Effect of the Pyridyl Orientation on Coordination Assembly: Construction of Ag(I) Coordination Polymers with Electrochemical and Antibacterial Behaviors

Three racemic ligands ( L 1 – L 3 ) containing 1,2-dihydroquinazoline units have been designed and synthesized as a continuation of our previous research work. Six Ag(I) coordination polymers, {[Ag L 1 ]BF 4 ·3MeCN} n ( 1 ), {[Ag 2 ( L 1 ) 2 ](NO 3 ) 2 ·MeCN·H 2 O} n ( 2 ), {[Ag 2 ( L 2 ) 2 (μ 2 –N 2 )](NO 3 ) 2 ·2H 2 O} n ( 3 ), {[Ag 2 ( L 2 ) 2 (μ 2 –N 2 )](BF 4 ) 2 ·2H 2 O} n ( 4 ), {[Ag( L 3 ) 2 ]tosylate·2MeCN·H 2 O} n ( 5 ), and {[Ag 2 ( L 3 ) 4 ](PF 6 ) 2 ·2MeOH} n ( 6 ), were synthesized upon reaction of these ligands with different Ag(I) salts. The structural diversity of the resulting complexes revealed the chiral self-discrimination or self-recognition processes of the racemic ligands when coordinated to Ag(I) ions. More importantly, the pyridyl orientation in the ligands has a crucial effect on the resulting structures of these complexes. In addition, with the combination of the biological activity of the 1,2-dihydroquinazoline derivatives and the redox behaviors of their resulting Ag(I) complexes, we investigated their antibacterial activity against two bacteria ( MDREC and MRSA ), and the synthesized Ag(I) complexes showed satisfactory antibacterial properties.