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Oral medications for chronic conditions often involve a variety of instructions, including time of day/dosing, drug interactions, and food intake restrictions. However, the extent to which patients follow these instructions is unclear. We surveyed patients from the US and Europe (UK, France, Germany, Italy, Spain) who were prescribed sulfonylureas (SU: glimepiride, glipizide, or gliclazide) for diabetes or levothyroxine for hypothyroidism. Patients kept a daily diary for 3–5 days documenting their adherence to three criteria: dosing regimen including time of day, warning labels including drug interactions, and food restrictions. A total of 421 US and 493 European patients took the study medications; 546 patients took SU and 368 took levothyroxine. Overall, 48% of patients were males; 46% were age 65 years or older. Despite most patients having received instructions on medication requirements (US 71%, EU 75%), most patients reported being only somewhat knowledgeable (US 69%; EU 71%). Adherence, measured by the proportion of the days a participant was adherent to each category out of the observational period (ranging from 3–5 days), varied by type of instruction, with the poorest adherence observed for food restriction requirements (US 34% of the observation days, EU 26%) compared to warning labels (US 77%, EU 67%) and dosing regimen (US 85%, EU 87%). Patients adhered to dosing and cautionary instructions across the majority of the study period but were largely non-adherent to food intake restrictions. Improved communication and increased emphasis on food intake restrictions is needed when advising patients on their medications.

The use of a remote template improves the yields of bipyridine-strapped porphyrins by up to 10 times.

Biphenol-based ligands have proven their ability to bind titanium(IV) centers and generate sophisticated self-assembled structures in which auxiliary nitrogen ligands often complete the coordination sphere of the metal and improve stability. Here, a central 4,4'-bipyridine, which acts as both a spacer and a source of monodentate nitrogen to complete the coordination sphere of the Ti(IV) complex, was incorporated within two bis-2,2'-biphenol strands

The synthesis of a series of novel tetra-(benzo-24-crown-8)-phthalocyanines (Mg(II), Ni(II) and Co(II)) as well as a modified procedure for the free-base ligand and its Zn(II) and Cu(II) complexes are reported. The tendency of these phthalocyanines to undergo supramolecular cofacial dimerization induced by interaction with a viologen ([Formula: see text]-di(but-3-ynyl)-4,4[Formula: see text]-bipyridinium) was investigated by UV-vis absorption and EPR spectral studies in solution. The nature of the metal cation in phthalocyanine, the concentration, as well as the solvent all influenced the assembly processes.

Single-molecule junctions (SMJs) have been fabricated using layers generated by diazonium electroreduction. This process creates a C-Au covalent bond between the molecule and the electrode. Rigid oligomers of variable length, based on porphyrin derivatives in their free base or cobalt complex forms, have been grafted on the surface. The conductance of the oligomers has been studied by a scanning tunneling microscopy break junction (STM-bj) technique and G(t) measurements, and the lifetime of the SMJs has been investigated. The conductance histograms indicate that charge transport in the porphyrins is relatively efficient and influenced by the presence of the cobalt center. With both systems, random telegraph G(t) signals are easily recorded, showing SMJ on/off states. The SMJs then stabilize and exhibit a surprisingly long lifetime around 10 s, and attenuation plots, obtained by both G(t) and STM-bj measurements, give identical values. This work shows that highly stable SMJs can be prepared using a diazonium grafting approach.

The design and synthesis of supramolecular assemblies derived from poprhyrins which are ranging from new hemoprotein models to self-assembled porphyrin wires and functional rotaxanes will be discussed. The properties of wires and light-responsive rotaxanes architectures as well as molecular break junctions derived from phenanthroline and bipyridine strapped porphyrins will be detailed, emphasizing the importance of weak interactions in the design and the properties of functional self-assemblies Figure 1

Polyoxometalates (POMs) can act as unique reservoirs for multiple electron transfers. As POMs display only weak absorption in the visible spectrum, they can be associated with chromophores such as porphyrins and porphyrin antennae. In this Minireview, the research dedicated to the combination of porphyrins and polyoxometalates is put in context and the state of the art identifying the challenges addressed in the optimization of hybrid materials for applications is detailed.

