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Photodynamic therapy (PDT) is an interesting and promising approach to tackle a broad spectrum of cancer types. With the combination of a photosensitizer, light and oxygen, PDT achieves a unique selectivity by the production of localized reactive oxygen species (ROS) inside cells, which leads to their destruction. In addition, the luminescence properties of photosensitizers can be exploited to develop imaging tools. Unfortunately, the cancer selectivity and homogeneity of most photosensitizers are frequently limiting the performances of PDT and cancer detection/characterization by luminescence imaging. Consequently, our study aims to use cellulose nanocrystals to transport and deliver radiolabeled photo-responsive metalla-assemblies to create a new generation of theranostic agents for PDT and imaging applications. The synthesis, structural characterization, cytotoxicity evaluation, and in vivo biodistribution imaging of the compounds are presented. The best candidates show excellent biological activity and selectivity towards ovarian carcinoma cell line (A2780), cisplatin resistant ovarian carcinoma cell line (A2780cis) versus normal human embryonic kidney cells (HEK293T), as well as efficient imaging properties, suggesting a potential use as multimodal theranostic agents.

The aggregative state of the Zn(II) tetra-spermine porphyrin derivative, ZnTCPPSpm4, has been investigated in the presence of different buffers at the same pH value: 5K (cacodylate) buffer, phosphate sodium salt buffer, and PBS. The photophysical characterizations (UV-vis, Fluorescence, and RLS) have indicated a precise self-assembly phenomenon depending on the buffered solution used. The porphyrin does not undergo a significant aggregation in 5K buffer, differently from what occurs in phosphate and PBS buffers. Here, the likely specific interaction between the phosphate molecules and spermine pendants leads to spontaneous porphyrin aggregation, as detected by the high fluorescence quenching, enhancement of the RLS signal, and a significant splitting of the porphyrin Soret band. As a result, the current paper aims to highlight the importance of the employed buffer throughout the experimental procedures performed in the presence of porphyrinoids.

Heterogeneous two-dimensional layered membranes reconstructed from natural or synthetic van der Waals materials enable novel ion transport mechanisms by coupling with the chemistry and optoelectron...

Constructing molecule@support composites is an attractive strategy to realize heterogeneous molecular electrocatalysis. Herein, we synthesized metal-organic framework (MOF)-supported molecular catalysts for hydrogen evolution and oxygen reduction reaction (HER/ORR). Ligand exchange strategy was used to prepare molecule@support hybrids due to the same functional group. A series of hybrids were obtained using Co porphyrin (1) and different MOFs including MIL-88(Fe), MOF-5(NiCo) and UIO-66(Zr). The 1@MOF-5(NiCo) had the best HER and ORR activity compared with 1@MIL-88(Fe) and 1@MOF-5(NiCo). These hybrids also exhibited tunable selectivity for ORR with four-electron process, which can be attributed to the synergistic effect of porphyrin molecules and MOFs. This work provides a possibility for molecular catalysts to improve activity of HER and tune selectivity of ORR.

Several 2D nanosheets of porphyrin MOFs with various transition-metal clusters as metal nodes were prepared via a simple solvothermal method to apply in the photocatalytic hydrogen evolution, in which the hydrogen production rate of the optimal NS-Cu was as high as 15.39 mmol•g−1•h−1. A series of experimental technologies especially cyclic voltammetry (CV) and Mott-Schottky (M-S) had been adopted to investigate the charge-transfer property of photo-generated electron-hole pairs, it was found that the uniformly dispersed Cu-clusters nodes in the original 2D MOFs played a key role in the electron transfer process, that was, the photo-generated electron transferred from excited state eosin-Y to the Cu-clusters nodes for the efficient hydrogen evolution. The excellent photocatalytic performance could be attributed to the reversible oxidation-reduction process of CuII/CuI, which had excellent electron-receiving and electron-outputting capabilities. Our results provided a novel avenue to adapt the uniformly dispersed metal nodes in the original MOFs as cost-effective noble-metal-free cocatalysts with very high atom-utilization efficiency to improve the photocatalytic hydrogen evolution performance in dye-sensitized system.

Morphology-controlled electrocatalysts with the ability of CO2 adsorption/activation, mass transfer, high stability and porosity are much desired in electrochemical CO2 reduction reaction (CO2RR). Here, three kinds of multi-dimensional nanostructures (i.e., hollow sphere, nanosheets and nanofibers) have been successfully produced through the modulation of porphyrin-based covalent organic frameworks (COFs) with various modulators. The obtained nanostructures with high-stability, large surface-area, and single metal sites enable efficient CO2RR into CH4. Notably, they all exhibit higher FECH4 (hollow sphere, 68.2%; nanosheet, 64.2% and nanofiber, 71.0%, -0.9 V) than COF-366-Cu (43.0%, -0.9 V) after morphology control. Noteworthy, the FECH4 of COF-366-Cu (HS) keeps higher than 52.4% over a wide potential range from -0.9 V to -1.1 V and the achieved FECH4+C2H4 (82.8%, -0.9 V) is superior to most of reported COFs and copper-based electrocatalysts. This work paves a new way in the exploration of COF-based multi-dimensional nanostructures applicable in efficient CO2RR to CH4.

