
TY  - JOUR
A1  - Cannon, JR 
A1  - Patrick, VA 
A1  - White, AH 
T1  - Color and Conformation of Some Derivatives of Benzil in the Solid-State: Crystal-Structures of 2,2&#8242;-Dimethoxy- 4,4&#8242;-Dimethoxy- , 4-4&#8242;Diethoxy- and 4,4'-Dibenzyloxy-benzil
JF  - Australian Journal of Chemistry
JO  - Aust. J. Chem.
Y1  - 1989
VL  - 42
IS  - 10
SP  - 1631
EP  - 1645
KW  - 
UR  - https://doi.org/10.1071/CH9891631 
N2  - The crystal structures of the colourless 2,2'-dimethoxybenzil (2) and 4,4'-diethoxybenzil (6), the yellow 4,4'-dimethoxybenzi (5), and the yellow polymorph of 4,4'-dibenzyloxybenzil (7) have been determined by single-crystal X-ray studies from diffractometer data at 295 K, and refined by full matrix least-squares techniques to residuals of 0.048 (1281 'observed' reflections), 0.041 (610), 0.052 (662) and 0.043 (2140) respectively. Crystals of 2,2&#8242;-dimethoxybenzil (2) are monoclinic, P21/c, a 7.861(4), b 7.991(2), c 21.557(9)Å, &#946;90.37(4)º, Z 4. Crystals of 4,4'-dimethoxybenzil (6) are monoclinic C2/c, a 21.912(9), b 4.055(2), c 15.197(5) Å,&#946; 102 13(3)º Z 4. Crystals of 4,4&#8242;-diethoxybenzil (6) are monoclinic C21/c, a 14.544(7), b 4.781(2), c 22.128(7), &#946; 99.06(3)º, Z 4. Crystals of the yellow modification of 4,4'-dibenzyloxybenzil (7) are monoclinic P21/c, a 19.126(4), b 6.91 1(2), c 16.673(7) Å &#946; 99.52(3)º, Z 4. It has been found that there is a correlation between the colour of the crystal and the conformation adopted by the molecule in the solid state with the colourless derivatives of benzil having the aromatic ring planes orthogonal. 
ER  -

