared porphyrin dimers and trimers with varying component unit sequences via consecutive Suzuki coupling reactions using the same key porphyrin compound under the same reaction conditions. The key porphyrin compound was synthesized on a gram scale in one batch, and the coupling reactions afforded the desired oligomers in good yields. Thus, the prepared porphyrin arrays showed unique physical properties depending on the sequence of the central metals. The reaction is potentially applicable for the automated synthesis of porphyrin arrays.

Double-decker complexes based on single-molecule magnets (SMMs) are a class of highly promising molecules for applications in molecular spintronics, wherein control of both the ligand oxidative states and the 2D supramolecular structure on carbon materials is of great importance. This study focuses on the synthesis and study of 2,3,7,8,12,13,17,18-octaethylporphyrin (OEP)-Tb(III) double-decker complexes with different electronic structures comprising protonated, anionic, and radical forms. Magnetic susceptibility measurements revealed that only the anionic and radical forms of the OEP-Tb(III) double-decker complexes exhibited SMM properties. The barrier heights for magnetic moment reversal were estimated to be 207 and 215 cm(-1) for the anionic and radical forms, respectively. Scanning tunneling microscopy (STM) investigations revealed that these OEP-Tb(III) complexes form well-ordered monolayers upon simple dropcasting from dilute dichloromethane solutions. All three complexes form an isomorphic pseudo-hexagonal 2D pattern, regardless of the differences in the electronic structures of their porphyrin-Tb cores. This finding is of interest for SMM technology as ultrathin films of these materials undergoing chemical transformations will not require any detrimental reorganization. Finally, we demonstrate self-assembly of the protonated 5,15-bisdodecylporphyrin (BDP)-Tb(III) double-decker complex as an example of successful supramolecular design to achieve controlled alignment of SMM-active sites.

Four different porphyrin-imide dyads bearing different central metals (zinc or rhodium) and different substituents on the porphyrin macrocycles (tert-butyl or methoxy) were synthesized for single molecular diode measurements. The molecules were designed to separate the donor component (porphyrin) from the acceptor component (imide) by bonding in a perpendicular arrangement, thus enhancing the rectification properties. UV/Vis absorption spectra and density functional theory calculations showed that the design was successful and that the molecular orbitals of the dyads were the summation of the two components, with minimal interaction between them. The effect of the central metal was found to be significant, with the lowest energy absorption for the zinc dyads being attributed to the mixed state of charge transfer from porphyrin to imide and the Q band, whereas that of the rhodium dyads indicated insignificant charge-transfer character.

The syntheses and X-ray structures of novel porphyrinoids, “N-fused porphyrins (NFPs)”, and their reactivity were described. NFP was spontaneously produced from the bromo-substituted N-confused tetraarylporphyrin in a pyridine solution at room temperature. X-ray diffraction analyses revealed that the porphyrinoid core containing a fused tri-pentacyclic ring is almost planar. The deviation from the mean plane of 4e‘, for example, was within 0.30 A. The peripheral aryl substituents were tilted 50.4, 53.5, 64.4, and 12.4° relative to the porphyrin mean plane, respectively. The occurrence of a three-centered hydrogen bonding in the NFP core was inferred by the downfield shift of the inner NH signal (e.g., 8.48 ppm for 4e‘) in 1H NMR and the short distances (within 2.4−2.9 A) among the inner core nitrogens, N2, N3, and N4. The optical absorption spectra of NFPs exhibit Soret-like transitions around 360, 500, and 550 nm and weak Q-like bands around 650, 700, 850, and 940 nm in CH2Cl2. The electrode process of 4...

The metal ion determines the reactivity upon electrochemical oxidation of metal porphyrins that are unsubstituted at the meso position. Thus, with Cu2+, Pd2+, and Ni+2 as the central ion (and for the free porphyrin base), directly linked meso,β porphyrin dimers 2 were formed, while Mg and Zn complexes afforded the corresponding directly linked meso,meso porphyrin dimers 1. Ar=3,4-tBu2C6H3.