Direct photocatalyzed hydrogen atom transfer (d-HAT) can be considered a method of choice for the elaboration of aliphatic C–H bonds. In this manifold, a photocatalyst (PCHAT) exploits the energy of a photon to trigger the homolytic cleavage of such bonds in organic compounds. Selective C–H bond elaboration may be achieved by a judicious choice of the hydrogen abstractor (key parameters are the electronic character and the molecular structure), as well as reaction additives. Different are the classes of PCsHAT available, including aromatic ketones, xanthene dyes (Eosin Y), polyoxometalates, uranyl salts, a metal-oxo porphyrin and a tris(amino)cyclopropenium radical dication. The processes (mainly C–C bond formation) are in most cases carried out under mild conditions with the help of visible light. The aim of this review is to offer a comprehensive survey of the synthetic applications of photocatalyzed d-HAT.

A facile synthetic strategy was developed for the synthesis of meso -tetrakis(4-formyl-phenyl)porphyrin and meso -tetrakis(3-formylphenyl)porphyrin from commercially available starting materials. This method gives facile access to practical amounts of these synthons in high purity and good overall yield, without employing laborious chromatographic separations. The reduction of the respective carboxylic acid-functionalized porphyrins by LiAlH4 afforded the tetra(benzylalcohol)porphyrin intermediates, subsequently utilized in a Parikh-Doering oxidation to selectively afford the desired tetraformylated products. The inherent ease of synthesis of these porphyrin building blocks provides a convenient pathway for the synthesis of various macromolecular and supramolecular architectures for applied chemical technologies.

In recent years, porphyrins with a similar structure to chlorophyll are often used as photosensitizers or reaction centers to improve the light absorption capacity or catalytic selectivity of existing photocatalytic systems. However, photocatalytic reactions include photoelectric conversion, photocarrier transport, and surface reaction, which requires the overall design of porphyrin-based photocatalysts. In this paper, the research work of porphyrin molecular design in heterogeneous photocatalysis in recent years is reviewed. Besides, the application of interface control and spatial confinement effect in porphyrin-based hybrid photocatalyst is introduced. Finally, the future development direction of porphyrin-based photocatalysts is prospected and the main challenges in the research of porphyrin-based photocatalysts is given.

Encapsulating metal nanoparticles (MNPs) inside the specific porous materials is considered as a feasible strategy to prepare ultrafine MNPs with high stability. Herein, ultrafine Ru nanoparticles (NPs) with a mean size of 3.2 nm encapsulated in a N-doped porous carbon (NC) derived from the pyrolysis of a new porphyrin framework (POF) were fabricated via a simple wet chemical method, in which POF was synthesized using 4,4'-biphenyldicarboxaldehyde and pyrrole as raw materials. Reconstructed slices tomographic characterization confirmed the successful encapsulation of Ru NPs in POF-NC600 (pyrolysis temperature T = 600 °C). Due to the confinement effects and anchoring effects of POF-NC600, Ru@POF-NC600 shows the smallest particle size of Ru NPs and the highest hydrogen production performance toward the methanolysis of ammonia borane (AB) among the investigated catalysts, providing a record initial turnover frequency (TOF) value of 727 min-1 at 25 °C as compared to those heterogeneous catalysts ever reported. Systematic investigations reveal that pyridinic-N plays a pivotal role in the particle size distribution of Ru NPs and catalytic activity of the catalyst. Extended theoretical calculations confirm that Ru atoms attached to pyridinic-N display a higher stability than those attached to pyrrolic-N and C atoms. As a result, pyridinic-N, as an efficient anchoring site, determinates the dispersity and size distribution of Ru NPs, thus affecting the catalytic activity of the catalyst. The more pyridinic-N, the better the catalytic activity. A series of isotopic experiments were performed, and it is found for the first time that the cleavage of the O-H bond in methanol is involved in the rate-determining step (RDS) of AB methanolysis. This work offers insights into rationally designing stable and ultrafine metal NPs confined in the pyridinic-N-rich composites for various application.

A series of tetraphenylporphyrin-based thermotropic liquid crystals containing oligo(dimethylsiloxane) were synthesized. These disc-coil hybrids form ordered nanostructures with periodic sizes on the sub-5 nm scale, including oblique columnar, lamellar, and hexagonal columnar phases. Films with sub-5 nm line patterns and homeotropically aligned columnar structures can be obtained by substrate-induced self-assembly.

