Mendeleev Chemistry Journal
(Zhurnal Ross.Khim.Ob-va im.D.I.Mendeleeva)
1994, vol.38, No.6
Nemukhin A.V., Weinhold F.
Lewis Concept In Modern Quantum Chemistry.
The results of computational quantum chemistry may be
rationalized in terms of the Lewis structure concept if
the transformation from canonical molecular orbitals to natu
ral bond orbitals is introduced. Applications of this formalism
to various problems including structure of ionic and hyper
valent compounds and treatment of electron correlation
are discussed.
Vishnetskaya M. V., Romanovsky B.V.
Mechanisms of Hydrocarbon Catalytic Conversions:
a new Approach.
Radical cations as reactive intermediates are suggested
to play a key role in such processes as cracking and
alkylation of hydrocarbons as well as of ethano! conversion
whiich occur upon common acidic catalysts. In the frame
of this model, the mechanisms of hydrocarbon isomerisation,
cracking and alkylation are discussed. Molekular oxygen af-
fects substantially the radical-catton pathways of hydro
carbon conversions over silica-aluminas. In protic media, it
may present as the strongly bound singlet species and
presumably mediate the formation of radical cations.
Depending on both the nature of parent molecules and
acid-base properties of reaction media, radical-cation species
makes it possible to initiate a radical or ion pathway.
The protic centers of an acid catalyst are supposed to
govern the ratio between these competing channels of the
process.
Summ B.D.
The Structre of Liquid Surface (Net Hypothesis).
The hypothesis of heterogeneous costruction of surface
layer of pure liquids has been put forward.
We suppose that near the surface a certain amount of
colloid particles is being formed, those accordingly form a
netlike gel structure. This net can provide the mechanical
features of the liquid surface. The net model presents
the synthesis of well known (classical) models of surface
layer, thus it is acceptable for a wide range of surface
phenomena (including the dynamical problems).
The Model points to the co-relation of surface tension
with heat and entropy of melttng. This conclusion is also
well in accordance with experimental data for liquefied inert
gases of alkali metals.
The net model gives the new possibilities for description
of dissipative structures on the liquid surface, that is
of importance for certain biological processes.
Dikhne A. M., Petrii O.A., Tsirlina G.A.
Nanoelectrochemistry and Nanotechnology.
The history of the development of a new scientific
direction -- nanoelectrochemisiry and also its most important
aspects are discussed. Attention is focused on the atomic-
resolution studies of electrochemical interfaces, which became
possible due to the development of the in silu scanning
tunneling microscopy (STM) method and its analogs. It is
shown that the electrochemical version of STM offers
additional possibilities for fundamental physical studies
of tunneling processes. Moreover, the information is summa-
rized on nanocompositions with special properties prepared
by electrochemical methods. Potentialities for the development
of local electroehemical nanotechnologies are analyzed.
Melikhov I.V.
Cristallosensorcs - novel method of investigation of sub-
sfances state.
Crystallization of specially selected substances (crystalli-
zants) have been analyzed for the revealing of supersatura-
tion, temperature, structure and velocity of the medium
where cristallization takes place. The ways for determination
of interaction potential between atoms in solids of crystal
surface energy, of surface complexes formation rates of
atoms mobility in surface zone of crystals and of
structure of near surface liquid layer on the boundary
with solid body have been described. The phenomena
of "morphological memory" and "ultra-molecular crystalliza-
tion" of crystalizants and their application in technology
have been considered. The previously unknown phenomenon
of growth random walk of crystals in supersaturated
vapour have been described.
Trushkov I.V.
Multl-dimensional Reaction Diagrams As a method for
Analysis and Prediction of Organic Reactivity.
The different methods for descripion and prediction
of reactivity are analyzed briefly. It is concluded, that all
methods may be divided into two groups: I) the sample
and visual approaches with small reliability and precision;
2) complicated precise but non-visual calculations.It is
proposed a new method for analysis and prediction of
reactivity-- multi-dimensional reaction coordinate diagrams.
This method may be seen as a bridge between above
two groups of approaches. In this method every reaction
is analyzed as a number of co-processes of bond making/
breaking and appropriate electron density redistribution.
Uning the simple quantitative equations allows to decribe
the mechanisms and kinetics of different organic reactions
with good both visuality and precision.
Babaev E.V.
The Alternation Rule: An Old Heuristic Principle or
the New Conservation Law?
Early concepts and models of polarity alternation along
the chains with polar groups are critically reviewed.The
proposed new model describes alternation along the chains as
the result of specific mutual disposition of Lewis' basic
and acidic centres. ldentical results can be obtained from
both the models of polar dichromatic multigraphs and the
model of "ions in molecule". This gives rise to separate
the specific class of molecules and ions (called "super
consonant"), whose polar dichromatic structure strictly
determines possibility of their presentation as ion assemblage.
