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}-2,6-pyridinedicarboxamide (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(I) interaction are identified, highlighting their relevance for future structural and computational analyses.