Tetrakis(4‐amino‐1,2,4‐triazole)platinum(II) Salts: Syntheses, Crystal Structures, and Properties

Transparent crystals comprising the nitrogen‐rich coordination unit [Pt(NH 2 trz) 4 ] 2+ were synthesized with counterions of various sizes but of the same charge (–1), yielding the compounds [Pt(NH 2 trz) 4 ]Cl 2 · 2H 2 O, [Pt(NH 2 trz) 4 ](NO 3 ) 2 and [Pt(NH 2 trz) 4 ](CF 3 SO 3 ) 2 , with NH 2 trz designating 4‐amino‐1,2,4‐triazole. Single‐crystal X‐ray diffraction analysis showed that NH 2 trz coordinates with only the nitrogen atom in 1‐position in all compounds. The [Pt(NH 2 trz) 4 ] 2+ units are stacked such that the platinum atoms form linear arrays with Pt–Pt spacings mostly uncorrelated to anion size. The compound with the smallest anion (Cl – ) has the smallest Pt–Pt spacing (4.72 Å) and shows a quasi‐one‐dimensional structure. Thermal decomposition of the compounds was observed around 200 °C. Electrical conductivity of [Pt(NH 2 trz) 4 ]Cl 2 and [Pt(NH 2 trz) 4 ](SO 3 CF 3 ) 2 was investigated and found to be humidity‐dependent. Finally, [Pt(NH 2 trz) 4 ] 2+ ions obtained by dissolution of the chloride salt are shown to be useful for the synthesis of new compounds such as the Magnus' salt derivative [Pt(NH 2 trz) 4 ][PtCl 4 ].