Implications of the Crystal Structure of the Ammonia Solvate [Au(NH3)2]Cl·4NH3

Abstract

Crystals of diammine gold(I) chloride ammonia (1/4), [Au(NH(3))(2)]Cl·4NH(3), have been grown from solutions of AuCl in liquid ammonia. The X-ray diffraction analysis (at 123 K) has shown that the crystals feature an extensive network of hydrogen bonds between the [H(3)N-Au-NH(3)](+) cations (with C(i) symmetry) and the Cl(-) anions, including also the ammonia molecules. There is no evidence for an emerging increase of the coordination number of the gold atom by adopting another ammonia molecule or by approaching a chloride anion. Moreover, the geometry of two distant and angular N-H···Au contacts is not a strong support of hydrogen bonds recently amply discussed in the literature.