Experimental detection of tetranitrogen.

Area of Science:

• * Chemistry, specifically theoretical and experimental inorganic chemistry.
• * Molecular physics and spectroscopy.

Background:

• * Tetranitrogen (N4) has been a molecule of significant theoretical interest due to its unusual bonding and potential as a high-energy material.
• * Previous research has focused on theoretical calculations, with experimental verification being challenging.

Purpose of the Study:

• * To experimentally prepare and detect tetranitrogen (N4) as a neutral molecule.
• * To investigate the molecular geometry and fragmentation patterns of N4.

Main Methods:

• * Neutralization-reionization mass spectrometry was employed for the detection of N4.
• * Analysis of the fragmentation patterns of isotopically labeled nitrogen molecules, (14)N2(15)N2, was used to infer structural information.

Main Results:

• * Tetranitrogen (N4) was successfully prepared and detected as a gaseous metastable molecule with a lifetime exceeding 1 microsecond.
• * The neutral N4 molecule was found to possess an open-chain geometry, consisting of two closely bound N2 units linked by a weaker bond.
• * The N4+ cation's geometry was also examined in relation to the neutral molecule's structure.

Conclusions:

• * The experimental synthesis and detection of tetranitrogen (N4) confirm its existence as a metastable molecule.
• * The determined open-chain structure provides crucial insights into the bonding of nitrogen allotropes.
• * This study opens avenues for further research into the properties and applications of novel nitrogen compounds.