A water soluble, phenanthroline-strapped zinc porphyrin bearing four arylsulfonate groups formed a stable host–guest complex with two per-[Formula: see text]-methylated [Formula: see text]-cyclodextrin cavities. In the host–guest assembly, the zinc porphyrin was capable of binding imidazole within the cavity between the zinc(II) ion and the phenanthroline strap in an aqueous medium. The formation of a hydrogen bond between the imidazole NH and the nitrogen atoms of the phenanthroline was an essential element of the binding event, as shown by comparative binding studies with a non-strapped tetrasulfonated zinc porphyrin and with [Formula: see text]-methylimidazole. This hydrogen bonding in an aqueous medium was possible due to the protected hydrophobic environment created by the cyclodextrins around the phenanthroline strap. This type of binding event may provide a biomimetic approach to study water soluble heme protein models.

Commercial 4,4'-bipyridine is a popular scaffold that is primarily employed as a linker in 3D self-assembled architectures such as metallo-organic frameworks or as a connector in 2D networks. The introduction of alkyl substituents on the bipyridine skeleton is instrumental when 4,4'-bipyridines are used as linkers to form 2D self-assembled patterns on surfaces. Here, several synthetic strategies to access 4,4'-bipyridines functionalized at various positions are described. These easily scalable reactions have been used to introduce a range of alkyl substituents at positions 2 and 2' or 3 and 3' and at positions 2,2' and 6,6' in the case of tetra-functionalization. Scanning tunneling microscopy studies of molecular monolayers physisorbed at the graphite-solution interface revealed different supramolecular patterns whose motifs are primarily dictated by the nature and position of the alkyl chains.

Porphyrins are conjugated, stable chromophores with a central core that binds a variety of metal ions and an easily functionalized peripheral framework. By combining the catalytic, electronic or cytotoxic properties of selected transition metal complexes with the binding and electronic properties of porphyrins, enhanced characteristics of the ensemble are generated. This review article focuses on porphyrins bearing one or more peripheral transition metal complexes and discusses their potential applications in catalysis or biomedicine. Modulation of the electronic properties and intramolecular communication through coordination bond linkages in bis-porphyrin scaffolds is also presented.

A new complex of oxovanadium, VOL has been synthesized from Schiff base ligand obtained by the condensation of o-phenylenediamine and 5-bromo-salicylaldehyde. All new compounds have been characterized by 1H NMR, IR spectra, UV–Vis spectroscopy, elemental analysis and mass spectrometry. The molar conductance data revealed that the metal complex is a non-electrolyte. Thermal analysis techniques (TGA/DTA) of the ligand and the complex were performed. The proposed structures for the free ligand and the corresponding vanadium complex were corroborated by the use of geometry optimization and conformational analysis. The solid state structure of complex VOL was fully determined by single crystal X-ray diffraction analysis. Similar electrochemical behavior for both the ligand and the corresponding complex have been observed by cyclic voltammetry (CV). The complex gave a metal-based one-electron quasi-reversible redox couple at 606 mV/SCE corresponding to the VOIV/VOV redox process which was consistent with the hydrodynamic voltammograms. Additional peaks in the CVs that were growing with the scan rate have been attributed to consecutive one-electron reduction of the ligand. The catalytic activity of the oxovanadium Schiff base complex VOL was tested in the oxidation reaction of cyclohexene. The efficiency of the catalyst was influenced by the nature of the oxidant. The results showed that the complex was highly active and selective for cyclohexenone in optimized conditions.

