Structural and computational evidence of rare synergic N(amide)H•••Au(I) and N(amidate)•••Au(I) secondary bonding interactions

Abstract

This work focusses on weak NH•••Au(I) non-covalent interactions (NCIs), a subject of ongoing debate. It reports the synthesis and characterization of new gold(I) complexes featuring the pincer ligand N,N'-bis{(2-diphenylphosphanyl)phenyl}-2,6pyridinedicarboxamide (L). Rare examples of N(amide)H•••Au(I) interactions in different coordination environments are examined. In the neutral complex [Au(L-H)] (3), both a directional N(amide)H•••Au(I) contact consistent with a metal-centered hydrogen bond, and an uncommon secondary N(amidate)•••Au interaction are identified, highlighting their relevance for future structural and computational analyses.