Hexachlorinated Boron(III) Subphthalocyanine as Acceptor for Organic Photovoltaics: A Brief Overview

A boron(III) complex of peripherally hexachlorinated subphthalocyanine, Cl6SubPc is a very promising small-molecule acceptor for application in organic photovoltaics. In this chapter the recent experimental results in the field are compared, and a critical review is given of the published works on the solar cells with the planar or bulk heterojunction architectures. The thin film properties of Cl6SubPc are also considered. The approaches to the further modification of the molecular structure of boron(III) subphthalocyanine-type compounds for the enhancement of their photoelectrical properties are discussed

Comparative study of reactions between µ-nitrido- or µ-oxo-bridged iron tetrasulfophthalocyanines and sulfur-containing reductants

A comparative study of reactivity of μ-nitrido- and μ-oxo-dimers of iron tetrasulfophthalocyanine has been performed in aqueous solutions of various acidity. The substantially higher stability of nitrido-bridged structure under both strongly acidic and strongly alkaline environments was demonstrated. Reactions of the complexes with sulfur-containing reductants (sodium dithionite, thiourea dioxide, sodium hydroxymethanesulfinate, L-cysteine) has been studied. Differences in reduction processes were explained

Porphyrazines with annulated diazepine rings. 3.⊗ MgII Complex of 4-tert-Butylphenyl Substituted Tetra(1,4-diazepino)porphyrazine: Synthesis and Peculiar Effect of Solvent on Its Spectral Properties

5,7-Di(4-tert-butylphenyl)-6H-1,4-diazepine-2,3-dicarbonitrile, prepared by condensation of di(4-tert-butylbenzoyl) methane with diaminomaleodinitrile, affords upon template cyclotetramerization in the presence of magnesium(II) butoxide in n-butanol the MgII complex of octa-4-tert-butylphenyl substituted tetra(1,4-diazepino)porphyrazine. The strong solvent effect on its UV-Vis and 1H NMR spectral properties is rationalized in terms of dimerization occurring very likely due to intermolecular hydrogen bonding between diazepine nitrogen atoms and water molecules. The monomer is present exclusively only in diluted solutions of aprotic solvents such as dimethyl sulfoxide and dimethylformamide. Addition of water or methanol leads to dimerization. The dimer exists also in pyridine and tetrahydrofuran solutions, as well in benzene and dichloromethane containing residual water or alcohol. The UV-Vis spectrum of the monomer is typical for MgII porphyrazines and contains a single Q band at ca. 680 nm. In its 1H NMR spectrum the resonance of the CH2 protons is not observed at ambient temperatures but appear as a broad signal at 4.4-4.5 ppm above 100 °C, which is characteristic for rapid inversion of the 1,4-diazepine ring in the 6H form. The Q band of the dimer is split into two components (major at 640-645 nm and minor at 680-685 nm). The dimer gives two doublets of the diastereotopic CH2 protons (5.9-7.1 ppm for the equatorial and 4.8-6.1 ppm for the axial CH2 protons, depending on the solvent) with characteristic geminal splitting of ca. 11-12 Hz. Formation of the dimer hinders the inversion of diazepine rings and two sharp doublets are observed even above 100 °C. © ISUCT Publishing

Novel families of phthalocyanine-like macrocycles—Porphyrazines with annulated strongly electron-withdrawing 1,2,5-thia/selenodiazole rings

Tetrakis(thiadiazole)porphyrazines and tetrakis(selenodiazole)porphyrazines, first described in the years 1998–2001, have later attracted the attention of different scientific groups in the world. Since the beginning and in the most recent times, a number of aspects concerning their relevance as phthalocyanine-like macrocycles, their distinct structural, electronic and UV–visible spectroscopic features, and electrochemical behavior have brought to knowledge the important role played by the externally annulated electron-withdrawing thia- and selenodiazole rings. Much has been learned about the acid–base properties of the new macrocycles, their facile electron uptake and negative charge redistribution capability within the entire macrocyclic framework. Further work has been directed to the synthesis and characterization of several low-symmetry species carrying peripherally annulated benzene or substituted benzene rings and thia- or selenodiazole rings and the structural and electronic effects caused by the progressive annulation of the heterocyclic rings in a basic phthalocyanine structure has been examined. Deselenation processes at the annulated selenodiazole rings in symmetrical and low-symmetry macrocycles and the formation of vicinal diamino functionalities have allowed diversified derivatization procedures with formation of new porphyrazine macrocycles by ring reclosure or designed external sites for exocyclic metalation in dinuclear species

