The crystal structure of the antitumor agent 3-ethoxy-2-oxobutyraldehyde bis(thiosemicarbazonato) copper(II)

✍ Scribed by Max R. Taylor; Jenny Pickworth Glusker; Eric J. Gabe; Jean A. Minkin

• Publisher: Elsevier Science
• Year: 1974
• Weight: 885 KB
• Volume: 3
• Category: Article
• ISSN: 0006-3061
• DOI: 10.1016/s0006-3061(00)80069-1

✦ Synopsis

The crystal structure of a triclinic form of the copper(D) complex of Sethoxy-2-oxobutymldehyde bis(thiosemicarbasone) (CuKTS) has been determined_ The KT8? coordinates to copper(I1) as a tetradentate ligand via two nitrogen and two sulphur atoms. The unit cell is triclinic, space group Pi, with dimensions o = 9.306(6), b = 10.443(7), c = 7_4i9(5) _?I, Q = 90.63(5), B = 114_25(5), y = 95.42(5)", observed density 1.720 g-cm-r, calculated density l-i21 g-cm-1, 2 = 2. The structure was refined by full-mat& least-square methods with anisotropic temperature parameters for non-hydrogen atoms to R = 0.096 for 24% reflections_ The ethosyethyl side chain is disordered. The molecules pack in sheets, but the hydrogen bonding is generally weak. In the crystal structure, sulphur atoms in adjacent molecules lie above and below the copper atom of a central molecule, completing coordination about the Cu(I1) with two long CU-S distances of 3.101(2) and 3.312(2) b_ These values may be compared to the molecular plane Cu-S bond lengths of 2.263( 1) and 2.267( 1) _% and Cu-N bond lengths of 1.%X0(2) and l-959(2) b. Thus there are potential binding sites in the axial positions of the copper atom. Binding at at least one of these sites probably occurs when the complex is carrying out its biological function, during which it is believed to act on a thiol group.