The Quantitative Evaluations of the Luminescent Sensing Ability to Cu2+ Based on Two Homologous Crystalline Coordination Polymers

Abstract

AbstractA systematic study has been well conducted on two new homologous Cd(II)‐based luminescent coordination polymers (LCPs), [Cd3(Httac)2(H2O)8]⋅(H2O)2 (1) and [Cd2(ttac)(H2O)6]⋅(H2O)6 (2), (H4ttac=1,1′,2′,1′′‐terphenyl‐4,4′,4′′,5′‐tetracarboxylic acid), to explore their sensing mechanisms to Cu2+. Both 1 and 2 are able to respond to Cu(NO3)2 through luminescent quenching but with the distinct quenching modes. The Stern‐Volmer curves of 1 and 2 both deviate from the linearity, indicating the coexistence of the dynamic and static quenching. Concentration‐dependent lifetime experiments have been carried out carefully to confirm the dynamic quenching and to calculate the dynamic constants quenching Kc; the static quenching is supported by time‐dependent intensity measurements where the intensities of 1 decrease along with time, while for 2, it's a constant in time; the corresponding constants Ks have also been obtained, thus achieving the quantitative evaluations of quenching processes. More importantly, the relationships between the sensing efficiency and inherent structures of two LCPs have been discussed, and the promotion suggestions have also been given finally.