Iron(II) complexes of hexaphenyl(1,2,5-thia/selenadiazolo)porphyrazine: the direct replacement of Se by S in the 1,2,5-selenadiazole ring

Iron(II) complexes of hexaphenyl(1,2,5-thia/selenadiazolo)porphyrazines have been prepared as bis(pyridine) adducts [PY2Fe(XN2)PAPh(6)] (X = S, Se) from the corresponding Mg-II complexes obtained by template co-cyclotetramerization of diphenylfumarodinitrile with 1,2,5-thia/selenadiazolo-3,4-dicarbonitriles, and the unusual direct replacement of Se by S in the reaction of [Py2Fe(SeN2)PAPh(6)] with H2S has been observed

Tetrapyrazinoporphyrazines and their metal derivatives. Part I: synthesis and basic structural information

Tetrapyrazinoporphyrazines (TPyzPzs), the heterocyclic azaanalogs of the phthalocyanine macrocycle, are known since 1937 and were intensively studied especially in the last fifteen years. Due to advances in the synthesis, peripherally substituted TPyzPzs and their innumerable metal derivatives have become one of the most easily accessible phthalocyanine analogues. External substituents endow these species with solubility in organic solvents or water, influence aggregation behavior, determine spectral, electrochemical, coordination, acid-base, catalytic and photochemical properties. Moreover, by the building of new exocyclic coordination sites, they enable formation of multimetallic porphyrazines. Aspects concerning the synthesis of precursors, TPyzPz macrocycles and their metal derivatives and the related available structural information are illustrated and discussed in detail in this review including also low symmetry species, oligomeric and polymeric TPyzPzs and higher TPyzPz homologues with fused benzene and heteroaromatic rings. (C) 2015 Elsevier B.V. All rights reserved

Tetrapyrazinoporphyrazines and their metal derivatives. Part II: Electronic structure, electrochemical, spectral, photophysical and other application related properties

Tetrapyrazinoporphyrazines (TPyzPzs), the heterocyclic azaanalogs of the phthalocyanine macrocycle, known since the 1930 s, but became an object of intensive studies in the last decades. In Part I (Coord. Chem. Rev. 2016, 309, 107–179) the synthesis of variously substituted TPyzPzs and their metal complexes as well as of their precursors was presented. In the present Part II, we consider the peculiarities of their electronic structure, electrochemical, spectral, acid–base and photophysical properties. The focus is made on the related perspectives of practical applications in the fields of nonlinear optical properties, liquid crystals, catalysis, sensors, dark quenchers of fluorescence, photodynamic therapy (PDT, including the specific aspects of water-soluble and targeting TPyzPzs, in vitro PDT results, bi- and multimodal therapy) and light harvesting

DFT Study of the Molecular and Electronic Structure of Metal-Free Tetrabenzoporphyrin and Its Metal Complexes with Zn, Cd, Al, Ga, In

The electronic and molecular structures of metal-free tetrabenzoporphyrin (H2TBP) and its complexes with zinc, cadmium, aluminum, gallium and indium were investigated by density functional theory (DFT) calculations with a def2-TZVP basis set. A geometrical structure of ZnTBP and CdTBP was found to possess D4h symmetry; AlClTBP, GaClTBP and InClTBP were non-planar complexes with C4v symmetry. The molecular structure of H2TBP belonged to the point symmetry group of D2h. According to the results of the natural bond orbital (NBO) analysis, the M-N bonds had a substantial ionic character in the cases of the Zn(II) and Cd(II) complexes, with a noticeably increased covalent contribution for Al(III), Ga(III) and In(III) complexes with an axial –Cl ligand. The lowest excited states were computed with the use of time-dependent density functional theory (TDDFT) calculations. The model electronic absorption spectra indicated a weak influence of the nature of the metal on the Q-band position