The microscopic origin of van der Waals- and magnetic-interactions in 4,4' methyl viologen cation-based units (MV+˙ and MV2+) was inspected using wave function (variational DDCI and perturbative MP2, CASPT2) and density functional theory (DFT) calculations. The analysis deepens the comprehension of the magnetic behavior of experimental bis-viologen cyclophanes ([CYC]2(+˙)), in which the MV+˙ units are connected through alkyl linkers of different lengths. The formation of the so-called long-multicenter bonds in such radical dimers, responsible for the quenching of the magnetic response, was analyzed in [MV2]2(+˙). Dynamical correlation effects, accessible from second-order perturbation corrections, were decisive in observing a bonding regime characterized by an equilibrium distance of 3.3 Å and a 45 kJ mol-1 dissociation energy. At larger intermolecular distances, our calculations on [MV2]2(+˙) indicate that the singlet and triplet states are energetically competing (i.e. weak exchange interactions, JAB). Despite the absence of any clear bonding regime at the MP2 level, the puzzling association of two di-cations into [MV2]4+ is anticipated at 3.3 Å using weakly screened point charges (ε = 1.5) to account for the Coulomb interactions between the solvated subunits. The main conclusion is that both dispersion interactions and environment effects are required to overcome the Coulomb repulsion associated with doubly-charged species. All these data provide some complementary insights into the nature and amplitude of interactions between cation and dication units, and their relevance in various experimental manifestations.

Porphyrin derivatives are highly relevant to biological processes such as light harvesting and charge separation. Their aromatic electronic structure and their accessible HOMO−LUMO gap render porphyrins highly attractive for the development of opto- and electro-active materials. Due to the often difficult covalent synthesis of multiporphyrins, self-assembly using metal complexation as the driving force can lead to well defined objects exhibiting a controlled morphology, which will be required to analyse and understand the electronic properties of porphyrin wires. This article presents two assembly approaches, namely by peripheral coordination or by binding to a metal ion in the porphyrin core, that are efficient and well designed for future developments requiring interactions with a surface.

The structure-property relationships were compared for the iron and iron-copper complexes of two functional cytochrome c oxidase models, 1 and 2 , both constructed upon a phenanthroline-strapped porphyrin bearing respectively pyridyl or picolinyl built-in proximal and distal ligands. The behavior of these heme models in the absence and in the presence of copper was studied by 1 H NMR, UV–visible absorption, EPR, Raman and FTIR spectroscopies, electrochemistry in solution and deposited on a rotating ring-disk graphite electrode. The distal binding site within the phenanthroline pocket of both 1 and 2 is available for the coordination of exogenic ligands, yet the oxygen binding affinity is higher for all complexes of 2 than for 1 . Despite this difference, [ 1Fe II Cu I ] more efficiently reproduced the electrocatalyzed reduction of oxygen to water than [ 2Fe II Cu I ]. The oxygenated complexes of both iron(II)-copper(I) species mimic the ability of cytochrome c oxidase to reversibly bind O 2 , as shown by competitive binding studies in the presence of CO. Differences in the binding and electrocatalytic properties of these models stem from difference in rigidity of scaffolds upon binding of both the proximal and distal ligands, as well as from the bulkiness of the distal ligand.

Two novel manganese (III) and iron (III) complexes of an N,N-bis(1-naphthalidimine)-o phenylene diamine ligand have been successfully synthesized and characterized by various analytical techniques including single crystal X-ray structure analysis. The ligand crystallizes in the monoclinic system with space group P21/c. The detailed analyses of Hirschfeld surface and fingerprint plots provide insight into the nature of non-covalent interactions in the ligand. Experimental data have been complemented and interpreted in the light of Density Functional Theory calculation was performed using the B3LYP method concerning molecular geometries, vibrational frequencies and electrochemical potentials. Cyclic voltammetry in dimethylformamide revealed reversible redox processes in both complexes, suggesting possible catalytic reactivity involving electron transfer process for these complexes. The catalytic efficiency and selectivity of manganese (III) and iron (III) complexes was tested in the oxidation of cyclohexene with molecular oxygen. The results show that the catalytic performance depends on the nature of metal, the most efficient catalyst in the presence of O2beingthe iron (III) complex. A plausible mechanism for cyclohexene oxidation by complexes is proposed and discussed hereafter.

The synthesis of a porphyrin rotaxane by dipolar cycloaddition takes advantage of the ditopic character of a phenanthroline-strapped porphyrin. The success of the click reaction was conditioned by the presence of both a coordinatively unsaturated metal in the porphyrin and a copper(I) bound to the phenanthroline, pointing at a new “tandem active metal template” mechanism.

