Density functional theory study of the fourier transform infrared and Raman spectra of dichloro-bis(2,4-pentanedionate)tin(IV).

Fourier transform infrared and Fourier transform Raman spectra of dichloro-bis(2,4-pentanedionate)tin(IV) have been obtained. Density functional theory (DFT) BLYP calculations, have been carried out with the purpose of understanding the metal-ligand region spectra of this compound. Vibrational wavenumbers calculated by BLYP/6-31G* force fields are closed with the experimental results. The percentage of deviation of the bond lengths and bond angles gives a good picture of the normal modes, and serves as a basis for the assignment of the wavenumbers. The calculated geometrical parameters show slight differences compared with the experimental ones, and these differences can be explained by the different physical state of Sn(acac)2Cl2. The DFT-BLYP calculations assumed a free molecule in the gas phase. The experimental wavenumbers are obtained from the spectra of solid samples.

Acetonyldichloro[(Z)-2-chloro-2-phenylvinyl]tellurium(IV), helical chains of metal complexes.

The primary geometry about the Te(IV) atom in the title compound, [TeCl2(C8H6Cl)(C3H5O)] or C11H11Cl3OTe, is a pseudo-trigonal-bipyramidal arrangement, with two Cl atoms in apical positions, and the lone pair of electrons and C atoms in the equatorial plane. The Te(IV) atom is involved in three secondary interactions, two intramolecular [Te...O = 2.842 (3) A and Te.Cl3 = 3.209 (1) A] and one intermolecular [Te...Cl = 3.637 (1) A], the latter giving rise to a helical chain. These helices are linked by C-H...O interchain interactions.

Hydrogen-bonded hexagonal and pseudo-hexagonal grid motifs in supramolecular cobalt(II) and nickel(II) cupferronato complexes incorporating neutral N-donors with intermolecular NH2 connectors and solvent molecules.

The cobalt(II) and nickel(II) cupferronato (N-nitroso-N-phenylhydroxylaminato) mixed-ligand complexes of 2-aminopyridine (2-NH(2)py) [Co(PhN(2)O(2))(2)(2-NH(2)py)(2)] (1), [Ni(PhN(2)O(2))(2)(2-NH(2)py)(2)] (2) and 2,6-diamino-4-phenyl-1,3,5-triazine (dpt) [Co(PhN(2)O(2))(2)(dpt)(2)].[Co(PhN(2)O(2))(2)(EtOH)(2)] (3) have been synthesized and characterized by X-ray diffraction analysis. The cobalt (1) and nickel (2) complexes are isostructural. The crystal lattice of (3) contains different neutral cobalt(II) complexes [Co(PhN(2)O(2))(2)(dpt)(2)] (3a) and [Co(PhN(2)O(2))(2)(EtOH)(2)] (3b). Molecules of (1)-(3) contain octahedral metal centres with all-cis-(1) and -(2) and all-trans-(3) disposal of the ligands. Intramolecular N-H.O hydrogen bonding between the NH(2) groups and the O atom of the cupferronato anion can be observed in (1)-(3). Intermolecular N-H.O and N-H.N interactions between symmetry-related molecules of (1) and (2) led to hexameric aggregates which connect through common edges into a two-dimensional supramolecular network of hexagonal-grid type. In complex (3) the self-complementary dpt units of the (3a) molecules are maintained by intermolecular N-H.N hydrogen bonds, generating infinite chains. These (3a) chains are crosslinked by the (3b) subunits via N-H.O and O-H.N hydrogen bonds, thus completing the parallel two-dimensional supramolecular network consisting of pseudo-hexagonal-grid sheets. In each crystal structure the two-dimensional supramolecular networks are controlled by both hydrogen bonds and pi.pi stacking interactions.

Genotoxicity of Some Metal-Based Antineoplastics, Evaluated by SOS Chromotest and Cytogenetic Analysis.

The paper reports the screening results of two metal-based antineoplastic drugs with mutagenic potential, such as Romcis (trademark of Cisplatinum, produced in Romania) and diphenylantimony(III) diisopropyldithiophosphate (PADTF). Their effects were compared with those induced by Cyclophosphamide. Two mutagenicity tests, the SOS Chromotest and cytogenetic analysis were applied. The tests were carried out with or without metabolic activation (addition of S(9)-mix), either in E. coli PQ 37 cultures, using four doses (0.3, 3, 30 and 300 pmol compound/assay) for the SOS Chromotest or in leukocyte cultures using 0.3 mM from each compound, for cytogenetics. The dose- response relationships and SOSIP values revealed an indirect mutagenic potential for Cyclophosphamide, amplified by S(9) mix in bacterial cultures and an antiproliferative, clastogenic effect on lymphocytes. For Romcis and diphenylantimony(III) diisopropyldithiophosphate, a significant positive response by SOS Chromotest was recorded, which correlated with increased frequencies of chromosomal aberrations.

Antitumour Organometallics. III. In Vivo Activity of Diphenylantimony(III) and Diorganotin(IV) Dithiophosphorus Derivatives Against P388 Leukemia.

