scholarly journals Halogen bonding in iron(II) and cobalt(II) tris(dichloroglyoximates)

2014 ◽  
Vol 70 (a1) ◽  
pp. C679-C679
Author(s):  
Anna Vologzhanina ◽  
Konstantin Lyssenko

The understanding of the interplay between intermolecular strong and weak interactions requires approaches that are able to identify and quantify all of them, and are applicable to as large number of objects as possible. The QTAIM approach [1] nicely meets the first criteria. Less rigorous approaches, such as the Stockholder [2] and the Voronoi [3] partitioning have the second advantage. The latter can also give qualitative, quantitative and visual representation of intermolecular interactions. We compared how all these approaches would perform for two polymorphs of Fe(Cl2Gm)3(BCH3)2 (monoclinic C (1a), and less stable monoclinic P (1b)) and Co(Cl2Gm)3(BCH3)2 (2) isostructural with 1b (Cl2Gm = dichloroglyoximate). The Voronoi and Stockholder partitionings showed that three fourths of molecular surfaces were attributed to Cl...X (X = Cl, O, N) and C-H...Cl bonds. According to the QTAIM theory, each chlorine atom takes part in at least four intermolecular contacts. The Voronoi tessellation was found to be valid for determinating of the graph of intermolecular bonding. Indeed, in the isostructural 1b and 2 the sets of weak interactions do not coincide due to various conformations of iron- and cobalt-containing clathrochelate cages. Nevertheless, the resulting graph of intermolecular bonding (the gpu-x net) is the same. Qualitative (for all three approaches) and quantitative (for two partitionings) correlation for various methods was demonstrated. This study was supported by the Council of the President of the Russian Federation (MK-5181.2013.3 and MD- 3589.2014.3).

2010 ◽  
Vol 63 (12) ◽  
pp. 1598 ◽  
Author(s):  
Jane S. Murray ◽  
Kevin E. Riley ◽  
Peter Politzer ◽  
Timothy Clark

The prototypical directional weak interactions, hydrogen bonding and σ-hole bonding (including the special case of halogen bonding) are reviewed in a united picture that depends on the anisotropic nature of the molecular electrostatic potential around the donor atom. Qualitative descriptions of the effects that lead to these anisotropic distributions are given and examples of the importance of σ-hole bonding in crystal engineering and biological systems are discussed.


2020 ◽  
pp. 3-5
Author(s):  
Y. G. Zakharenko ◽  
N. A. Kononova ◽  
V. L. Fedorin ◽  
Z. V. Fomkina ◽  
K. V. Chekirda

The results of the work to create a complex of high-precision hardware for the unit of length reproduction and transferring carried out at “D. I. Mendeleyev Institute for Metrology (VNIIM)” are represented. This complex will serve as the basis for the further development of the reference base of the Russian Federation in the field of length measurements and will allow reproduction of the unit of length at two wavelengths of 633 nm and 532 nm, as well as measurements of the wavelength of laser sources in vacuum in the range from 500 to 1050 nm.


2018 ◽  
pp. 131-141 ◽  
Author(s):  
A. N. Savrukov ◽  
N. T. Savrukov ◽  
E. A. Kozlovskaya

The article analyzes the current state and level of development of publicprivate partnership (PPP) projects in the subjects of the Russian Federation. The authors conclude that a significant proportion of projects is implemented on a concession basis at the municipal level in the communal sphere. A detailed analysis of the project data showed that the structure of the projects is deformed in favor of the central regions of the Russian Federation, and a significant share in the total amount of financing falls on the transport sector. At the stage of assessing the level of development by the subjects of the Russian Federation, criteria were proposed, and index and integral indicators were used, which ensured comparability of the estimates obtained. At the end of the analysis, the regions were ranked and clustered according to the level of PPP development, which allowed to reveal the number and structure of leaders and outsiders.


2020 ◽  
pp. 105-116
Author(s):  
N. I. Shagaida

The article clarifies the concept of “agricultural holding”, using an approach to assessing the size on the basis of the total revenue of all agricultural organizations within the agricultural holding. It has been revealed that only 100 of the total number of agricultural holdings that were identified can be attributed to large business entities. They comprise about 3% of agricultural organizations in the country, while their share in the proceeds is about 37%. A large share of agricultural holdings — large business subjects under the control of Russian entities operate in one, and under the control of foreign legal entities — in three or more regions of the Russian Federation. Vertical integration within the framework of large agricultural holdings with different schemes for including the stages of processing and sale of products produced in their agricultural organizations allows them to receive advantages. Strengthening the role of large business entities in agriculture puts on the agenda the issue of differentiating approaches to taxation and state support in agriculture, depending on the size of the companies’ agricultural businesses.


2007 ◽  
pp. 63-75 ◽  
Author(s):  
A. Navoi

The article analyzes the situation with attraction of foreign direct investments (FDI) into the Russian Federation. Sharply increased inflow of international financial resources into national economy has highlighted the problem of definitions, the reasons of this phenomenon and its economic contents. The article considers methodological aspects and economic essence of modern FDI. Special accent is made on the estimation of the situation with their attraction into Russia, FDI structure and effectiveness. The conclusions about basic directions of the increase of their effectiveness in the Russian economy are formulated.


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