Reaction of the thermo-labile triazenide Na[tBu3SiNNNSiMe3] with CO2: formation of the imido carbonate (tBu3SiO)(Me3SiO)CN-SitBu3 and carbamine acid (tBu3SiO)CONH2

Abstract

The thermo-labile triazenide Na[tBu₃SiNNNSiMe₃] was prepared by the reaction of Me₃SiN₃ with Na(thf)₂[SitBu₃] in pentane at −78 °C. Treatment of Na[tBu₃SiNNNSiMe₃] with an excess of carbon dioxide in pentane at −78 °C yielded the imido carbonate (tBu₃SiO)(Me₃SiO)CN-SitBu₃ and the carbamine acid (tBu₃SiO)CONH₂ along with other products. From the reaction solution we could isolate the imido carbonate (tBu₃SiO)(Me₃SiO)CN-SitBu₃ and carbamine acid (tBu₃SiO)CONH₂. At first single crystals of the carbamine acid (tBu₃SiO)CONH₂ (triclinic, space group P) were grown from this solution at room temperature. A second crop of crystals were obtained by concentrating the solution. The second charge consisted of the imido carbonate (tBu₃SiO)(Me₃SiO)CN-SitBu₃ (monoclinic, space group P2₁/n).