Synthesis, photophysical, theoretical and electrochemical evaluation of a new Rhodamine-ChalcogenoAmino-Thymidine (RhoCAT) hybrid derivative

Abstract

The synthesis of a new class of dyes based on Rhodamine-ChalcogenoAmino-Thymidine derivatives (RhoCAT) is described. The respective compounds were obtained in moderate to excellent yields using a straightforward protocol, employing Rhodamine-B (RhB) and Aryl-chalcogenoamine-thymidine, via an amidation reaction. The photophysical evaluation showed typical behaviour of rhodamine derivatives with bands centered in the visible region, emission peaks between 450–580 nm and lifetimes ranging from 3.00 to 24 ns, in the solvents studied. The electrochemical behaviour of the derivatives showed processes related to the inserted chalcogen atom and the reactive oxygen species (ROS) generation data indicate the preferential formation of singlet oxygen species and superoxide radicals, depending on the chalcogen atom as well as the aryl substituent. The In silico calculations show the characteristic differences between the absorption spectra of Rhodamine and RhoCAT compounds.