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This study employed a computational approach, particularly Density Functional Theory at B3LYP−D3/6‐31+G(d) level to design two new classes of three‐dimensional (3D) Lantern Organic Frameworks (LOFs) materials based on trisilasumanene and porphyrin core building units. Particularly, we detail strategies for transitioning from 1D‐LOF nanowires to extended 3D structures: first by connecting planar‐molecule base units of trisilasumanene or porphyrin using benzene‐based linkers, and then connecting silicon anchoring atoms on the bases with other bases that are vertically stacked by sp3‐hydrocarbon chains. The 3D‐LOF structures are designed to have different pore sizes through the use of various bases, bridges, and linkers. Comparisons of electronic properties of these 3D structures lead to one designing rule. That is, the gap between highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the 3D materials depends only on its base and is nearly independent of the stack size or the length of the sp3‐hydrocarbon bridges. Additionally, connecting base units with linkers also extends π‐electron conjugation system leading to a reduction in HOMO‐LUMO gap. For instance, linking two trisilasumanene molecules significantly narrows HOMO‐LUMO gap by 1.75 eV while stacking these bases vertically and connecting them by linear pentane‐based bridges yield insignificant change to the gap. [ABSTRACT FROM AUTHOR]

Non‐covalent interactions offer an alternative way for developing stimulus‐responsive materials such as sensors, machines, and drug‐delivery systems. We recently reported that a urethane‐equipped tetrakis(porphyrin) forms one‐handed helical supramolecular polymers in solution in response to chirality of chiral solvents. Conformational changes in helical sense were detected using circular dichroism (CD) spectroscopy, which showed that the tetrakis(porphyrin) can possibly be used as a sensor for determining the enantiomeric excess of a chiral analyte. Hence, we studied the scope and limitations of the chiral‐induction behavior of tetrakis(porphyrin) to deepen the understanding of tetrakis(porphyrin)‐based chiral sensing systems. Herein, we report the chiral‐induction behavior of tetrakis(porphyrin) in various chiral solvents, which was found to be CD‐active in many chiral solvents. Notably, the tetrakis(porphyrin) was CD active in a cryptochiral molecular solvent, which is exciting because the chiralities of acyclic saturated hydrocarbons are hard to sense. Consequently, this study highlights the potential advantages of supramolecular chiral sensors capable of targeting a wide range of analytes, including molecules that are absorption‐silent in the UV/vis region, ones devoid of anchoring functional groups, and acyclic, saturated hydrocarbons. [ABSTRACT FROM AUTHOR]

This work reported “trinitarian” porphyrin nanobelts, contained hetero‐trimetal ions. The high‐resolution mass spectrometry and X‐ray crystallography proved PNBNiCuPd consisting of three different bent porphyrin(2.1.2.1) metal complex moieties. The redox properties indicate porphyrin nanobelts demonstrate the multielectron donating and accepting properties, more than nine redox processes. [ABSTRACT FROM AUTHOR]

Aromaticity and antiaromaticity are foundational principes in organic chemistry, regularly invoked to explain stability, structure, and magnetic and electronic properties. There are ongoing challenges in assigning molecules as aromatic or antiaromatic using optical spectroscopy. Here we report spectroelectrochemical and computational analyses of porphyrin (18π neutral, aromatic) and norcorrole (16π neutral, antiaromatic), and their oxidized (16π porphyrin dication) and reduced (norcorrole 18π dianion) forms. Our results show that while the visible spectra are characteristic of (anti)aromaticity consistent with Hückel's rules, the IR spectra are much less informative, owing to the relative rigidity of norcorrole. The results have implications for the assignment of (anti)aromaticity in both ground‐state and time‐resolved spectra. [ABSTRACT FROM AUTHOR]

Porphyrins are excellent light‐harvesting complexes. Presently they are unsuitable for photovoltaic applications, as their excellent light absorbance is compensated to a large extent by their poor transport properties, where most excitons are lost by recombination. Arranging porphyrins in regular, strongly bound, lattices of surface‐anchored metal‐organic frameworks (PP‐SURMOFs) may facilitate charge carrier dissociation, but does not significantly enhance the conductive properties. In most cases, photogenerated excitons traverse undirected, Brownian motion through a hopping process, resulting in a substantial diffusion length to reach electrodes, leading to significant exciton loss through recombination. Here, we propose to guide exciton diffusion indirectly by an external electric field. We show that electric fields, even as strong as 1 V nm−1, do not affect the HOMO‐LUMO gap of the porphyrins. However, fields of 0.1 V nm−1 and even less demonstrate a notable Stark effect, with slight band gap reductions, for some PP‐SURMOFs. When applied as an electric field gradient, for instance, via the substrate, it creates a unidirectional hopping pathway for the excitons. Consequently, we expect a significant reduction of exciton diffusion length leading to increased utilization of photogenerated excitons as they reach the electrodes. This strategy holds promise for integrating photoactive molecules in photovoltaic and photocatalytic applications. [ABSTRACT FROM AUTHOR]

