Y. Okada, K. Nakatsu, A. Shimada
Apr 1, 1971
Citations
1
Influential Citations
6
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The crystals of 3,4-furandicarboxylic acid dimethylester are monoclinic of the space group P⁄21a, with unit cell dimensions a=12.64, b=8.16, c=7.97 A, and β=100.0°. An approximate structure was determined by application of the symbolic addition phase determining procedure. After several cycles of least-squares refinement, the discrepancy index for the 901 observed reflections was reduced to 14%. In the molecule the furan ring is planar, and one carbomethoxy group is almost on the same plane as the furan ring, while the other makes an angle of 10.5° with the ring. The bond lengths and angles do not differ appreciably from the values found in the other compounds, except for those of C(3)–C(4)=1.41 A, C(4)–C(3)–C(6)=131° and C(3)–C(4)–C(7)=132°, the latter two being larger than normal values probably because of interaction between the carbonyl-oxygens. The mode of packing of the molecules and a scheme of twinning found in this crystal is discussed.