Electrical, spectroscopic and DFT studies of synthesized bridged bis (2-oxy benzylidene) hydrazine-carbonothioly-hydrazono cobalt(II)phthalocyanine

The synthesis, characterization, spectroscopic and bonding features of the new Co (II) phthalocyanine (Co-Pc) 4, containing two (2-oxy benzylidene) thiocarbohydrazone are explained. After synthesizing 2-[(3,4-dicyanophenoxy)benzylidene]-2-[(2-hyroxybenzylidene)hydrazine-1-carbothiohyrazine] phthalonitrile 3, Co-Pc 4 was obtained by chemical reaction with Co-salt in DMF, at hot and under vacuum. Compound 3 and 4 were identified by elemental analysis, UV-Vis, FT-IR, 1H NMR and Q-TOFF spectrometry. Additionally, Density Functional Theory (DFT) and Time Dependant-Density Functional Theory (TD-DFT) computations were carried out to investigate structural and electronic properties of 4. Electrical properties of the film of Co-Pc were researched as a function of frequency (40-105 Hz) at some temperatures between 295 K-523 K. DC conductivity values of the film were determined as 1.61 x 10-10 S/cm at 295 K and increased to 2.45 x 10-5 S/cm at 523 K. Activation energy value of the film was evaluated from linear part of the ln sigma dc - 1/T curve (Arrhenius plot) as 0.77 eV. It is concluded from the impedance spectroscopy measurements that increase in temperature caused to decrease the bulk resistance of the film of Co-Pc indicating semiconductor property. Additionally, since the dc conductivity of the compound Co-Pc increased 1.5 x 105 times as the temperature increased from 295 K to 523 K, the compound can be considered potential candidate as a temperature sensor. Co-Pc will be a first in the literature due to this feature.

Automated summary

The synthesis, characterization, spectroscopic and bonding features of a new Co (II) phthalocyanine compound containing two thiocarbohydrazone groups were explained. The compound showed semiconductor properties and potential as a temperature sensor.