We present the fabrication of a novel Starfruit‐shaped metal‐organic framework (SMOF) composed of zirconium and Tetra(4‐carboxyphenyl)porphine linkers. The SMOF exhibits a unique morphology with edge‐sharing two‐dimensional (2D) nanosheet petals. Our investigation unravels a captivating transformation process, wherein three‐dimensional (3D) shuttle‐shaped MOFs form initially and subsequently evolve into 2D nanosheet‐based SMOF structures. The distinct morphology of SMOF showcases superior catalytic activity in detoxifying G‐type nerve agent and blister agent simulants, surpassing that of its 3D counterparts. This discovery of the 3D‐to‐2D transition growth pathway unlocks exciting opportunities for exploring novel strategies in advanced MOF nanostructure development, not only for catalysis but also for various other applications. [ABSTRACT FROM AUTHOR]

Since the development of the first method for porphyrin synthesis by Rothemund in 1935, porphyrin derivatives have been widely investigated and have played an essential role in chemical sciences. Most synthetic routes of porphyrins involve oxidative aromatization. Herein, we present a synthetic method to produce ABCD‐porphyrins, including chiral ones, through a one‐pot reaction involving "coordination, cyclization, and dehydrative aromatization" using a mono‐dipyrrinatoPt(II)Cl(COE) (COE=cyclooctene) complex as a platinum template. [ABSTRACT FROM AUTHOR]

A new fluorinated manganese porphyrin, (Mn‐TPP‐p‐CF3) is reported capable of providing, based on the Mn(III)/Mn(II) equilibrium, dual 1H relaxivity and 19F NMR response to redox changes. The physical‐chemical characterization of both redox states in DMSO‐d6/H2O evidenced that the 1H relaxometric and 19F NMR properties are appropriate for differential redox MRI detection. The Mn(III)‐F distance (dMn−F=9.7–10 Å), as assessed by DFT calculations, is well tailored to allow for adequate paramagnetic effect of Mn(III) on 19F T1 and T2 relaxation times. Mn‐TPP‐p‐CF3 has a reversible Mn(II)/Mn(III) redox potential of 0.574 V vs. NHE in deoxygenated aqueous HEPES/ THF solution. The reduction of Mn(III)‐TPP‐p‐CF3 in the presence of ascorbic acid is slowly, but fully reversed in the presence of air oxygen, as monitored by UV‐Vis spectrometry and 19F NMR. The broad 1H and 19F NMR signals of Mn(III)‐TPP‐p‐CF3 disappear in the presence of 1 equivalent ascorbate replaced by a shifted and broadened 19F NMR signal from Mn(II)‐TPP‐p‐CF3. Phantom 19F MR images in DMSO show a MRI signal intensity decrease upon reduction of Mn(III)‐TPP‐p‐CF3, retrieved upon complete reoxidation in air within ~24 h. 1H NMRD curves of the Mn(III)/(II)‐TPP‐p‐CF3 chelates in mixed DMSO/water solvent have the typical shape of Mn(II)/Mn(III) porphyrins. [ABSTRACT FROM AUTHOR]

Selective and sensitive detection of inorganic pyrophosphate (PPi) are of great significance both for clinical applications and fundamental research. In this work, a ratiometric fluorescent probe was developed by decorating a porphyrin‐based metal‐organic framework (PCN‐224) with sulfur nanodots (S‐dots). The red‐fluorescence of PCN‐224 was significantly promoted (more than 6‐fold) by S‐dots through inhibiting molecular motion of porphyrin ligand, which also provided active sites for the detection of Cu2+ and PPi. Cu2+ could selectively quench the red‐fluorescence of PCN‐224 through coordination with porphyrin ligand, and the competition reaction between PPi and Cu2+ resulted in the decomposing of coordination and recovery of red‐fluorescence. The blue‐fluorescence from S‐dots was deemed as effective reference, which provided a built‐in correction in complex environments. Based on these photophysical properties, a ratiometric fluorescence assay was developed for the quantitative detection of Cu2+ and PPi, with a limit of detection of 0.11 and 2.66 μM, respectively. The accuracy and practical applications of assays were also demonstrated by detection in tap water and human serum samples. [ABSTRACT FROM AUTHOR]

