Suitable parameter sets for the CHARMm force field were derived for the structural units in polychlorophosphazene [P=N, P-N, P-CI] using the Dinur-Hagler energy second derivative procedure based on quantum mechanical SCF calculations using the 6-31G* basis set. To validate the reliability of the parameter set, structural results obtained with CHARMm for the adopted model compounds (OP2NCl5 and OP3N2Cl7) were compared with those derived from ab initio quantum mechanics using the 6-31G* basis set. Application of molecular dynamics (MD) simulations in combination with the available X-ray diffraction data provided structural and conformational information on the polymer. The calculation made using the periodic boundary conditions (PBC) agree well with the polychlorophosphazene ordered in a monoclinic unit cell (a=5.98, b=12.99, c=4.92 Angstrom; beta=111.7 degrees). This model was stabilized mainly by the image atoms contribution to the electrostatic energy term and had a quasi-planar conformation of the backbone chain (glide symmetry). The MD calculations also provided evidence that the difference between single and double PN bonds is less marked than that measured experimentally. This result is, however, in agreement with more recent and accurate X-ray studies on poly(methylphosphazene). Validation of the polymer model provided a complete picture, otherwise experimentally inaccessible, of the internal fluctuations of the polymeric chains.

Molecular Dynamics Simulations of Polyphoshazenes: Poly[Bis(cloro)phosphazene][NPCl2]n / M. E., Amato; A., Grassi; K. B., Lipkowitz; G. M., Lombardo; G., Pappalardo; Sadun, Claudia. - In: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS. - ISSN 1053-0495. - STAMPA. - 6,3:(1996), pp. 237-253. [10.1007/BF01057749]

Molecular Dynamics Simulations of Polyphoshazenes: Poly[Bis(cloro)phosphazene][NPCl2]n

SADUN, Claudia
1996

Abstract

Suitable parameter sets for the CHARMm force field were derived for the structural units in polychlorophosphazene [P=N, P-N, P-CI] using the Dinur-Hagler energy second derivative procedure based on quantum mechanical SCF calculations using the 6-31G* basis set. To validate the reliability of the parameter set, structural results obtained with CHARMm for the adopted model compounds (OP2NCl5 and OP3N2Cl7) were compared with those derived from ab initio quantum mechanics using the 6-31G* basis set. Application of molecular dynamics (MD) simulations in combination with the available X-ray diffraction data provided structural and conformational information on the polymer. The calculation made using the periodic boundary conditions (PBC) agree well with the polychlorophosphazene ordered in a monoclinic unit cell (a=5.98, b=12.99, c=4.92 Angstrom; beta=111.7 degrees). This model was stabilized mainly by the image atoms contribution to the electrostatic energy term and had a quasi-planar conformation of the backbone chain (glide symmetry). The MD calculations also provided evidence that the difference between single and double PN bonds is less marked than that measured experimentally. This result is, however, in agreement with more recent and accurate X-ray studies on poly(methylphosphazene). Validation of the polymer model provided a complete picture, otherwise experimentally inaccessible, of the internal fluctuations of the polymeric chains.
1996
01 Pubblicazione su rivista::01a Articolo in rivista
Molecular Dynamics Simulations of Polyphoshazenes: Poly[Bis(cloro)phosphazene][NPCl2]n / M. E., Amato; A., Grassi; K. B., Lipkowitz; G. M., Lombardo; G., Pappalardo; Sadun, Claudia. - In: JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS. - ISSN 1053-0495. - STAMPA. - 6,3:(1996), pp. 237-253. [10.1007/BF01057749]
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/86688
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? 7
social impact