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Vinylporphyrins containing one vinyl group at the pyrrole or benzene ring and their complexes with Cu²⁺ and Zn²⁺ have been obtained by the Wittig reaction. The compounds obtained were characterized by physicochemical methods. X-ray diffraction analysis of 5-(4-vinylphenyl)-10,15,20-triphenylporphyrin has been carried out. It is likely that the inclusion of the vinyl group is accompanied by weak electron effects on the macrocycles. The radical-induced copolymerization of meso-tetraphenylporphyrin monomers with the vinyl group in a benzene or pyrrole ring and their copper and zinc complexes with styrene and methacrylate was studied. Porphyrin comonomers decrease the overall polymerization rate and the number-average molecular weight of the products formed compared with the weight of polystyrene obtained under similar conditions. The main reasons for termination of chain growth by vinylporphyrins were revealed and some quantitative parameters of these reactions were obtained. IR and electronic absorption spectra of porphyrin-containing copolymers are discussed. According to the ESR spectra, the copper-containing centres in the copolymers are fairly remote from each other, and the metal-containing polymeric systems are magnetically dilute. The spectral luminescence properties of solutions of zinc 5-(4-vinylphenyl)-10,15,20-triphenylporphyrin–methyl methacrylate copolymers with various contents of porphyrin groups were studied. It was shown that a new long-wave band appears in the absorption spectra of the copolymers, the intensity of which depends on the copolymer composition, and the quantum yield of fluorescence decreases with increasing molar fraction of porphyrin groups.

This article reports the first perbromination of β-pyrrole and meso-phenyl groups of the 5,10,15,20-tetrakis(3',5'-dimethoxyphenyl)porphinato copper(II) to generate highly brominated porphyrin, 2,3,7,8,12,13,17,18-octabromo-5,10,15,20-tetrakis(2',6'-dibromo-3',5'-dimethoxyphenyl)-porphinato copper(II), CuT(3',5'-DMP)PBr₁₆ complex. Its crystal structure exhibited unusual five-coordination geometry with saddle shaped conformation of the porphyrin core. H₂T(3',5'-DMP)PBr₁₆ and its metal complexes exhibited large anodic shift of oxidation potentials with marginal changes in reduction potentials relative to their corresponding octabromotetraphenylporphyrin, MTPPBr₈ derivatives. The enhanced electron deficiency of the ZnT(3',5'-DMP)PBr₁₆ complex was probed by axial ligation of various Lewis bases with differing pK_a values. The ZnT(3',5'-DMP)PBr₁₆ complex exhibited decrease in equilibrium constants for the ligation of bases relative to sterically unhindered ZnTPPBr₈. This has been ascribed to the sterics induced by the bulky ortho-bromo phenyl substituents that prevents the facile binding of Lewis bases to the Zn(II)-center.

“Non-fluorescent” chlorophyll catabolites (NCCs) were named “rusty pigments” originally, as they easily oxidized to yellow chlorophyll catabolites (YCCs) and other colored natural “phyllobilins.” In the present work, binding of Zn(II)-ions by YCC and its methyl ester YCC-Me, and structural investigations of the resulting Zn(II)-complexes are reported. Binding of Zn-ions to the weakly luminescent YCC or YCC-Me in DMSO produces orange-yellow complexes that exhibit strong green emission. The Zn-complex of YCC-Me was isolated and characterized by UV-vis-, fluorescence-, mass- and NMR-spectra. The data revealed a 2:1 complex, Zn(YCC-Me)${}_2$, in which YCC-Me serves as bidentate ligand. The Zn(II)-center in Zn(YCC-Me)${}_2$ is, thereby, deduced to be coordinated in a pseudo tetrahedral fashion. Formation of Zn(YCC-Me)${}_2$ (and of Zn(YCC)${}_2)$ is compatible with an isomerization of the lactam form of ring D to the corresponding lactim tautomer in these neutral Zn(II)-complexes.

A new series of mono-/di-aminated meso-tetraarylporphyrins has been synthesized and characterized by conventional spectroscopic methods. Crystal structure analysis shows that interactions involving halogens are the major contributors, and the relative contributions are 56% and 53% respectively for MB2c and MB3c. All the compounds were electrochemically analyzed under different reaction conditions and showed a positive shift in the reduction and oxidation potentials. The HOMO–LUMO energy gap was altered with respect to the nature of the supporting electrolyte and reference electrodes used. The linear behavior of Randles-Sevcik plots indicate that the redox processes are diffusion controlled; the first reduction/oxidation is a reversible one-electron step whereas the second reduction/oxidation is a quasi-reversible one-electron process. Results also reveal that the mono-aminated porphyrins are more electron deficient than non-aminated and di-aminated porphyrins.

Expanded nonaromatic stable porphyrins(2.1.2.1) were successfully synthesized by 2,3-di(1H-pyrrol-2-yl)naphthalene as buliding blocks and aromatic aldehydes under acid catalyzed condensation conditions in acceptable isolated yields. NMR, X-ray diffraction analysis, absorption, electrochemical, and density functional theory revealed these macrocycles to be non-aromatic due to highly saddle-shaped molecular structures of dinaphthoporphyrin(2.1.2.1). The saddle-shaped dinaphthoporphyrins(2.1.2.1) with embedded naphthalene units as $\pi$-conjugation units show perturbations to molecular structure, optical and electronic properties. The dinaphthoporphyrins(2.1.2.1) are effective macrocyclic ligands giving copper(II) and nickel(II) complexes.