Three new complexes of 1,3-diethyl-2-thiobarbituric acid (C8H11N2O2S, HDETBA) with Li+, Na+, K+ alkali ions were synthesized. The complexes have been prepared by neutralization of 1,3-diethyl-2-thiobarbituric acid with the corresponding metal hydroxide in aqueous solution. The colorless crystals have been investigated using X-ray single crystal and powder techniques and characterized by differential scanning calorimetry, thermogravimetry and infrared spectroscopy. The compounds of MDETBA with M = Li and M = Na crystallize in the monoclinic lattice with a = 10.678(1) Å, b = 7.2687(9) Å, c = 13.202(2) Å, β = 108.841(2)°, Z = 4, V = 969.8(2) Å3, S.G. P21/n and a = 10.534(2) Å, b = 7.604(1) Å, c = 14.186(1) Å, β = 108.964(4)°, Z = 4, V = 1074.6(3) Å3, S.G. P21/n, respectively. Сompound KDETBA crystallizes in the orthorhombic lattice with a = 4.2541(6) Å, b = 14.739(2) Å, c = 16.635(3) Å, Z = 4, V = 1043.1(3) Å3, S.G. P212121. In Li(I) and Na(I) complexes, the DETBA− ion is in cis-configuration and, in the K(I) complex, this ion is in trans-configuration. The reason for the transformation from cis- to trans-configuration has been rationalized.
Радиофизический факультет
The cis-trans isomer transformation spectroscopic and thermal properties of Li, Na, K 1,3-diethyl-2-thiobarbiturate complexes