We have developed a new synthetic strategy for the preparation of a series of isoindolin-1-imines and isoindolin-1-ones from aromatic ketones and phthalonitrile. Self-condensation reactions of these isoindolin-1-imines led to the formation of a novel class of benzo-fused, highly electron-deficient core-extended azadipyrromethene chromophores ("MB-DIPY"). The influence of temperature, catalyst, and the template ions on the self-condensation reaction rate, yield, and stereoselectivity was examined in detail. New chromophores (sodium, zinc, and metal-free compounds) were characterized by NMR, UV−vis, fluorescence, high-resolution mass spectroscopies, and in many cases, Xray crystallography. Their redox properties were probed by electrochemical and spectroelectrochemical approaches that revealed the remarkable electron-accepting nature of the new systems. Stepwise one-and two-electron reduction of the new MB-DIPYs and their zinc complexes was investigated by spectroscopic and spectroelectrochemical methods. Both one-and two-electron reduced forms of all zinc complexes studied have strong absorption in the near-infrared region up to ∼1200 nm. Unusual spectroscopic and electrochemical properties of these dyes were correlated with their electronic structures and excitedstate natures predicted by density functional theory (DFT) and time-dependent DFT calculations. Despite some structural similarities with well-known aza-BODIPYs, the new MB-DIPYs differ remarkably from them in spectroscopic and redox properties.
Electronic and geometric structures of Ca(II) and Zn(II) complexes with porphyrazine (Pz) and tetrakis(1,2,5-thiadiazole)porphyrazine (TTDPz) were investigated by density functional theory (DFT) calculations and compared. The perimeter of the coordination cavity was found to be practically independent on the nature of a metal and a ligand. According to the results of the natural bond orbital (NBO) analysis and quantum theory of atoms in molecules (QTAIM) calculations, Ca–N bonds possess larger ionic contributions as compared to Zn–N. The model electronic absorption spectra obtained with the use of time-dependent density functional theory (TDDFT) calculations indicate a strong bathochromic shift (~70 nm) of the Q-band with a change of Pz ligand by TTDPz for both Ca and Zn complexes. Additionally, CaTTDPz was synthesized and its electronic absorption spectrum was recorded in pyridine and acetone.
Sulfo derivatives of cobalt phthalocyanine containing naphthalene fragments have been synthesized, and their self-association and molecular complexation with pyridine in aqueous solution have been studied by spectrophotometry. The dissociation constants of the dimeric associates have been determined. The effects of the number of functional groups in the peripheral substituents and of the axial ligand on the phthalocyanine dimerization process have been revealed.
Enhancement of the catalytic activity of phthalocyanine catalysts by immobilizing them on polymer matrix has been studied. It has been found that the immobilization of cobalt(II) phthalocyanines on polymers enhances their catalytic activity in the oxidation of sodium diethyldithiocarbamate by air oxygen under mild conditions.
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