{Ba[Au(SCN) 2 ] 2 } n : a three-dimensional net comprised of monomeric and trimeric gold(I) units

The noteworthy structural feature of the title complex, poly[acetonitrile­tetra-μ 2 -thio­cyanato-barium(II)digold(I)], {[Au 2 Ba(SCN) 4 (CH 3 CN)]} n , is that the bis­(thio­cyanato)­aurate(I) anion adopts both monomeric and trimeric motifs. The trimer unit has an Au⋯Au distance of 3.1687 (3) Å. In both the monomeric and trimeric units, the Au I atoms are also bonded to two S atoms. Within the trimeric unit, the Au I atoms exist in differing environments; one Au atom has a T-shaped three-coordinate geometry while the other has a square-planar four-coordinate geometry. The Au I atom of the monomer adopts a linear two-coordinate geometry. The extended structure can be described as a three-dimensional coordination polymer consisting of chains of Ba atoms bridged by thio­cyanate N atoms. These chains are cross-linked via the gold monomeric and trimeric units.