Photochemistry of tetrasulfur tetranitride: laser flash photolysis and quantum chemical study

Dissociation Without Detonation: A DFT Analysis of the Thermally Induced Fragmentation of Binary Sulfur-Nitrogen Rings and Cages

Potential thermal dissociation pathways available to binary sulfur nitrides have been explored by density functional theory methods, and the results interpreted in terms of their known thermochemical behavior. The cyclic cation/anion pair S3N3± both undergo concerted (4 + 2) cycloreversions to afford the 3-membered thiadiazirine ring c-NSN and, respectively, the SNS± cation/anions. A similar pathway has been identified for S4N2, leading to S3 and c-NSN. More complex multistep routes for the elimination of c-NSN have been identified for the bicyclic cation/anion pair S4N5±, as well as for the neutral cage structures S4N4 and S5N6. For the S4N5+ cation a transition state for competing skeletal scrambling via a 1,3-nitrogen σ-bond shift has been located. For the multiply charged cations S3N22+ and S4N42+, dissociation mechanisms are driven by charge repulsion effects, affording SNS+/SN+ and S3N3+/SN+ respectively. Channels leading to loss of NS+ from the cyclic cation species S4N3+ and S5N5+ have also been examined, and the possible role of open-chain and cyclic S3N2-based intermediates in the formation of S2N2 during the thermal cracking of S4N4 over silver wool is explored.

Neutral binary chalcogen-nitrogen and ternary S,N,P molecules: new structures, bonding insights and potential applications

Early theoretical and experimental investigations of inorganic sulfur-nitrogen compounds were dominated by (a) assessments of the purported aromatic character of cyclic, binary S,N molecules and ions, (b) the unpredictable reactions of the fascinating cage compound S4N4, and (c) the unique structure and properties of the conducting polymer (SN)x. In the last few years, in addition to unexpected developments in the chemistry of well-known sulfur nitrides, the emphasis of these studies has changed to include nitrogen-rich species formed under high pressures, as well as the selenium analogues of well-known S,N compounds. Novel applications have been established or predicted for many binary S/Se,N molecules, including their use for fingerprint detection, in optoelectronic devices, as high energy-density compounds or as hydrogen-storage materials. The purpose of this perspective is to evaluate critically these new aspects of the chemistry of neutral, binary chalcogen-nitrogen molecules and to suggest experimental approaches to the synthesis of target compounds. Recently identified ternary S,N,P compounds will also be considered in light of their isoelectronic relationship with binary S,N cations.