Silver(I) complexes with nitrile ligands: new materials with versatile applications

Abstract

In the present study, the structure, thermal stability, conductive properties, and antimicrobial activity of silver(I) complexes with nitrile ligands were investigated. For the construction of the materials, 2 cyanopyridine (2-cpy), 4-cyanopyridine (4-cpy), 1,2-dicyanobenzene (1,2-dcb), and 1,3 dicyanobenzene (1,3-dcb) were used in addition to the silver nitrite and nitrate. Four new compounds were isolated and structurally characterized: one molecular complex [Ag4(1,2-dcb)4(NO3)4], two 1-D coordination polymers [Ag2(2-cpy)2(NO2)2], [Ag3(1,3-dcb)2(NO3)2] and one 3-D coordination polymer [Ag(4-cpy)(NO2)]. The results indicate that the nitrite complexes display good antimicrobial properties against the tested bacterial and fungal strains. The presence of weakly coordinating CN groups increases the release of silver ions into the bacterial and yeast cell environments. Moreover, these materials exhibit unusual electrical properties in thin-layer devices. On the other hand, the nitrite and nitrate counterions give rise to the low thermal stability of the complexes.