Steric Factors in Quaternary Salt Formation

1943 ◽  
Vol 65 (10) ◽  
pp. 1841-1845 ◽  
Author(s):  
Weldon G. Brown ◽  
Sherman Fried
Keyword(s):  
Quaternary Salt ◽  
Salt Formation ◽  
Steric Factors

The Absence of Quaternary Salt Formation between Phosphoryl Chloride and Pyridine1

1953 ◽  
Vol 75 (3) ◽  
pp. 751-753 ◽  
Author(s):  
B. M. Zeffert ◽  
P. B. Coulter ◽  
Rudolph Macy
Keyword(s):  
Quaternary Salt ◽  
Salt Formation ◽  
Phosphoryl Chloride

Quaternary Salt Formation of Substituted Oxazoles and Thiazoles1

1960 ◽  
Vol 82 (1) ◽  
pp. 186-189 ◽  
Author(s):  
Vernon N. Kerr ◽  
Donald G. Ott ◽  
F. Newton Hayes
Keyword(s):  
Quaternary Salt ◽  
Salt Formation

Kinetics and mechanism of the reaction of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione

1990 ◽  
Vol 55 (8) ◽  
pp. 1984-1990 ◽  
Author(s):  
José M. Hernando ◽  
Olimpio Montero ◽  
Carlos Blanco
Keyword(s):  
Aqueous Solution ◽  
Metal Ion ◽  
Activation Parameters ◽  
Enol Form ◽  
Kinetics And Mechanism ◽  
Kinetic Constants ◽  
Steric Factors ◽  
Kinetics Of ◽  
Mechanism Of The Reaction

The kinetics of the reactions of iron(III) with 6-methyl-2,4-heptanedione and 3,5-heptanedione to form the corresponding monocomplexes have been studied spectrophotometrically in the range 5 °C to 16 °C at I 25 mol l-1 in aqueous solution. In the proposed mechanism for the two complexes, the enol form reacts with the metal ion by parallel acid-independent and inverse-acid paths. The kinetic constants for both pathways have been calculated at five temperatures. Activation parameters have also been calculated. The results are consistent with an associative activation for Fe(H2O)63+ and dissociative activation for Fe(H2O)5(OH)2+. The differences in the results for the complexes of heptanediones studied are interpreted in terms of steric factors.

scholarly journals Oligosilanylated Silocanes

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 244
Author(s):  
Mohammad Aghazadeh Meshgi ◽  
Alexander Pöcheim ◽  
Judith Baumgartner ◽  
Viatcheslav V. Jouikov ◽  
Christoph Marschner
Keyword(s):  
Cyclic Voltammetry ◽  
Solid State ◽  
Xrd Analysis ◽  
29Si Nmr ◽  
Single Crystal Xrd ◽  
Substitution Pattern ◽  
Silyl Group ◽  
Steric Factors ◽  
Single Crystal Xrd Analysis ◽  
29Si Nmr Spectroscopy

A number of mono- and dioligosilanylated silocanes were prepared. Compounds included silocanes with 1-methyl-1-tris(trimethylsilyl)silyl, 1,1-bis[tris(trimethylsilyl)silyl], and 1,1-bis[tris(trimethylsilyl)germyl] substitution pattern as well as two examples where the silocane silicon atom is part of a cyclosilane or oxacyclosilane ring. The mono-tris(trimethylsilyl)silylated compound could be converted to the respective silocanylbis(trimethylsilyl)silanides by reaction with KOtBu and in similar reactions the cyclosilanes were transformed to oligosilane-1,3-diides. However, the reaction of the 1,1-bis[tris(trimethylsilyl)silylated] silocane with two equivalents of KOtBu leads to the replacement of one tris(trimethylsilyl)silyl unit with a tert-butoxy substituent followed by silanide formation via KOtBu attack at one of the SiMe3 units of remaining tris(trimethylsilyl)silyl group. For none of the silylated silocanes, signs of hypercoordinative interaction between the nitrogen and silicon silocane atoms were detected either in the solid state. by single crystal XRD analysis, nor in solution by 29Si-NMR spectroscopy. This was further confirmed by cyclic voltammetry and a DFT study, which demonstrated that the N-Si distance in silocanes is not only dependent on the energy of a potential N-Si interaction, but also on steric factors and through-space interactions of the neighboring groups at Si and N, imposing the orientation of the pz(N) orbital relative to the N-Si-X axis.

scholarly journals Challenges of Mechanochemistry: Is In Situ Real-Time Quantitative Phase Analysis Always Reliable? A Case Study of Organic Salt Formation

2017 ◽  
Vol 4 (9) ◽  
pp. 1700132 ◽  
Author(s):  
Adam A. L. Michalchuk ◽  
Ivan A. Tumanov ◽  
Sumit Konar ◽  
Simon A. J. Kimber ◽  
Colin R. Pulham ◽  
...  
Keyword(s):  
Real Time ◽  
Phase Analysis ◽  
Organic Salt ◽  
Quantitative Phase Analysis ◽  
Salt Formation ◽  
Quantitative Phase
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