abstract the influence of cation?? and anion?? interactions on the strength and nature of n…h hydrogen bond has been investigated by quantum chemical calculations in s-triazine…3hf complex. ab initio calculations were performed at mp2/6-311++g(d,p) level of theory. the natural bond orbital (nbo) analysis and the bader’s quantum theory of atoms in molecules (aim) were also used to elucidate the interaction characteristics of these complexes. for better understanding the geometrical changes in these complexes, bonding parameters were calculated as bond orders from natural resonance theory (nrt) calculations. it is found that the continuum of n…h interactions ranging from weak to medium hydrogen bonds is observed in investigated systems. also with regard to ion type, proper and improper hydrogen bonds have been observed. keywords: cation–?, anion–?, hydrogen bond, s-triazine, ab initio