Ionic co‐assembly of tetra‐anionic porphyrins has been extensively researched in the construction of hierarchically organized architectures with potential application value in organic semiconductors, sunlight catalysts and supramolecular chirality systems. However, such architectures are difficult to grow to a size suitable for single‐crystal X‐ray diffraction (SCXRD); the lack of single‐crystal structures of these architectures leads to challenges in gaining deeper comprehension about that. This study reports a hierarchically organized cocrystal of meso‐tetra(4‐sulfonato‐phenyl)‐porphyrin (TSPP4−) and N, N′‐diethyl‐viologen (DEV2+), wherein wave‐like and saddle‐like TSPP4− ions co‐aggregate at a stoichiometric ratio of 1 : 2 to form unique porphyrin arrays; the spectrum characteristics and calculated coulombic exciton coupling energy show that these porphyrin arrays are J‐aggregates. We prove that the distortion of porphyrin ring of TSPP4− strongly correlates with the deflection of its phenyl groups. The crystal comprises six different ionic conformations, and the multiplicity of ionic conformation leads to intricate supramolecular interactions. [ABSTRACT FROM AUTHOR]

Tetrathiatriarylmethyl radicals (TAM or trityl) are receiving increasing attention in various fields of magnetic resonance such as imaging, dynamic nuclear polarization, spin labeling, and, more recently, molecular magnetism and quantum information technology. Here, a trityl radical attached via a phenyl bridge to a copper(II)tetraphenylporphyrin was synthesized, and its magnetic properties studied by multi‐frequency continuous‐wave electron paramagnetic resonance (EPR) spectroscopy and magnetic measurements. EPR revealed that the electron spin‐spin coupling constant J between the trityl and Cu2+ spin centers is ferromagnetic with a magnitude of −2.3 GHz (−0.077 cm−1, +JS→1S→2 ${+J{\vec{S}}_{1}{\vec{S}}_{2}}$ convention) and a distribution width of 1.2 GHz (0.040 cm−1). With the help of density functional theory (DFT) calculations, the obtained ferromagnetic exchange coupling, which is unusual for para‐substituted phenyl‐bridged biradicals, could be related to the almost perpendicular orientation of the phenyl linker with respect to the porphyrin and trityl ring planes in the energy minimum, while the J distribution was rationalized by the temperature weighted rotation of the phenyl bridge about the molecular axis connecting both spin centers. This study exemplifies the importance of molecular dynamics for the homogeneity (or heterogeneity) of the magnetic properties of trityl‐based systems. [ABSTRACT FROM AUTHOR]

We report the synthesis of conceptually new prototypes of molecular winches with the ultimate aim to investigate the work performed by a single ruthenium‐based molecular motor anchored on a surface by probing its ability to pull a load upon electrically‐driven directional rotation. According to a technomimetic design, the motor was embedded in a winch structure, with a long flexible polyethylene glycol chain terminated by an azide hook to connect a variety of molecular loads. The structure of the motor was first derivatized by means of two sequential cross‐coupling reactions involving a penta(4‐halogenophenyl)cyclopentadienyl hydrotris(indazolyl)borate ruthenium(II) precursor and the resulting benzylamine derivative was next exploited as key intermediate in the divergent synthesis of a family of nanowinch prototypes. A one‐pot method involving sequential peptide coupling and Cu‐catalyzed azide‐alkyne cycloaddition was developed to yield four loaded nanowinches, with load fragments encompassing triptycene, fullerene and porphyrin moieties. [ABSTRACT FROM AUTHOR]

Imines are important intermediates in drug synthesis. Photocatalytic aerobic oxidative coupling of amines has been considered as a clean and promising way to produce imines and has attracted great attention. Herein, we designed and synthesized a novel two‐dimensional porphyrin‐based covalent organic framework (Por‐BC‐COF) which adopts an AA stacking mode with excellent crystallinity, high Brunauer–Emmett–Teller surface areas (1200 m2 g−1), wide light absorption range (200–1300 nm) and good stability in a variety of organic solvents. Por‐BC‐COF can be used as a metal‐free heterogeneous photocatalyst for the photocatalytic oxidation of amines to imines under visible light and red light with a high yield (97 %). This work presents a novel and efficient COF photocatalyst in the application of light‐driven organic synthesis. [ABSTRACT FROM AUTHOR]

