@article{c8eb92283eac484ca6e000eda72f432f,
title = "X-Ray examination of the structure of poly(difluorophosphazene)",
abstract = "X-Ray diffraction photographs of oriented poly(difluorophosphazene) fibres reveal the existence of two molecular conformers, one of which occupies a cis-trans-planar conformation: 19F n.m.r. results and elasticity data indicate an unusually high chain flexibility.",
author = "Allcock, {H. R.} and Konopski, {G. F.} and Kugel, {R. L.} and Stroh, {E. G.}",
note = "Funding Information: Fourier calculations based on this structure show good agreement with the observed intensities. F%.v F N /p-\-N P-It is interesting to note that (NPF,), is elastomeric down to temperatures of -80{"} to -95{"} [compared with -63{"} for (NPCl,),lo and -15{"} for (NPBr,)$], and that the 19F n.m.r. spectrum of the unstretched solid remains a sharp doublet at least down to -70{"}. These facts indicate considerable backbone torsional mobility in this molecule and we believe that this is consistent with the low intra- molecular interactions calculated for (NPF,),.{"} We thank the U.S. Army Research Office, Durham, for the support of this work. (Received, June 29th, 1970; Corn. 1025.) 1 K. H. Meyer, W. Lotmar, and G. W. Pankow, Helv. Chim. Ada, 1936,18, 930. 2M. L. Huggins, J. Chem. Phys., 1945, 13, 37. 3 E. Giglio, F. Pompa, and A. Ripamonti, J. Polymer Sci., 1962, 59, 293. 4 D. Cordischi, A. D. Site, A. Mele, and P. Porta, J. Macromol. Chem., 1966, I, 219. H. R. Allcock, G. F. Konopski, R. L. Kugel, and E. G. Stroh, unpublished work. 6 T. R. Manley and D. A. Williams, Polymev, 1969, 10, 307. 7 F. Seel and J. Langer, 2.anorg. Chem., 1958,295, 317. 8 M. W. Dougill, J. Chem. Soc., 1963, 3211. * H. McD. McGeachin and F. R. Tromans, J. Chem. Soc., 1961, 4777. 10 H. R. Allcock, R. L. Kugel, and K. J. Valan, Inorg. Chem., 1966,5, 1709. 11 H. R. Allcock. J. E. Lehnsen, and J. J. Meister, unpublished work.",
year = "1970",
doi = "10.1039/C29700000985",
language = "English (US)",
pages = "985",
journal = "Journal of the Chemical Society D: Chemical Communications",
issn = "0577-6171",
publisher = "Royal Society of Chemistry",
number = "16",
}