Conformational Analysis of Poly(trimethylene imine) and Poly(N-methyltrimethylene imine) by the Rotational Isomeric State Scheme with up to Fourth-Order Intramolecular Interactions

2005 ◽  
Vol 38 (8) ◽  
pp. 3519-3532 ◽  
Author(s):  
Yuji Sasanuma ◽  
Fumiko Teramae ◽  
Hiroki Yamashita ◽  
Ippei Hamano ◽  
Satoshi Hattori
Keyword(s):  
Conformational Analysis ◽  
Fourth Order ◽  
Isomeric State ◽  
Intramolecular Interactions ◽  
Rotational Isomeric State

scholarly journals Conformational Analysis of CmH2m+1OCH2CH2OH (m = 1-4): The Role of CH.cntdot..cntdot..cntdot.O Intramolecular Interactions

1995 ◽  
Vol 99 (20) ◽  
pp. 8066-8070 ◽  
Author(s):  
Francisco P. S. C. Gil ◽  
A. M. Amorim Da Costa ◽  
J. J. C. Teixeira-Dias
Keyword(s):  
Conformational Analysis ◽  
Intramolecular Interactions

scholarly journals Conformational analysis and intramolecular interactions in monosubstituted phenylboranes and phenylboronic acids

2013 ◽  
Vol 9 ◽  
pp. 1127-1134 ◽  
Author(s):  
Josué M Silla ◽  
Rodrigo A Cormanich ◽  
Roberto Rittner ◽  
Matheus P Freitas
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Bonding ◽  
Conformational Analysis ◽  
Conformational Equilibrium ◽  
Intramolecular Hydrogen Bonding ◽  
Intramolecular Interactions ◽  
Coupling Constant ◽  
Intramolecular Hydrogen ◽  
Phenylboronic Acids ◽  
Electron Donation

A 1 TS J F,H(O) coupling pathway, dictated by a hydrogen bond, in some 2-fluorobenzoic acids has been observed, while such an interaction does not occur in 2-fluorophenol. Thus, this work reports the conformational analysis of 2-fluorophenylboronic acid (1), in order to evaluate a possible intramolecular OH∙∙∙F hydrogen bond in comparison to an nF→pB interaction, which mimics the quantum nF→σ*OH hydrogen bond that would be expected in 2-fluorophenol. 2-Fluorophenylborane (3), which does not experience hydrogen bonding, was used to verify whether nF→pB interaction governs the conformational equilibrium in 1 due to a predominant OH∙∙∙F hydrogen bond or to other effects. A series of 2-X-phenylboranes (X = Cl, Br, NH2, PH2, OH and SH) were further computationally analyzed to search for electron donors to boron, capable of influencing the conformational equilibrium. Overall, the intramolecular OH∙∙∙F hydrogen bond in 1 is quite stabilizing and dictates the 1 h J F,H(O) coupling constant. Moreover, electron donation to the empty p orbital of boron (for noncoplanar BH2 moiety relative to the phenyl ring) is also significantly stabilizing for the NH2 and PH2 derivatives, but not enough to make the corresponding conformers appreciably populated, because of steric effects and the loss of πCC→pB resonance. Thus, the results found earlier for 2-fluorophenol about the lack of intramolecular hydrogen bonding are now corroborated.

scholarly journals Application of Rotational Isomeric State Theory to Ionic Polymer Stiffness Predictions

2005 ◽  
Vol 20 (9) ◽  
pp. 2443-2455 ◽  
Author(s):  
Lisa Mauck Weiland ◽  
Emily K. Lada ◽  
Ralph C. Smith ◽  
Donald J. Leo
Keyword(s):  
Isomeric State ◽  
Mechanical Response ◽  
Physical Structure ◽  
State Theory ◽  
Chain Conformation ◽  
Ionic Polymer ◽  
Polymer Morphology ◽  
Rotational Isomeric State ◽  
Material Stiffness ◽  
Chain Lengths

Presently, rotational isomeric state (RIS) theory directly addresses polymer chain conformation as it relates to mechanical response trends. The primary goal of this work is to explore the adaptation of this methodology to the prediction of material stiffness. This multiscale modeling approach relies on ionomer chain conformation and polymer morphology and thus has potential as both a predictive modeling tool and a synthesis guide. The Mark–Curro Monte Carlo methodology is applied to generate a statistically valid number of end-to-end chain lengths via RIS theory for four solvated Nafion® cases. For each case, a probability density function for chain length is estimated using various statistical techniques, including the classically applied cubic spline approach. It is found that the stiffness prediction is sensitive to the fitting strategy. The significance of various fitting strategies, as they relate to the physical structure of the polymer, are explored so that a method suitable for stiffness prediction may be identified.

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