Infrared and 1H-NMR study of molecular conformation of some N,N′-arylalkylureas

Sudha, L.; Sathyanarayana, D. N.

doi:10.1016/0022-2860(84)85326-0

Cited by 30 publications

(17 citation statements)

References 25 publications

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“…(Figure a) . The affinity between these fragments is described as weak as K a =30 m −1 ,, and is due in part to the closed pyridylurea substructure arising from intramolecular hydrogen bonding, which must be broken for pairing. However it was thought that it might be sufficient for our purpose to achieve reversible folding/unfolding.…”

Section: Figurementioning

confidence: 99%

Reversible Stereoselective Folding/Unfolding Fueled by the Interplay of Photoisomerism and Hydrogen Bonding

2017

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A linear molecular architecture equipped with complementary three-fold hydrogen-bonding units embedded with a photoswitchable trans-tetrafluoroazobenzene moiety was synthesized. The transto cis photoisomerism of the azobenzene unit induced drastic changes in the molecular architecture as a result of intramolecular hydrogen bonding as evidenced by NMR spectroscopy and size exclusion chromatography. A minute stereogenic element in the linear trans state enabled stereoselective folding into the cis state, thus producing a globular architecture with enhanced chiroptical property.

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Section: Figurementioning

confidence: 99%

Reversible Stereoselective Folding/Unfolding Fueled by the Interplay of Photoisomerism and Hydrogen Bonding

2017

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“…In N-substituted thioureas, the substituents can adopt four different conformations with respect to the central C9S bond. The preferred conformations have been investigated using 1 H, 13 C, and 15 N NMR spectroscopy in solution (22)(23)(24) as well as in the solid state (25). The stability of different conformers has been predicted by using molecular mechanics (22).…”

Section: Introductionmentioning

confidence: 99%

Oxidation of thiourea and substituted thioureas: a review

Sahu

Sahoo

Patel

et al. 2011

Journal of Sulfur Chemistry

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“…. H-N, are essential in the determination of the properties and activity of dialkylureas in all media [13][14][15]. In 1987 we have proposed [16] the model of the structure of a dialkylurea linear aggregate, in which one molecule of urea is involved with four hydrogen bonds (similar to the hydrogen-bonded water molecules), as shown in Fig.…”

Section: Introductionmentioning

confidence: 99%

Dielectric Relaxation in Hydrogen Bonded Urea-Based Supramolecular Polymer N,N'-di(2,2-dipentylheptyl)urea

et al. 2006

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Results of the dielectric relaxation studies, performed for supramolecular polymer formed by N, N-di(2,2-dipentylheptyl)urea dissolved in carbon tetrachloride, are presented. The measurements were done for N, N-di(2,2-dipentylheptyl)urea concentration up to about 7% (in mole fraction) in the frequency region from 100 kHz to 100 MHz and at the temperatures from 5 • C to 50 • C. The analysis of the experimental data were performed with the Havriliak-Negami equation. In the studied range of N, N-di(2,2-dipentylheptyl)urea concentration and temperature, the obtained values of exponents α and β of the Havriliak-Negami equation are equal to 0.9 ± 0.1 and 0.7 ± 0.1, respectively, showing an anomaly in the dielectric relaxation behavior close to the Davidson-Cole type. Two examples of the modeling of dielectric properties of the supramolecular polymer solutions were presented.

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Infrared and 1H-NMR study of molecular conformation of some N,N′-arylalkylureas

Cited by 30 publications

References 25 publications

Reversible Stereoselective Folding/Unfolding Fueled by the Interplay of Photoisomerism and Hydrogen Bonding

Reversible Stereoselective Folding/Unfolding Fueled by the Interplay of Photoisomerism and Hydrogen Bonding

Oxidation of thiourea and substituted thioureas: a review

Dielectric Relaxation in Hydrogen Bonded Urea-Based Supramolecular Polymer N,N'-di(2,2-dipentylheptyl)urea

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