Nicolay I. Dodoff

Platinum(II), platinum(IV), and palladium(II) complexes of amino substituted phosphine oxides: Synthesis, characterization, and antitumor activity

The complexes [Pt(dapo)2Cl2], [PtNH3(dapo)Cl2], [Pt(py)(dapo)Cl2], [Pt(mbpo)Cl2].H2O, [Pt(mbpo)(OH)2Cl2].H2O, [Pd(dapo)2Cl2], and [Pd(mbpo)Cl2], where dapo is dimethyl aminomethylphosphine oxide and mbpo is methyl bis(aminomethyl)phosphite oxide have been synthesized and characterized by elemental analyses, electric conductivity, infrared, 1H NMR and electronic spectra. The ligands are found to be coordinated only via the amino groups. The complexes are of cis-square planar configuration with the exception of [Pt(mbpo)(OH)2Cl2].H2O which is pseudo-octahedral. An in vivo antitumor screening of the complexes against Leukemia L1210 was performed. A considerable activity (T/C = 233%) was observed for [PtNH3(dapo)Cl2]. The activity of the remaining complexes was below the accepted criterion.

Structure and vibrational spectroscopy of methanesulfonic acid hydrazide: an experimental and theoretical study

A comprehensive study of the molecule of methanesulfonic acid hydrazide (MSH) is presented. The X-ray structure shows that in the crystal two centrosymmetrically oriented MSH molecules are held together by N–H···N hydrogen bonding interactions. This feature is unprecedented for the known arylsulfonic hydrazide analogues. The energetics of the various MSH staggered conformers and the stabilisation due to dimerisation are evaluated by HF abinitio calculations. Moreover, the pathways that interconvert the conformers as well as their enantiomers are outlined. The transition states between conformers correspond to the eclipsed conformation about the S–N linkage while those between enantiomers require planarisation of the N atom bound to sulfur. Some interconversions require two steps and two barriers to be bypassed. The IR and Raman spectra of MSH have been recorded and a normal coordinate analysis (NCA) has been carried out. The assignments have been double-checked through the abinitio calculated frequencies. The latter techniques also allow evaluation of the normal modes of vibration due to interacting MSH monomers, which can be experimentally detected.

PLATINUM (II) COMPLEXES OF BENZOIC- AND 3-METHOXYBENZOIC ACID HYDRAZIDES. SYNTHESIS, CHARACTERIZATION, AND CYTOTOXIC EFFECT

The complexes [Pt(bah)2X2], [Pt(NH3)(bah)Cl2].0.5H2O, [Pt(mbah)2X2], and [Pt(NH3)(mbah)Cl2] (bah = benzoic acid hydrazide, mbah = 3-methoxybenzoic acid hydrazide; X = Cl, Br, I) have been prepared and characterized by elemental analysis, electric conductivity, IR, 1H NMR, and electronic spectra. A cis-square planar structure with hydrazide ligands coordinated via the NH2-groups has been proposed for these complexes. The complexes have shown a growth-inhibitory effect against Friend leukemia cells in culture comparable to that of the antitumor drug cisplatin.

Platinum(II) complexes of 4-methoxy- and 4-chlorobenzoic acid hydrazides. Synthesis, characterization, and cytotoxic effect.

The complexes [Pt(NH3)(pmbah)Cl2], [Pt(NH3)(pcbah)Cl2], [Pt(pmbah)2X2] and [Pt(pcbah)2X2] (pmbah = 4-methoxybenzoic acid hydrazide, pcbah = 4-chlorobenzoic acid hydrazide; X = Cl, Br, I) have been synthesized and characterized by elemental analysis, electric conductivity, 1H NMR, IR, and electronic spectra. A cis-square planar structure with hydrazide ligands coordinated via the NH2 groups has been proposed for these compounds. The complexes, but not the free ligands, have shown a strong growth inhibitory effect in Friend leukemia cells in vitro, most of which are more active than cisplatin.

Schiff Bases of Methanesulfonylhydrazine. Synthesis, Spectroscopic Characterization, Conformational Analysis, and Biological Activity

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.

