Integrated approach for 13C nuclear magnetic resonance shift prediction, spectral simulation and library search

Cheng, H. N.; Kasehagen, Leo J.

doi:10.1016/0003-2670(94)85025-9

Cited by 29 publications

(24 citation statements)

References 47 publications

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“…1c. With the help of 2D NMR, known assignments of related polymers (Dubois, Desilets, Ait-Kadi, & Tanguy, 1995;Pegoraro, Galbiati, & Ricca, 2003), and shift additivity rules (Cheng & Kasehagen, 1994), we were able to provide complete assignments of the 13 C and 1 H spectra; these are shown in Fig. 1a and b. On the 13 C spectrum, it is of interest that the peaks of the carbons ortho to the carbamate substituents on the ring are broadened (i.e., position 1 at ca.…”

Section: Nmr Analysismentioning

confidence: 99%

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Microwave-assisted synthesis of cyclodextrin polyurethanes

Biswas

Appell

Liu

et al. 2015

Carbohydrate Polymers

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Section: Nmr Analysismentioning

confidence: 99%

“…2. The assignments have been made in this work by drawing analogy from the ␤-CD/TDI assignments, from spectra of related MDI polymers in the literature (Brandolini & Hills, 2000;Delides, Tethrick, Cunliffe, & Klein, 1981), and from 13 C shift additivity rules (Cheng & Kasehagen, 1994); these are shown directly on Fig. 2.…”

Section: Nmr Analysismentioning

confidence: 99%

Microwave-assisted synthesis of cyclodextrin polyurethanes

Biswas

Appell

Liu

et al. 2015

Carbohydrate Polymers

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“…The two spectra were similar in appearance, suggesting that a similar polymer structure was obtained. Detailed spectral assignments were made from empirical shift additivity rules and from appropriate references in the literature. For sorbitol, we used the values reported by Pallagi et al ., with the 13 C shifts of C1, C2, C3, C4, C5, and C6 given as 62.7, 69.5, 70.9, 70.9, 72.3, and 62.3 ppm, respectively.…”

Section: Resultsmentioning

confidence: 99%

Preparation of sorbitol‐based polyurethanes and their semiinterpenetrating polymer networks

Biswas

Cheng

Kim

et al. 2019

J of Applied Polymer Sci

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Sorbitol is a useful agro‐based substance that is inexpensive and commercially available. In the interest of adding value to bio‐based raw materials, we have synthesized polyurethanes from sorbitol and toluene‐2,4‐diisocyanate (TDI) through both conventional heat and microwave processes. Relative to conventional heat, the microwave process achieved the same reaction at a faster rate, thereby saving time and energy. The nature of the resulting polyurethane products depended on the stoichiometry of the reaction. At increasing TDI levels, a viscous liquid, a soft gel, or a hard thermoset could be obtained. The polymers were fully characterized with 13C‐NMR, Fourier transform infrared, size exclusion chromatography, and thermogravimetric analysis. The polyurethanes obtained near the gel point could be used to make semiinterpenetrating polymer networks (semi‐IPNs) with a second polymer, thereby imparting some of the properties of the second polymer onto the sorbitol‐based polyurethane. For illustration, the sorbitol‐based polyurethane semi‐IPNs were made in combination with poly(vinyl pyrrolidone) and poly(lactic acid). © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47602.

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“…From 13 C chemical shift rules, 27 the assignments for cardanol have been tentatively assigned in Figure S3a, where phenolic carbons are labelled as P x , triene as T x , diene as D x , and mono-ene as M x , where x = carbon number. In sample C-1 (partial addition of DEAD to cardanol), the spectrum ( Figure S3b) indicates that the triene peaks decrease about 60% in intensities, dienes decrease about 50%, and mono-ene stays unchanged.…”

Section: Resultsmentioning

confidence: 99%

Derivatives of Cardanol through the Ene Reaction with Diethyl Azodicarboxylate

Biswas¹,

Alves²,

Trevisan³

et al. 2016

Journal of the Brazilian Chemical Society

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Cardanol is an alkyl/alkenyl phenolic material obtained from cashew nut shell liquid (CNSL), which is a byproduct of cashew nut processing. In an effort to develop new uses, cardanol was derivatized for the first time with diethyl azodicarboxylate (DEAD) through the ene reaction. The reaction was facile and required only the application of heat without a catalyst. Both conventional heating and microwave heating were shown to be effective; the latter entailed much shorter reaction time and substantial energy savings. The reaction product (a hydrazino-ester derivative of cardanol) was characterized by nuclear magnetic resonance (NMR). The product increased in viscosity with time and may be useful as a viscosifier in oil-based commercial formulations and as a synthon for further organic reactions.

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Integrated approach for 13C nuclear magnetic resonance shift prediction, spectral simulation and library search

Cited by 29 publications

References 47 publications

Microwave-assisted synthesis of cyclodextrin polyurethanes

Microwave-assisted synthesis of cyclodextrin polyurethanes

Preparation of sorbitol‐based polyurethanes and their semiinterpenetrating polymer networks

Derivatives of Cardanol through the Ene Reaction with Diethyl Azodicarboxylate

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