Nano-gold-based synthesis, characterization and band gap energies of gold(III)-2(3)-tetrakis(allyloxy)-substituted phthalocyanine and gold(III)-phthalocyanine dyes

Abstract

In this study, we have attempted to synthesize Au (III)-phthalocyanine (Au-Pc) and Au (III)-2 (3)-tetrakis (allyloxy) phthalocyanine (Au-AoPc) by using phthalonitrile (Pn), 3 allyloxy-substituted phthalonitrile (Ao-Pn) and gold nanoparticles (AuNPs) as the starting materials. The N,N '-dimethyl amino ethanol (DMAE)-stabilized AuNPs were prepared from the HAuCl4 solution. The purple color AuNPs were obtained by the reduction of HAuCl4 solution by the addition of DMAE and adjusting pH 6-7 at room temperature. Then, the blue color Au-Pc and the green color Au-AoPc dye materials were synthesized at 120 degrees C temperature by the reactions of the AuNPs with Pn and AoPn. The obtained AuNPs, Au-Pc and Au-AoPc complexes were characterized using optical microscopy, transmission electron microscopy (TEM), UV-Vis absorption, FT-IR and electrospray ionization-mass spectrometry. The TEM analysis results showed that the sizes of AuNPs were mostly 30-40 nm and distributed within the range of 10-100 nm. By using the Tauc method, the optical band gap energies (E-g) were calculated as 1.66 eV for the Q-band and 3.12 eV for the B-band of the Au-Pc, and as 1.79 eV for the Q-band and 3.32 eV for the B-band of the Au-AoPc. The DMAE-stabilized AuNPs, the Au-Pc and the soluble Au-AoPc dyes with low band gap energy can be utilized for various technologies in electronics, imaging, sensors and solar cells.