Molecular CsF5 and CsF2+

D_5h star‐like CsF₅, formally isoelectronic with known XeF₅⁻ ion, is computed to be a local minimum on the potential energy surface of CsF₅, surrounded by reasonably large activation energies for its exothermic decomposition to CsF+2 F₂, or to CsF₃ (three isomeric forms)+F₂, or for rearrangement to a significantly more stable isomer, a classical Cs⁺ complex of F₅⁻. Similarly the CsF₂⁺ ion is computed to be metastable in two isomeric forms. In the more symmetrical structures of these molecules there is definite involvement in bonding of the formally core 5p levels of Cs.     

Nitryl Cyanide,NCNO2

The elusive nitryl cyanide, NCNO₂, has been synthesized and characterized. It was prepared in good yield, isolated by fractional condensation, characterized by NMR and vibrational spectroscopy, and studied by theoretical calculations. Nitryl cyanide holds promise as a high energy density material (HEDM) and might also prove useful as a HEDM building block. The simplicity and inherent stability of nitryl cyanide, together with the known multitude of nitriles in interstellar space, suggest that the compound might also be a potential candidate for observations in atmospheric and interstellar chemistry.