Formation and structure of two luminescent salts of [Au(SCSN3)2]− obtained through the [2 + 3] cyclization of carbon disulfide and azide ionCCDC 988198 and 988199. For crystallographic data in CIF or other electronic format see DOI: 10.1039/c4dt01902d

• Main Authors: Lim, Sang Ho, Schmitt, Jennifer C, Shearer, Jason, England, Kellie R, Olmstead, Marilyn M, Balch, Alan L
• Format: Journal Article
• Language: English
• Published: 19.08.2014
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/c4dt01902d

The colorless, two-coordinate gold( i ) complex, [(H 2 O) 3 Na][Au(SCSN 3 ) 2 ], has been synthesized through the [2 + 3] cyclic reaction of carbon disulfide and sodium azide in the presence of the labile complex (tht)AuCl. Metathesis of [(H 2 O) 3 Na][Au(SCSN 3 ) 2 ], with tetra(phenyl)arsonium chloride produced colorless needles of (Ph 4 As)[Au(SCSN 3 ) 2 ]. The structure of [(H 2 O) 3 Na][Au(SCSN 3 ) 2 ] involves linear gold coordination by two exocyclic sulfur atoms of the 1,2,3,4-thiatriazole-5-thiolate anions. These two-coordinate anions self-associate to form extended, zig-zag chains that are connected by aurophilic bonding with Au Au distances of 3.2653(3) Å and 3.3090(3) Å. Remarkably, the individual S-Au-S units that are connected though aurophilic interactions are eclipsed. The structure of (Ph 4 As)[Au(SCSN 3 ) 2 ] also contains linear, two-coordinate gold ions with bonding to the 1,2,3,4-thiatriazole-5-thiolate anionic ligands through the exocyclic sulfur atoms. However, in this salt, the anions self-associate through Au Au bonds (Au Au distance of 3.2007(3) Å) to form simple dimers, which also have an eclipsed arrangement of the ligands. Electronic structure calculations strongly suggest that the staggered geometry for the [(Au(SCSN 3 )) 2 ] + dimer is energetically favored relative to the eclipsed geometry. However, attractive π-stacking interactions appear to promote the observed eclipsed arrangement of the ligands. The salts, [(H 2 O) 3 Na][Au(SCSN 3 ) 2 ] and (Ph 4 As)[Au(SCSN 3 ) 2 ] contain anions that associate through aurophilic interactions and adopt an unusual eclipsed arrangement of the ligands as seen in the illustration.