|
Tetranitrogen is a neutrally charged polynitrogen allotrope of the chemical formula and consists of four nitrogen atoms. Tetranitrogen cation refers to the positively charged ion, , which is more stable than the neutrally charged tetranitrogen and is thus more studied. The structure, stability and properties of these molecules have been of great interest to research scientists in the last ten years. == History == Polynitrogen compounds have been well known and characterized by chemists for many years. Molecular nitrogen () was first isolated by Daniel Rutherford in 1772〔 and the azide ion () was discovered by Theodor Curtius in 1890.〔 Discoveries of other related nitrogenous allotypes during the twentieth century include the aromatic molecule pentazole and the radical molecule . However, none of these complexes could be isolated or synthesized on a macroscopic scale like and azide; it was not until 1999 that a large scale synthesis was devised for a third nitrogen allotrope, the pentazenium () cation.〔 This increased interest in polynitrogen compounds in the late twentieth century was due to the advance of computational chemistry which predicted that these types of molecules could be used as potential high energy density matter (HEDM) sources.〔 The cation was first discovered in 1958 upon analysis of anomalous background peaks of molecular weight 56+ and 42+ in the mass spectra of molecular nitrogen, which corresponded with formation of and , respectively.〔 Explicit synthesis of was first carried out in 2001 by a similar mechanism of electron bombardment of .〔 Theoretical chemistry predicted several possible synthesis mechanisms for including reaction of a neutral N atom with a radical, binding of two molecules in the excited state, and extrusion from polycyclic compounds, none of which could be accomplished experimentally. However, in 2002 a method for synthesis of tetranitrogen was devised from the deionization of through neutralization-reionization mass spectrometry (NRMS).〔 In the synthesis, (which was first formed in the ionization chamber of the mass spectrometer) underwent two high energy collision events. During the first collision, contacted a target gas, , to yield a small percentage of neutral molecules.〔 : A deflecting electrode was used to remove any unreacted ions as well as the target gas, , and any additional unintended reaction products, leaving a stream of molecules. In order to affirm the synthesis and isolation of , this stream then underwent a second collision event, contacting a second target gas, , reforming the cation.〔 : The disappearance and reemergence of this "recovery peak" confirms the completion of both reactions, providing ample evidence for the synthesis of by this method. Because the "flight time" between the two reactions, carried out in separate chambers of the mass spectrometer, was on the order of 1 μs, the molecule has a lifetime of at least this long.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tetranitrogen」の詳細全文を読む スポンサード リンク
|