Sinem Tuncel

Photophysical and photochemical properties of a novel thiol terminated low symmetry zinc phthalocyanine complex and its gold nanoparticles conjugate

A novel thiol functionalized zinc phthalocyanine complex (ZnPcSH) is reported in this work. This complex was conjugated to gold nanoparticles. The photophysical and photochemical properties of the complex and the conjugate were investigated. Upon conjugation a blue shift was observed from the UV-Vis spectra. The conjugate showed a decrease in the fluorescence quantum yield and lifetime. An increase in the triplet quantum yield and lifetime was observed for ZnPcSH following conjugation to gold nanoparticles. Both ZnPcSH and its conjugate with gold nanoparticles showed high singlet oxygen quantum yields with the conjugate being higher than the Pc alone.

Distribution of single-walled carbon nanotubes in pyrene containing liquid crystalline asymmetric zinc phthalocyanine matrix

A novel pyrene containing asymmetric Zn(II) phthalocyanine (AB3 type) was synthesized and characterized by various spectroscopic techniques as well as elemental analysis. A symmetric polyoxyethylene substituted Zn(II) phthalocyanine (B4 type) derivative was also prepared in order to compare the properties and determine the effect of the pyrene group on the phthalocyanine molecule. Composites of synthesized zinc(II) phthalocyanine-single wall carbon nanotubes (ZnPc-SWCNTs) containing 1 and 2 wt% carbon nanotubes were prepared by mixing these two components in dichloromethane followed by removal of the solvent and drying under vacuum. The liquid crystalline properties of the pure compounds and their composites were investigated in comparison with symmetric polyoxyethylene substituted Zn(II) phthalocyanine (B4 type) by using polarized optical microscopy, differential scanning calorimetry and X-ray diffraction analysis. The distribution of the SWCNTs in the ordered matrix of the columnar mesophase of these derivatives was studied by the method of polarized Raman spectroscopy and scanning electron microscopy (SEM). It was shown that the nature of the mesophases was not altered in these composites. The I(V) dependencies for the films deposited onto interdigitated electrodes were measured and it was shown that the lateral conductivity tends to increase with increasing SWCNT concentration.

Synthesis and characterizations of peripheral octa-amino and octa-amidophthalocyanines

Novel 2,3,9,10,16,17,23,24-octaamino substituted Ni(II) phthalocyanine (2) was synthesized from tosylamido (tosyl: toluene-p-sulphonyl) derivative by the cleavage of tosyl groups in the presence of 90% sulfuric acid. Octa-hexanoylamido Ni(II) phthalocyanine (3a) and octa-lauroylamido Ni(II) phthalocyanine (3b) were obtained by reacting of octa-amino Ni(II) phthalocyanine (2) with hexanoyl chloride and lauroyl chloride, respectively. The new compounds have been characterized by elemental analysis, FT-IR, NMR and UV-vis spectroscopy and mass spectrometry. The aggregation behaviors of new compounds were investigated by UV-vis spectroscopy.

Liquid crystalline octasubstituted lead(II) phthalocyanines: effects of alkoxy and alkylthio substituents on film alignment and electrical properties

Octasubstituted lead(II) phthalocyanines containing alkylthio- and alkoxy- groups in peripheral positions have been synthesized and characterized using 1H and 13C NMR, UV-Vis, IR and mass spectroscopies as well as elemental analysis. The mesogenic properties of the octasubstituted lead(II) phthalocyanines have been investigated by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. The sandwich structures ITO/PbPc/In were prepared to investigate the J(V) characteristics of thin films of these molecules. The dissimilar behavior of the films before and after heat-treatment is expected to result in changing the alignment inside the columnar stacking of the molecules in the films.

Copper Phthalocyanine Functionalized Single-Walled Carbon Nanotubes: Thin Film Deposition and Sensing Properties

Thin films of non-covalently hybridised single-walled carbon nanotubes (SWCNT) and tetra-substituted copper phthalocyanine (CuPcR4) molecules have been produced. The π-π interaction between SWCNTs and CuPcR4 molecules has been revealed by using different characterisation techniques. Scanning electron microscopy (SEM) measurements have shown that films obtained from the acid-treated SWCNTs/CuPcR4 hybrids demonstrated more homogenous surface. Using total internal reflection ellipsometry spectroscopy (TIRE), thin films of the new hybrid have been examined as an optical sensing membrane for the detection of benzo [pyrene in water to demonstrate the sensing properties of the hybrid.

Thin Films of Liquid Crystalline Phthalocyanines and their its Composites with Single-Walled Carbon Nanotubes: Properties and Alignment

In this study, liquid crystalline copper phthalocyanine and single walled carbon nanotubes were dispersed in solution to prepare novel composites. Thin films of these composites prepared by solving of the composite in dimetylformamide and then by spin coating the solution onto the substrates were studied by the methods of polarizing microscopy, polarized Raman and optical absorption spectroscopies. It was shown that pure CuPcR4 forms the films with a herringbone arrangement of phthalocyanine molecules within adjacent columns. An addition of carbon nanotubes (0.5-2 wt %) to CuPcR4 leads to formation of the films with edge-on orientation of the molecules. The higher conductivity values were found for the films of phthalocyanine containing SWCNT. The lateral conductivity tends to decrease with the increase of SWCNT concentration from 0.5 to 2 wt %.