Cooperative C-H•••O H-bonds in 'bay area' and crystal structure of 1-(4-methylphenyl)-3-(4-methoxyphenyl)-2-propene-1-one)

The title compound (C17H16O2, M-r = 252.30) crystallizes in the monoclinic system, space group P2(1)/c with a = 11.5763(14), b = 11.0321 (11), c = 11.5094(13) Angstrom, beta = 114.581(3)degrees, V = 1336.7(3) Angstrom(3), Z = 4, D-c = 1.254 g/cm(3) mu(MoKa) = 0.081 cm(-1) and F(000) = 536.00. The final R and wR are 0.0527 and 0.1285, respectively for 3058 observed reflections (1 > 2sigma(I)). In the title molecule, two phenyl rings are rotated oppositely with respect to the central part C(1)-C(2)=C(3)-C(4) (plane 3) and the dihedral angle between them is 14.8degrees. The phenone 0(l) atom deviates from plane 3 by 0.291 Angstrom. In the crystal the molecules form H-bond chains of R-2(1)(6) and R-2(1)(5) types along [001]. The molecule chains interacted through three cooperative C-H...O H-bonds (R-3(1)(11)) in the 'bay area' (Fig. 3), extending along [010] and forming layer (100). Between the layers, there exist C-H/pi interactions along [101]. Studies on the cooperative C-H...O H-bonds R-3(1) (11) in the similar crystals are also presented.