Polymeric phthalocyanines and their precursors, 17. Structure and photoelectrochemical properties of thin films of polymeric phthalocyanines from bridged diphthalonitriles

Abstract

Thin films of polymeric phthalocyanines 4a-c were prepared by in-situ syntheses from oxyand phenoxy-bridged diphthalonitriles 3a-c with copper layers deposited on Ti plates and KCI crystals. The structure of the polymers was characterized by VIS, IR and photoelectron spectra, and scanning electron microscopy. The most uniform structure was obtained for polymer 4c, in which phthalocyanine rings were linked two-dimensionally by flexible bridges of phenoxy groups. Polymers 4a and 4b are structurally not uniform, and formation of phthalocyanine rings was incomplete especially in polymer 4 a. Photoelectrochemical properties of polymeric phthalocyanine electrodes were investigated in Ti/4a-~/Fe(cN),~-'~-/Pt cells. The electrode of 4a shows n-type semiconducting behavior under illumination. The current-voltage curve for the electrode of 4b did not show remarkable rectification or photocurrents. On the other hand, cathodic photocurrents were obtained for the electrode of 4 c, indicating a p-type semiconducting behavior under illumination. The photoelectrochemical properties were related to the structural uniformity of the polymers.

Toward Tailorable Porous Organic Polymer Networks: A High-Temperature Dynamic Polymerization Scheme Based on Aromatic Nitriles

“…This reaction occurs already at temperatures of about 180 °C in presence of metal salts. The polymerization of such monomers has already been carried out extensively, with the aim to prepare crystalline polyphthalocyanine materials. − o -Dicyanobenzenes might undergo three different reactions: the cyclization to phthalocyanine, the nitrile trimerization to triazines, and also linear polymerization leading to polyiminoisoindolines. Heating o -DCB in the presence of 10 equiv of ZnCl 2 at 400 °C leads to an amorphous, black polymer network, free of soluble phthalocyanines.…”

Phthalocyanines in Macromolecular Phases - Methods of Synthesis and Properties of the Materials

“…[68] In contact with an aqueous electrolyte containing the redox couple K 3 Fe(CN) 6 /K 4 Fe(CN) 6 , the electrodes show photoelectrochemical behavior. In dependence on the kind of bridging group in 8, p-or n-type conductivity can be adjusted.…”

Syntheses of structurally uniform polymeric phthalocyanines

“…The catalytic oxidation of thiols by polymeric Co phthalocyanines coated on inorganic carriers (SiO 2 , Al 2 O 3 or active carbon) is enhanced compared to low-molecular-weight Pcs (MEROX process for gasoline sweetening) [59]. Thin films of the polymers exhibit also improved electrochemical and photoelectrochemical properties [39,57,58,[60][61][62][63].…”

“…Because polymeric phthalocyanines are insoluble and not vaporizable, special techniques must be employed. They include the reaction of films or coatings of metals or metal salts on the mentioned surfaces with gaseous tetracarbonitriles [57][58][59][60][61][62][63].…”