Synthesis, spectral-luminescent and ionochromic properties of rhodamine B containing terminal (4-hydroxybenzyl)triphenylphosphonium chloride substituent

Abstract

A rhodamine B derivative containing a terminal (4-hydroxybenzyl)triphenylphosphonium chloride substituent was synthesized. Its structure was determined using IR, 1H NMR and 13C spectroscopy. The spectral luminescent properties and complexation of the compound obtained in solutions with Co2+, Cu2+, Ni2+ and Zn2+ cations were studied. These ions cause a contrasting ionochromic naked-eye effect with the change of colorless solution to crimson-red color due to the isomerization of the spirolactam form of rhodamine into an open form. The process is accompanied by the appearance of fluorescence in the region of 560-600 nm. The complex with zinc(II) cation exhibits particularly intensive emission, which gives the obtained rhodamine the properties of a highly sensitive and effective chemosensor for Zn2+ ions.