Supra­molecular assembly of (methanol)[10,15,20‐tris­(4‐cyano­phenyl)‐5‐(4‐pyridyl)­porphyrin­ato]­zinc(II) by inter­molecular hydrogen bonding and weak coordination

The crystal structure of the title compound, [Zn(C₄₆H₂₄N₈)(CH₄O)], consists of two‐dimensional supra­molecular arrays sustained by O—H⋯N(pyrid­yl) hydrogen bonding and weak Zn⋯NC coordination. The inter­layer organization in the crystal structure is characterized by tight stacking of the corrugated layers.     

Quantum Chemical and Corrosion Inhibition Studies of (4-Chlorophenyl)-N-(4-Methylphenyl) Nitrone

The compound (4-chlorophenyl)-N-(4-methylphenyl) nitrone (4CPNMPN) has been selected as one of the new nitrone derivative for our study. The molecular structure of the compound was investigated based on frontier orbital analysis and natural bond orbital (NBO) theory. The present work also focuses on the inhibition efficiency of the compound. It is an attempt to find the correlation between the molecular structure of the compound and possible behaviour like corrosion inhibitors. The NBO analysis and the values of electric dipole moment (μ) of the investigated molecule were computed using DFT calculations. The molecule orbital contributions were studied by using the total (TDOS) density of states. The strong evidences that the compound can be used as an efficient nonlinear optical (NLO) of 4CPNMPN were demonstrated by considerable polarizability and hyperpolarizability values obtained at DFT levels.     

Porphyrin nanochannels reinforced by hydrogen bonding

Carboxyl groups were introduced at the peripheral positions of dodecaphenylporphyrin to link nanochannel structures with intermolecular hydrogen bonds to make the supramolecular structures robust.     

Interwoven hydrogen‐bonded network assembly and supramolecular isomerism of meso‐5,10,15,20‐tetrakis(4‐carboxyphenyl)porphyrin as its dimethylformamide solvate

Molecules of the title compound, porphyrin‐5⁴,10⁴,15⁴,20⁴‐tetrabenzoic acid, C₄₈H₃₀N₄O₈, lie on sites of 2/m symmetry in the space group Cmca. The crystals consist of doubly interwoven two‐dimensional supramolecular arrays sustained by multiple (COOH)₂ cyclic dimeric hydrogen bonds, each molecule of the porphyrintetrabenzoic acid coordinating to four neighbouring species. This structure, which encloses substantial spaces occupied by disordered dimethylformamide solvent molecules, represents yet another supramolecular isomer of this porphyrin.     

Hydrogen‐bonded supra­molecular arrays of aqua­[20‐(4‐carboxy­phen­yl)‐5,10,15‐triphenyl­porphyrinato]zinc(II) in crystals of its nitro­benzene disolvate

Crystals of the title compound, [Zn(C₄₅H₂₈N₄O₂)(H₂O)]·2C₆H₅NO₂, consist of multiporphyrin supra­molecular assemblies sustained by inter­molecular COOH⋯COOH and Zn(H₂O)⋯COOH hydrogen bonds. One of the two nitro­benzene solvent mol­ecules hydrogen bonds peripherally to these arrays.     

A Clean Clay Catalysed Synthesis of á,N-Diarylnitrones

Abstract: The first clean and the facile clay catalysed synthesis of á,N-diarylnitrones in good yield is reported.     

Clathrate solvates of tetra­kis(4‐methoxy­carbonyl­phenyl)porphyrin and its zinc(II)–pyridine complex,in which the porphyrin host structures are stabilized by porphyrin–porphyrin stacking and C—H⋯O attractions