Chromium(III), Cobalt(II), Nickel(II) and Copper(II) Complexes of (Dimethyl-Phosphinyl)Methanamine. Crystal Structure of fac-Tris{(Dimethyl-Phosphinyl)Methanamine-N, O}Nickel(II) Chloride Trihydrate

Abstract The complexes CrL3Cl3.2H2O (I), CoL3Cl2.3H2O (2), CoL3Br2.H2O (3), NiL3Cl2.3H2O (4) and CuLCl2 (5), where L is (dimethylphosphinyl)methanamine, were synthesized and characterized by infrared and electronic spectra. The X-ray single crystal analysis of 4 (trigonal, space group R 3c, a = 11.340(2), c = 63.708(8) A, V = 7095(2) A, Z = 12) revealed a structure containing tris-chelated fac[NiL3]2 + cations in which L is coordinated via the amino nitrogen and phosphoryl oxygen atoms. The statistically disordered chloride ions and water molecules occupy voids between the cations. On the basis of spectral data, 1,2 and 3 are formulated as consisting of pseudo-octahedral tris-chelate cations [ML3]n + (n = 2 or 3) and non-coordinated halide ions and water molecules. A polymeric structure in which Cu(II) is surrounded by four bridging chlorides and two bridging L ligands is ascribed to 5.

Dimethyl Sulfoxide Containing Platinum(II) and Palladium(II) Chelate Complexes of Glyoxylic and Pyruvic Acid Thiosemicarbazones. A New Class of Cytotoxic Metal Complexes

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.

IR and Raman study of Pt(II) and Pd(II) complexes of amino substituted phosphine oxides: Normal coordinate analysis

Abstract IR and Raman spectra of Pt(dapo) 2 Cl 2 and Pd(dapo) 2 Cl 2 (dapo=dimethyl(aminomethyl)phosphine oxide) have been measured in the 200–4000 cm −1 frequency range. Both the IR and Raman spectra show that dimethyl(aminomethyl)phosphine oxide ligands are monodentate coordinate. The results from the normal coordinate analysis calculations confirm the monodentate coordination of the ligands in agreement with some literature data. For Pd(dapo) 2 Cl 2 complex the possibility for bidentate coordination of one dapo ligand is also considered.

Synthesis and vibrational study of platinum(II) and palladium(II) complexes of glyoxilic acid oxime

Abstract New platinum(II) and palladium(II) complexes of glyoxilic acid oxime (gao) have been prepared and characterised by infrared (4000–150 cm−1) and Raman (4000–200 cm−1) spectra. The gao acts as bidentate ligand bonding through the oxime nitrogen and carboxyl oxygen atoms to form neutral bis-chelate square-planar complexes. The lowest energy conformer of the gao ligand (ectt) was selected among 16 theoretically possible conformers on the basis of ab initio calculations at HF/3-21G*, HF/6-31G* and HF/6-311** levels of the theory from which structural parameters and conformational stabilities have been obtained. A complete vibrational assignment of the gao was performed for the lowest energy ectt conformer on the basis of ab initio optimised parameters and normal coordinate analysis calculations (PED). NCA calculations of the complexes studied were also performed.

Effect of Platinum(II) Complexes of Benzoic and 3-Methoxybenzoic Acid Hydrazides on Saccharomyces cerevisiae

Abstract The inhibitory effect of benzoic acid hydrazide (bah) and 3-methoxybenzoic acid hydrazide (mbah) on Saccharomyces cerevisiae strains has been compared to that of their platinum(II) complexes: cis-[Pt(bah)2X2], cis- [Pt(NH3)(bah)Cl2]-0.5 H2O. cis-[Pt(mbah)2X2] and cis- [Pt(NH3)(mbah)Cl2] (X = Cl, Br = I), and cis- [Pt(NH3)2Cl2]. The minimal inhibitory concentrations for bah and mbah were 5000-20.000 μm whereas for their Pt(II) complexes they were much less (25-800 jam) and did not exceed these of cisplatin (100-800 μm ) . The activity of the Pt(II) complexes of bah and mbah varied in wide ranges for the different yeast strains tested. Osmotically unstable mutants were found to be more susceptible. The most active complexes were [Pt(NH3)(bah)Cl2] · 0.5 H2O and [Pt(NH3)(mbah)Cl2