Peripherally Metalated Secoporphyrazines:  A New Generation of Photoactive Pigments

Abstract

Base-catalyzed cross condensation of dipropylmaleonitrile 1 with bis(dimethylamino)maleonitrile 2 in an equimolar ratio afforded the porphyrazines 3a, 4a, 5a, 6a and 7a. Subsequent demetalation of 5a with TFA followed by remetalation with Zn(OAc)(2) gave ligand 5c in good yield. Compound 5c was, in turn, selectively oxidized and further peripherally functionalized using Pt(PhCN)(2)Cl(2) and PdCl(2) to yield the novel seco solitaire porphyrazines 10a and 10b. The photophysical profiles of the seco solitaire porphyrazines 10a and 10b were evaluated by means of absorption, emission, and transient absorption spectroscopy. The new pigments 10a and 10b were found to be photochemically more stable than the solitaire complexes 3d and 3e and mediated the generation of singlet oxygen with quantum yields of 0.59 and 0.45, respectively.

Synthesis, spectroscopic and electrochemical investigations of supramolecular nickel(II)tetraazaporphyrin complexes

“…They offer a wide synthetic choice for creating varied molecular architectures and are being used as building blocks for the construction of artificial systems and catalysts for a verity of substrates [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. The metalloporphyrins/ tetraazaporphyrins and ruthenium(II) polypyridyls are versatile and robust chromophores possessing strong visible region absorption and reversible redox behavior.…”

Novel peripherally functionalized seco-porphyrazines: synthesis, characterization and spectroscopic evaluation

“…Recently, a variety of porphyrazines (pzs) have been obtained showing interesting redox and electronic properties. 5 -8 As it has been described previously, 9,10 the preparation of pzs with novel physicochemical properties, including fluorescence and efficient intersystem crossing, is of particular importance since these compounds may find applications as biomedical imaging agents or as novel compounds for photodynamic therapies. In order to be of medical use, any macrocycle of the porphyrazine class must be of sufficient solubility in biological media under standard physiological conditions.…”

Mechanistics and photo‐energetics of macrocycles and photodynamic therapy: An overview of aspects to consider for research

“…As such, they display similar UV–Vis spectra profiles to that of phthalocyanines by the presence of both an efficient B‐band (300–400 nm) and stronger Q‐band (580–700 nm) which can be split with reduced core symmetry (N 2 ‐H 2 core) . These features have established their applications to various industrial fields and more recently, medical research …”