Some Chemistry of Poly (Fluoroaluminium-Phthalocyanine), [Al(Pc)F]n

Fzea, Adnan Hadi (1992) Some Chemistry of Poly (Fluoroaluminium-Phthalocyanine), [Al(Pc)F]n. PhD thesis, University of Glasgow.

Abstract

This thesis describes a study of partial oxidation or protonation of the compound poly(fluoroaluminium-phthalo-cyanine), [Al(Pc)F]n, by different types of oxidising agents and strong protonic acids. Oxidation reactions were carried out in the presence of acetonitrile, in the absence of a solvent and by exposing thin films of the [Al(Pc)F]n polymer deposited on KCl and silica substrates, to the vapours of the oxidants. Chapter one summarises previous studies made of the hexafluorides, UF6, MoF6, WF6 or NOPF6, the halogens, Cl2, Br2 or I2 and the pentafluorides, PF5, AsF5 or IF5 which were all used in the present work. It is concerned with the preparations, structures and redox chemical behaviour under different conditions and in different solvents. Previously reported studies involving several me tal-phthalocyanine complexes and analogous organic compounds are also described in this chapter. Chapter two describes the methods used to prepare and purify the reagents used in the reactions and the main experimental techniques, vibrational and electronic spectroscopy and transmission electron microscopy, which were used in the investigation of reaction products. In chapter three, investigations of the solubility of the [Al(Pc)F]n polymer in several organic solvents and its interactions with the strong protonic acids CF3SO3H, H2SO4 and CF3COOH are reported. On the basis of the observations made, it has been concluded that the [Al(Pc)F]n polymer behaves as a base and dissolves in the strong protonic acids through the protonation of the outer nitrogen atoms of its phthalocyanine (Pc) rings. However, the degree of protonation and, hence, the solubility of this polymer depends on the strength of the acid used as determined by its Hammett acidity value (Ho). In some cases evidence for depolymerization of [Al(Pc)F]n was obtained from the electronic spectra of the products formed, indicating that protonation and depolymerization are related. In chapter four, the reactions between [Al(Pc)F]n and binary hexafluorides MF6 (where M = U, Mo and W) or the NO+ cation in the presence of MeCN, in the absence of a solvent, or by using thin films of the polymer on silica and KCl substrates are described and discussed. The products isolated from these reactions were characterised by infrared and u. v./visible spectroscopy and in some cases by transmission electron microscopy. In all cases the products had different colours and different vibrational and electronic spectra than those of [Al(Pc)F]n. Unlike pristine [Al(Pc)F]n, the oxidised products were very soluble in acetonitrile. The anions MF6- (M = U, Mo and W) and PF6-were identified by vibrational spectroscopy. In chapter five the reactions between thin films of [Al(Pc)F]n deposited on silica substrates and non-metal pentafluorides or halogen vapours, AF5 (where A = P, As or I) and X2 (where X = Cl, Br or I) are described and discussed. The films after the reactions were examined by electronic spectroscopy; several spectral changes involving phthalocyanine electronic transitions in the region 1000-200 nm were observed. Chapter six deals with a study of the lattice structure of the epitaxial thin films of [Al(Pc)F]n on KCl substrates using transmission electron microscopy. A comparison is made between the present study and previous work reported in the literature. Results from the examination of selected samples from the reactions described in chapters 3-5 indicated that in all cases the oxidation or protonation of [Al(Pc)F]n introduced distortion into the structure of the polymer. It appeared likely that the polymeric chains were broken during the reactions. In chapter seven, comparisons among the spectroscopic results obtained from the reactions described in chapters 3-6 are made. The conclusions from all the reactions carried out in the present study and future work were also described in this chapter.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Organic chemistry
• Date of Award: 1992
• Depositing User: Enlighten Team
• Unique ID: glathesis:1992-78416
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 30 Jan 2020 15:28
• Last Modified: 30 Jan 2020 15:28
• URI: https://theses.gla.ac.uk/id/eprint/78416