The present article belongs to the area of organic chemistry, namely, to chemistry of heterocyclic compounds. For the purpose of optimization of a method of synthesis the threecyclic heteroaromatic systems containing a pyridi-ne, thiophen and pyrimidine ring in one molecule, - tetrahydropyridothienopyrimidinon and dihydropyri-dothienopyrimidinon – reaction 3-aminothieno[2,3-b]-pyridine-2-carbokxamides with aromatic aldehydes is studied, some of which contain pharmacolodical groups. Reaction was carried out in the conditions of an acid catalysis – is used p-TsOH. Influence of the nature of solvent (toluene, ethanol, mix ethanol-dimethilform-amide (1:1)) on the course and the direction of reaction are studied. It is established that carrying out reaction in toluene leads to the dihydropyrimidine containing in situation 2 phenyl, 4-bromphenyl deputies. In the presence in a molecule of initial aldehyde of the deputy in orto-situation tetrahydropyrimidine are formed. Use of ethanol mainly leads to formation of a tetrahydro-pyrimidine ring. Boiling of initial substances in mix ethanol-DMF yields the results similar to use of toluene, but time of reaction is reduced twice. The way of receiving the dihydroderivatives short-term boiling of tetrahydropyrimidine is found in mix isopropanol-DMF (a volume ratio of solvents 1:3). Identity of the received substances is proved by method of a thin layer chroma-tography. The structure of the synthesized connections is confirmed with the element analysis. The structure of tertagidropirimidinon and digidropirimidinon is proved with use of data of IK and NMR 1H of the spectral analysis
By the method of the dipole moments the connections of (p-XC6H4)3As=N-C6H4-Y series have been examined. The method of the vector-statistical analysis of the dipole moments helped to define the ranges and directions of the moments of (Сар)3As=N-Cар, (Сар)3As=N и N-Cар series. There has been shown that the substitution of the para-assistants X and Y in aromatic groups doesn't lead to an additional interaction influencing the electronic properties of the (Сар)3As=N-Cар group. The comparative analysis of the (Сар)3Ð=N-Cар (Ð=P, As) group moments specifies the essencial shift of the electron density to Сар(N) when replacing atom P to As
Correlations between experimental dipoles moments and values of the difference of first potentials ionization of atoms and molecules (ΔE) for three -coordinated molecules of types ÐÐ¥3 (Ð=N, P, As, Sb are carried out; X=F, Cl, Br, I ) are described.
Exponential functions of dependence μ= f(ΔE) for rows ÐF3 andÐCl3 are received. Within the valence of shell electron pair repulsion theory it is shown, that the molecular dipole moments can be divided to dipol moments of ions of separate atoms, which, naturally changing, are transferred in the ranks of molecules ÐÐ¥3
The article presents the results of the development of
an alternative model for calculating the values of
atomic radius. A formula was derived for calculating
the atomic radius of the elements of the Periodic
System of DI Mendeleev. The optimal calculation
conditions for the proposed model are found. It is
shown that the curve of the dependence of the value of
the correction coefficient x on the atomic number of
the element in form coincides with the dependence of
the ionization energy on the charge number
The article is devoted to research of binary mixtures of fat acids by means of experimental and calculation methods
The article is devoted to the research of triple mixtures of fatty acids by means of experimental and calculation methods
The article presents the results of studies of changes in
the atomic radii of isotopes of the elements of the
periodic table. With using the mass-radial model of
calculations, the values of atomic radii for isotopes of
chemical elements were obtained. It is shown that the
atomic radius of different isotopes of one element is
different and depends on the mass and radius of the
nucleus. To study the changes in ∆Rav values in the
groups and periods of the Periodic Table of Chemical
Elements, the ∆Rav dependences on the period number
and group number are constructed. It is found that the
values depending on the number ∆Rav period / group
for the d-elements lie in the low ∆Rav values for selements
- in high ∆Rav values, and p-elements - in
average values ∆Rav. It is shown that when the atomic
nucleus is increased by 1 neutron, the atomic radius
increases from 0.01 to 4.76 pm, which is due to the
physical effect inside the atom
Studying natural phenomena in all their diversity,
humanity worked experienced in every field of
science the model of perceiving the world and
methods of obtaining information. The development
of science currently cannot be imagined without
research on the intersection of its regions. This
article presents the results of the automated systemcognitive
analysis of the size of atoms from the
main characteristics that are of research at the
interface of General chemistry elements and
intelligent systems. Dependence of nuclear radius,
mass and of the atom and the charge number are
identical in shape and size, which is probably
connected with the linear increase of these
parameters in the Periodic system of chemical
elements. There is also a similar form of the
dependences of radii of atoms from the factors ex
and x, because these factors are interrelated. The
obtained results of the ask analysis have confirmed
the theoretical assumptions and the formulae of the
dependence of main characteristics of the atom
In the article we have estimated sorption capacity of sorbents and analyzed the factors influencing it; we have also selected the optimal conditions for the sorption process, depending on the circumstances and nature of the treatment facilities. The possibility of purification of oil-contaminated water from heavy metal ions synthesized inorganic sorbent has been shown
Correlations between values of the differences of first
potentials ionization of atoms and molecules (ΔE) and
valency angels α for three coordinated molecules of
types ÐÐ¥3 (Ð=N, P, As, Sb are carried out; X=F, Cl,
Br, I, CH3), and also ÐÐ¥2 (Ð=O, S, Se, Te;
X = CH3, SiH3, GeH3) are described in this article.
It is shown, that the entered value ΔE can serve as
additive measure of change of the valency angle α in
the basic and raised stances. We have also established
that the functional dependences correlate with changes
in the of hybridization of orbitals and the R
parameters characterizing the interaction of electronic
pairs near the central Ð atom