Rhodamine tethered 1,1’-unsymmetrical ferrocene functionalization: Metal sensing, cell imaging and logic gate properties

Abstract

Selective funtionalization of ferrocenyl species with fluorescent active rhodamine moiety using a solvent free solid state method led to the synthesis of 1,1’- unsymmetrical ferrocene based turn-on fluorescent hydrazone molecular system, 1,1’-[CH3C(O)(η5-C5H4)Fe{(η5-C5H4)C(CH3)N-NC(O)-X}], (X = Rhodamine-6G) (1) and 1,1’-[HC(O)(η5-C5H4)Fe{(η5-C5H4)C(H)N-NC(O)-X}], (X = Rhodamine-6G (2), Rhodamine-B (3)). The unsymmetrical molecular system was structurally characterized by single crystal X-ray diffraction crystallography. Their fluorescence based signaling and sensing behavior has been explored with metal cations to observe remarkable fluorescence enhancement capabilities in the intracellular matrix. The interaction behavior of the unsymmetrical ferrocene based rhodaminyl organometallic receptor has been established by DFT study and spectroscopic analysis. The study showed some significant intracellular metal recognition and imaging characteristics to understand their potential in applications related to bioimaging of heavy metal ions. Molecular logic Gate property was also studied corresponding to INHIBIT, OR and a combinational logic operations using the fluorometric molecular compound.