Dedicated to Prof. Tomás Torres on the occasion of his 70th birthday; International audience; Our groups are involved in a research program on the development of molecular and supramolecular systems combining pillar[5]arene building blocks with porphyrins. Functionalization of both rims of the pillar[5]arene scaffold with metalloporphyrins generated giant molecular machines mimicking the blooming of a flower as well as light-harvesting devices. On the other hand, we have also used the host-guest properties of pillar[5]arene derivatives to prepare photoactive mechanically interlocked molecules. In such compounds, complementary subunits are associated into a single molecular ensemble but without being connected through covalent bonds. Inter-component photo-induced energy transfer processes remain however extremely fast in these systems despite the exclusive link through mechanical bonds. All these results are described in the present review.

Choosing the right photosensitizers (PSs) as well as the right light source is very critical in antimicrobial photodynamic therapy (aPDT). Some light sources, such as ultraviolet, have high cytotoxicity and poor penetration and some PSs are hydrophobic with low solubility in water, and easy aggregation. To address these issues, we modified TiO2 nanoparticles with urea and TCPP (TCPP=tetra(4-carboxyphenyl) porphyrin) as a PS and prepared N-doped-TiO2 (NT), TCPP/TiO2 (PT), and TCPP/N-doped-TiO2 (PNT). Urea is a safe compound used here as a source of nitrogen (N). Nitrogen doping produces a localized N state within the TiO2 bandgap which broadens the absorption in the visible light region. Both urea and TCPP shifted the bandgap of TiO2 to the visible area and enabled the photodegradation of methylene blue after 30 min of aging under visible light. O-1(2) production was monitored by the rapid and irreversible conversion of anthracene to its corresponding endoperoxide. Meanwhile, different scavengers such as p-benzoquinone (p-BQ) and tert-butanol (t-BuOH) were employed in a photocatalytic process to specify the existence of superoxide and hydroxyl radical species, respectively. PNT showed a promising photobactericidal activity and reached 100% of inhibition activity against both types of bacteria after 120 and 180 min, respectively under LED lamp (15 W) irradiation. The interaction between PNT and bacteria was also examined by FESEM. Both urea and TCPP shifted the bandgap of TiO2 to the visible area and enabled the photodegradation of methylene blue after 30 min of aging under visible light. O-1(2) production was monitored by the rapid and irreversible conversion of anthracene to its corresponding endoperoxide. Meanwhile, different scavengers such as p-benzoquinone (p-BQ) and tert-butanol (t-BuOH) were employed in a photocatalytic process to specify the existence of superoxide and hydroxyl radical species, respectively. PNT showed a promising photobactericidal activity and reached 100% of inhibition activity against both types of bacteria after 120 and 180 min, respectively under LED lamp (15 W) irradiation. The interaction between PNT and bacteria was also examined by FESEM. Refereed/Peer-reviewed

Biomimetic chiral optoelectronic materials can be utilized in electronic devices, biosensors and artificial enzymes. Herein, this work reports the chiro-optical properties and architectural arrangement of optoelectronic materials generated from self-assembly of initially nonchiral oligothiophene-porphyrin derivatives and random coil synthetic peptides. The photo-physical- and structural properties of the materials were assessed by absorption-, fluorescence- and circular dichroism spectroscopy, as well as dynamic light scattering, scanning electron microscopy and theoretical calculations. The materials display a three-dimensional ordered helical structure and optical activity that are observed due to an induced chirality of the optoelectronic element upon interaction with the peptide. Both these properties are influenced by the chemical composition of the oligothiophene-porphyrin derivative, as well as the peptide sequence. We foresee that our findings will aid in developing self-assembled optoelectronic materials with dynamic architectonical accuracies, as well as offer the possibility to generate the next generation of materials for a variety of bioelectronic applications. Funding Agencies|Swedish Research Council [621-2013-4754, 2016-00748, 2018-4343]; Swedish e-Science Research Centre (SeRC); Swedish Foundation for Strategic Research [FFL15-0026]; Ministry of Education, Youth and Sports of the Czech Republic (ERDF/ESF "Nano4Future") [CZ.02.1.01/0.0/0.0/16_019/0000754]; EC Research Innovation Action under the H2020 Programme [HPC-EUROPA3 INFRAIA-2016-1-730897]

To estimate the adsorption distribution of cationic dyes on the inorganic nanosheets, the fluorescence behavior of cis-DMPyP, which is a di-cationic porphyrin, was investigated using self-fluoresce...

