DEPENDENCE OF OPTICAL RESPONSE ON pH OF A WATER-SOLUBLE Zn(II)-METALLOPORPHYRIN

Nowadays, porphyrin derivatives are extensively used as analytical reagents. This work put the basis for a rapid, simple and inexpensive method developed for pH determination. It was demonstrated the potential for a water soluble metalloporphyrin, 5,10,15,20-tetrakis(N-methyl-4-pyridyl)porphyrin-Zn(II) tetrachloride (Zn-TNMPyP) to be a potential optical pH sensor in the 5.5-10.5 domain. Monitoring of the variations in the absorption spectra of the Zn-TNMPyP, both regarding the Soret and the Q(0,1) band, generated by the exposure to different base concentrations allowed us to notice the linearity of the response at different pH values

UV SENSING EFFECT IN LANGMUIR-BLODGETT COMPLEX FILMS CONTAINING A NOVEL SYNTHESIZED Fe(III) PORPHYRIN

A novel structure of metalloporphyrin, namely: 5,10,15,20-tetrakis(3,4-dimethoxyphenyl)-porphyrin Fe(III) chloride, was successfully synthesized. UV sensitive structure based on barium stearate functionalized with the novel synthesized porphyrin and carbon nanotubes was obtained. A five monolayers structure was deposited from solution by Langmuir -Blodgett technique onto a ceramic substrate with interdigital platinum electrodes. The complex film shows sensitivity to UV radiation due to the fact that an electron is excited from a Fe d orbital into a porphyrin antibonding π orbital and is moved onto the ligand that is attached, facilitating the charge separation, while the presence of SWCNT activates the transport of the charge carriers