Electroanalytical method of TCPP and its supramolecular system with cyclodextrins.
In this paper, electroanalytical method of tetrakis (4-carboxylphenyl) porphyrin (TCPP) has been established. In a supporting electrolyte of KH(2)PO(4)-Na(2)HPO(4) (pH 7.0), a sensitive second derivative reduction peak of TCPP was found by single-sweep oscillopolarography. The potential peak is -0.70V (versus SCE).The relationship between peak height and the concentration of TCPP is linear from 1x10(-7) to 2x10(-5)moll(-1), the relative standard deviation (R.S.D.) was 0.41% (n=8), and the recovery of TCPP varied from 95.8-105.4%.The interaction of cyclodextrins (CD) with TCPP in NH(3)-NH(4)Cl (pH 8.0) has been studied by polarography. The TCPP can form the 1:1 inclusion complex with beta-CD, gamma-CD, hydroxylpropyl-beta-CD, sulfurbutylether-beta-CD and trimethyl-beta-CD. "Current method" has been used to determine the formation constants of TCPP with five CDs. The result shows that the inclusion ability of hydroxylpropyl-beta-CD is very strong. Moreover, modified beta-CD has stronger inclusion capacity than native beta-CD. The formation constant of TCPP with gamma-CD is much greater than that of TCPP with beta-CD, because the gamma-CD has a bigger cavity that can match with the size of the meso-phenyl of TCPP. The supramolecular data will provide useful information for further application of TCPP.
Liu
Yun
Y
Chemistry Department, School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan 030006, PR China.
Pan
Jing-Hao
JH
Wei
Ying-Li
YL
Zhang
Yong
Y