Tetra­kis(4‐methoxy­carbonyl­phenyl)porphyrin, or tetra­methyl 4,4′,4′′,4′′′‐porphyrin‐5,10,15,20‐tetra­benzoate, crystallizes as a nitro­benzene 1.9‐solvate, C₅₂H₃₈N₄O₈·1.9C₆H₅NO₂, (I). The solvent mol­ecules are contained in extended channels which propagate through the host lattice between parallel screw/glide‐related columns of offset‐stacked porphyrin entities. Side packing of these columns involves π–π inter­actions between the methoxy­carbonyl­phenyl residues. Mol­ecules of the porphyrin host lie on crystallographic inversion centres. The zinc(II)–pyridine derivative pyridine­(tetra­methyl 4,4′,4′′,4′′′‐porphyrin‐5,10,15,20‐tetra­benzoato)zinc(II), [Zn(C₅₂H₃₆N₄O₈)(C₅H₅N)], (II), is a square‐pyramidal five‐coordinate complex with pyridine as an apical ligand, which crystallizes as a chloro­form–pyridine solvate. The metallo­porphyrin–pyridine units form an open layered arrangement, occluding the non‐coordinated solvent moieties within the intra­layer inter­porphyrin voids. Within such arrays, the host porphyrin mol­ecules are in contact with one another through the peripheral methoxy­carbonyl substituents. The crystal packing consists of a bilayered arrangement of inversion‐related porphyrin layers, with the axial ligands mutually penetrating into the voids of neighbouring arrays and tight offset stacking of these bilayers.     

Rational design of supramolecular chirality in porphyrin assemblies: the halogen bond case

Asymmetric functionalization of the tetraarylporphyrin scaffold, combined with directional supramolecular halogen bonding, yields chiral architectures.     

Effect of para-Substituents on meso-Functionalized Oxidovanadium(IV) Porphyrins as Catalysts for Oxygen Atom Transfer Mediated Oxidation of Benzoin to Benzil under Mild Conditions

Systematic analysis of the effect of para-substituents (H, Cl, Br and OMe) on the meso-phenyl group in vanadyl meso-tetraphenylporphyrins ([V^IVO(TPP)] (R=H, 1 ), [V^IVO(TCPP)] (R=Cl, 2 ), [ V^IVO(TBPP)] (R=Br, 3 ) and [V^IVO(TMPP)] (R=OMe, 4 )) on their properties and catalytic oxygen atom transfer (OAT) for oxidation of benzoin to benzil using DMSO as well as 30 % aqueous H₂O₂ as the sacrificial oxygen source have been studied. Electrochemical and theoretical (density functional theory) studies are in good agreement with the influence of these substituents on the catalytic property of these complexes. Complex [V^IVO(TCPP)] ( 2 ) displayed the best catalytic activity for the conversion (92 %) of benzoin to benzil in 30 h with >99 % product selectivity when DMSO was used as an oxygen source, whereas excellent conversion (~100 %) of benzoin to benzil was noticed in 18 h with 95 % product selectivity when 30 % aqueous H₂O₂ was used as a source of oxygen. Furthermore, among these complexes, the electron-withdrawing nature of the chloro substituent at the p-position of meso-phenyl group significantly influences the oxygen atom transfer. Experimental and simulated EPR studies confirmed the +4 oxidation of vanadium in these complexes. The structure of 2 , 3 and 4 , confirmed by single crystal X-ray diffraction method, are domed in shape, and the displacement of V(IV) ion from the mean porphyrin plane follows the order: 2 (0.458 Å) < 3 (0.459 Å) < 4 (0.479 Å). We observed that the electron-withdrawing nature of chloro substituent at the p-position of meso-phenyl group influence the oxygen atom transfer from vanadyl porphyrin to dimethyl sulfide much.     

Framework coordination polymers of tetra(4-carboxyphenyl)porphyrin and lanthanide ions in crystalline solids

Targeted synthesis of framework coordination polymers was achieved by reacting meso-tetra(4-carboxyphenyl)porphyrin with common salts of lanthanide metal ions. The large size, high coordination numbers and strong affinity for oxo ligands of the latter, combined with favourable hydrothermal reaction conditions in acidic environments, allowed the formation of open three-dimensional single-framework architectures in which the tetra-dentate porphyrin units are inter-coordinated by multinuclear assemblies of the bridging metal ions, which serve as construction pillars, into infinite architectures. Three different modes of coordination polymerisation were characterized by single-crystal X-ray diffraction. They differ by the nuclearity of the metal connectors. All structures exhibit, however, layered organization of the porphyrin-metal domains, and periodically spaced solvent accessible channel voids that penetrate through these layers throughout the corresponding crystals. Thermal analysis provided additional insight into the stability of these polymeric materials.