In Nature, the various properties of tetrapyrrolic macrocycles are mostly due to their proteic environment and result from an evolutionary process difficult to reproduce in the lifetime of a synthetic chemist. Thus, the task of synthetic chemists attempting to reproduce the biological role of porphyrin architectures performing functions from catalysis to light harvesting is significantly complicated. This account describes how a phenanthroline-strapped porphyrin architecture initially designed to afford new hemoprotein models led, over the last two decades, to the preparation of highly linear self-assembled nano-objects inspired by light-harvesting architectures. The approach summarized in the next pages mimics, in a very modest way, the polyvalence of tetrapyrrolic macrocycles in Nature.

The oxovanadium (IV) complex “VOL” of a tetradentate Schiff base ligand derived from the condensation of diaminoethane and 2-hydroxy-1-naphthaldehyde was efficiently prepared via ultrasound irradiation and the template effect of VO(acac)2. The resulting product was characterized by elemental analysis, infrared, electronic absorption and molar conductance measurement. Single X-ray structure analysis showed that the complex is a monomeric five-coordinate with a distorted square pyramidal geometry. It crystallizes in monoclinic system having unit cell parameters a = 8.3960 (5) A; b = 12.5533 (8) A and c = 18.7804 (11) A; α = γ = 90°; β = 104.843°(2), with P 21/c space group. Cyclic voltammetry of the complex, carried out on a glassy carbon (GC) electrode in DMF, showed reversible cyclic voltammograms response in the potential range 0.15–0.60 V involving a single electron redox wave VV/VIV, the diffusion coefficient is determinedusing GC rotating disk electrode. The Levich plot Ilim = f(ω1/2), was used to calculate the diffusion-convection controlled currents.

The O2 adduct of an aqueous synthetic heme/copper model system built on a porphyrin/cyclodextrin supramolecular complex has been characterized., In mitochondria, cytochrome c oxidase (CcO) catalyses the reduction of oxygen (O2) to water by using a heme/copper hetero-binuclear active site. Here we report a highly efficient supramolecular approach for the construction of a water-soluble biomimetic model for the active site of CcO. A tridentate copper(ii) complex was fixed onto 5,10,15,20-tetrakis(4-sulfonatophenyl)porphinatoiron(iii) (FeIIITPPS) through supramolecular complexation between FeIIITPPS and a per-O-methylated β-cyclodextrin dimer linked by a (2,2′:6′,2′′-terpyridyl)copper(ii) complex (CuIITerpyCD2). The reduced FeIITPPS/CuITerpyCD2 complex reacted with O2 in an aqueous solution at pH 7 and 25 °C to form a superoxo-type FeIII–O2–/CuI complex in a manner similar to CcO. The pH-dependent autoxidation of the O2 complex suggests that water molecules gathered at the distal Cu site are possibly involved in the FeIII–O2–/CuI superoxo complex in an aqueous solution. Electrochemical analysis using a rotating disk electrode demonstrated the role of the FeTPPS/CuTerpyCD2 hetero-binuclear structure in the catalytic O2 reduction reaction.

The ability of three bis-viologen cyclophanes to act as redox-triggered contractile switches is investigated. Odd/even effects in the formation of cyclic bis-viologens are circumvented by the use of a Zincke salt intermediate and a tetrathiafulvalene template to prepare a flexible cyclophane with hexyl linkers. Comparative spectro-electrochemical studies of this macrocycle with two other pentyl- or heptyl-linked cyclic bis-viologens show that the development of intramolecular interactions in aqueous solution depends on the length of the bridges. This dependence is confirmed by EPR and DFT studies of the magnetic coupling in the diradical dication species. The anti-ferromagnetic or ferromagnetic nature of the coupling depend, respectively, on the odd or even number of methylene groups in the spacer.

A phenanthroline-strapped porphyrin bearing two pyridine side arms attached to opposite meso positions was designed as a potential cytochrome c oxidase model and its zinc and copper(I)-zinc complexes were prepared. In the zinc porphyrin complex, the pyridine arms underwent a rapid exchange of their coordination to the zinc atom on the open face of the strapped-porphyrin, as demonstrated by variable temperature NMR studies. Only the β2 atropoisomer was observed for the zinc complex because of the rapid exchange. This swinging motion no longer occurred when Cu I was bound within the phenanthroline strap. In this Cu I / Zn II complex, the αβ atropoisomer predominated and one pyridine was coordinated to the zinc atom on the proximal side and the other pyridine was bound to the copper on the distal face. This work shows that allostery can be effective to control atropoisomery in phenanthroline strapped porphyrin as heme protein models.

Energy collection in photosynthetic microorganisms occurs through vectorial energy transfer along organized assemblies of chromophores. This process has inspired many research groups and yielded numerous examples of self-assembled photoactive structures. Dye sensitization of solar cells usually requires covalent anchoring of dyes onto the surface of metal oxides. A new porphyrin derivative that self-assembles upon non-covalent interaction with a surface has been designed and characterized by AFM. Interaction with metal oxide surfaces is further documented by the sensitization of metal oxide surfaces and the generation of photocurrent in non-optimized dye sensitized solar cells.

The preparation of porphyrins functionalized with one or two carbazoles (or phenoxazines) is described. The electron donors were introduced into one or two porphyrin meso positions by using the inexpensive Ullmann coupling procedure. Very good yields were obtained, and for two new compounds, the X-ray structures were solved. Preliminary electrochemical data coupled with electronic spectroscopy are also reported.

Here comes the sun! Hydrogen can be produced on a windowsill under daylight irradiation of TiO2 -supported platinum by using a self-buffered electron-donor solution that optimizes the interfacial processes.

An efficient noncovalent assembly process involving high geometrical control was applied to a linear bis(imidazolyl zinc porphyrin) 7Zn, bearing C(18) substitutents, to generate linear multiporphyrin wires. The association process is based on imidazole recognition within the cavity of the phenanthroline-strapped zinc porphyrin. In chlorinated solvents, discrete soluble oligomers were obtained after (7Zn)(n) was end-capped with a terminal single imidazolyl zinc porphyrin derivative 4Zn. These soluble species, as well as their destabilization in the presence of protic solvents, were studied by UV-visible and time-resolved luminescence. In the solid state, assemblies as long as 480 nm, which corresponds to 190 iterative units or a total of 380 porphyrins, were observed by atomic force microscopy measurements on mica. The length and linearity of the porphyrin wires obtained illustrate the potential of phenanthroline-strapped porphyrins for the directional control of self-assembly processes.

Yellow crystals of [Zn(N,N′-bis (5-bromosalicylidene) 2,3-diaminopyridine)] Pyridine, [Zn(C19H11Br2N3O2)]C5H5N, have been obtained and characterized by elemental analysis, FT-IR, UV–Vis, 1H NMR spectroscopy and MALDI-TOF mass spectrometry. The structure has been determined by single crystal X-ray crystallography. The complex crystallizes in the triclinic space group P-1 with two molecules in the asymmetric unit and with unit cell dimensions a = 8.0103(3) A, b = 12.8340(5) A, c = 22.3682(11) A, α = 91.715(2)°, β = 93.918(2)°, γ = 103.708(2)°. V = 2226.30(16) A3, Z = 4, R 1 = 0.0780 and wR 2 = 0.1192. X-ray structure determination revealed that the complex consists of a [Zn(C19H11Br2N3O2)] moiety with a coordinated pyridine molecule on the metallic centre. The zinc atom adopts a distorted square pyramidal geometry as it is shown in the crystal structure. A single crystal description of a unsymmetrical structure, spectroscopic and characterization with 2D NMR ROESY spectrum

Accessible and hindered phenanthroline-strapped Zn(II) porphyrin receptors exhibited suitable topography tailored to strongly and selectively bind N(1)-unsubstituted imidazoles and imidazoles appended to free-base porphyrins. Distal binding was clearly driven by the formation of strong bifurcated hydrogen bonds with the phenanthroline unit of the receptors. An extensive physicochemical study emphasized the influence of bulkiness of the substrate and of the porphyrin receptor on the binding and self-assembly mechanism. Knowledge of the corresponding spectroscopic, thermodynamic, and kinetic data were of fundamental importance to elucidate and to model the photoinduced properties which occur within the self-assembled porphyrin dyads.

