Compatibility of a Gaseous Dielectric with Al, Ag, and Cu and Gas‐Phase Synthesis of a New N‐Acylamidine Copper Complex

Herein we describe the compatibility of 2‐(trifluoromethyl)‐2,3,3,3‐tetrafluoropropane nitrile, an insulating gas for gas‐insulated equipment, with aluminum, silver and copper. In an autoclave metal samples, oxygen, the gaseous 2‐(trifluoromethyl)‐2,3,3,3‐tetrafluoropropane nitrile and a small amount of water were mixed at elevated pressure and heated up to 225 °C for several weeks. When Cu was present a multi‐step gas phase reaction occurred, and single crystals of a copper complex were isolated. The square planar copper(II) complex contains two perfluorinated N‐acylamidine ligands. The structure of the complex was obtained by single‐crystal X‐ray diffraction. A new N‐acylamidine copper complex was observed when 2‐(trifluoromethyl)‐2,3,3,3‐tetrafluoropropane nitrile, a new insulating gas for gas‐insulated equipment, was brought in contact with copper in the presence of oxygen and small amounts of water. The new complex offers interesting properties; however, in gas‐insulated high voltage equipment such complex formation by reaction of the insulating gas should be avoided.