The rate coefficient is expressed by the following Arrhenius equations: For ethyl N-benzyl-N-cyclopropylcarbamate For ethyl diphenylcarbamate The presence of phenyl and bulky groups at the nitrogen atom of the ethylcarbamate showed a decrease in the rate of elimination. Steric factor may be ...
In a molecule of the form X2A, ab initio molecular orbital calculations showed that the RAX bond distance was the major factor influencing the X–A–X angle, particularly if A is a first-row element. For example, the HOH angle widens considerably as the OH distance is reduced. Similar ...
Steric factor Steric crowding Steric strain (or steric tension) Steric interactions, whether between electrons or atoms, always result in a rise in the energy of a system. Systems with higher energies are more unstable than systems with lower energies. Figure 1 depicts cyclohexane conformations as ...
The contamination of water caused by the release of various organic compounds has emerged as a widespread problem that has been well-documented in recent years. This hazardous problem was attributed completely to the growing activities in the petrochemicals, chemical-based, agricultural, and medical se...
(orange) and tetramethylethylenediamine (red) complexes of [RuII(terpy)(N^N)Cl]+ to illustrate the steric hindrance caused by the methyl substituents during substitution of Cl− by water, and water by Cl− and thiourea that leads to a deceleration of the reactions by a factor of between...
possible combinations of steric-gate residues. When the interactions with all six gate residues are perturbed, the free-energy barrier is increased by 2.5–2.7kBT(Fig.5d), which corresponds to a decrease in the rate by a factor of 12–15. However, similar increases in the barrier are also...
图4颗粒效率因子随无因次时间的变化Fig 4 Variation of effectiveness factor with dimensionless time 由表1可知, ξm1的值均接近于1 。说明催化剂颗粒的大部分体积均是进行烧炭反应的第二阶段, 因此按照反应第二阶段的效率因子表达式计算粒径不同的颗粒的效率因子,如图5所示。可以看出,催化剂颗粒很小时,效率因子...
The steric interaction between the olefin nucleophile and the coordinated ligands seems to be a very important factor in determining the ease of substitution.doi:10.1246/bcsj.48.1233Yoshiro TeraiHiroaki KidoJunnosuke FujitaKazuo SaitoBulletin of the Chemical Society of Japan...
Two dimensionless kinetic factors (i. e., reduced addition-reaction rate constant and reduced rotational diffusion constant), supercooling, and steric tolerance anlge range, control process kinetics and distribution of single elements in the cluster's surroundings. Rate reduction factor responsible for ...
The steric interaction energy has been included in the theoretical calculation of the aggregation rate constant by means of Fuchs' stability factor. Good agreement between simulation, experimental, and theoretical calculations was obtained. 漏 2000 American Institute of Physics.Romero-Cano...