A comparative study of proton conduction between two new Cd(II) and Co(II) complexes and in vitro antibacterial study of the Cd(II) complex
Yuyan Li, Duqingcuo Li, Tianrui Qin, Zhan Shi, Pengkun Fu, Dingqi Xiong, Xiu‐Yan Dong
Abstract
Two new complexes based on 4,4′‐[1,3‐phenylenebis(oxy)]diphthalic acid (H 4 L) ligands were synthesized, namely, [Cd 2 (L)(1,10‐phen) 2 (H 2 O)] n ( 1 ) and [Co 2 (L)(1,10‐phen) 2 (H 2 O)] n ( 2 ), in which 2D structures transform into 3D supramolecular structures by CH···π interaction. The proton conductivity of complexes 1 and 2 at low temperature is close (σ 1 = 3.12 × 10 −8 S cm −1 and σ 2 = 3.81 × 10 −8 S cm −1 at 30°C), but these two complexes show different conduction mechanisms. The Vehicular mechanism in 1 is caused by the O···H/H···O contact in 1 , which is stronger than 2 , and the Grotthuss mechanism in 2 is caused by the N···H/H···N contact in 2 , which is stronger than 1 . At the same time, complex 1 showed excellent antibacterial properties in vitro, mainly reflected in that five kinds of bacteria ( Escherichia coli , Bacillus amyloliquefaciens , Pantoea agglomerans , Pseudomonas putida , and Pectobacterium carotovora ) could play an obvious inhibitory effect in the concentration range of 20 μg·ml −1 .