Synthesis of Metastable SiIIX2 Solutions (X = F, Cl). A Novel Binary Halide for Synthesis

Thermodynamic data for gaseous SiF2 and SiCl2 known from literature show that these binary subhalides are formed nearly quantitatively at 1376 degrees C and 1076 degrees C, respectively, as products of the reaction of elemental silicon with SiF4 or SiCl4 at 1 x 10(-2) mbar. Applying the co-condensation technique SiF2 as well as SiCl2 can be trapped at -196 degrees C and prepared in synthetic scale. Herein, first analysis of metastable SiF2 and SiCl2 solutions are presented, showing that SiF2 is more reactive than SiCl2 leading to compounds of low boiling point of so far unknown composition. The metastable SiCl2 solution can be used as a SiCl2 source, which is shown by the trapping reaction with Idipp [Idipp = 1,3-bis( 2,6-iPr(2)-C6H3) imidazol-2-ylidene] leading to Idipp-SiCl2. The reactivity of the solution might be fine-tuned by changing the donor opening the door for further applications.