Synthesis, characterization, OFET and electrochemical properties of novel dimeric metallophthalocyanines
By Ozer, Lale Meyanc[i without dot]; Ozer, Metin; Alt[i without dot]ndal, Ahmet; Ozkaya, Ali R[i without dot]za; Salih, Bekir & Bekaroglu, Ozer
Published in Dalton Trans.
The Royal Society of Chemistry
2013
Abstract
The synthesis of 4, 4[prime or minute]-[6, 6[prime or minute]-methylenebis (2-(2-(3, 4-dicyanophenoxy)-5-methylbenzyl)-4-methyl-6, 1-phenylene)] bis (oxy) diphthalonitrile 1 was achieved starting from 4-nitrophthalonitrile and 6, 6[prime or minute]-methylenebis(2-(2-hydroxy-5-methylbenzyl)-4-methylphenol in DMF at 50 [degree]C by the catalysis of K2CO3 under argon. The corresponding dimeric metallophthalocyanines (Zn2Pc22 and Co2Pc23) were tetramerized in dimethylaminoethanol with the appropriate metal salt. Newly synthesized compounds were characterized by elemental analysis, UV-vis, FT-IR (ATR), MALDI-TOF mass and 1H-NMR spectroscopy techniques. The electrochemical properties of the complexes were examined by cyclic voltammetry, differential pulse voltammetry, controlled potential coulometry and in situ spectroelectrochemistry in nonaqueous media. The results showed that while there is considerable weak interactions between the two metal phthalocyanine units in dimeric zinc phthalocyanine, these interactions in dimeric cobalt phthalocyanine is remarkable. The catalytic performances of dimeric cobalt phthalocyanine in the reduction of oxygen in a medium similar to the working conditions of the polymer electrolyte membrane fuel-cells were found to be much higher than that of dinuclear zinc phthalocyanine. Solution-processed films of the complexes were utilized as an active semiconducting layer in the fabrication of organic field-effect transistors (OFETs) in the bottom-gate configurations. The output characteristics of the resulting p-type OFET devices were investigated to evaluate the performances such as the field effect mobility ([small mu ]F). A relatively high field effect mobility of 7.3 [times] 10-3 cm2 V-1 s-1 was observed for dimeric cobalt phthalocyanine.