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Mixed acyl dihydroquercetin derivatives were synthesized for the first time. The cytotoxicity of the acylation products of this flavonoid was determined against cultures of HeLa tumor cells and murine fibroblasts.

Starting from 2,2-di-(p-hydroxyphenyl)propane and phenylphosphonic acid tetraethylamide we have prepared the first oligoarylenephosphonites with spatially separated phosphorus functionalities. We have studied the principal chemical properties of these compounds. We have shown the capacity of oligoarylenediphosphonites to coordinate with transition metals through one or all phosphorus atoms with formation of mono- and oligo complexes. We have found that monocomplexes can undergo degenerated metallotropic rearrangements.

The hydrolytic activity of ethriol phosphite and triphenyl phosphite in the p-xylene/water two-phase system was studied by the31P NMR method. It was shown that the rate of hydrolysis can be controlled by varying the pH of the aqueous phase. Hydrolysis of triphenyl phosphite is much slower than that of ethriol phosphite in the tested pH range. Coordination of ethriol phosphite with a rhodium carbonyl complex completely suppresses its hydrolysis.

Complexes of cuprous phenylacetylenide (CPA) were obtained with various amides of phosphorous acid, which are cubane-like tetramers (PhC=CCuL)4. Copper is coordinated at the phosphorus atom in these complexes. The coordination shift of the ligands in the31P NMR spectra are directly dependent on the electronegativity of the heteroatoms at phosphorus.

1. The chemical shift of the OH group of the phenol monomer was determined. 2. In phenolinert solvent systems a monomer-trimer equilibrium is observed, with the exception of low concentrations of phenol (~0.03 mole fraction). 3. The chemical shift of the signal of the OH group of the phenol trimer depends on the temperature. 4. The solvent CCl4 is not entirely inert. 5. The constants and thermodynamic parameters of association in systems of phenol and in inert solvent were determined. 6. In all the systems studied the enthalpy remains constant, while the entropy varies from system to system.

The δ (C13) values of the ring carbon atoms for the C13-NMR spectra of 3-methylsydnone and 3-methylsydnoneimine, described for the first time, are compared with the values calculated by the Karplus-Pople method. The interrelationship between the δ(C13) values of conjugated carbocycles, heterocycles, alkenes, and a number of carbonyl-containing compounds and the effective charges of the corresponding carbon atoms calculated by the complete neglect of differential overlap (CNDO/2) method is analyzed thoroughly.

1. The thermodynamic parameters of the reactions for the formation of the complexes of p-chloro- and p-fluorophenol with a number of oxygen-containing donors (pyridine N-oxide, phosphoryl derivatives, triethylamine) were determined. The thermodynamics of these reactions obeys the linear relation between ΔH° and ΔS° that is general for donor-acceptor complexes. 2. The chemical shifts of the hydroxyl protons of the monomeric p-chloro- and p-fluorophenol molecules and of their complexes were determined. Based on an analysis of these shifts it was concluded that the formation of the hydrogen bond O-H... D leads to a decrease in the electron density on the hydrogen atom, which is greater the higher the energy of the H bond (in the energy range from 0 to 12 kcal/mole).