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Fifteen isomers of [Si,N,C,O]2+ system are obtained at UB3LYP/6-311G(d) and UCCSD(T)/6-311+G(2df) (single-point) levels. The analyses are made for predicting the structures of optimized isomers, while ionic fragments with lower energies are suggested. The calculatedresults indicate that linear isomer SiNCO2+(2П) is thermodynamically the most stable species in [Si,N,C,O]2+ system, followed by linear SiOCN2+ (2П), SiCNO2+ (2П), and SiC(NO) (2A“) with NCO three-membered ring. The order of stability of several kinetically stable isomers is SiNCO2 >SiCNO2+ (2П)>SiOCN2+ >SiC(NO)2+>OSiNC2+ (2П). The obtained results by analyzing the isomerizations and ionic fragment patterns show that the signal peaks of [Si,N,C,O]2+ are attributed to the contribution of linear SiNCO2+ species, which is metastable and can dissociate to the ionic fragments in the mass spectrometry experiments.
Fifteen isomers of [Si, N, C, O] 2+ systems are obtained at UB3LYP / 6-311G (d) and UCCSD (T) / 6-311 + G (2df) (single- point) levels. made for predicting the structures of optimized isomers, while ionic fragments with lower energies are suggested. The calculated results show that linear isomer SiNCO2 + (2П) is thermodynamically the most stable species in [Si, N, C, O] 2+ system, followed by The order of stability of several kinetically stable isomers is SiNCO2> SiCNO2 + (2П)> SiOCN2 + (2П), and SiC (NO) (2A ”) with NCO three-membered ring. ) 2+> OSiNC2 + (2П). The obtained results by analyzing the isomerizations and ionic fragment patterns show that the signal peaks of [Si, N, C, O] 2+ are attributed to the contribution of linear SiNCO2 + species, which is metastable and can dissociate to the ionic fragments in the mass spectrometry experiments.