Meghdadi, SoraiaAmirnasr, MehdiKiani, MahsaTirani, Farzaneh FadaeiBagheri, MaryamSchenk, Kurt Job2017-09-052017-09-052017-09-05201710.1080/00958972.2017.1336231https://infoscience.epfl.ch/handle/20.500.14299/140365WOS:000406491100005Two carboxamide ligands, H(2)bqbenzo {3,4-bis(2-quinolinecarboxamido)benzophenone} and H(2)bqb {N,N-bis[(2-quinolinecarboxamide)-1,2-benzene]}, have been prepared using tetrabutylammonium bromide as an environmentally benign reaction medium. Two new Pd(II) complexes, [Pd-II(bqbenzo)] (1) and [Pd-II(bqb)] (2), have been synthesized, characterized, and their structures determined by single crystal X-ray diffraction. The di-anionic ligands, bqbenzo(2-) and bqb(2-), are coordinated via two N-amide atoms and the nitrogens of the two quinoline rings, with Pd-N-amide<Pd-N-quinoline bond lengths. The geometry around palladium(II) in both complexes is distorted square planar. The electrochemical behaviors of the ligands and their Pd(II) complexes have been investigated by cyclic voltammetry in DMF. An irreversible Pd-II/I reduction is observed at -1.06V for 1 and at -1.177V for 2, indicating the influence of the R substituent on the central phenyl ring of carboxamide ligands on the Pd-II/I reduction potential. The ligands and palladium complexes were also screened for in vitro antibacterial activity. The Pd(II) complexes show strong biological activity against S.typhi and E.coli as Gram -ve and B.cereus and S.aureus as Gram+ve bacteria comparable to the antibiotic penicillin. The antibacterial results also reveal that coordination of Pd(II) significantly improves the activity. [Graphics] .Carboxamide ligandsPd(II) complexesX-ray crystal structurecyclic voltammetryantibacterial activitytext::journal::journal article::research article