The synthesis and characterization of nonperipherally tetra terminal alkynyl substituted phthalocyanines and glycoconjugation via the click reaction

Abstract

In order to obtain nonperipherally tetra terminal alkynyl substituted phthalocyanines (Pcs), new 3-pent-4-ynyloxy phthalonitrile (3) was prepared by the nucleophilic displacement reaction of 3-nitrophthalonitrile (1) and 4-pentyn-1-ol (2) and then cyclotetramerization was attained in the presence of zinc acetate, cobalt acetate, and/or DBU in n-pentanol without protection/deprotection. For the first time, the glycoconjugation of the nonperipherally tetra terminal alkynyl substituted zinc phthalocyanine (ZnPc) (6) can be easily achieved via the click reaction in a high yield. The electronic absorption spectrum of the glucopyranosyl substituted ZnPc (10) derivative showed a red-shifted Q band at 751 nm in dichloromethane due to the protonation of the meso nitrogens of the Pc macrocycle. Deacylation yielded ZnPc (11) bearing glucose substituents at nonperipheral positions with an improved water-solubility and non-aggregation in DMSO. The chemical structures of the new compounds were characterized by (1)H NMR, (13)C NMR, FT-IR, UV-Vis, mass spectrometry and elemental analysis. Moreover, the phthalonitrile compound was characterized using X-ray.

A Molecular Chameleon: Reversible pH- and Cation-Induced Control of the Optical Properties of Phthalocyanine-Based Complexes in the Visible and Near-Infrared Spectral Ranges

“…Initially, researchers tended to interpret the solvatochromic behavior of α-AlkO-substituted ZnPc complexes in terms of the formation of J-aggregates, via coordination of the α-O atom to the Zn ion of a neighboring molecule. − Indeed, the addition of pyridine to such aggregates could cause their dissociation with the formation of monomeric species. However, some research groups have proposed that this process occurs because of the protonation of molecules. − In particular, in chlorinated solvents, it can be caused by traces of HCl that inevitably form upon storage of CHCl 3 or C 2 H 2 Cl 4 , especially upon exposure to light. The addition of pyridine removes the proton from the Pc molecule, restoring the spectral appearance.…”

Preferential Formation of Side‐Pocket‐Substituted Zinc Phthalocyanines Emitting Beyond 800 nm

“…The additional Q‐band absorption has been previously observed and was attributed to solvatochromism, occurring most significantly in CH 2 Cl 2 [39] . Some reports have discussed the possibility that in CH 2 Cl 2 , this is due to the protonation of the meso ‐N as a result of the acid impurities in the solvent [40–42] …”

Electropolymerization of Metallophthalocyanines Carrying Redox Active Metal Centers and their Electrochemical Pesticide Sensing Application

“…The solvents were stored over molecular sieves. 4‐Pent‐4‐ynyloxy‐phthalonitrile ( 1 ) and 3‐pent‐4‐ynyloxy‐phthalonitrile ( 2 ) were synthesized according to the literature . Column chromatography was performed on silica gel 60 for purification (Merck Kieselgel 60 (0.040–0.063 mm)).…”