First tellurium-containing phthalocyanine analogues: strong effect of tellurium on spectral, redox and conductivity properties of porphyrazines with annulated chalcogenodiazole ring(s)

Molecular Structure, Thermodynamic and Spectral Characteristics of Metal-Free and Nickel Complex of Tetrakis(1,2,5-thiadiazolo)porphyrazine

The Knudsen effusion method with mass spectrometric control of the vapor composition was used to study the possibility of a congruent transition to the gas phase and to estimate the enthalpy of sublimation of metal-free tetrakis(1,2,5-thiadiazolo)porphyrazine and its nickel complex (H₂TTDPz and NiTTDPz, respectively). The geometrical and electronic structure of H₂TTDPz and NiTTDPz in ground and low-lying excited electronic states were determined by DFT calculations. The electronic structure of NiTTDPz was studied by the complete active space (CASSCF) method, following accounting dynamic correlation by multiconfigurational quasi-degenerate second-order perturbation theory (MCQDPT2). A geometrical structure of D_2h and D_4h symmetry was obtained for H₂TTDPz and NiTTDPz, respectively. According to data obtained by the MCQDPT2 method, the nickel complex possesses the ground state ¹A_1g, and the wave function of the ground state has the form of a single determinant. Electronic absorption and vibrational (IR and resonance Raman) spectra of H₂TTDPz and NiTTDPz were studied experimentally and simulated theoretically.

Synthesis and characterization of heteroleptic rare earth double-decker complexes involving tetradiazepinoporphyrazine and phthalocyanine macrocycles

Reaction of (2,3,9,10,16,17,23,24-octabutylphthalocyaninato)lanthanide(iii) acetylacetonates (BuPcLn(acac), 1a-c, Ln = Lu (a), Eu (b), La (c)) with a tetrakis(5,7-bis(4-tert-butylphenyl)-6H-1,4-diazepino)[2,3-b,g,l,q]porphyrazine ligand (tBuPhDzPzH2, 2) produced sandwich compounds (tBuPhDzPz)Ln(BuPc) (3a-c), which represent the first heteroleptic double-deckers incorporating both Pc and DzPz decks. A combination of high-resolution mass spectrometry, UV-Vis/NIR, MCD, and 1H NMR spectroscopy, and square-wave voltammetry provided unambiguous characterization of target complexes 3 indicating that their spectral and electrochemical properties are generally intermediate with respect to their homoleptic relatives. Based on the data of solution-state 1H-1H NMR (COSY, NOESY) correlation spectroscopy supported by DFT calculations, a dimerization tendency of compounds 3 proportional to the Ln(iii) ion size was found. The spectroelectrochemical study of 3 and the corresponding homoleptic double-deckers revealed a pronounced tendency to aggregation of the one-electron oxidized forms of DzPz-containing double-decker complexes compared to homoleptic Pc2Ln compounds.

Photodynamic properties of aza-analogues of phthalocyanines

Spectral and photophysical properties and in vitro photodynamic activity of aza-analogues of phthalocyanines are summarized.

DFT Study of molecular and electronic structure of magnesium (II) tetra(1,2,5-chalcogenadiazolo) porphyrazines, [TXDPzMg] (X = O, S, Se, Te)

The influence of the chalcogen atom (X) on the molecular and electronic structures for the series of Mg[Formula: see text] tetra(1,2,5-chalcogenadiazolo)porphyrazines [TXDPzMg] (X [Formula: see text] O, S, Se, Te) and their monoaqua complexes [TXDPzMg(OH[Formula: see text]] was studied using DFT methods (B3LYP and PBE0 functionals) with cc-pVTZ basis sets. The chalcogen atom X changes strongly the geometry of the fused 1,2,5-chalcogenadiazole rings, but has only a weak influence on the dimensions of the coordination cavity of the porphyrazine macrocycle in [TXDPzMg] leading to its slight expansion in the sequence S < Se < Te < O. The electron density distribution was considered in terms of the natural bond order (NBO) and the natural population analysis (NPA). The frontier molecular orbitals are destabilzed along with the decrease of electronegativity of the chalcogen atoms. The a[Formula: see text] and e[Formula: see text] orbitals (HOMO and LUMO) are mainly localized on atoms constituting the internal 16-membered macrocycle, while the chalcogen atoms have the strongest effect on the composition of the filled [Formula: see text]-MOs having the a[Formula: see text] symmetry – 2a[Formula: see text] and lower lying 1a[Formula: see text] orbitals. The Gouterman type a[Formula: see text] orbital with predominant localization on the nitrogen atoms of the internal 16-membered macrocycle is 2a[Formula: see text] for the O- and S-containing complexes and for the Se- and Te-analogs it becomes 1a[Formula: see text], while the higher lying 2a[Formula: see text] orbital resides mainly on the fused heterocycles (Se/Te and C[Formula: see text] atoms). The lowest excited states have been calculated for [TXDPzMg] and used for the explanation of the peculiarities and tendencies observed in the experimental electronic absorption spectra available for the S, Se- and Te-containing Mg[Formula: see text] complexes.

Novel luminescent β-ketoimine derivative of 2,1,3-benzothiadiazole: synthesis, complexation with Zn(ii) and photophysical properties in comparison with related compounds

2,1,3-Benzothiadiazoles and their Zn complexes show fluorescence in different wavelength regions, one of the complexes reveals white emission.

Novel soluble thieno[3,2-b]thiophene fused porphyrazine

The synthesis of the first soluble thieno[3,2-b]thiophene based porphyrazine (ZnTTPz) is reported from the cyclisation of 2,3-dicyano-5-octylthieno[3,2-b]thiophene.

Breathing some new life into an old topic: chalcogen-nitrogen π-heterocycles as electron acceptors

Recent progress in the design, synthesis and characterization of chalcogen-nitrogen π-heterocycles, mostly 1,2,5-chalcogenadiazoles (chalcogen: S, Se and Te) and their fused derivatives, possessing positive electron affinity is discussed together with their use in preparation of charge-transfer complexes and radical-anion salts-candidate building blocks of molecule-based electrical and magnetic functional materials.