Crystal Structure of Form I of Syndiotactic 1,2-Poly(4-methyl-1,3-pentadiene)

Title data

Immirzi, Attilio ; Tedesco, Consiglia ; Valdo Meille, Stefano ; Famulari, Antonino ; van Smaalen, Sander:
Crystal Structure of Form I of Syndiotactic 1,2-Poly(4-methyl-1,3-pentadiene).
In: Macromolecules. Vol. 36 (2003) Issue 10 . - pp. 3666-3672.
ISSN 1520-5835
DOI: https://doi.org/10.1021/ma0257853

Official URL:

Abstract in another language

The crystal structure of the form I of syndiotactic 1,2-poly(4-methyl-1,3-pentadiene) has been determined studying the X-ray fiber diffraction pattern recorded onto a Fuji image plate. The chain conformation (T6G2T2G2), previously proposed by Meille et al. on the basis of the identity period, has been confirmed, but with deviations of chain torsion angles from the 60 and 180° values. The crystal system is triclinic, a = 17.513(8) Å, b = 9.117(6) Å, c = 11.251(14) Å, α = 95.20(4)°, β = 98.01(3)°, γ = 92.74(5)°, and V = 1768(3) Å3. The space group is P1̄, with two chains per cell, each formed by six nonequivalent CH2CH[CHC(CH3)2] chemical units. The crystal structure was determined and refined by the least-squares method, keeping bond lengths fixed and assuming that chemically equivalent bond angles are equal to each other. The refined model shows unrealistic values for some side group bond angles, in particular for the angle between methyl groups. Quite satisfactory results are obtained fixing this angle to the value of 122.7°, as suggested by searching the Cambridge Structural Database. Final disagreement indices are R1 = 14.3% and R2 = 15.0%.

Further data

Item Type:	Article in a journal
Refereed:	Yes
Institutions of the University:	Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography > Chair Crystallography - Univ.-Prof. Dr. Sander van Smaalen Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences
Result of work at the UBT:	Yes
DDC Subjects:	500 Science > 530 Physics
Date Deposited:	18 Mar 2016 08:22
Last Modified:	27 Jul 2023 13:57
URI:	https://eref.uni-bayreuth.de/id/eprint/31913