Abstract
Herma Cuppen answered: Rotation barriers about the C–NH3+ bond depend on the motive of the hydrogen bonding network in the crystalline phases. For DL-norleucine this motive stays intact during the transition, and I therefore do not expect a large difference for the two phases. The changes occur where the aliphatic chains interact. In a previous study,1 we determined the rotation barrier of the methyl group by means of molecular dynamics simulations for both phases. We found them to be identical, and to be in agreement with experimental values for DL-norvaline2 and DL-norleucine.3 We did not find any correlation between internal movement of the molecules and the onset of the transition.
| Original language | English |
|---|---|
| Pages (from-to) | 503-542 |
| Number of pages | 40 |
| Journal | Faraday Discussions |
| Volume | 179 |
| Early online date | 17 Jun 2015 |
| DOIs |
|
| Publication status | Published - 1 Jul 2015 |
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Keywords
- solid state NMR
- phase transition
- crystalline phases
Cite this
}
Nucleation in complex multi-component and multi-phase systems : General discussion. / Price, Sarah; Rimez, Bart; Sun, Wenhao; Peters, Baron; Christenson, Hugo; Hughes, Colan; Sun, Changquan Calvin; Veesler, Stéphane; Pan, Haihua; Brandel, Clement; Biscans, Beatrice; Meekes, Hugo; Rosbottom, Ian; Roth, Wieslaw J.; Seton, Linda; Taulelle, Francis; Black, Simon; Threlfall, Terence; Vekilov, Peter; Poornachary, Sendhil; Diemand, Jürg; Toroz, Dimitrios; Salvalaglio, Matteo; Tipduangta, Pratchaya; Sefcik, Jan; Booth, Samuel; Rasmuson, Ake; Janbon, Sophie; Ter Horst, Joop; Simone, Elena; Hammond, Robert; Bertran, Celso Aparecido; Vetter, Thomas; Sear, Richard; De Yoreo, Jim; Harris, Kenneth; Ristic, Radoljub; Kavanagh, Anne; Roberts, Kevin; Breynaert, Eric; Myerson, Allan; Coquerel, Gerard; Wu, David; Cölfen, Helmut; Cuppen, Herma; Smets, Mireille; Wu, David T.
In: Faraday Discussions, Vol. 179, 01.07.2015, p. 503-542.Research output: Contribution to journal › Comment/debate
TY - JOUR
T1 - Nucleation in complex multi-component and multi-phase systems
T2 - General discussion
AU - Price, Sarah
AU - Rimez, Bart
AU - Sun, Wenhao
AU - Peters, Baron
AU - Christenson, Hugo
AU - Hughes, Colan
AU - Sun, Changquan Calvin
AU - Veesler, Stéphane
AU - Pan, Haihua
AU - Brandel, Clement
AU - Biscans, Beatrice
AU - Meekes, Hugo
AU - Rosbottom, Ian
AU - Roth, Wieslaw J.
AU - Seton, Linda
AU - Taulelle, Francis
AU - Black, Simon
AU - Threlfall, Terence
AU - Vekilov, Peter
AU - Poornachary, Sendhil
AU - Diemand, Jürg
AU - Toroz, Dimitrios
AU - Salvalaglio, Matteo
AU - Tipduangta, Pratchaya
AU - Sefcik, Jan
AU - Booth, Samuel
AU - Rasmuson, Ake
AU - Janbon, Sophie
AU - Ter Horst, Joop
AU - Simone, Elena
AU - Hammond, Robert
AU - Bertran, Celso Aparecido
AU - Vetter, Thomas
AU - Sear, Richard
AU - De Yoreo, Jim
AU - Harris, Kenneth
AU - Ristic, Radoljub
AU - Kavanagh, Anne
AU - Roberts, Kevin
AU - Breynaert, Eric
AU - Myerson, Allan
AU - Coquerel, Gerard
AU - Wu, David
AU - Cölfen, Helmut
AU - Cuppen, Herma
AU - Smets, Mireille
AU - Wu, David T.
PY - 2015/7/1
Y1 - 2015/7/1
N2 - Kenneth Harris opened a general discussion of the paper by Herma Cuppen: It is well established from solid-state NMR and other techniques that the NH3+ group in crystalline amino acids undergoes rapid rotation about the C–NH3+ bond. Is the phase transition between the β and α phases of DL-norleucine associated with any significant discontinuity in the rate of this motion, and/or the temperature dependence of the rate of this motion? Furthermore, is there any evidence for disorder (dynamic or static) of the alkyl chain of the norleucine molecules in the α and β phases, and if so, does the nature of this disorder change significantly at the phase transition?Herma Cuppen answered: Rotation barriers about the C–NH3+ bond depend on the motive of the hydrogen bonding network in the crystalline phases. For DL-norleucine this motive stays intact during the transition, and I therefore do not expect a large difference for the two phases. The changes occur where the aliphatic chains interact. In a previous study,1 we determined the rotation barrier of the methyl group by means of molecular dynamics simulations for both phases. We found them to be identical, and to be in agreement with experimental values for DL-norvaline2 and DL-norleucine.3 We did not find any correlation between internal movement of the molecules and the onset of the transition.
AB - Kenneth Harris opened a general discussion of the paper by Herma Cuppen: It is well established from solid-state NMR and other techniques that the NH3+ group in crystalline amino acids undergoes rapid rotation about the C–NH3+ bond. Is the phase transition between the β and α phases of DL-norleucine associated with any significant discontinuity in the rate of this motion, and/or the temperature dependence of the rate of this motion? Furthermore, is there any evidence for disorder (dynamic or static) of the alkyl chain of the norleucine molecules in the α and β phases, and if so, does the nature of this disorder change significantly at the phase transition?Herma Cuppen answered: Rotation barriers about the C–NH3+ bond depend on the motive of the hydrogen bonding network in the crystalline phases. For DL-norleucine this motive stays intact during the transition, and I therefore do not expect a large difference for the two phases. The changes occur where the aliphatic chains interact. In a previous study,1 we determined the rotation barrier of the methyl group by means of molecular dynamics simulations for both phases. We found them to be identical, and to be in agreement with experimental values for DL-norvaline2 and DL-norleucine.3 We did not find any correlation between internal movement of the molecules and the onset of the transition.
KW - solid state NMR
KW - phase transition
KW - crystalline phases
UR - http://www.scopus.com/inward/record.url?scp=84937706627&partnerID=8YFLogxK
U2 - 10.1039/c5fd90039e
DO - 10.1039/c5fd90039e
M3 - Comment/debate
VL - 179
SP - 503
EP - 542
JO - Faraday Discussions
JF - Faraday Discussions
SN - 1359-6640
ER -