ABSTRACT
The crystal structure of [C(n)mim]NTf(2) (n = 2, 4, 6) was studied for the first time simultaneously by X-ray diffraction method and IR spectroscopy. The temperature-dependent IR spectrum for crystalline [C(4)mim]NTf(2) was demonstrated to correlate with both the X-ray data and the calorimetric results obtained earlier. Therefore, it was found that IR spectroscopy is able to establish the correspondence between the X-ray and the calorimetric data in this case. The joint use of X-ray diffraction, IR spectroscopy, and quantum-chemical calculations allowed us to determine the structure of all [C(2)mim]NTf(2) crystalline modifications obtained earlier by adiabatic calorimetry measurements. Thus, a new approach for the future identification of ionic liquid crystal structure by use of temperature-dependent infrared spectroscopy is suggested and justified.
ABSTRACT
A reductive transformation of the peroxide products of ozonolysis of derivatives of 3beta-O-acetyl-22(17-->28)-abeo-lupa-17(28),20(29)-diene and the subsequent intramolecular ketalization led to a compound with a trioxane fragment. This is a new approach to a skeletal modification of triterpenoid cycle E. An activity of the synthesized compounds was found toward the viruses of type A influenza and herpes simplex.