Novel porphyrins substituted with aryl and nitro substituents at the β-position were prepared by the tetramerization of 2-hydroxymethyl-3-aryl-4-nitropyrroles. Aggregation properties of these porphyrins are investigated by means of UV–VIS, 1H-NMR and EPR spectroscopy. Porphyrin 4a substituted with 4-methoxyphenyl and nitro groups was found to form a strong cofacial aggregate in solution (K = 900–1300 dm3 mol–1). The extent of aggregation decreases in the following order: porphyrin 4a (nitro and 4-methoxyphenyl substituents) > 4b (nitro and phenyl substituents) > TMTP (methyl and phenyl substituents) > OEP (ethyl substituents). EPR spectra of Cu–4a support the dimer structure of 4a, and the distance between two porphyrins is estimated to be about 4 A.

Pyrroles fused with crown ethers are prepared by the reaction of 3,4-dihydroxy pyrrole 1 and polyethylene glycol ditosylate 2 in the presence of cesium fluoride using a convenient high dilution method. These pyrroles can be converted into the corresponding porphyrins with four crown ether moieties, which are expected to form ion channels.

Single-walled carbon nanotube (SWNT) was physically adsorbed by several kinds of particles including porphyrin, naphthalenediimide (NDI) and polyoxometalate (POM). Nanoscale electrical properties of the complexes were measured by point-contact current imaging atomic force microscopy (PCI-AFM), and rectification appeared at the interface of particle and SWNT. Rectification ratio (RR) and plateau width (PW) could be controlled by the particle size of NDI. Reversible rectification direction was observed in the case of POM. Charge transfer between SWNT (Pt cantilever) and nanoparticle was considered as the reason of rectification.

A tetraphenylporphyrin based Tb(III) double-decker complex has been synthesized and the crystal structure of both protonated and deprotonated forms has been determined. The ac magnetic susceptibility measurements revealed that the SMM properties of the double-decker complex can be reversibly switched by only a single proton.

The new N-confused porphyrin (NCP) derivatives, meso-unsubstituted beta-alkyl-3-oxo N-confused porphyrin (3-oxo-NCP) and related macrocycles, were synthesized from appropriate pyrrolic precursors by a [3+1]-type condensation reaction. 3-Oxo-NCP forms a self-assembled dimer in dichloromethane that is stabilized by complementary hydrogen-bonding interactions arising from the peripheral amide-like moieties. The protonated form of 3-oxo-NCP was observed to bind halide anions (F(-), Cl(-)) through the outer NH and the inner pyrrolic NH groups, thus affording a dimer in dichloromethane. The structure of the chloride-bridged dimer in the solid state was determined by X-ray diffraction analysis.

The preparation and properties of tert-dodecanethiol protected gold nanoparticles amenable to very rapid surface functionalization by associative mechanism is described. The new material can be easily prepared by controlling the reaction time, because only a limited but enough number of tert-dodecanethiol to stabilize the gold clusters is bond to the surface until about an hour. Accordingly, it can be isolated as a solid and handled much like the highly stabilized Brust-Schiffrin analogues, but reacted very rapidly with any molecular species containing one or multiple functional groups such as thiol, disulfide, pyridine, etc., These characteristics are ideal for the preparation of a variety of new organic–inorganic hybrid nanomaterials by coordinative self-assembly. This possibility was illustrated using meso-tetra(4-pyridyl)porphyrin, which promptly bonded to the reactive protected gold nanoparticles generating a solid that can be grown as thin films with layer-by-layer control on a suitably modified surface.

Nanocomposites of long conjugated porphyrin polymers with both ends substituted by gold nanoparticles were prepared by mixing a polymer bearing thiol groups at both ends with gold nanoparticles pro...

Electrochemical oxidation of [5,15-bis(3,5-di-tert-butylphenyl)porphyrinato]zinc(II) 1, [5,15-bis(4-methoxycarbonylphenyl)porphyrinato]zinc(II), [5,15-bis(pentafluorophenyl)porphyrinato]zinc(II) or [10-bromo-5,15- diphenylporphyrinato]zinc(II) in benzonitrile using a platinum net as the working electrode afforded the corresponding meso,meso-linked oligomer porphyrin arrays, and up to the octamer porphyrin array could be isolated for 1.