title: On copper(I) fluorides, the cuprophilic interaction, the preparation of copper nitride at room temperature, and the formation mechanism at elevated temperatures.
abstract: Our attempts to synthesize the hitherto unknown binary copper(I) fluoride have led to first successes and a serendipitious result: By conproportionation of elemental copper and copper(II) fluoride in anhydrous liquid ammonia, two copper(I) fluorides were obtained as simple NH3 complexes. One of them presents an example of ligand-unsupported "cuprophilic" interactions in an infinite [Cu2 (NH3 )4 ](2+) chain with alternating Cu-Cu distances. We discovered that both copper(I) fluorides can easily be converted into Cu3 N at room temperature, just by applying a vacuum. Additionally, we investigated the formation mechanism of the classical synthesis route of Cu3 N that starts with CuF2 and flowing NH3 in the temperature range between ambient and 290 °C by means of thermal analysis and in situ neutron diffraction. The reaction proceeds at elevated temperatures through the formation of a blue and amorphous ammoniate Cu(NH3 )2 F2 , the reformation of CuF2 , and finally the redox reaction to form Cu3 N.
authors.affiliation: Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg (Germany) http://www.uni-marburg.de/fb15/ag-kraus/
authors.forename: Patrick
authors.initials: P
authors.lastname: Woidy
authors.forename: Antti J
authors.initials: AJ
authors.lastname: Karttunen
authors.forename: Marc
authors.initials: M
authors.lastname: Widenmeyer
authors.forename: Rainer
authors.initials: R
authors.lastname: Niewa
authors.forename: Florian
authors.initials: F
authors.lastname: Kraus
keywords: copper; cuprophilic interactions; fluorides; nitrides; structure elucidation