Conformational Analysis of Poly(propylene oxide) and Its Model Compound 1,2-Dimethoxypropane

Sasanuma, Yuji

doi:10.1021/ma00129a023

Cited by 50 publications

(77 citation statements)

References 13 publications

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“…This is a more stable interaction due to the shorter length and stronger strength than the intermolecular hydrogen bond. The ab initio calculations have also suggested that the existing of the intra-molecular (C-H)· · ·O attractions and point out this intra-molecular attractions have a stabilizing effect for the polar gauche state conformation of PPO [23,24]. On the other hand, the breakdown of this intra-molecular hydrogen bond may result in a decrease of gauche conformers of the PPO chain.…”

Section: Microenvironment and Conformation Of Peo-ppo-peo Triblock Comentioning

confidence: 89%

Microenvironmental and conformational structure of triblock copolymers in aqueous solution by 1H and 13C NMR spectroscopy

Chen

Tang

et al. 2006

Journal of Colloid and Interface Science

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Section: Microenvironment and Conformation Of Peo-ppo-peo Triblock Comentioning

confidence: 89%

Microenvironmental and conformational structure of triblock copolymers in aqueous solution by 1H and 13C NMR spectroscopy

Chen

Tang

et al. 2006

Journal of Colloid and Interface Science

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“…34 Then the oxygen and hydrogen atoms have partial charges of -0.777 and +0.221, respectively. Thus an electrostatic interaction such as the (C-H)‚‚‚O attraction found in ethers [35][36][37] is suggested to exist in such alcohols and to stabilize these conformations. The g ( g -states have a free energy of 1.25 kcal mol -1 , which is close to the sum of -0.27 (g ( t) and 1.47 (tg ( ) kcal mol -1 .…”

Section: Conformational Energies Of the Free State Listed Inmentioning

confidence: 99%

Conformational Analysis of Amphiphilic Molecules Incorporated in Hexagonal, Lamellar, and Reversed Hexagonal Aggregates of a Ternary System of Sodium Octanoate, 1-Decanol, and Water by the Rotational Isomeric State Scheme Combined with the Maximum Entropy Method

2000

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Conformational and orientational characteristics of amphiphiles incorporated in the hexagonal, lamellar, and reversed hexagonal aggregates formed by a ternary lyotropic system of sodium octanoate, 1-decanol, and water have been investigated. Deuterium NMR quadrupolar splittings observed from the randomly and selectively deuterated compounds were simulated by a combined use of the rotational isomeric state scheme and the maximum entropy method. For the individual mesophases, the bond conformations and orientational order parameters of octanoate and 1-decanol were evaluated and related to the aggregate structures. In the lamellar phase, in particular, the 1-decanol chain was found to exhibit peculiar conformations; the C-C bond nearest the OH group is fixed in the gauche state, the adjacent C-C bond also shows a gauche preference, and the second C-C bond from the methyl terminal has a high gauche probability. It follows that the chain length of 1-decanol is almost equal to that of octanoate in the all-trans conformation. Ab initio molecular orbital calculations at the MP2/6-31+G*//HF/6-31G* level for 1-butanol have revealed the inherent conformational preference of the head portion of the alcohol chains; the first C-C bond from the headgroup prefers the gauche state to the trans state by 0.27 kcal mol -1 , and the g ( g ( states in the first and second C-C bonds from the OH group have a comparatively small free energy of 0.42 kcal mol -1 relative to the tt state.

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“…All physical constants in Equation , except the relative dielectric constant, ε, are well known, as mentioned above. Here, we used C n with 3.96 for PEG ( n = 16–27) from our earlier work using IM‐MS, which covers the same range of chain length, and a bond length of 1.463 Å . We thus can immediately estimate ε of PEG being 7.22.…”

Section: Resultsmentioning

confidence: 99%

Obtaining the Dielectric Constant of Polymers from Doubly Charged Species in Ion-Mobility Mass Spectrometry

Kokubo

Vana

2017

Macromol. Chem. Phys.

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Ion‐mobility mass spectrometry of doubly charged polyethylene glycol (PEG) is performed after electrospray‐ionization time‐of‐flight mass spectrometry and the dependency of the effective collision cross‐section, CCSeff, on the number of monomer units, n, is evaluated with the help of molecular dynamics simulations. Assuming a balance between elastic and Coulomb forces inside short and asymmetric doubly charged chains, a method is developed for evaluating the dielectric constant, ε, which is found to be 7.87 for PEG for n = 14–28. From the same experiment at higher chain lengths, the characteristic ratio Cn of 4.30 for PEG (n ≥ 63) can be evaluated according to an earlier reported method, which is demonstrated here to also work with doubly charged species. The proposed method enables an extremely swift and precise measurement both of ε and Cn of polymer that is free of solvent or impurities from one single experiment.

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Conformational Analysis of Poly(propylene oxide) and Its Model Compound 1,2-Dimethoxypropane

Cited by 50 publications

References 13 publications

Microenvironmental and conformational structure of triblock copolymers in aqueous solution by 1H and 13C NMR spectroscopy

Microenvironmental and conformational structure of triblock copolymers in aqueous solution by 1H and 13C NMR spectroscopy

Conformational Analysis of Amphiphilic Molecules Incorporated in Hexagonal, Lamellar, and Reversed Hexagonal Aggregates of a Ternary System of Sodium Octanoate, 1-Decanol, and Water by the Rotational Isomeric State Scheme Combined with the Maximum Entropy Method

Obtaining the Dielectric Constant of Polymers from Doubly Charged Species in Ion-Mobility Mass Spectrometry

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