A photoelectron spectroscopic and theoretical study of the halogen and hydrogen thiocyanates and isothiocyanates

Studies on Reactions INCX → IXCN (X = O, S, and Se)

The reactions of INCO to IOCN, INCS to ISCN, and INCSe to ISeCN have been studied at the MP2/6-311++G(2df)//B3LYP/6-311++G(2df) level. Geometries of reactants, transition states, and products have been optimized, and geometries of transition states are reported for the first time. The reasons that INCO, ISCN, and ISeCN are easily detected instead of IOCN, INCS, and INCSe have been explained successfully. The breakage and formation of chemical bonds along the reaction paths have been discussed by the topological analysis method of electronic density. The calculated results show that there are two kinds of structure transition states (STS) in the reactions studied.

Preparations of Pure ISeCN, ISCN, and INCO

Pure INCO, ISCN, and the hitherto unknown molecule ISeCN have been prepared in the HeI photoelectron spectrometer (PES) by the heterogeneous reactions of ICl gas with AgNCO, AgSCN at room temperature, and AgSeCN at -9 (+/- 1) degrees C, respectively. They were characterized on line by PES experiments and OVGF calculations. The well-matched results between the PES experiments and OVGF calculations not only show that the new reaction is a good reaction to prepare pure INCO and pure ISCN, but also that the new compound prepared by passing the ICl gas over the freshly AgSeCN powder at -9 (+/- 1) degrees C is the hitherto unknown ISeCN.