Stabilization of gold(III) with bis(pyrazol-1-yl)amine

Bis(3,5-R2pyrazol-1yl)amine (R = H (L1), Me (L2), tBu (L3)) reacts with H[AuCl4] to form the three salts [AuL1][AuCl4]2 (1), [AuL2][AuCl4]2 (2) and [AuL3]Cl2 (3) respectively. The composition of these salts was established via mass spectrometry and microanalysis and confirmed by single crystal X-ray studies for 2. Room temperature 1H NMR spectrum of these salts after a D2O wash showed two triplets for the inequivalent CH2 groups in the ligand backbone, while prior to the D2O washing the 1H NMR spectrum indicated interactions of the amine proton with this two CH2 groups.