Source of materialTo an ethanolsolution (4 ml)of3,5-dichloro-2-hydroxybenzaldehyde (191.0 mg,1 .0 mmol) was added an ethanol solution (4 ml) of 2-aminophenylethanone oxime (150.2 mg,1.0 mmol). After stirring at 333 Kfor 12 h, the mixture was filtered. The residue was washedsuccessively with ethanol and hexane. The isolated compound was dried under reduced pressure to yield 231.5 mg of pale-yellow solid (yield 71.3 %, m.p. 469-470 K). The block-shaped single crystals were obtained by slow evaporation from an acetonitrile solution at room temperature. Elemental analysis -found: C, 55.93 %; H, 3.97 %; Cl, 22.16
DiscussionThe oxime-type compounds are potentially multidentate ligands [1,2] because they can accommodate one, two or more transition metal centers and form metal complexes with interesting properties [3-6], such as excellent catalytic activity for epoxidation or aziridination [7], models of reaction centers of metalloenzymes [8], nonlinear optical materials [9],and for molecular recognition and biological activity [10]. The title crystal structure is only built up by the C 15 H 12 Cl 2 N 2 O 2 molecules, in which all bond lengths are in normalranges. The two benzene rings form ad ihedral angle of 89.46°. Therea re strong intramolecular O-H×××Oh ydrogen bonds between the hydroxyl(O2-H2A) groups and the oxime oxygen (O1) atoms, with d(N2×××O2) =2.604 Å. In the crystal structure, the molecules are held together by two pairs of intermolecular O1-H1×××Cl1 and N2-H2×××O1 hydrogen bonds. Because of the two pairs of intermolecular hydrogen bonds, the molecules form an infinite 2D supramolecular network [11,12].