Self-assembly of 2-hydroxy-tri-tert-butylphthalocyaninato zinc into J-type dimer: UV-vis, DFT and spectropotentiometric study

Abstract

The role of the base nature during complexation of 2-hydroxy-9(10),16(17),23(24)-tri-tert-butyl-29H,31H-phthalocyanine ligand (1) with zinc acetate was studied by the UV-vis spectroscopy and DFT calculations. The latter allowed us to explain the selective formation of double-coordinated J-type dimer in the presence of lithium methoxide. Spectropotentiometry was used to study the nucleophilic properties of the dimeric complex in comparison with the corresponding monomer and has demonstrated the strong intramolecular interactions of macrocycles.

Peripheral substitution as a tool for tuning electron-accepting properties of phthalocyanine analogs in intramolecular charge transfer

“…The Q-band of 1Zn was significantly broader than that for the other compounds. 21,22 No such observations were made for 3Zn and its absorption spectrum perfectly overlapped the one of 2Zn. In addition, an increasing temperature did not alter the spectrum, which confirmed the presence of only the monomeric form in solution.…”

“…Of note, the hydroxy group in Pcs was reported to form an intermolecular coordinating bond to the central zinc of the next macrocycle thus forming highly stable J-dimers with a modified Q-band shape. 21,22 No such observations were made for 3Zn and its absorption spectrum perfectly overlapped the one of 2Zn.…”

Synthesis of Stable Dimeric Phthalocyanine J-Type Complexes and Investigation of Their Nucleophilic Properties

“…Thus, study of the protonation equilibrium with the spectropotentiometric method showed that the phthalocyanine macrocycles in dimer 2a represent an uniform molecular system. [17] Similar investigations were carried out for complex 2b. The results are shown in Figure 2 and Table 2.…”

“…[9] For magnesium complex 2b, the first destruction stage is observed over a wider range (250-400 o C) than that for a similar zinc complex (250-350 o C), which may be due to the more advanced potential energy surface (PES) of the macrocycles slippage. [17] Preliminary analysis has revealed the greater number of local minima that, along with a larger distortion of the structure makes it difficult to destroy of the dimeric molecule. Thus, complex 2b is characterized by minimal distance between the oxygen and magnesium atoms (2.25 Å), that leads to ion displacement from the plane of the macrocycle and distortion of the geometry of the latter (Table 1, Figure 1c).…”

A Covalently Linked Dyad Based on Zinc Phthalocyanine and Methylpheophorbide a: Synthetic and Physicochemical Study

“…However, our recent research has allowed to increase the yields of these compounds up to 50 % [23] making them available for the further synthetic and applied studies. [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] In one of these studies, [32] we reported the first synthesis of a covalently linked dyad comprising Pc and methylpheophorbide a (Pheo) subunits. Since Pc metal complexes are known to be better PSs than the corresponding free-base ligands, herein, we extend the range of Pc-Pheo dyads by a derivative bearing a zinc(II) Pc (PcZn) subunit.…”