Polyimide memory materials with a donor–acceptor structure based on a charge‐transfer mechanism exhibit great potential for next‐generation information storage technology due to their outstanding high‐temperature resistance and good dimensional and chemical stability. Precisely controlling memory performance by limited chemical decoration is one of core challenges in this field. Most reported work mainly focuses on designing novel and elaborate electron donors or acceptors for the expected memory behavior of polyimides; this takes a lot of time and is not always efficacious. Herein, we report a series of porphyrinated copolyimides coPI−Znx (x=5, 10, 20, 50, 80), where x represents the mole percentage of Zn ion in the central core of the porphyrin. Experimental and theoretical analysis indicate that the Zn ion could play a vital bridge role in promoting the formation and stabilization of a charge‐transfer complex by enhancing the hybridization of local and charge transfer (HLCT) excitations of porphyrinated polyimides, endowing coPI−Znx with volatile random access memory performance and continuously tunable retention time. This work could provide one simple strategy to precisely regulate memory performance merely by altering the metal content in porphyrinated polyimides. [ABSTRACT FROM AUTHOR]

PorphyStruct, a new digital tool for the analysis of non‐planar distortion modes of different porphyrinoids, and its application to corrole structures is reported. The program makes use of the normal‐coordinate structure decomposition technique (NSD) and employs sets of normal modes equivalent to those established for porphyrins in order to describe the out‐of‐plane dislocation pattern of perimeter atoms from corroles, norcorroles, porphycenes and other porphyrinoids quantitatively and in analogy to the established terminology. A comparative study of 17 porphyrin structures shows very similar results to the original NSD analysis and no systematic error. Application to corroles is successful and reveals the necessity to implement an extended basis of normal modes for a large share of experimental structures. The results frequently show the concomitant occurence of several modes but remain interpretable. For group XI metal corroles the phenomenon of supersaddling was unravelled, allowing for more in‐depths discussions of structure‐function correlations. [ABSTRACT FROM AUTHOR]

Photodynamic therapy (PDT) is a promising alternative to overcome the resistance of melanoma to conventional therapies. Currently applied photosensitizers (PS) are often based on tetrapyrrolic macrocycles like porphyrins. Unfortunately, in some cases the use of this type of derivative is limited due to their poor solubility in the biological environment. Feasible approaches to surpass this drawback are based on lipid formulations. Besides that, and inspired in the efficacy of potassium iodide (KI) for antimicrobial photodynamic therapy (aPDT), the combined effect of singlet oxygen (1O2) with KI was assessed in this work, as an alternative strategy to potentiate the effect of PDT against resistant melanoma cells. [ABSTRACT FROM AUTHOR]

The complexation processes of N,N'‐dibutyl‐1,4,5,8‐naphthalene diimide (NDI) into two types of π‐electron‐rich molecular containers consisting of two Zn(II)‐porphyrins connected by four flexible linkers of two different lengths, were characterized by means of absorption and emission spectroscopies and molecular dynamics simulation. Notably, the addition of NDI leads to a strong quenching of the fluorescence of both cages only when they are in an open conformation suitable for guest encapsulation, a situation triggered by silver(I) ions binding to the lateral triazoles. Molecular dynamics simulations confirm the fast binding of NDI, likely assisted by NDI‐silver(I) interactions. Upon NDI complexation, the two porphyrin macrocycles get closer, with an optimized face to face orientation, suggesting an induced‐fit mechanism through π–π interactions with the NDI aromatic cycle. Ultrafast transient absorption experiments allowed to identify the process of quenching of the Zn‐porphyrin fluorescence as an efficient photoinduced electron transfer reaction between the cage porphyrin and the included NDI guest. The process occurs on fast and ultrafast time scales in the two complexes (1.5 ps and ≤300 fs) leading to a short‐lived charge separated state (charge recombination lifetimes in the order of 30–40 ps). The combined computational and experimental approach used here is able to furnish a reliable model of the NDI‐cage complexation mechanism and of the corresponding electron transfer reaction, attesting the allosteric control of both processes by the silver(I) ions. [ABSTRACT FROM AUTHOR]

