4712-49-6Relevant academic research and scientific papers
THE SYNTHESIS AND STRUCTURE OF 4,6-DIOXOPYRIMIDO-2,1,3-THIADIAZOLES
Kravtsov, V. Kh.,Chumakov, Yu. M.,D'yachenko, S. A.,Biyushkin, V. N.,Bureneva, M. I.,Malinovskii, T. I.
, p. 311 - 317 (1990)
Synthesis and spectral indices were reported for four 4,6-dioxopyrimido-2,1,3-thiadiazoles.An x-ray diffraction structural analysis carried out using an automatic diffractometer, λMoKα radiation, 1433 reflections yielded the structure of 4,6-dioxo-5,7-dimethylpyrimido-2,1,3-thiadiazole (R = 4.7percent, Rw = 5.0percent).The molecule, with the exception of the methyl group hydrogen atoms, is planar.Bond delocalization is found within the heterocycles.A CNDO/2 calculation using the spd basis taking account of all the valence electrons showed that the sulfur 3d orbitals playa significant role in the formation of the S-N bonds.Anomalously short intermolecular S...O (3.033 Angstroem) and C...O contacts (2.914 Angstroem) were found in the crystal structure.
