Isolation of a Cationic Platinum(II) sigma-Silane Complex

The platinum complex [Pt((IBuPr)-Bu-t-Pr-i')((IBuPr)-Bu-t-Pr-i)][BArF] interacts with tertiary silanes to form stable (<0 degrees C) mononuclear Pt-II sigma-SiH complexes [Pt((IBuPr)-Bu-t-Pr-i')((IBuPr)-Bu-t-Pr-i)(eta(1)-HSiR3)][BArF]. These compounds have been fully characterized, including X-ray diffraction methods, as the first examples for platinum. DFT calculations (including electronic topological analysis) support the interpretation of the coordination as an unusual eta(1)-SiH. However, the energies required for achieving a eta(2)-SiH mode are rather low, and is consistent with the propensity of these derivatives to undergo Si-H cleavage leading to the more stable silyl species [Pt(SiR3)((IBuPr)-Bu-t-Pr-i)(2)]-[BArF] at room temperature.