First evidence of unhindered silanimines obtained by flash vacuum thermolysis and vacuum gas‐solid reaction

Abstract

The unhindered silanimines 1,1‐dimethyl‐N‐phenylsilanimine (2) and N‐isopropyl‐1,1‐dimethylsilanimine (10) have been generated by flash vacuum thermolysis of the N‐allylsilanamine 1 and vacuum gas‐solid reaction of the 1‐chlorosilanamine 9, respectively. The silanimines 2 and 10 have been characterized by MS as well as by chemical trapping to yield 3 or dimerization to the cyclodisilazane 11.

Gas-Phase Characterization of Unhindered Silanimines by Photoelectron Spectroscopy: Experimental and Theoretical Study of the SiN Double Bond1

“…Reported methods have been used for the synthesis of precursors 2b , 2c and 2d , and 3d 6 . 1-Isopropyl-2,2,3-trimethyl-1-aza-2-silacyclobutane ( 3c ) has been prepared, in the way described for 3d , from N -allyl- N -isopropyl-1,1-dimethylsilanamine and purified by GC at 120 °C on a SE30 column [ 1 H NMR (CDCl 3 ): δ = 0.20 (s, 3 H), 0.25 (s, 3 H), 0.96 (d, J = 6.3 Hz, 6 H), 1.10 ((d, J = 7.6 Hz, 3 H), 1.53 (ddq, J = 8.4, 7.6 and 5.2 Hz, 1 H), 2.80 (dd, J = 6.3 and 5.2 Hz, 1 H), 2.83 (hept, J = 6.3 Hz, 1 H), 3.55 ppm (dd, J = 8.4 and 6.3 Hz, 1 H). 13 C NMR: δ = −0.84, 2.84, 15.00, 17.57, 22.99, 48.52, 55.84 ppm].…”

Flash Vacuum Thermolysis: First Gas-Phase Generation of Unhindered Silylidenephosphanes and Characterization by Photoelectron Spectroscopy

“…In the last two decades, the use of flash vacuum thermolysis (FVT) has allowed the observation of many reactive, monomeric species having a double-bonded silicon atom, and we have reported the generation by FVT of several unstabilized silanimines , as well as, very recently, their unambiguous characterization by photoelectron spectroscopy (PES) . Our investigations have pointed out the usefulness of cyclodisilazanes and azasilacyclobutanes as precursors of these silanimines.…”

Flash Vacuum Thermolysis Synthesis of New Reactive Compounds Containing a Silicon−Heteroatom Double Bond

“…Upon FVT, compounds 1 (thermally too stable) and 2 (which more easily gave the N-silylated imine 4), proved to be poor precursors of N-isopropylsilanimine 5. Compound 5 was, however, obtained [19] by dehydrochlorination of the corresponding chlorosilanamine under VGSR (vacuum gas-solid reaction) conditions [20] (Scheme 2). On the other hand, FVT of 3 yielded, as expected, N-phenylsilanimine 6, characterized in the gas phase by FVT/HRMS, and by its adduct 7 with tert-butyl alcohol.…”

“…On the other hand, FVT of 3 yielded, as expected, N-phenylsilanimine 6, characterized in the gas phase by FVT/HRMS, and by its adduct 7 with tert-butyl alcohol. [19] The relative ease of formation of a CϭN double bond, compared to an SiϭN one, as observed in the case of 2, has been also exploited in the synthesis by FVT of the reactive methanimine H 2 CϭNϪSiMe 2 H. [21] Scheme 2…”