Dipole moments of poly(oxytetramethylene) and poly(oxydecamethylene) chains

Riande, Evaristo

doi:10.1002/macp.1977.021780715

Cited by 17 publications

(5 citation statements)

References 41 publications

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“…In most of the conformational analyses of polyethers [−(CH 2 ) y −O−] x , − ,,− for the C−O bond dipole moment ( m C - O ) values of 0.99 and 1.07 D have been employed and the C−C bond dipole moment ( m C - C ) has always been assumed to be null. Recently, however, Smith et al have pointed out that the m C - O value of 1.07 D is too small to reproduce the dipole moments obtained by their ab initio MO calculations at the MP2/D95+(2df,p) level for conformers of 1,3-dimethoxypropane and recommended use of m C - O = 1.16 D instead.…”

Section: C−o Bond Dipole Moment21mentioning

confidence: 99%

“…The thick solid curves stand for the calculated 〈 r 2 〉 0 / nl 2 and 〈μ 2 〉/ nm 2 values. The horizontal solid and dotted lines represent ranges of the experimental 〈 r 2 〉 0 / nl 2 and 〈μ 2 〉/ nm 2 values, respectively: 5.38 (ref ) ≤ 〈 r 2 〉 0 / nl 2 ≤ 6.13 (ref ) and 0.41 (ref ) ≤ 〈μ 2 〉/ nm 2 ≤ 0.42 (ref ). …”

Section: Characteristic Ratio and Dipole Moment Ratio Of Ptmomentioning

confidence: 99%

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Conformational Characteristics of Poly(tetramethylene oxide)

Law

Sasanuma

1998

Macromolecules

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Conformational characteristics of poly(tetramethylene oxide) (PTMO) have been investigated on the basis of the conformational energies evaluated for its monomer model 1,4-dimethoxybutane (DMB) from the ab initio molecular orbital (MO) calculations at the second-order Møller−Plesset correlation level with the 6-31+G* basis set. The reliability of our conformational energies was examined by comparison between calculations and observations of NMR vicinal 13C−H and 1H−1H coupling constants of DMB and the characteristic ratio and dipole moment ratio of PTMO. Then the C−O bond dipole moment (m C - O) for the rotational isomeric state analysis of polyethers was determined from the MO and 1H NMR data reported previously for 1,2-dimethoxypropane, a monomeric model compound of poly(propylene oxide). The optimal m C - O value was obtained as 1.18 D. The conformational energies reproduced the experimental observations very well. The relationship between the conformational characteristics and crystal structures of polyethers [−(CH2) y −O−] x (y ≥ 4) is also discussed.

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Section: C−o Bond Dipole Moment21mentioning

confidence: 99%

Section: Characteristic Ratio and Dipole Moment Ratio Of Ptmomentioning

confidence: 99%

Conformational Characteristics of Poly(tetramethylene oxide)

Law

Sasanuma

1998

Macromolecules

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“…Complexation of enzymes with polyelectrolytes offers a route to immobilized and, possibly, more stable forms of enzymatically active insulin,8 catalase,9 and urease and penicillin amidase.10 Other changes in protein activity that accompany complex formation are also of interest, such as the reduction of oxygen affinity for hemoglobin in complexes with polyanions11 which could lead to new blood substitutes. 12 The stoichiometry of colloid titrations of proteins with polyelectrolytes may help to shed light on the number and location of ionizable groups on the protein surface. 13,14 Complex formation between proteins and strong synthetic polyelectrolytes may provide useful models for theories about the nonspecific affinity of DNA-binding proteins15 such as RNA polymerase, which appear to interact with nucleic acids largely through electrostatic effects.…”

Section: Bovine Serum Albuminmentioning

confidence: 99%

Dipole moments of some styrene copolymers

Küçükyavuz¹,

Baysal²

1988

Macromolecules

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Dipole moments of poly(styrene-co-p-chlorostyrene), poly(styrene-co-p-methoxystyrene), poly(styrene-co-4-vinylpyridine), and poly(styrene-co-N-vinylcarbazole) copolymers were determined in toluene solutions at different temperatures. The samples were synthesized by using free-radical initiators. The effects of the nature of the polar group, composition, and temperature on the dipole moment ratio were investigated.The mean-square dipole moment per structural unit shows a positive deviation from linearity, in agreement with calculations by Mark based on rotational isomeric state theory. The results are compared with other experimental and theoretical studies. IntroductionThe mean-square dipole moment of a chain ( p 2 ) is an important configuration-dependent property that can be determined experimentally in dilute solutions or in bulk,

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“…1. Dipole Moments of Poly(thiodiethylene glycol) Chains E. Riande* and J. Guzmán Instituto de Plásticos y Caucho (CSIC), Madrid-6 Spain. Received February 5,1979 ABSTRACT: Mean-square dipole moments of poly(thiodiethylene glycol), an alternating copolymer of ethylene oxide and ethylene sulfide, were determined from dielectric constant measurements on dilute solutions of the polymer in benzene. Since the configuration-dependent properties of one of the parent homopolymers, poly(ethylene sulfide), are unknown, because of its insolubility in ordinary solvents, the results were preferably compared with those of poly(oxyethylene) chains.…”

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confidence: 99%

“…The emission spectra of several polymers in dilute solution, such as poly(l-vinylnaphthalene) (PVN) and poly(N-vinylcarbazole) (PVCz), are characterized by emission from excimers formed from two neighboring pendant aromatic groups on the same polymer chain. 5 The low-energy sandwich-type excimers of PVN (Xmai ~400 nm) and PVCz (Xmai ~420 nm) are accompanied by emission from a monomer state (Xmax ~355)6 and a higher-energy excimer state (Xm" ~370 nm),7 respectively.…”

mentioning

confidence: 99%