Structural Studies of Curcuminoids. II. Crystal Structure of 1,7-Bis(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione--Methanol Complex.

Abstract
The crystal and molecular structure of the curcumin derivative 1,7-bis(4-hydroxyphenyl)-1,6-heptadiene-3,5-dione-methanol complex (B4HPHDD) was determined at 121.degree. K by X-ray crystallographic methods using 2090 reflections observed by counter methods. The crystals are monoclinic, space group P21/n with unit cell dimensions a = 6.781(2) .ANG., b = 7.606(1) .ANG., c = 33.024(5) .ANG., .beta. = 93.73(2).degree.. The structure was refined to a conventional R-factor of 0.033. Estimated standard deviations are 0.003 .ANG. and 0.2.degree. in interatomic distances and angles when hydrogen atoms are not involved. The enol-ring is found to be asymmetric.