Dinitrogen difluoride
Dinitrogen difluoride is a chemical compound with the formula N2F2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition product of the azide N3F. It has the structure F-N=N-F and exists in both a cis- and trans-form. The cis configuration lies in a C2v symmetry and the trans-form has a symmetry of C2h. These isomers are thermally interconvertible but can be separated by low temperature fractionation. The trans-form is less thermodynamically stable but can be stored in glass vessels. The cis-form attacks glass over a time scale of about 2 weeks to form silicon tetrafluoride and nitrous oxide: