TY - JOUR
T1 - Molecular-dynamics simulation of crystalline 18-crown-6
T2 - thermal shortening of covalent bonds
AU - van Eerden, J.
AU - Harkema, S.
AU - Feil, D.
PY - 1990
Y1 - 1990
N2 - Molecular-dynamics simulations of crystalline 18-crown-6 have been performed in a study of the apparent thermal shortening of covalent bonds observed in crystal structures. At 100 K, a shortening of 0.006 _+ 0.001 A for C-C and C-O bonds was obtained. This result was found to be independent of details of the force field and the simulation. There was agreement between computational and experimental values for the thermal parameters, as well as for the molecular geometry (bond and dihedral angles) of 18-crown-6. Some differences are attributed to the inability of the force field to reproduce hydrogen-bonding geometries. Simulation at 295 K resulted in an estimated shortening of 0.019_+ 0.005 A. Thus at room temperature for C--C bonds (apparent) thermal shortening and (real) chemical shortening, resulting from the electronegative oxygen substituents, are of the same order of magnitude. In the simulation at 295 K occasional dihedral transitions were observed, which may reflect the proximity of the melting point (312 K).
AB - Molecular-dynamics simulations of crystalline 18-crown-6 have been performed in a study of the apparent thermal shortening of covalent bonds observed in crystal structures. At 100 K, a shortening of 0.006 _+ 0.001 A for C-C and C-O bonds was obtained. This result was found to be independent of details of the force field and the simulation. There was agreement between computational and experimental values for the thermal parameters, as well as for the molecular geometry (bond and dihedral angles) of 18-crown-6. Some differences are attributed to the inability of the force field to reproduce hydrogen-bonding geometries. Simulation at 295 K resulted in an estimated shortening of 0.019_+ 0.005 A. Thus at room temperature for C--C bonds (apparent) thermal shortening and (real) chemical shortening, resulting from the electronegative oxygen substituents, are of the same order of magnitude. In the simulation at 295 K occasional dihedral transitions were observed, which may reflect the proximity of the melting point (312 K).
U2 - 10.1107/S0108768189011560
DO - 10.1107/S0108768189011560
M3 - Article
VL - 46
SP - 222
EP - 229
JO - Acta crystallographica. Section B: Structural science, crystal engineering and materials
JF - Acta crystallographica. Section B: Structural science, crystal engineering and materials
SN - 2052-5192
ER -