The control of the second coordination sphere in a coordination complex plays an important role in improving catalytic efficiency. Herein, we report a zinc porphyrin complex ZnPor8T with multiple flexible triazole units comprising the second coordination sphere, as an electrocatalyst for the highly selective electrochemical reduction of carbon dioxide (CO2) to carbon monoxide (CO). This electrocatalyst converted CO2 to CO with a Faradaic efficiency of 99 % and a current density of −6.2 mA cm−2 at −2.4 V vs. Fc/Fc+ in N,N‐dimethylformamide using water as the proton source. Structure‐function relationship studies were carried out on ZnPor8T analogs containing different numbers of triazole units and distinct triazole geometries; these unveiled that the triazole units function cooperatively to stabilize the CO2‐catalyst adduct in order to facilitate intramolecular proton transfer. Our findings demonstrate that incorporating triazole units that function in a cooperative manner is a versatile strategy to enhance the activity of electrocatalytic CO2 conversion. [ABSTRACT FROM AUTHOR]

We have prepared Zn and free‐base porphyrins appended with a fac‐Re(phen)(CO)3Br (where phen is 1,10‐phenanthroline) at the meso position of the porphyrin, and performed photocatalytic CO2 reduction using porphyrin–Re dyads in the presence of either triethylamine (TEA) or 1,3‐dimethyl‐2‐phenyl‐2,3‐dihydro‐1H‐benzo[d]imidazole (BIH) as an electron donor. The Zn porphyrin dyad showed a high turnover number for CO production compared with the free‐base porphyrin dyad, suggesting that the central Zn ion of porphyrin plays an important role in suppressing electron accumulation on the porphyrin part and achieving high durability of the photocatalytic CO2 reduction using both TEA and BIH. The effect of acids on the CO2 reduction was investigated using the Zn porphyrin–Re dyad and BIH. Acetic acid, a relatively strong Brønsted acid, rapidly causes the porphyrin's color to fade upon irradiation and dramatically decreases CO production, whereas proper weak Brønsted acids such as 2,2,2‐trifluoroethanol and phenol enhance the CO2 reduction. [ABSTRACT FROM AUTHOR]

Two‐photon excited fluorescent (TPEF) materials are highly desirable for bioimaging applications owing to their unique characteristics of deep‐tissue penetration and high spatiotemporal resolution. Herein, by connecting one, two, or three electron‐deficient zinc porphyrin units to an electron‐rich triazatruxene core via ethynyl π‐bridges, conjugated multipolar molecules TAT‐(ZnP)n (n=1–3) were developed as TPEF materials for cell imaging. The three new dyes present high fluorescence quantum yields (0.40–0.47) and rationally improved two‐photon absorption (TPA) properties. In particular, the peak TPA cross section of TAT‐ZnP (436 GM) is significantly larger than that of the ZnP reference (59 GM). The δTPA values of TAT‐(ZnP)2 and TAT‐(ZnP)3 further increase to 1031 and up to 1496 GM, respectively, indicating the effect of incorporated ZnP units on the TPA properties. The substantial improvement of the TPEF properties is attributed to the formation of π‐conjugated quadrapole/octupole molecules and the extension of D‐π‐A‐D systems, which has been rationalized by density function theory (DFT) calculations. Moreover, all of the three new dyes display good biocompatibility and preferential targeting ability toward cytomembrane, thus can be superior candidates for TPEF imaging of living cells. Overall, this work demonstrated a promising strategy for the development of porphyrin‐based TPEF materials by the construction and extension of D‐π‐A‐D multipolar array. [ABSTRACT FROM AUTHOR]

In this study a bispidine ligand has been applied to the complexation of gallium(III) and radiolabelled with gallium‐68 for the first time. Despite its 5‐coordinate nature, the resulting complex is stable in serum for over two hours, demonstrating a ligand system well matched to the imaging window of gallium‐68 positron emission tomography (PET). To show the versatility of the bispidine ligand and its potential use in PET, the bifunctional chelator was conjugated to a porphyrin, producing a PET/PDT‐theranostic, which showed the same level of stability to serum as the non‐conjugated gallium‐68 complex. The PET/PDT complex killed >90 % of HT‐29 cells upon light irradiation at 50 μm. This study shows bispidines have the versatility to be used as a ligand system for gallium‐68 in PET. [ABSTRACT FROM AUTHOR]