Whether nanosciences or real life, a straight line is usually the fastest way from point A to point B. If linearity is very frequent among inorganic scaffolds due to the crystalline character of the structures employed, the linearity in organic materials is significantly more difficult to control. An intermediate situation is found in the case of carbon nanotubes which can be grown in mats with a great deal of control over their orientation and size. The scope of this review is to provide, through selected examples, a general overview of the strategies available to obtain organic linear structures with interesting electronic properties. When available for the examples provided, physical data related to the electronic properties will be examined to outline the limitations expected in the case of organic nanowires and nanocables. Although these materials will hardly compete with inorganic solids, they still have a bright future complementary to the inorganic approach, and because of their production via soft chemical synthesis.

Two self-complementary phenanthroline-strapped porphyrins bearing imidazole arms and C 12 or C 18 alkyl chains were synthesized, and their surface self-assembly was investigated by atomic force microscopy (AFM) on mica and highly ordered pyrrolitic graphite (HOPG). Upon zinc(II) complexation, stable porphyrin dimers formed, as confirmed by DOSY (1)H NMR and UV-visible spectroscopy. In solution, the dimers formed J-aggregates. AFM studies of the solutions dip-coated onto mica or drop-casted onto HOPG revealed that the morphologies of the assemblies formed were surface-tuned. On mica, fiber-like assemblies of short stacks of J-aggregates were observed. The strong influence of the mica's epitaxy on the orientation of the fibers suggested a surface-assisted assembly process. On HOPG, interactions between the alkyl chains and the graphite surface resulted in the stabilization and trapping of monomer species followed by their subsequent association into coordination polymers on the surface. Interdigitation of the alkyl chains of separate polymer strands induced lateral association of wires to form islands that grew preferentially upon drop-casting and slow evaporation. Clusters of laterally assembled wires were observed for the more mobile functionalized porphyrins bearing C 12 chains.

The electrochemical behavior of three cytochrome c oxidase models has been investigated. All the models are derived from a phenanthroline-strapped, porphyrin framework that binds zinc(II) or iron(III) chloride in the porphyrin subunit, and copper(I) in the phenanthroline site. The iron complex and the bimetallic zinc(II) copper(I) complex of the parent ligand have been characterized by X-ray diffraction. One model consists of the parent structure on which C 12 alkyl chains have been added. This soluble model achieves electrochemical 2-electron reduction of oxygen in organic solvents without the addition of an exogenous axial base, and in the presence of an organic or inorganic source of protons. The two other models comprise the parent phenanthroline-strapped porphyrin framework, on which two pendant imidazoles have been incorporated. These models adsorbed on ring-disk electrodes with an edge-oriented, pyrolytic graphite (EOPG) disk and a platinum ring, efficiently catalyze the 4-electron reduction of oxygen in dioxygen saturated water at neutral pH.

Viologens can exist in three redox states varying from dicationic to neutral. This work emphasizes the control of the host–guest properties in bis-viologen cyclophanes. Two flexible cyclophanes were prepared by a cyclisation method sensitive to the odd/even number of carbons in the flexible chains linking two viologens. C5 and C7 cyclophanes were characterised by X-ray diffraction in their tetracationic state and their diradical dicationic state. In the presence of tetrathiafulvalene or methyl viologen as guests, inclusion complexes were obtained, including a mixed valence species.

In addition to the need for functional models of cytochrome c oxidase, structural models are still required for a better understanding of the small reorganizations occurring during the catalytic cycle. An efficient synthetic approach has been designed to prepare several phenanthroline-strapped porphyrins, two of them bearing two pendant imidazoles. These built-in bases are both potentially able to act as axial bases for the metalloporphyrin and as complementary ligands for copper if necessary. Diamagnetic zinc(II) was used to demonstrate that the distal/proximal selectivity demonstrated by exogenic bases binding studies can be extended to the coordination of iron(III). Combination of EPR and paramagnetic 1H NMR shows that the imidazole binding on the zinc species can be further extended to the iron(III) species in dilute conditions.