3, 7, 23, 27-Tetrabromo[36]octaphyrin 2 was synthesized as a novel octaphyrin bearing two meso-free positions. Surprisingly, its ZnII and NiII complexation reactions produced a directly fused porphyrin(2.1.1.1) dimer 6, and a meso-α fused N-confused porphyrin (NCP) dimer 7, as the first example of NCP tape, respectively, via transannular C−C bond formation. While 6 exhibits a diatropic ring-current effect owing to the global 36π Möbius aromaticity, 7 shows a paratropic ring-current effect due to the global Hückel 36π antiaromaticity. In addition, the oxidation of 7 with PbO₂ allowed for formation of its two-electron oxidized species 9 that exhibited a diatropic ring-current effect due to the global Hückel 34π aromaticity. This work has demonstrated that meso-free large expanded porphyrins can be a promising platform to produce novel fused porphyrinoids.

Developing large-scale electrocatalysts using molecular complexes for the oxygen evolution reaction (OER) is of great importance. Herein, four cobalt porphyrins and corroles are deposited on electrode substrates using a simple and fast electropolymerization method. Our results showed that Co-1-P@CC, formed by electropolymerizing Co tetrakis(p-N-pyrrolylphenyl)porphyrin (Co-1-P) on carbon cloth (CC), is the most active OER catalyst in the examined Co porphyrins and corroles in alkaline aqueous solutions by displaying an onset overpotential of 380 mV. Long-term electrolysis tests confirmed the stability of these electropolymerized films by functioning as OER electrocatalysts.

Porphyrin-based photosensitizers are conventional photodynamic agents that are used clinically. However, their clinical applications have been overshadowed by poor water solubility. In addition, they have weak tumor selectivity, which may cause undesirable side effects. The preparation of novel porphyrin derivatives has been explored for potential applications in photodynamic therapy (PDT). To achieve this goal, lactose-conjugated porphyrin nanoparticles (Lac-Por NPs) have been synthesized and characterized. PDT with Lac-Por NPs exhibited tumor-specific cytotoxicity in lactose receptor-overexpressing HepG2 cells in vitro and in vivo. In summary, we designed and synthesized lactose conjugate porphyrins with enhanced water solubility and tumor selectivity. This work expands the application range of porphyrin-based photosensitizers for cancer treatment.

Photocatalysis plays a significant role in the field of environment purification and energy conversion. In this work, a series of visible-light-responsive tetraphenylporphyrin (TPP)/BiOBr nanocomposite was prepared via a facile solvothermal method, and their photocatalytic activity toward the degradation of tetracycline (TC) and ciprofloxacin was evaluated and compared. Spectroscopic analysis demonstrates that TPP/BiOBr nanocomposite displays higher carrier mobility, results in generating numerous superoxide radical, hydroxyl radical, and holes under visible-light photoirradiation. And the degradation rate constant of TC for 1 wt% TPP/BiOBr is about 0.013 min−1, 2.1 times higher than that of single BiOBr. The introduction of TPP into BiOBr is found to act as a key role in determining photocatalytic efficiency. Based on the favorable photoelectrochemical properties and photocatalytic performance, porphyrin modified semiconductor catalyst can be employed as a high-performance photocatalyst in the treatment of antibiotic wastewater.

In the past decades, many attempts have been made to mimic the energy transfer (EnT) in photosynthesis, a key process occurring in nature that is of fundamental significance in solar fuels and sustainable energy. Metal-organic frameworks (MOFs), an emerging class of porous crystalline materials self-assembled from organic linkers and metal or metal cluster nodes, offer an ideal platform for the exploration of directional EnT phenomena. However, placing energy donor and acceptor moieties within the same framework with an atomistic precision appears to be a major synthesis challenge. In this work, we report the design and synthesis of a highly porous and photoactive N,N'-bicarbazole- and porphyrin-based mixed-ligand MOF, namely, NPF-500-H2TCPP (NPF = Nebraska porous framework; H2TCPP = meso-tetrakis(4-carboxyphenyl)porphyrin), where the secondary ligand H2TCPP is incorporated precisely through the open metal sites of the equatorial plane of the octahedron cage resulting from the underlying (4,8) connected network of NPF-500. The efficient EnT process from N,N'-bicarbazole to porphyrin in NPF-500-H2TCPP was captured by time-resolved spectroscopy and exemplified by photocatalytic oxidation of thioanisole. These results demonstrate not only the capability of NPF-500 as the scaffold to precisely arrange the donor-acceptor assembly for the EnT process but also the potential to directly utilize the EnT process for photocatalytic applications.