The preparation of an entirely supramolecular, multichromophoric azaborondipyrromethene (ABDP)/zinc tetraphenylporphyrin (ZnTPP)/exfoliated graphene (GR) nanoensemble was accomplished. The ABDP derivative bears glycol chains for enhancing solubility and a pyridine functionality for allowing coordination with ZnTPP. The ABDP/ZnTPP/GR nanoensemble was characterized in terms of morphology and composition by using complementary microscopy imaging, thermogravimetric analysis, Raman as well as steady‐state and time‐resolved absorption and emission spectroscopy. The photophysical and electrochemical assessment of ABDP/ZnTPP/GR as well as the binding properties of the ABDP/ZnTPP complex, employed as a reference, are presented. Energy and electron transfer events were observed in ABDP/ZnTPP upon photoexcitation. However, in the case of ABDP/ZnTPP/GR, the graphene‐induced aggregation of the chromophores alters their electronic interactions, enhancing the energy/electron transfer process between them. [ABSTRACT FROM AUTHOR]

A symbiotic experimental/computational study analyzed the Ru(TPP)(NAr)2‐catalyzed one‐pot formation of indoles from alkynes and aryl azides. Thirty different C3‐substituted indoles were synthesized and the best performance, in term of yields and regioselectivities, was observed when reacting ArC≡CH alkynes with 3,5‐(EWG)2C6H3N3 azides, whereas the reaction was less efficient when using electron‐rich aryl azides. A DFT analysis describes the reaction mechanism in terms of the energy costs and orbital/electronic evolutions; the limited reactivity of electron‐rich azides was also justified. In summary, PhC≡CH alkyne interacts with one NAr imido ligand of Ru(TPP)(NAr)2 to give a residually dangling C(Ph) group, which, by coupling with a C(H) unit of the N‐aryl substituent, forms a 5+6 bicyclic molecule. In the process, two subsequent spin changes allow inverting the conformation of the sp2 C(Ph) atom and its consequent electrophilic‐like attack to the aromatic ring. The bicycle isomerizes to indole via a two‐step outer sphere H‐migration. Eventually, a ′Ru(TPP)(NAr)′ mono‐imido active catalyst is reformed after each azide/alkyne reaction. [ABSTRACT FROM AUTHOR]

The controlled self‐assembly of porphyrin derivatives (TCPP, tetrakis(4‐carboxyphenyl)porphyrin) within Fmoc‐protected (Fmoc=9‐Fluorenylmethyloxycarbonyl) dipeptide (Fmoc‐TL‐NH2) nanofibers is demonstrated. The biocatalytic co‐assembly in aqueous medium generated an energy transfer hydrogel. Depending on the concentrations of porphyrin used, the resulting nanofibrous gels show two distinct regions of self‐assembly behavior that is, integration of TCPP into nanostructures to produce two‐component co‐assembly fibers, or heterogeneous self‐aggregation of TCPP within the self‐assembled matrix observed at higher concentrations. The mode of assembly directly impacts on the energy transfer efficiency of these nanostructures. These results show that reversible biocatalytic co‐assembly of structural and functional components enables fine‐tuning of peptide/porphyrin energy transfer nanostructures. [ABSTRACT FROM AUTHOR]

A new family of porous metal–organic frameworks (MOFs), namely alkali phosphonate MOFs, is reported. [Na2Cu(H4TPPA)]⋅(NH2(CH3)2)2 (GTUB‐1) was synthesized using the tetratopic 5,10,15,20‐tetrakis[p‐phenylphosphonic acid] porphyrin (H8‐TPPA) linker with planar X‐shaped geometrical core. GTUB‐1 is composed of rectangular void channels with BET surface area of 697 m2 g−1. GTUB‐1 exhibits exceptional thermal stability. The toxicity analysis of the (H8‐TPPA) linker indicates that it is well tolerated by an intestinal cell line, suggesting its suitability for creating phosphonate MOFs for biological applications. [ABSTRACT FROM AUTHOR]

A systematic series of superbenzene–porphyrin conjugates was synthesized and characterized. All conjugates show a high degree of cluster formation that correlates to the amount of tert‐butylated hexa‐peri‐hexabenzocoronenes (tBuHBCs) attached to the porphyrin's periphery. Determined by mass spectrometry and X‐ray diffraction, van der Waals (vdW) interactions like London dispersions (LD), stemming from solubilizing tert‐butyl groups, were identified to be the major reason for the cluster formation. Cluster sizes comprised of more than twenty molecules with masses up to 70 000 Da were observed, which are rare examples of large architectures based on synthetic functional molecules, assembled by dispersion interactions. Novel strategies towards the design of solution processable functional materials, capable of dynamic transformations based on non‐covalent synthesis can be envisioned. Superbenzene‐porphyrin conjugates were synthesized that show a high cluster formation ability. The cluster size correlates to the amount of tert‐butylated hexa‐peri‐hexabenzo‐coronenes attached to the porphyrin's periphery. Determined by mass spectrometry and X‐ray diffraction, London dispersion interactions stemming from the tert‐butyl groups were identified to be the major reason for the cluster formation. [ABSTRACT FROM AUTHOR]

