2016/07/07 by Boris Bazanov, Uzi Geiger, Raanan Carmieli +3 · 5 citations
Chemistry · #Synthesis and Biological Evaluation #Molecular Sensors and Ion Detection #Mass Spectrometry Techniques and Applications
paper · doi:10.1002/anie.201605400
openalex publication_date 2016/07/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/25
Abstract Compelling evidence has been found for the formation and direct detection of the cyclopentazole anion (cyclo‐N 5 − ) in solution. The anion was prepared from phenylpentazole in two steps: reduction by an alkali metal to form the phenylpentazole radical anion, followed by thermal dissociation to yield cyclo‐N 5 − . The reaction solution was analyzed by HPLC coupled with negative mode mass spectrometry. A signal with m / z 70 was eluted about 2.1 min after injection of the sample. Its identification as N 5 was supported by single and double labeling with 15 N, which yielded signals at m / z= 71 and 72, respectively, with identical retention times in the HPLC column. MS/MS analysis of the m / z= 70 signal revealed a dissociation product with m / z= 42, which can be assigned to N 3 − . To our knowledge this is the first preparation of cyclo‐N 5 − in the bulk. The compound is indefinitely stable at temperatures below −40 °C, and has a half‐life of a few minutes at room temperature.