High-efficiency photocatalysis in metal-organic frameworks (MOF) and MOF nanosheets (NSs) are often limited by their short-lived charge separation as well as self-quenching. Here, we propose to use the energy-transfer process (EnT) to increase charge separation, thus enhancing the catalytic performance of a series of MOF NSs. With the use of NS, the photocatalyst can also be well isolated to reduce self-quenching. Tetrakis(4-carboxyphenyl) porphyrin (H4 TCPP) and 1,3,6,8-tetrakis(p-benzoic acid)pyrene (H4 TBAPy) linkers were chosen as the acceptor and donor moieties, respectively. Accounting for the precise spatial design afforded by the MOF NSs, the donor and acceptor moieties could be closely positioned on the NSs, allowing for an efficient EnT process as well as a high degree of site isolation. Two templates, donor-on-acceptor NS and acceptor-on-donor NS catalysts, were successfully synthesized, and the results show that the second one has much enhanced catalytic performances over the first one due to site-isolated active photocatalysts.

Site-specific functional polymers are generally synthesized from functionalized chain transfer agents (CTA) in the presence of catalysts. However, the poor solubility or chemical inertness of CTAs may lead to polymerizations uncontrollable. Now, this issue is addressed by proposing a strategy of designing chain-transfer-catalyst (CTC) that combines catalyst and CTA into one. The occurrence of catalytic effect naturally triggers the chain transfer process to give catalyst-labeled polymers with well-defined structures. As a proof-of-concept, cobalt(III) porphyrin catalysts with one, two and four hydroxyl groups act as efficient CTCs, giving the corresponding site-specific functional poly(propylene carbonate)s (PPC), diversifying the topology of polymers. Furthermore, porphyrin-capped PPCs with controllable Mn in the range of 1,000–16,800 g mol−1 were obtained by using monofunctional CTC (CTCOH). Moreover, different from traditional “catalyst+CTA” systems, a novel dynamic network transfer mechanism of CTCOH was proposed. This study provides a CTC strategy for the synthesis of site-specific functional polymers.

Herein, we reported a self-assembled fabrication of a network nanozyme (TMPyP-pSC4@GNPs) and a glucose-recognition molecule (APBA) for highly stable and selective glucose sensing. By involving the ...

Accurate control of the layer number of orderly stacked 2D polymers has been an unsettled challenge in self-assembly. Herein we describe the fabrication of a bilayer 2D supramolecular organic framework from a monolayer 2D supramolecular organic framework in water by utilizing the cooperative coordination of a rod-like bipyridine ligands to zinc porphyrin subunits of the monolayer network. The monolayer supramolecular framework is prepared from the co-assembly of an octacationic zinc porphyrin monomer and cucurbit[8]uril (CB[8]) in water through CB[8]-encapsulation-promoted dimerization of 4-phenylpyridiunium subunits that the zinc porphyrin monomer bear. The bilayer 2D supramolecular organic framework exhibits structural regularity in both solution and the solid state, which is characterized by synchrotron small-angle X-ray scattering and high-resolution transmission electron microscopic techniques. Atomic force microscopic imaging confirms that the bilayer character of the 2D supramolecular organic framework can be realized selectively on the micrometer scale.

The crystal structure of a bisporphyrin cleft molecule revealed that the head-to-head dimeric structure is directed by the intermolecular self-complementary hydrogen-bonding interactions of amide g...

Local charge carrier dynamics in diketopyrrolopyrrole (DPP)-tetrabenzoporphyrin (BP)-based bulk heterojunction (BHJ) films are investigated by optical pump-terahertz probe spectroscopy. Here we foc...

The photo-isomerization of azobenzene (AZB) provides the essential stimulation for the controlled regulation of spin-crossover in the iron(III)porphyrin complex. We have performed theoretical simul...

As two pivotal functional segments, triazine and porphyrin can be coupled to form a highly cross-linked conjugated polymer. Although the obtained conjugated polymers are almost insoluble in most so...

Corroles, macrocycles that owe their name to the cobalt-chelating prosthetic group of vitamin B12 and share numerous features with the iron-chelating porphyrin present in heme proteins/enzymes, constantly cross new boundaries ever since stable derivatives became easily accessible. Particularly important is the increasing utilization of corroles and the corresponding metal complexes for the benefit of mankind, in terms of new drug candidates for treating various diseases and as catalysts for sustainable energy relevant processes. One challenge is to gain access to the plain macrocycle, as to allow for full elucidation of the most fundamental properties of corroles. We have obtained the substituent-free corrole by several surprising and conceptually different pathways. Selected features of the corresponding metal complexes are illuminated, for pointing towards unique phenomena that are anticipated to largely expand the horizon regarding their utilization for contemporary catalysis.

Grain boundary management is critical to the performance and stability of polycrystalline perovskite solar cells (PSCs), especially large-area devices. However, typical passivators are insulating in nature and limit carrier transport. Here, we design a supramolecular binder for grain boundaries to simultaneously passivate defects and promote hole transport across perovskite grain boundaries. By doping the monoamine porphyrins (MPs, M = Co, Ni, Cu, Zn, or H) into perovskite films, MPs self-assemble into supramolecules at grain boundaries. Organic cations in perovskites protonate MPs in supramolecules to form ammonium porphyrins bound on the perovskite grain surface, to passivate defects and extract holes from the perovskite lattice. Periodic polarons in supramolecules (especially NiP-supramolecule) promote the transport of extracted holes across boundaries, reducing nonradiative carrier recombination. The NiP-doped PSCs reveal a certified efficiency of 22.1% for an active area of 1.0 cm2 with the remarkably improved open-circuit voltage and fill factor. The unencapsulated device retained over 80% initial performance under AM 1.5G solar light continuous illumination or heating at 85 °C over 3000 h.

Cytochrome P450 selectively hydroxylates the ω and ω-1 positions of fatty acids. Among synthetic oxidizing catalysts, Suslick’s bis-pocket porphyrin Mn or Fe complex achieved ω oxidation for the fi...

We herein describe the development of a mild and selective catalytic aerobic oxidation process of olefins. This catalytic aerobic oxidation reaction was designed based on experimental and spectrosc...

Reactions of InIIIClPc or TlIIIClPc phthalocyanines with monodeprotonated tetraphenylporphyrin HTPP[Formula: see text] anions have been studied under reduction or in the presence of [Formula: see text]-methylimidazole ([Formula: see text]-MeIm). Formation of salt {InIII[Formula: see text]-MeIm)2(TPP[Formula: see text]}[Formula: see text]{InIII(Pc[Formula: see text]}[Formula: see text]⋅4C6H4Cl2 (1) justifies partial abstraction of indium(III) atoms from InIIIClPc to form cationic {InIII(TPP[Formula: see text]}[Formula: see text] porphyrins[Formula: see text]solvated by [Formula: see text]-MeIm and double-decker {InIII(Pc[Formula: see text]}[Formula: see text] anions. Crystals of TlI(HTPP[Formula: see text] (2) have been only obtained at the interaction of HTPP[Formula: see text] with TlIIIClPc under reduction indicating that TlIII is reduced to TlI and is abstracted by HTPP[Formula: see text]. To confirm the possibility of TlI formation under reduction we have studied reduction of TlIIIClPc by sodium fluorenone in the presence of cryptand[2.2.2]. Crystals of {Cryptand(Na[Formula: see text]}(TlI(Pc[Formula: see text]}[Formula: see text]⋅C6H4Cl[Formula: see text] (3) have been isolated indicating metal-centered reduction of TlIIIClPc to form TlI and preserving dianionic Pc[Formula: see text] macrocycles. Optical spectra and structures of the obtained compounds are discussed and compared with those of pristine MIIIClPc. It is shown that 1– 3 are EPR silent due to the formation of diamagnetic components.

Report of the construction of the supramolecular light harvesting composed of zinc(II) phthalocyanine tetrasulfonic acid (ZnPcS[Formula: see text], as electron donor, and meso-tetra([Formula: see text]-methyl-4-pyridyl)porphyrin toluene sulfonate (TMPP), as electron acceptor. The steady-state absorption and fluorescence spectra of TMPP in MeOH showed the formation of monomer form ([Formula: see text] = 426 nm and [Formula: see text] = 654 and 715 nm). In water, different spectral features were recorded, suggesting the formation of aggregated forms. The formation of aggregated form in water was confirmed by recording the remarkable decrease of the fluorescence intensities of the singlet excited TMPP with increasing the concentrations of TMPP. In cationic micelle CTAB, both the absorption and fluorescence spectra were significantly decreased with increasing the concentrations of CTAB with a break at critical micelle concentration (CMC) at 6.00 × 10[Formula: see text] M. In an anionic micelle (SDS), the CMC value was found to be 1.00 × 10[Formula: see text] M. Upon interacting with ZnPcS4 in water, the steady state absorption measurement showed clear evidence for the formation of light harvesting porphyrin-phthalocyanine supramolecular complex through [Formula: see text]–[Formula: see text] and ionic interactions. The emission intensity of the singlet TMPP was found to significantly decrease in the presence of ZnPcS4 suggesting the intra-supramolecular electron transfer process from the electron donating ZnPcS4 to the electron deficient TMPP. From the fluorescence lifetime measurements, the rate and quantum yield of electron transfer were found to be 7.67 × 108 s[Formula: see text] and 0.81, respectively. The finding of the examined light-harvesting supramolecular complex ZnPcS4-TMPP shows the ability to absorb the light in a wide range of the solar spectrum (UV-vis-NIR), in addition to the efficient electron transfer process in an aqueous medium, rendering it as a simple model of the artificial photosynthetic reaction center.

