Rui-Qin Fang

Synthesis, Characterization, and Antibacterial and Cytotoxic Study of Metal Complexes with Schiff Base Ligands

The synthesis of 16 metal complexes from four Schiff bases prepared from 5-chloro-2-hydroxybenzaldehyde and primary amines has been described. The synthesized Schiff base ligands and their complexes were characterized by elemental analyses, spectroscopic (UV, IR, 1H and 13C NMR, electrospray ionization-mass spectrometry) methods, and magnetic and conductance measurements. Furthermore, complexes 1a, 1b, 3d, 4a, and 4d were characterized by X-ray diffraction analysis. After the structural characterization, all the compounds were tested in vitro for their antibacterial (Bacillus subtilis, Escherichia coli, Pseudomonas fluorescens, and Staphylococcus aureus) activities. The cytotoxic activities of the synthesized compounds were evaluated in vitro against human chronic myeloid leukaemia cells (K562) and a human nasopharyngeal epidermoid tumour cell line. The results indicated that most of the complexes showed good cytotoxic activity against human cancer cell lines but weak cytotoxic activity against a human normal cell line (L02). Among the compounds tested, the cobalt complexes 1a, 2a, 3a, and 4a showed the most favourable antibacterial and cytotoxic activities.

(E)‐4‐Chloro‐2‐[(cyclopentylimino)methyl]phenol

Allen, F. H., Kennard, O., Watson, D. G., Brammer, L., Orpen, A. G. & Taylor, R. (1987). J. Chem. Soc. Perkin Trans. 2, pp. S1–19. Bruker (2001). SMART, SAINT, SADABS and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA. Li, Y.-G., Huang, K.-X., Ai, L. & Zhu, H.-L. (2006). Acta Cryst. E62, o2219– o2220. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Shi, L., Ge, H.-M., Tan, S.-H., Li, H.-Q., Song, Y.-C., Zhu, H.-L. & Tan, R.-X. (2007). Eur. J. Med. Chem. 42, 558–564. organic compounds

Bis(2-amino­pyridine)dibenzoatocobalt(II). Erratum

Erratum to Acta Cryst. (2006), E62, m1012—m1013.

(E)-2-[(1-Benzyl­piperidin-4-yl)imino­meth­yl]phenol

There are two molecules in the asymmetric unit of the title compound, C19H22N2O. Both molecules have an E conformation about their C=N bonds and both piperdine rings adopt chair conformations with their N atoms adopting pyramidal geometries [bond angle sums = 329.8 (4) and 330.2 (4)°]. Both molecules feature an intramolecular O—H⋯N hydrogen bond, which generates an S(6) ring. The dihedral angles between the phenyl and benzene ring planes are 45.97 (18) and 66.0 (2)°. Short O—H⋯O contacts occur in the crystal.

(E)-4-Fluoro-2-[(4-hy­droxy­pheneth­yl)imino­meth­yl]phenol

The title compound, C15H14FNO2, has an E conformation about the C=N bond, which facilitates the formation of an intramolecular O—H⋯N hydrogen bond. The F atom is disordered over two adjacent sites in a 0.65 (7):0.35 (7) ratio. The dihedral angle between the benzene ring planes is 14.2 (2)°. In the crystal, molecules are linked by O—H⋯O hydrogen bonds, forming C(14) [010] chains.

2-Fluoro-6-[(E)-(pyridin-2-yl)imino­meth­yl]phenol

The title compound, C12H9FN2O, is almost planar (r.m.s. deviation for the 16 non-H atoms = 0.019 Å), a conformation stabilized by an intramolecular O—H⋯N hydrogen bond, which generates an S(6) ring. In the crystal, inversion dimers linked by pairs of C—H⋯O hydrogen bonds generate R 2 2(16) loops.

Ethyl 4-[(E)-(2-hy-droxy-benzyl-idene)amino]-piperidine-1-carboxyl-ate.

In the title compound, C15H20N2O3, the piperidine ring adopts a chair conformation, although the amide N atom is almost planar (bond angle sum = 359.7°). The molecule adopts an E conformation about the C=N bond, which allows for the formation of an intramolecular O—H⋯N hydrogen bond. In the crystal, molecules are linked by C—H⋯O interations, resulting in C(6) chains propagating in [010].

A novel heterocyclic compound: catena-poly[[[diaquasodium(I)]-di-μ-aqua] hemi(1,5-dihydroxy-4,8,9-trioxa-2,6-diazabicyclo[3.3.1]nona-2,6-diene-3,7-diolate)]. Retraction

The paper by Fang et al. [Acta Cryst. (2007), C63, m193–m194] is retracted. It has subsequently been shown that the crystal studied was borax.