Synthesis, characterization and ethanol sensing properties of carboxylic acid-terminated naphthoxy substituted phthalocyanines

• Published in: Synthetic metals 2018-12, Vol.246, p.7-15
• Main Authors: Neccaroğlu Işık, Seher, Keser Karaoğlan, Gülnur, Can Ömür, Birsel, Altındal, Ahmet, Gümrükçü Köse, Gülşah
• Format: Article
• Language: English
• Subjects: Alcohols; Alkanes; Amines; Atomic force microscopy; Carboxylic acid; Chemical analysis; Copper compounds; Dependence; Detection; Ethanol; Ethanol sensing; Metal phthalocyanines; Naphthol; Nickel; NMR; Nuclear magnetic resonance; Operating temperature; Phthalocyanine; Properties (attributes); Response time; Sensitivity; Sensitivity analysis; Substitutes; Synthesis; Thin films
• ISSN: 0379-6779; 1879-3290
• DOI: 10.1016/j.synthmet.2018.09.004

•Synthesis of carboxylic acid-terminated naphthoxy substituted free metal and metallophthalocyanines.•An ethanol sensor based on Pc compounds is proposed and investigated.•The influence of COOH group on the ethanol vapor sensing properties.•Highly sensitive detection of ethanol vapor by [2,9,16,23-tetra-(4-(6-carboxy-2-naphthoxy)-phthalocyaninato-nickel (II)].•Both surface ionization energy of central metal atom and oxygen-displacement play role in the ethanol adsorption. A new mono substituted phthalonitrile derivative of 4-(6-carboxy-2-naphthoxy)phthalonitrile was prepared by a nucleophilic displacement reaction of 4-nitrophthalonitrile with 6-hydroxy-2-naphthoic acid. Metallophthalocyanines of [2,9,16,23-tetra-(4-(6-carboxy-2-naphthoxy)-phthalocyaninato-zinc(II)], cobalt(II), copper(II), nickel (II), and metal free phthalocyanines bearing carboxylic acid groups at the peripheral positions have been designed and synthesized by cyclotetramerisation of the phthalonitrile to investigate the influence of the central metal atom on the ethanol vapor sensing properties. All newly synthesized compounds were characterized by UV–Vis, FTIR, 1H-NMR, MALDI-TOF MS and elemental analysis spectral data. The influence of COOH group on the organic vapor sensing performance towards 5 different groups of analytes (alkanes, chlorinated hydrocarbons, amines, alcohols and aromatics) were examined. Ethanol adsorption onto the thin films of these compounds and the effects of operating temperature on the sensing properties were also studied. The sensing data show that all the films of phthalocyanine compounds show response to ethanol, among which, [2,9,16,23-tetra-(4-(6-carboxy-2-naphthoxy)-phthalocyaninato-nickel (II)] based sensor show the highest response, demonstrating central metal atom dependence of ethanol sensitivity. Surface topography of the sensing films were analyzed by atomic force microscopy.