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The main factors governing the dimer–monomer self-assembly in 6H-1,4-diazepinoporphyrazines are shown.

Octaaryl-substituted Si(iv) corrolazine complexes, obtained by reductive ring contraction reaction of the appropriate SiPzAr8, exhibit high ability for single oxygen generation. The crucial role of acid in the Pz → Cz transformation is revealed.

Novel electron-deficient low-symmetry perhalogenated azaanalogues of subphthalocyanine, [Cl2F8N2subPc] and [Cl4F4N4subPc], were prepared by mixed co-cyclotrimerization of tetrafluorophthalonitrile and 5,6-dichloropyrazine-3,4-dicarbonitrile in p-xylene in the presence of BCl3. They were characterized by MALDI mass-spectrometry, UV-VIS, IR, [Formula: see text]C, and [Formula: see text]F NMR spectroscopy, and the molecular structure of [Cl2F8N2subPc] was established by single crystal X-ray diffraction. The spectral-luminescence and redox properties of [Cl2F8N2subPc] and [Cl4F4N4subPc] as well as peculiarities of their electronic structure are compared with the corresponding symmetrically substituted compounds - perfluorosubphthalocyanine, [F[Formula: see text]subPc], and hexachlorotripyrazinosubporphyrazine, [Cl6N6subPc]. Consecutive substitution of one and two tetrafluorobenzene fragments by dichloropyrazine units leads to stabilization of the frontier [Formula: see text]-molecular orbitals and widening of the HOMO–LUMO gap. As a result, electron-affinity of the macrocycle is increased and the first reduction potentials are increasingly shifted in the less negative region from -0.43 V for [F[Formula: see text]subPc] to -0.31 V for [Cl2F8N2subPc], -0.19 V for [Cl4F4N4subPc], and the maxima of the Q-band is shifted hypsochromically from 573 nm to 565 and 553 nm, respectively. Preliminary photoelectrical measurements indicate that novel compounds can be used as acceptor materials in non-fullerene photovoltaic cells.

Anionic crystalline complexes of free-base tetrapyrazinoporphirazines with alkyl- and phenanthrene-substituents have been isolated. Their structures and properties have been studied and discussed.

Phosphorus(v) tetrapyrazinocorrolazines having HO groups in the para-position of axial aryloxy ligands exhibit a pH-switchable PET effect and can be used for the development of solvent- and pH-sensitive fluorophores and photosensitizers.

Electronic and geometric structures of metal-free, Al, Ga and In complexes with tetrapyrazinoporphyrazine (TPyzPA) and octachlorotetrapyrazinoporphyrazine (TPyzPACl8) were investigated by density functional theory (DFT) calculations and compared in order to study the effect of chlorination on the structure and properties of these macrocycles. The nature of the bonds between metal atoms and nitrogen atoms was described using the NBO-analysis. Simulation and interpretation of electronic spectra were performed with the use of time-dependent density functional theory (TDDFT). A description of calculated IR spectra was carried out based on the analysis of the distribution of the potential energy of normal vibrational coordinates.

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.