FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2004184482> ?p ?o ?g. }

• W2004184482 endingPage "172" @default.
• W2004184482 startingPage "161" @default.
• W2004184482 abstract "Rates of rotation for amines in a variety of crystalline environments are reported, and the trends are explained in terms of the strengths of local hydrogen bonding interactions. Proton spin-lattice relaxation times (T1) and deuterium broad-line NMR spectra have been measured for D-, DL- and L- aspartic acid, two polymorphs of glycine, alanine, and leucine in the temperature range from −40 to 110 °C. The energy barriers for amine rotation are 27 ± 2 kJ mol−1 for D- or L-aspartic acid and 22 ± 2 kJ mol−1 for DL-aspartic acid; these energies are slightly lower than the previously reported value for the L form based on direct proton T1 measurements at 60 MHz. The values for the α and γ forms of glycine were 24 ± 2 and 30 ± 2 kJ mol−1 respectively, that for L-alanine was 40 ± 2 and that for L-leucine was 49 ± 3 kJ mol−1. These are all in rough agreement with previously reported values (although the differences for the polymorphs of glycine and for L- vs. DL-aspartic acid were not reported). Crystal structures of these amino acids indicate differences in hydrogen bonding environments around the R-NH3+ groups that are probably responsible for the different activation barriers. A molecular mechanics calculation of the rotation energy barriers for L- and DL-aspartic acid based on the crystal structures gave satisfactory agreement with experimental results if a uniform (and arbitrarily chosen) dielectric constant of 2.5 was assumed. Differences between L- and DL-aspartic acids and between two polymorphs of glycine were well represented qualitatively. Including additional neighboring molecules not involved in the hydrogen bonding or including periodic boundary conditions to describe the crystal packing did not significantly affect these results. If vacuum dielectric constants are used, the barriers are uniformly overestimated, and if the experimental macroscopic dielectric constant values are used, the barriers are generally underestimated. Dielectric constants differ substantially from one amino acid to another and significantly affect the estimated barriers; in fact, the bulk dielectric constants appear to be the major difference between the highest and the lowest values. The difficulty of accurately including dielectric relaxation into molecular mechanics calculations resulted in the disagreement between experimental measurements and theoretical calculations." @default.
• W2004184482 created "2016-06-24" @default.
• W2004184482 creator A5026152378 @default.
• W2004184482 creator A5078395420 @default.
• W2004184482 creator A5085362874 @default.
• W2004184482 date "1996-12-01" @default.
• W2004184482 modified "2023-09-27" @default.
• W2004184482 title "Hydrogen bonding effects on amine rotation rates in crystalline amino acids" @default.
• W2004184482 cites W1639798753 @default.
• W2004184482 cites W1964044039 @default.
• W2004184482 cites W1973054489 @default.
• W2004184482 cites W1974663677 @default.
• W2004184482 cites W1974711152 @default.
• W2004184482 cites W1979046104 @default.
• W2004184482 cites W1979977275 @default.
• W2004184482 cites W1983318669 @default.
• W2004184482 cites W1987358723 @default.
• W2004184482 cites W1993801027 @default.
• W2004184482 cites W1999462487 @default.
• W2004184482 cites W2001676859 @default.
• W2004184482 cites W2008099016 @default.
• W2004184482 cites W2017842995 @default.
• W2004184482 cites W2018731214 @default.
• W2004184482 cites W2021534482 @default.
• W2004184482 cites W2023941304 @default.
• W2004184482 cites W2025976880 @default.
• W2004184482 cites W2029049428 @default.
• W2004184482 cites W2029204985 @default.
• W2004184482 cites W2047852300 @default.
• W2004184482 cites W2049802226 @default.
• W2004184482 cites W2055409705 @default.
• W2004184482 cites W2058953939 @default.
• W2004184482 cites W2068787970 @default.
• W2004184482 cites W2077456051 @default.
• W2004184482 cites W2078610595 @default.
• W2004184482 cites W2082067731 @default.
• W2004184482 cites W2090280755 @default.
• W2004184482 cites W2091369239 @default.
• W2004184482 cites W2103522839 @default.
• W2004184482 cites W2131124255 @default.
• W2004184482 cites W2155524113 @default.
• W2004184482 cites W2159725925 @default.
• W2004184482 cites W2177655263 @default.
• W2004184482 cites W2198141639 @default.
• W2004184482 cites W2214055845 @default.
• W2004184482 cites W2319401054 @default.
• W2004184482 cites W2328137231 @default.
• W2004184482 cites W2407951372 @default.
• W2004184482 cites W2467531389 @default.
• W2004184482 cites W3005445942 @default.
• W2004184482 cites W332618692 @default.
• W2004184482 cites W4233566129 @default.
• W2004184482 cites W997830207 @default.
• W2004184482 doi "https://doi.org/10.1016/s0926-2040(96)01259-3" @default.
• W2004184482 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/9050153" @default.
• W2004184482 hasPublicationYear "1996" @default.
• W2004184482 type Work @default.
• W2004184482 sameAs 2004184482 @default.
• W2004184482 citedByCount "51" @default.
• W2004184482 countsByYear W20041844822012 @default.
• W2004184482 countsByYear W20041844822016 @default.
• W2004184482 countsByYear W20041844822017 @default.
• W2004184482 countsByYear W20041844822018 @default.
• W2004184482 countsByYear W20041844822020 @default.
• W2004184482 countsByYear W20041844822023 @default.
• W2004184482 crossrefType "journal-article" @default.
• W2004184482 hasAuthorship W2004184482A5026152378 @default.
• W2004184482 hasAuthorship W2004184482A5078395420 @default.
• W2004184482 hasAuthorship W2004184482A5085362874 @default.
• W2004184482 hasBestOaLocation W20041844821 @default.
• W2004184482 hasConcept C112887158 @default.
• W2004184482 hasConcept C115624301 @default.
• W2004184482 hasConcept C121332964 @default.
• W2004184482 hasConcept C131468747 @default.
• W2004184482 hasConcept C131779359 @default.
• W2004184482 hasConcept C147789679 @default.
• W2004184482 hasConcept C178790620 @default.
• W2004184482 hasConcept C185592680 @default.
• W2004184482 hasConcept C2776580952 @default.
• W2004184482 hasConcept C2777756961 @default.
• W2004184482 hasConcept C2779856020 @default.
• W2004184482 hasConcept C2781208047 @default.
• W2004184482 hasConcept C32909587 @default.
• W2004184482 hasConcept C515207424 @default.
• W2004184482 hasConcept C54516573 @default.
• W2004184482 hasConcept C55493867 @default.
• W2004184482 hasConcept C58364064 @default.
• W2004184482 hasConcept C62520636 @default.
• W2004184482 hasConcept C71240020 @default.
• W2004184482 hasConcept C8010536 @default.
• W2004184482 hasConcept C95121573 @default.
• W2004184482 hasConceptScore W2004184482C112887158 @default.
• W2004184482 hasConceptScore W2004184482C115624301 @default.
• W2004184482 hasConceptScore W2004184482C121332964 @default.
• W2004184482 hasConceptScore W2004184482C131468747 @default.
• W2004184482 hasConceptScore W2004184482C131779359 @default.
• W2004184482 hasConceptScore W2004184482C147789679 @default.
• W2004184482 hasConceptScore W2004184482C178790620 @default.

• next