Localized molecular orbital studies of three-, four-, five-, and six-membered ring molecules and ions formed from sulfur and nitrogen

Notes on Valence Bond Structures for S2N2 and Related Systems

“…In refs. [15][16][17][18][19][20][21] for example, consideration is given to VB structures III and IV (without thin bond lines for fractional electron-pair p-bonds). Inspection of III$IV shows that this resonance must exclude the SÀS singlet diradical structure 2 from its set of component Lewis structures, which are 1 and 3-6 and four undisplayed VB structures (labeled as 7-10) with p-electron occupancies Similarly, V$VI excludes the NÀN singlet diradical structure 1 from its set of component Lewis structures, which are 2 and 3-10.…”

“…One of them involves giving equal weight to each of III-VI, and using the parameters k 1 and k 2 for the bonding orbitals in structures III and IV, and k and l for the bonding orbitals in structures V and VI. We shall not pursue here either this matter, or an examination of the VB structure [21] VII (Figure 6). …”

Activation of Small Molecules by Phosphorus Biradicaloids

“…Another way to stabilize biradicals is achieved by isolobal substitution of carbon atoms by suitable main group elements [2,8,9] or through the introduction of moieties adjacent to the radical centers allowing delocalization. [10][11][12] However, all these approaches come at the expense of a decrease of biradical character. Singlet biradicaloids usually display a small energy gap between their lowest energy singlet and triplet state.…”

Experimental Observation of the 16‐Electron Molecules SPN, SNP, and Cyclic PSN

“…[3] The recent direct observation of diatomic PN in supergiant star VY CMa [4] suggests the existence of more phosphorus molecules in the presence of oxygen or sulfur. Moreover, elusive species such as N 2 S, [5,6] P 2 O/P 2 S, [7,8] and OPN/SPN [9,10] have been of great interest. Dinitrogen sulfide (N 2 S), first produced by the thermolysis of thiatriazoles, was confirmed to be a linear molecule with sulfur at the terminal position.…”

“…Dinitrogen sulfide (N 2 S), first produced by the thermolysis of thiatriazoles, was confirmed to be a linear molecule with sulfur at the terminal position. [5,6] The diphosphorus compounds P 2 O [7] and P 2 S [8] have first been identified in solid argon matrices by its P = O stretching vibration (1270.4 cm À1 ) and the isotope pattern of the P=S mode ( 32 S: 891.4 cm À1 , 34 S: 887.8 cm À1 ), respectively. Both adopt a linear structure featuring a terminal PP bond.…”