Abstract: We report a suite of coordination‐driven self‐assembled prisms for heterogeneous electrocatalytic oxygen reduction (ORR) differing in the molecular clips linking two porphyrin faces in a cofacial arrangement. ORR activities and selectivities of monomeric CoTPyP along with cofacial prisms Ox‐Co, Oxa‐Co, and Benzo‐Co were probed using cyclic voltammetry and rotating ring‐disk techniques. All species were immobilized as heterogeneous catalysts on glassy carbon electrodes using a Nafion ink method. The selectivities of Ox‐Co, Oxa‐Co, and Benzo‐Co prisms towards H2O as determined by RRDE were 87, 97, and 75 %, respectively. The current density of the Oxa‐Co plateaus at five times that of Pt/C when normalized per Co/Pt. The high synthetic yield (79 %), competitive overpotential (η ≈800 mV) and high selectivity (%H2O ≈97 %) of the Oxa‐Co highlights how self‐assembly can be used to address multi‐electron multi‐proton transformations using polynuclear catalysts. [ABSTRACT FROM AUTHOR]

Abstract: PtII‐catalyzed cyclization of β‐to‐β ethynylene‐bridged meso‐amino NiII porphyrin dimer 4 followed by oxidation with PbO2 afforded 1,5‐naphthyridine‐fused porphyrin dimer 5 in good yield. This dimer possesses a redox‐active 1,4‐diazabutadiene linkage that is interconvertible with its reduced 1,2‐diaminoethene linkage upon treatments with NaBH4 or PbO2. The dimer 5 exhibits an intense NIR absorption and a narrow HOMO–LUMO gap with a remarkably low reduction potential mainly due to effective bonding interactions in the LUMO through the 1,4‐diazabutadiene linkage. In contrast, the reduced dimer 7 is fairly electron‐rich with high HOMO energy and shows a relatively large HOMO–LUMO gap compared to that of 5. [ABSTRACT FROM AUTHOR]

Pillar[5]arene derivatives bearing peripheral porphyrin subunits have been efficiently prepared from a deca-azide pillar[5]arene building block ( 17) and ZnII-porphyrin derivatives bearing a terminal alkyne function ( 9 and 16). For the resulting deca-ZnII-porphyrin arrays ( 18 and 20), variable temperature NMR studies revealed an intramolecular complexation of the peripheral ZnII-porphyrin moieties by 1,2,3-triazole subunits. As a result, the molecules adopt a folded conformation. This was further confirmed by UV/Vis spectroscopy and cyclic voltammetry. In addition, we have also demonstrated that the coordination-driven unfolding of 18 and 20 can be controlled by an external chemical stimulus. Specifically, addition of an imidazole derivative ( 22) to solution of 18 or 20 breaks the intramolecular coordination at the origin of the folding. The resulting molecular motions triggered by the addition of the imidazole ligand mimic the blooming of a flower. [ABSTRACT FROM AUTHOR]

Three new metal-organic porphyrinic framework compounds of zinc and 5,10,15,20-tetrakis(4-pyridyl)porphyrin (TPyP) have been synthesized under solvothermal conditions. The compounds [Zn5(C40H24N8)(C8H4O4)2(NO3)6(DMA)2] (DMA)3(H2O)8 ( 1; DMA=dimethylacetamide), [Zn3(C40H24N8)(C8H4O4)2(DMF)](DMF)5(H2O)12 ( 2), and [Zn3(C40H24N8)(C12H6O4)2(DMA)2](H2O)7 ( 3) have two ( 1) and three dimensionally ( 2 and 3) extended structures. All the three structures contain porphyrinic units connected through the carboxylate linkers. The nitrates bind the metal centers and are not hydrogen bonded. The different binding modes of nitrate in the structure of 1 are observed for the first time in a porphyrin-based MOF. The openness of the structure allowed us to explore metal exchange through a room-temperature metathetic route. Compound 2 undergoes 100 % exchange with copper, whereas compound 3 exchanges 70 % with copper. The copper-exchanged compounds Cu∈ 2 and Cu∈ 3 were observed to be good heterogeneous catalysts for many important organic reactions. The chemo and regioselective enamination of β-ketoesters, preparation of propargylamine derivatives as well as regioselective cycloadditions of alkyne and azide (click reactions) have been carried out with good yields and selectivity. All the compounds have been characterized by PXRD, IR, UV/Vis, atomic absorption spectroscopy (AAS), and energy-dispersive X-ray spectroscopy (for Cu exchange). [ABSTRACT FROM AUTHOR]

