A trigonal coordination of Au(I) phosphane complexes stabilized by O-H ⋯ X (X = Cl - , Br - , I - ) interactions.

In this work, we show that intramolecular hydrogen bonding can be used to stabilize tri-coordinated phosphane-gold(I) complexes. Two molecular structures of 2-(diphenylphosphino)benzoic acid (L) coordinated to a gold(I) atom were determined by single-crystal X-ray diffraction. The linear L-Au-Br shows a standard linear coordination and dimerizes via hydrogen bonds of the carboxylic acid. Upon addition of two additional phosphane ligands the complex [L3 Au]X is formed which is stabilized by three intramolecular -C(O)O-H … X hydrogen bonds as proven by the X-ray structure of the respective chlorido-complex. X-ray powder diffractograms suggest the same structure also for X-  = Br- and I- .

Supplementary Information: The online version contains supplementary material available at 10.1007/s00706-021-02843-2.