Increasing the number of meso-methine carbons of porphyrin has led to a creation of a series of vinylogous expanded porphyrins, while the introduction of an ortho-phenylene-unit as a pyrrole-connecting two-carbon bridge usually leads to prevention of effective macrocyclic conjugation. Cyclopentene can serve as a conjugative bridge to increase the macrocyclic conjugation owing to its cis-geometry. In this work, ortho-phenylene-cyclopentene-bridged tetrapyrrole 5 was prepared on the basis of a coupling strategy. The tetrapyrrole 5 exhibited slightly more conjugative features as compared to ortho-phenylene-bridged tetrapyrrole 4. Oxidation of 5 with [bis(trifluoroacetoxy)iodo]benzene (PIFA) at low temperature afforded a partly fused tetrapyrrolic compound 9 having a spiro-connected pyrrolo[2,1-[Formula: see text]]isoindole moiety.

The host-guest chemistry of metal-organic nanocages is typically driven by thermodynamically favorable interactions with their guests such that uptake and release of guests can be controlled by switching this affinity on or off. Herein, we achieve this effect by reducing porphyrin-walled cationic nanoprisms 1a12+ and 1b12+ to zwitterionic states that rapidly uptake organometallic cations Cp*2Co+ and Cp2Co+, respectively. Cp*2Co+ binds strongly (Ka = 1.3 × 103 M-1) in the neutral state 1a0 of host 1a12+, which has its three porphyrin walls doubly reduced and its six (bipy)Pt2+ linkers singly reduced (bipy = 2,2'-bipyridine). The less-reduced states of the host 1a3+ and 1a9+ also bind Cp*2Co+, though with lower affinities. The smaller Cp2Co+ cation binds strongly (Ka = 1.7 × 103 M-1) in the 3e- reduced state 1b9+ of the (tmeda)Pt2+-linked host 1b12+ (tmeda = N,N,N',N'-tetramethylethylenediamine). Upon reoxidation of the hosts with Ag+, the guests become trapped to provide unprecedented metastable cation-in-cation complexes Cp*2Co+@1a12+ and Cp2Co+@1b12+ that persist for >1 month. Thus, dramatic kinetic effects reveal a way to confine the guests in thermodynamically unfavorable environments. Experimental and DFT studies indicate that PF6- anions kinetically stabilize Cp*2Co+@1a12+ through electrostatic interactions and by influencing conformational changes of the host that open and close its apertures. However, when Cp*2Co+@1a12+ was prepared using ferrocenium (Fc+) instead of Ag+ to reoxidize the host, dissociation was accelerated >200× even though neither Fc+ nor Fc have any observable affinity for 1a12+. This finding shows that metastable host-guest complexes can respond to subtler stimuli than those required to induce guest release from thermodynamically favorable complexes.

Tetraphyrins(1.1.1.1) (Porphyrins) were merged with amino acids forming a direct bond between a meso-position of macrocycle and a nitrogen available in the side chain of the amino acid. The following intramolecular fusion observed for a free base porphyrin forms a structure with extended [Formula: see text]-delocalisation on the additional carbocyclic fragment, that substantially modifies the observed absorption and emission. A further modulation of electron behaviour has been observed for a deprotonated form of the fused system. A nitrogen atom introduced into the system can be treated as a switching factor that controls the delocalisation significantly influencing the emission by shifting between the available amine and imine tautomeric forms.

An emerging concept, nanoarchitectonics, is supposed to work on the preparation of functional materials systems from nanoscale components. Because porphyrin derivatives show their importance in many research targets, discussions on nanoarchitectonics with porphyrins and related molecules would provide meaningful opportunities to consider effective usages of the nanoarchitectonics. This review article explains various examples of nanoarchitectonics approaches with porphyrin derivatives. The examples are especially focused on two topics: (i) materials nanoarchitectonics for nanofibers, metal-organic frameworks, covalent organic frameworks, and hydrogen-bonded organic frameworks; (ii) interfacial nanoarchitectonics for surface monolayers (self-assembled monolayers), Langmuir-Blodgett films, and layer-by-layer assemblies. Functions and properties can be enhanced upon their organization in specific dimensions and arrangements in nanostructured frameworks. In many cases, interface-specific organization would lead to advanced performances with high efficiency and specificity. Even though only limited examples are described here, various possibilities are actually suggested. Not limited to porphyrin families, nanoarchitectonics for functional materials has to be considered with a wide range of materials.