To explore stable organic diradicaloids, meso-thienylquinonoid-substituted porphyrins Pn and hexaphyrins Hn, where 'n' denotes the number of thienyl units in the meso-substituents, were synthesized. P0 was identified as a closed-shell quinonoid, whereas P1 was shown to possess significant diradical character with diradical character index ( y) of 0.99 and quite small singlet-triplet energy gap (Δ ES-T) of −0.13 kcal mol−1. P1 was certainly stable, allowing its isolation, but decomposed gradually in solution. In the hexaphyrin series, it was shown that H0 and H1 were closed-shell quinonoids, but H2 was a highly stable diradicaloid with y=0.85 and Δ ES-T of −3.72 kcal mol−1. The high stability of H2 was ascribed to effective spin delocalization over the entire conjugated network. Characteristically, H2 displays an intense absorption band in NIR region at λmax=1175 nm with molar absorption coefficient ( ϵ) of 8.81×104 mol−1 L cm−1, a narrow HOMO-LUMO gap of 0.69 eV, and nine reversible redox potential waves. [ABSTRACT FROM AUTHOR]

Diphenylphosphine-oxide-fused NiII porphyrin 8 was synthesized from 3,5,7-trichloroporphyrin 5 via a reaction sequence of nucleophilic aromatic substitution with lithium diphenylphosphide, oxidation with H2O2, and palladium-catalyzed intramolecular cyclization. Reduction of 8 with HSiCl3 gave diphenylphosphine-fused NiII porphyrin 9. The embedded P=O and P moieties serve as a strong electron-accepting and electron-donating group to perturb the optical and electrochemical properties of the NiII porphyrin. NiII porphyrin 9 is diamagnetic with a low-spin NiII center in solution but becomes paramagnetic with a five-coordinated NiII center with high-spin ( S=1) state in the solid state. Diphenylphosphine-oxide-fused ZnII porphyrin 10 was also synthesized and shown to form a face-to-face dimer with mutual O-Zn bonds in the crystal and in nonpolar and moderately polar solvents. The dimerization of 10 in CDCl3 has been revealed to be an entropy-driven process with a large entropy gain (Δ SD=207 J K−1 mol−1). [ABSTRACT FROM AUTHOR]

Non-covalent interactions between halopyridine substrates and catalytically inert building blocks, namely zinc(II)-porphyrins and zinc(II)-salphens, influence the catalytic outcome of Suzuki-Miyaura and Mizoroki-Heck palladium-catalysed cross-coupling reactions. The weak Zn⋅⋅⋅N interactions between halopyridine substrates and zinc(II)-containing porphyrins and salphens, respectively, were studied by a combination of 1H NMR spectroscopy, UV/Vis studies, Job-Plot analysis and, in some cases, X-ray diffraction studies. Additionally, the former studies revealed unique supramolecular polymeric and dimeric rearrangements in the solid state featuring weak Br⋅⋅⋅N (halogen bonding), C−H⋅⋅⋅π, Br⋅⋅⋅π and π⋅⋅⋅π interactions. The reactivity of halopyridine substrates in homogeneous palladium-catalysed cross-coupling reactions was found to correlate with the binding strength between the zinc(II)-containing scaffolds and the corresponding halopyridine. Such observation is explained by the unfavourable formation of inactive over-coordinated halopyridine⋅⋅⋅palladium species. The presented approach is particularly appealing for those cases in which substrates and/or products deactivate (or partially poison) a transition-metal catalyst. [ABSTRACT FROM AUTHOR]

A structurally prearranged carbaporphyrin, 22-methyl- m-benziporphyrin, provided the perfect macrocyclic platform to form gold(III) 22-methyl- m-benziporphyrin, which facilitates the specific m-benzene ring contraction yielding gold(III) 21-methyl 21-carbaporphyrin with remarkably high yield. [ABSTRACT FROM AUTHOR]