Synthesis,spectroscopic characterization,and X-ray crystal structure of tris(trimethylsilyl)cyanurate

Tris(trimethylsilyl)cyanurate, C₁₂H₂₇N₃O₃Si₃ (1), has been synthesized and characterized by elemental analysis, IR, Raman, ¹³C and ²⁹Si NMR, and thermogravimetric methods. The molecular and crystal structure has been determined by single crystal X-ray diffraction. This compound crystallized in space group P6₃/m (176), Z = 2 with a = 11.017(2), b = 11.017(2), c = 9.676(3) Å; α = 90°, β = 90°, γ = 120°. The geometry of the molecule is compared with tris(trimethylsilyl)cyamelurate.     

Theoretical interpretation of the vibrational spectra of methyl-substitutedS-triazine

The problems of normal vibrations of mono-, di-, and trimethyl-substituted S-triazine are solved. Assignments of the frequencies of fundamental vibrations for an aromatic ring and methyl groups are suggested. Corrections for methyl substitution for the force constants of S-triazine are determined. The groups of characteristic and noncharacteristic vibrations of the aromatic ring of S-triazine on substitution of hydrogen are established. Saratov State University, 83, Astrakhanskaya St., Saratov, 410601, Russia. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 65, No. 3, pp. 322–325, May–June, 1998.