The author's quantum chemical AM1 calculations proved
charge alternation even at the structures of non-polar super
consonant molecules and/or their ions. The hypothesis of
"alternation conservation" in ionic processes is claimed,
that permits one to consider the consonant set of molecules
to be closed (for the p-elemenls of 2-row) in relation
to polar reactions. Wide applications of this hypothesis
and rare counterexamples are discussed. Simple genetically
interrelationship among the structures of the super consonant
series is proposed as the model of computer generation
of non-trivial synthetic equivalence types.
Babin V.N, Domaradskii I.V., Dubinin A.V, Kondrakova O.A.
Blochemical and molecular Aspects of Man -- Microflora
Symbiosis.
Molecular and biochemical aspects of interactions between
mammalian organisms (including man) and their microflora
are examined in this paper.
The role of microflora in physiology of the host organism,
in particular, the ability to protect the host from different
infectional agents is discussed.
Analysis of our own and literature data allows to
suggest a number of hypotheses conserning nature and intimate
mechanisms of interaction in microflora -- host system. The
authors develope their own idea about existence of the
balance relations between the components of the host --
microflora system in physiological condittons on different
levels.
Erokhin A.S.
Chemical evolution as a result of the self-development
of opened photocatalytic systems.
It has been considered the script of the chemical evolution,
in which the basic photocatalytic process through
reaction of one of his product (hydrated electron) with medium
generates a lot of organic compounds, which can modify
photocatalyst. The new model of the developing phase
separated system (sulphide vesicle) has been proposed. The
role of abiotic reduction Krebs cycle in pre biological evolution
has been demonstrated. The evolution of matter from
processes occurring on stars to initiation of pre biotic
metaboiism has been considered with point of view of the
theory of generalized catalysis proposed by the author.
Spiridonov V.P.
A Ouantum Field Theory of Electronic-Nuclear Systems.
A survey is given of a quantum field theory of electronic-nuclear
systems developed recently which proceeded from
a continuous distribution of negative electric charge. This
charge was considered as a source of the internal
electromagnetic field suitable coupling between electronic
and electromagnetic fields being ensured. Also, the electronic
distribution was adequately described by a set of quasielectrons
introduced to retain unity between continuous and
discontinuous properties of matter.
First, a non-relativistic scalar field theory was formulated
and a set of quantized non-linear integral-differential
field equations was obtained which exhibited close
similarity to those of Hartree.
In pursuit of a method to adequately account for
spin and magnetic effects the spinor Pauli-like classical
field equation was derived, the vector potential and magnetic
field entering this equation being associated with the
magnetic component of the internal electromagnetic field
generated by the electronic system. A set of quantized
field equations was further obtained provided two groups
of quasi-electrons were iniroduced: the one consisting of
quasi-electrons having a spin orientation associated with the
psi(1)-component of a spinor; the other one consisting of
remaining quasi-electrons having an opposite spin orientation
and associated with the psi(2)-component of a spinor.
In a similar formulation of a relativistic version of a
theory the Klein -- Gordon one-particle equation was taken and
adapted to describe spin-I/2 having particles. First,
this equation was re-formulated to take the Hamiltonian
form and thin a set of quantized relativistic field equations
correct through terms of order l/c(2) and involving an
additional massvelocity term was obtained in a way quite
similar to that of the above non-relativistic spinor version
of a theory.
In conclusion, some probiems of interpretation of quantum
mechanics are briefly discussed.
Zvirblis V.E.
Desigh of the Space of Space Life.
The space where the "arrow of time" exists as a
physical reality and where life and consciousness may originate
is a continuous, uniform, and isotropic material (yet directly
unobservable) medium, a structure lacking mirror symmetry,
the field of space-time torsion. Each point of the medium
has symmetry of pseudoscalar and dimensionality of the
density of energy flow generated by the forceless
field of the vector potential structured as a continuous
infinite-order spiral (three-dimensional fractal). Consideration
is given to experimental situations where the physical
vacuum manifests itself indirectly in macroscopic nonlocal
effects of transfer of energy and information by transferring
the angular momentum, which in physical, chemical, and
biological systems produces changes in the height of the
potential barrier and macrofluctuations featuring the spectrum
of flicker noise.
Voroncova E.R.
Partition of atomic and molecular masses (PAMM).
Atomic and molecular weights (masses) as independent
constants characterizing organic and inorganic substances are
recommended as major key in reference books and information
retrieval system.
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