Diphenylantimony(III) and diorganotin(IV) derivatives of dithiophosphorus ligands, i.e. Ph(2)SbS(2)PR'(2) (R' = Ph, OPr-i) and R(2)Sn(S(2)PR'(2))(2) (R = n-Bu, Ph, R' = Ph; R = Ph, R' = OPr-i), have been screened against P388 leukemia in mice. All the compounds showed marginal activity towards this tumor system, some of them increasing the life span of the animals with more than 20%. The best results were obtained with (di-iso-propylphosphorodithioato)diphenylantimony(III) which exhibited a T/C value of 136%, at a dose of 5 mg/kg, administered on days 1,2 and 3 after tumor transplantation.

Antitumor Organometallics. IV. The Mutagenic Potential of Some Diphenylantimony(III) Dithiophosphorus Derivatives.

Two diphenylantimony(III) derivatives of dithiophosphorus ligands, i.e. Ph(2)SbS(2)PPh(2) and Ph(2)SbS(2)P(OPr-i)(2), which were previously found to exhibit antitumor properties, have been now investigated for potential mutagenic effects in healthy and Ehrlich ascites tumor-bearing mice. Two short-term tests, i.e. the micronucleus test and the cytogenetic analysis, were used as end-points for mutagenicity. The results are consistent with a mutagenic potential for both organoantimony(III) compounds tested, the effect being higher for the phosphorodithioato derivative.

Antitumor organometallics. I. Activity of some diphenyltin(IV) and diphenylantimony(III) derivatives on in vitro and in vivo Ehrlich ascites tumor.

Diphenyltin(IV) and diphenylantimony(III) derivatives of dithiophosphorus ligands, i.e. Ph2Sn(S2PPh2)2 (1), Ph2Sn[S2P(OPr)2]2 (2), Ph2SbS2PPh2 (3) and Ph2SbS2P(OPri)2 (4), have been tested in vitro and in vivo against Ehrlich ascites tumor. All four compounds were almost equally effective in vitro, exhibiting inhibitory effects on cell proliferation, viability and protein synthesis, and exacerbated respiration and Ca-ATPase activity. In mice bearing Ehrlich ascites tumor cells, all four compounds inhibited the tumor growth, the organometallic phosphorodithioates being more active than phosphinodithioate analogues, and the organoantimony derivatives more active than organotins. Compound 4 (5 mg/kg/day, i.p., on days 1,3 and 5) produced an increase in life span of 83% and a cure rate of 30% in mice bearing this tumor.

Antitumor organometallics. II. Inhibitory effects of two diphenyl-antimony (III) dithiophosphorus derivatives on in vitro and in vivo Ehrlich ascites tumor.

(Diphenylphosphinodithioato) diphenylantimony (III), Ph2SbS2PPh2 (1) and (diisopropylphosphorodithioato) diphenylantimony(III), Ph2SbS2P(OPri)2 (2) were tested in vivo in male AKR mice and in vitro against Ehrlich ascites tumor cells. Both compounds exhibited dose-dependent inhibitory effects on in vivo tumor growth and on in vitro cell proliferation, cell viability, respiration and protein synthesis. The activities of some enzymes involved in energetic metabolism (Ca-ATPase, LDH, G6Pase) were exacerbated in vitro. The inhibitory effects could be related to the imbalance between ATP-producing and ATP-consuming processes in Ehrlich ascites tumor cells and also to their cell-cycle specificities.

The first organoantimony(III) compounds possessing antitumor properties: diphenylantimony(III) derivatives of dithiophosphorus ligands.

Two organoantimony (III) derivatives, i.e., diphenylantimony diphenyl-dithiophosphinate, Ph2SbS2PPh2, and diphenylantimony diizopropyldithiophosphate, Ph2SbS2P(OPri)2, were shown to exhibit antitumor properties. Both compounds produced strong tumor inhibition effects in mice bearing Ehrlich ascites tumor. Moreover, the dithiophosphate (15 mg/kg, i.p., in days 1, 3 and 5) produced a cure rate of 30%.

Rhodium, iridium, copper and gold antitumor organometallic compounds (review).

Recent results on the antitumor activity of organometallic compounds of rhodium, iridium, copper and gold are reviewed. Coordination compounds of some organic ligands are also briefly mentioned. The most promising seem to be copper and gold complexes which exhibited remarkable activity against several tumor systems.

Pretreated bright palladium electrode in potentiometric redox titrations Titration of Cr(2)O(7)(2-) and Ce(4+) with Fe(2+).

The behaviour of the bright palladium electrode toward the redox systems Cr(2)O(7)(2-)/Fe(2+) and Ce(4+)/Fe(2+) (in potentiometric titration) has been investigated as a function of pretreatment of the electrode. Anodization of the electrode at potentials higher than 800 mV increases DeltaE at the equivalence point by 300-400 mV for the dichromate titration. The sharp change in potential is due to the reaction between PdO(2) and Fe(2+). The equivalence point corresponds to the beginning of the potential drop, rather than the inflexion point, especially for dilute solutions. If the electrode is ignited before use the surface oxide PdO is oxidized to PdO(2) by Cr(V), the potential increases during the titration and DeltaE is 200 mV bigger than when an untreated electrode is used. In the titration of Ce(4+) with Fe(2+) the DeltaE is largest with untreated electrodes, and if the anodized electrode is used, the titration curves clearly show the reaction between PdO(2) and Fe(2+).