Pyrrole-bridged Zn(II) porphyrin dimer, Zn2DEP, has been utilized as an efficient tweezer host for the binding of guest (substrate) inside the cavity due to its large vertical flexibility. Aromatic monodentate substrate binds in an exo−endofashion to form a discrete monomeric complex while it converts to anexo−exo upon increasing the bulk of the guest. Shorter bidentate guest, on the other hand, forms 1:1 sandwich complex. In contrast, a longer bidentate guest binds in an exo−endo fashion but to form a polymeric structure. The complexes have been isolated in the solid state and structurally characterized while their complexation process in solution has been monitored spectroscopically. We also provide here a comprehensive account of the substrate binding ability of flexible Zn2DEP towards preferential formation of discrete monomeric exo–endo, exo–exo and sandwich complexes as well as 1D polymer just upon varying the size and type of axial guests. This work can contribute towards the rational design of receptors as highly efficient probes for molecular recognition and chirality sensing devices.

The aim of this review is to offer a succinct overview of the main synthetic techniques used in the preparation of conjugates containing porphyrins, including chlorins and bacteriochlorins and phthalocyanines for biomedical applications and photodynamic therapy (PDT). To illustrate the conjugation techniques representative examples from the literature will be presented.

As a new family of porphyrinoids with broad absorption bands that efficiently harvest sunlight, the metal complexes of a porphyrin quadruply substituted with [Formula: see text]-carbazolyl groups at the meso positions were photometrically and structurally characterized. The porphyrins exhibited characteristic broad bands in the range of 450–500 nm, due to the charge transfer band from carbazole to porphyrin. Ligand exchange at the axial position of the zinc complex with an aquo ligand affected the absorption spectrum, and a hyper-hypsochromic shift of the broad band was observed by the coordination of methanol. Furthermore, the lowest unoccupied molecular orbital (LUMO) levels of the metalloporphyrins were lowered by the electron-withdrawing effect of the perpendicularly oriented carbazolyl groups. In the solid state, zinc-porphyrin was self-assembled into a one-dimensional coordination polymer by intermolecular axial coordination.

Immobilizing catalysts on supports is considered to be one of the promising methods for synthesizing heterogeneous catalysts. Herein, we employed a simple one-pot method to obtain the metalloporphyrin modified carbon nanotubes (ZnTImP-CP/CNTs), using 1,4-bis(bromomethyl)-benzene (BBMB) and zinc 5,10,15,20-tetrakis(4-(imidazole)phenyl)porphyrin (ZnTImP) as monomers. With the Lewis acid sites (Zn-porphyrin) and nucleophilic groups (Br−), this composite material has displayed excellent activity and stability for catalyzing the chemical fixation of CO2 to synthesize value-added cyclic carbonates. The remarkable performance of ZnTImP-CP/CNTs is not only due to the synergy of the Lewis acid and base but also to the large specific surface area.

The present work focuses on the hydrothermal synthesis and properties of porous coordination polymers of metal-porphyrin framework (MPF) type, namely, {[Pr-4 (H2TPPS)(3)]center dot 11H(2)O}(n) (UPJS-10), {[Eu/Sm(H2TPPS)]center dot H3O+center dot 16H(2)O}(n) (UPJS-11), and {[Ce-4(H2TPPS)(3)]center dot 11H(2)O}(n) (UPJS-12) (H2TPPS = 4,4',4 '',4'''-(porphyrin-5,10,15,20-tetrayptetrakisbenzenesulfonate(4)). The compounds were characterized using several analytical techniques: infrared spectroscopy, thermogravimetric measurements, elemental analysis, gas adsorption measurements, and single-crystal structure analysis (SXRD). The results of SXRD revealed a three-dimensional open porous framework containing crossing cavities propagating along all crystallographic axes. Coordination of H2TPPS4- ligands with Ln(III) ions leads to the formation of 1D polymeric chains propagating along the c crystallographic axis. Argon sorption measurements at -186 degrees C show that the activated MPFs have apparent BET surface areas of 260 m(2)g(-1) (UPJS-10) and 230 m(2) g(-1) (UPJS-12). Carbon dioxide adsorption isotherms at 0 degrees C show adsorption capacities up to 1 bar of 9.8 wt % for UPJS-10 and 8.6 wt % for UPJS-12. At a temperature of 20 degrees C, the respective CO2 adsorption capacities decreased to 6.95 and 5.99 wt %, respectively. The magnetic properties of UPJS-10 are characterized by the presence of a close-lying nonmagnetic ground singlet and excited doublet states in the electronic spectrum of Pr(III) ions. A much larger energy difference was suggested between the two lowest Kramers doublets of Ce(III) ions in UPJS - 12. Finally, the analysis of X-band EPR spectra revealed the presence of radical spins, which were tentatively assigned to be originating from the porphyrin ligands.