title: Crystal structures of 3,5-bis-[(E)-3-hy-droxy-benzyl-idene]-1-methyl-piperidin-4-one and 3,5-bis-[(E)-2-chloro-benzyl-idene]-1-methyl-piperidin-4-one.
abstract: The title compounds, C20H19NO3, (1), and C20H17Cl2NO, (2), are the 3-hy-droxy-benzyl-idene and 2-chloro-benzyl-idene derivatives, respectively, of curcumin [systematic name: (1E,6E)-1,7-bis-(4-hy-droxy-3-meth-oxy-phen-yl)-1,6-hepta-diene-3,5-dione]. The dihedral angles between the benzene rings in each compound are 21.07 (6)° for (1) and 13.4 (3)° for (2). In both compounds, the piperidinone rings adopt a sofa confirmation and the methyl group attached to the N atom is in an equatorial position. In the crystal of (1), two pairs of O-H⋯N and O-H⋯O hydrogen bonds link the mol-ecules, forming chains along [10-1]. The chains are linked via C-H⋯O hydrogen bonds, forming undulating sheets parallel to the ac plane. In the crystal of (2), mol-ecules are linked by weak C-H⋯Cl hydrogen bonds, forming chains along the [204] direction. The chains are linked along the a-axis direction by π-π inter-actions [inter-centroid distance = 3.779 (4) Å]. For compound (2), the crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.116 (6):0.886 (6).
authors: Laboratory of Organic Synthesis, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Riau University, Pekanbaru 26293, Indonesia.
authors: Yum
authors: Y
authors: Eryanti
authors: Laboratory of Organic Synthesis, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Riau University, Pekanbaru 26293, Indonesia.
authors: Adel
authors: A
authors: Zamri
authors: Department of Chemistry, Faculty of Mathematics and Natural Sciences, Padjadjaran University, Jalan Raya Bandung-Sumedang Km 21, Jatinangor 45363, Sumedang, Indonesia.
authors: Tati
authors: T
authors: Herlina
authors: Department of Chemistry, Faculty of Mathematics and Narural Sciences, Padjadjaran University, Jalan Raya Bandung-Sumedang Km 21, Jatinangor 45363, Sumedang, Indonesia.
authors: Unang
authors: U
authors: Supratman
authors: X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia.
authors: Mohd Mustaqim
authors: MM
authors: Rosli
authors: X-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia; Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, Riyadh 11451, Saudi Arabia.
authors: Hoong-Kun
authors: HK
authors: Fun
keywords: benzyl­idene; crystal structure; hydrogen bonding; methyl­piperidin-4-one; piperidinone