Search Results

You are looking at 1 - 6 of 6 items

  • Author: Nicolay I. Dodoff x
Clear All Modify Search

The complexes cis-[Pd(PMSA)2Cl2] cis-[Pt(PMSA)2X2], trans-[Pt(PMSA)2I2] and [Pt(PMSA)4]Cl2 (PMSA = N-3-pyridinylmethanesulfonamide; X = Cl, Br, I) have been synthesized and characterized by elemental analysis, molar electric conductivity, IR and 1H NMR spectra. A detailed assignment of the IR spectra (4000-150 cm-1) of the complexes, supported by an approximate normal coordinate analysis, has been performed. The complexes are of square-planar type and the PMSA ligand is coordinated via the pyridine nitrogen atom.

Crystals of N-3-pyridinyl-methanesulfonamide, PMSA (monoclinic, P21/c, a = 5.6436(7), b = 33.875(4), c = 8.3356(10) Å , β = 96.885(2)°) contain two non-equivalent molecules differing considerably in their conformations. The structure is stabilized by a network of hydrogen bonds, the strongest one being between the pyridine N atom and the sulfonamide H atom. Crystals of trans-[Pt(PMSA)2I2] (monoclinic, C2/c, a = 22.912(2), b = 5.2397(5), c = 17.3376(17) Å , β = 92.631(2)◦) contain centrosymmetric complex molecules in which PMSA is coordinated via the pyridine N atom, and Pt has a planar coordination. A system of hydrogen bonds of the types N−H· · ·O and C−H· · ·O links the complex molecules.

The complexes [M(MSH)4Cl2] (MSH = CH3SO2NHNH2; M = Mn (1), Fe (2), Co (3) and Ni (4)) were synthesized and characterized by elemental analysis, molar electric conductivity, IR and d-d electronic spectra. The X-ray single crystal analysis revealed for 3 (triclinic, P1̄ , a = 8.077(2), b = 8.622(2), c = 8.742(2) A° , α = 71.98(3), β = 75.30(3), γ = 64.11(3)°, V = 515.8(2)A° 3, Z = 1) and 4 (triclinic, P1̄ , a = 8.050(2), b = 8.588(2), c = 8.686(2) Å , α = 73.35(3), β = 75.76(3), γ = 63.94(3)°, V = 511.8(2) Å3, Z = 1) that MSH is coordinated via the amino N atom, the donor atoms and the metal are coplanar, and the Cl ligands are in trans-configuration. On the basis of IR data a similar structure is suggested for 1 and 2. The electronic spectra of 3 and 4 are interpreted by the Angular Overlap Model and bonding parameters are derived: eσ(N) = 3384(15), eσ(Cl) = 2788(25), eπ(Cl) = 150(21) cm-1 for 3, and eσ(N) = 3668(21), eσ(Cl) = 2602(150), eπ(Cl) = -21(128) cm-1 for 4.

Three novel Schiff bases: salicylaldehyde methanesulfonylhydrazone (1), 2-hydroxyacetophenone methanesulfonylhydrazone (2) and 2-hydroxy-1-naphthaldehyde methanesulfonylhydrazone (3) have been synthesized. Compounds 1-3, as well as acetone methanesulfonylhydrazone (4) have been characterized by TLC, 1H NMR and IR spectra. The spectroscopic results for 1-3 have revealed the presence of an intramolecular hydrogen bond between the hydroxyl group and the imine N atom. The conformational isomerism of 1-4 with respect to the rotations around the SN and NN bonds have been studied by the method of molecular mechanics. Compounds 1-4 and methanesulfonylhydrazine exhibit antibacterial and cytotoxic effects.

Abstract

The complexes [Pt(DMSO)(GT)]·DMSO (1), [Pt(DMSO)(PT)]· 1/2 DMSO (2) and [Pd(DMSO)- (PT)] (3), where DMSO = dimethyl sulfoxide, H2GT = glyoxylic acid thiosemicarbazone and H2PT = pyruvic acid thiosemicarbazone, have been synthesized and characterized by elemental analysis, molar electric conductivity, IR, electronic and NMR (1H and 13C) spectra. The single crystal X-ray diffraction analysis has revealed for 1 (orthorhombic, Pnma, a = 12.941(3), b = 7.108(2), c = 15.148(3) Å , Z = 4) that the doubly deprotonated thiosemicarbazone molecule is coordinated to Pt(II) via the carboxylato O, azomethine N and thiolato S atoms forming two condensed fivemembered chelate rings. The fourth coordination site of Pt(II) is occupied by the S atom of DMSO. All the atoms of the complex molecule are coplanar except the methyl groups. The O atom of DMSO is in cis-position towards the thiolato-S atom (point group Cs). A system of hydrogen bonds of the type N-H· · ·O links the complex molecules between them and with the lattice DMSO molecules. Similar structures have been deduced for the remaining two complexes on the basis of spectroscopic data. The three complexes and the ligand H2GT exhibit cytotoxic activity against F4N leukemia cells, whereas the ligand H2PT is inactive.

The series of complexes: cis-[Pd(PMSA)2X2], cis-[Pt(PMSA)2X2], trans-[Pt(PMSA)2I2] and [Pt(PMSA)4]Cl2 (PMSA = N-3-pyridinylmethanesulfonamide; X = Cl, Br, I), previously synthesized and characterized by us, as well as the free ligand PMSA, were tested for their cytotoxic activity without electroporation - against murine leukemia F4N and human SKW-3 and MDA-MB-231 tumour cell lines - and with electroporation - against the latter two cell lines. The majority of the complexes exhibited cytotoxic effects (IC50 < 100 μmol/l) under the conditions of electroporation. Both cis- and trans-[Pt(PMSA)2I2] had pronounced cytotoxic effects (29 - 61 μmol/l against MDA-MB-231 cells).