A highly soluble phenanthroline strapped porphyrin is prepared on multigram scale by appropriate functionalization with C 12 chains after the cyclization of the tetrapyrrolic macrocycle.

The respective affinities of various imidazole derivatives, imidazole (ImH), 2-methylimidazole (2-MeImH), 2-phenylimidazole (2-PhImH), N-methylimidazole (N-MeIm), 2-methylbenzimidazole (2-MeBzImH), and 4,5-dimethylbenzimidazole (4,5-Me(2)BzImH), for two phenanthroline (Phen) strapped zinc(II) porphyrin receptors porphen-Zn 1-Zn and 2-Zn have been studied. The formation of a supplementary H-bond considerably enhances the affinity of the zinc(II)-porphen receptor for imidazoles unsubstituted on the pyrrolic nitrogen (ImH) versus N-substituted imidazoles such as N-MeIm. The ImHs subset porphen-Zn complexes are formed with association constants up to 4 orders of magnitude superior to those measured either for N-MeIm as substrate or TPP-Zn as receptor. Distal or proximal binding of the substrates was determined by (1)H NMR measurements and titration. In two cases, the very high stability of the inclusion complex enabled the use of 2D NMR techniques. Excellent correlation between solution and solid-state structures has been obtained. A total of six X-ray structures are detailed in this article showing that the evolution of the shape of the zinc(II) receptor is mostly dependent on the steric constraints induced by the substitution on the imidazole. Hindered guests also progressively induce considerable mobility restrictions and severe distortions on the receptor, especially in the case of 2-MeBzImH and 2-PhImH.

Mononuclear zinc(II) complex, [Zn(II)L], where L is a dianionic ligand, has been synthesized and characterized by elemental analysis, electronic, IR and NMR [1H, 13C, DEPT, 1H–1H COSY, ROESY, HSQC and HMBC] spectroscopic techniques. Structural analysis of the complex by single crystal X-ray crystallography shows the presence of a distorted square planar coordination geometry (NNOO) of the metal center. The crystal of the title complex C28H18N2O2Zn belongs to the orthorhombic system with space group Pmn21. Electrochemical behavior of the Zn(II)L complex has been investigated by cyclic voltammetry on glassy carbon and platinum electrodes in DMF at 100 mV/s scan rate.

The preparation of porphyrins functionalized with one or two carbazoles (or phenoxazines) is described. The electron donors were introduced into one or two porphyrin meso positions by using the inexpensive Ullmann coupling procedure. Very good yields were obtained, and for two new compounds, the X-ray structures were solved. Preliminary electrochemical data coupled with electronic spectroscopy are also reported.

The tremendous efforts made in order to control the coordination chemistry of hemoprotein models have considerably enhanced the synthesis of functionalized porphyrins, whose carefully designed architectures allowed for selective bindings of exogenic substrates. The common use of zinc(II) in place of pentacoordinated iron(II) has induced the use of zinc(II) porphyrins as building blocks for selective receptors. These receptors offer a convenient combination of multi-point recognition of substrates, and monitoring of the complexation due to the chromophoric nature of the tetrapyrrolic unit. This review is dedicated to recent progress made in the field of molecular recognition involving multi-point selective binding processes, in whichthe establishment of a strong coordination bond is finely tuned by one or more weak interactions adequately introduced in the architecture of a functionalized zinc(II)-porphyrin.

Imidazole-porphyrin coordination has become an important tool in the design of self-assembled materials. A combination of spectrophotometric and stopped-flow techniques has been used to gain insight into the control of imidazole binding in the distal pocket of phenanthroline-strapped porphyrins. The binding studies of a variety of imidazole substrates in combination with both hindered and accessible receptors have permitted the determination of the thermodynamic and kinetic parameters associated with the imidazole binding.

A method leading to the preparation of the free base or zinc meso-ethynyl functionalized octaethylporphyrin has been developed, which will open the access to various meso-ethynyl metalloporphyrins.