The effect of solvation by acetone on the basicity of silylalkylamines

1979 ◽  
Vol 44 (9) ◽  
pp. 2828-2831 ◽  
Author(s):  
Zlata Papoušková ◽  
Vlasta Fialová ◽  
Václav Chvalovský

The relative basicity of fifteen methylethoxysilylalkylamines of the type (CH3)3-m(C2H5O)m.Si(CH2)nNH2 in acetone has been studied by potentiometric titration. For n 1 the basicity increases with increasing m, which is likely due to increasing electronic interaction of the oxygen of acetone with the silicon of silylalkylamines. The basicity of silylmethylamines (n = 1) changes nonsystematically, probably as a consequence of the competing action of opposite effects.

2019 ◽  
Vol 944 (2) ◽  
pp. 57-63
Author(s):  
V.A. Pavlova ◽  
E.L. Uvarova

The authors describe modern trends in development of the cadastral system. The main features of the procedure of cadastral registration and software systems that act as accounting and registration of automated databases are highlighted. The technological process of maintaining the unified state register of real estate is analyzed in detail. The modern system of information electronic interaction in the real estate register is designated. The role of information and communication technologies in the Russian cadastral system is shown. The authors propose a classification of online services of Rosreestr in a number of ways. The fourth group of online services is allocated as the most promising as it provides opportunities to obtain additional information at the common activity fields of different Executive authorities. The authors conclude that changes in the cadastral system of the Russian Federation are greatly influenced by global trends which in turn are aimed at expanding the functions of the cadastre as an information basis of land management.


1979 ◽  
Vol 44 (3) ◽  
pp. 750-755 ◽  
Author(s):  
Josef Pola ◽  
Marie Jakoubková ◽  
Václav Chvalovský

Relative basicity of the oxygen in alkoxysilanes (RO)nSi(CH3)3-n having n = 1-4 and various electrondonating and electronwithdrawing groups R measured as Δν(OH) of phenol due to its interaction with these compounds in CCl4 is shown to be chiefly controlled by the electronic effect of substituents R. Linear regression analysis of the Δν(OH) vs n relatioship for individual series (RO)nSi(CH3)4-n suggests the operation of the polarizability effect of RO groups becoming more important with increasing electronwithdrawing nature of R.


1984 ◽  
Vol 49 (10) ◽  
pp. 2355-2362 ◽  
Author(s):  
Juraj Leško ◽  
Marie Dorušková ◽  
Jan Tržil

Boron oxide in the Na2O.P2O5-x B2O3 system behaves as a Lux base. Its addition to Na2O.P2O5 brings about transformation of a Co(II) indicator from octahedral to tetrahedral configuration, increase in the optical basicity ΛPb(II), increase in the relative basicity of the melt as determined by means of a galvanic cell, and depolymerization reactions releasing PO43- ions. In the Na2O-B2O3 system free of P2O5, boron oxide behaves as a Lux acid. The amphoretic nature of B2O3 is explained in terms of Lux's acid-base theory extended in analogy with the protolysis theory. The theoretical optical basicity values do not indicate the amphoretic behaviour of B2O3 because in this approach boron oxide is a priori regarded as more acidic than Na2O.P2O5.


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