Giuseppina Faraglia

Platinum(II) and palladium(II) complexes with dithiocarbamates and amines: synthesis, characterization and cell assay

The [M(ESDT)Cl]n (M = Pd or Pt; ESDT = EtO2CCH2(CH3)NCS2, methylamino-acetic acid ethyl ester-dithiocarboxylate) species have been reacted with various amines (py, pyridine; PrNH2, n-propylamine; c-BuNH2, cyclobutylamine; en, ethylenediamine) in dichloromethane or chloroform with the aim to obtain mixed ligand complexes. The neutral complexes [M(ESDT)(L)Cl] (L = py, PrNH2 or c-BuNH2) and the ionic species ([M(ESDT)(L)2]Cl and [M(ESDT)(En)]Cl) have been isolated, and characterized by IR and proton NMR spectroscopies. The crystal structure of [Pd(ESDT)(PrNH2)Cl] has been determined by X-ray crystallography. The behaviour of the complexes in various solvents was described on the basis of the proton NMR spectra. The complexes and the dithiocarbamato intermediates have been tested for in vitro cytostatic activity against human leukemic HL-60 and HeLa cells.

Complexes of organometallic compounds V. Diphenyltin(IV) and triphenyltin(IV) oxinates

Abstract The complexes formed between diphenyltin(IV) and triphenyltin(IV) cations and 8-quinolinol were prepared and studied spectrophotometrically in ethanol solution. It was shown that diphenyltin dioxinate is very probably a chelate complex, with a coordination number of six for the tin atom, and that triphenyltin oxinate probably is not a chelate complex, and has a coordination number of four for the tin atom. Triphenyltin oxinate has been prepared in the solid state for the first time.

Organometallic chemistry of uranium II. The preparation and properties of CpUCl3·DME

Abstract Cyclopentadienyluranium(IV) chloride has been prepared as the dimethoxyethane adduct of formula CpUCl 3 ·DME by treatment of uranium tetrachloride with cyclopentadienylthallium in dimethoxyethane. It has been characterized by IR and electronic spectra.

Complexes of platinum(II) halides with dithiocarbamic esters

Abstract Platinum(II) halides form either 1:1 or 1:2 complexes with dithiocarbamic esters (R 2 NC(S)SR′). Complexes of both stoichiometries have been obtained with the ligands TMDT (R  R′  Me) and DMDTE (R  Me; R′  Et), whereas with TEDT (R  R′  Et) only the 1:1 adducts were isolated. From IR spectra the complexes of formula PtL- 2 X 2 (L = TMDT, DMDTE; X = Cl, Br, I) have a trans square planar configuration by two halide and two thiocarbonyl sulfur atoms. In the complexes of formula PtLX 2 , for which a cis square planar configuration is suggested, the ligands act probably as bidentate through either thiocarbonyl or thioether sulfur. All the complexes have been tested for cytostatic activity on KB cells.

Organometallic chemistry of uranium I. Dicyclopentadienyluranium(IV) chloride

Abstract Dicyclopentadienyluranium(IV) chloride (Cp 2 UCl 2 ) has been prepared by reaction of uranium tetrachloride with cyclopentadienylthallium in dimethoxyethane, and has been characterized by elemental analysis and UV and IR spectra.

Dioxouranium(Vl) complexes with pentadentate bases containing acetal groups

Abstract The new ligands [(OCH 3 ) 2 CHHOC 6 H 2 ClCH N(CH 2 ) 2 ] 2 NH, H 2 (NAC), and [(OCH 3 ) 2 CHHOC 6  H 2 ClCHN(CH 2 ) 2 ] 2 S, H 2 (SAC), and the related uranyl complexes [UO 2 (NAC)] and [UO 2 (SAC)] have been prepared and characterized by infrared, 1 H and 13 C NMR and electronic spectroscopy. Thermogravimetric and mass spectrometry data are also reported. The crystal structures of the complexes have been determined by X-ray crystallography. [UO 2 (SAC)] is monoclinic, space group P 2 1 / n , with a = 20.591(5), b = 11.948(8), c = 11.780(8) A, β = 90.11(3)°; D c = 1.86 g cm −3 for Z = 4. The structure was refined to the conventional R of 4.6%. [UO 2 (NAC)] is tetragonal, space group P 4 1 2 1 2, with a = 12.605(8) and c = 17.801(5) A; D c = 1.87 g cm −3 for Z = 4. The structure was refined to the conventional R of 5.7%. In both compounds the pentadentate dianionic ligand binds equatorially to UO 2 2+ leading to seven-coordinated uranium in a distorted bipyramidal coordination geometry. Selected bond distances for [UO 2 (SAC)] are: UO (uranyl) 1.77 A (mean), UO (ligand) 2.22 A (mean), UN 2.61 A, (mean) and US 3.003(3) A. In [UO 2 - (NAC)] the corresponding values are: UO (uranyl) 1.72 A, UO (ligand) 2.21 A (mean), UN 2.56 A, and UNH 2.60 A.

N,N-dimethyl O-ethylthiocarbamate complexes of palladium(II) and platinum(II) halides

Complexes of formula M(DMTC)2X2 (where M = Pd, Pt; DMTC = N,N-dimethyl O-ethylthiocarbamate; X = Cl, Br, I) have been prepared and studied by visible, IR and 1H nmr spectroscopy. The ligand acts as sulfur donor towards the metal atom. The complexes have generally a trans square-planar geometry. Whereas the structure of solid Pd(DMTC)2Cl2 could not be determined, in solution a trans configuration is suggested. Cis-Pt(DMTC)2X2 (X = Cl, Br) have been also isolated, which in solution slowly isomerize to trans. The compounds have been tested for possible cytotoxic effects.

Palladium and platinum dithiocarbamato complexes containing mono- and diamines

The [M(DMDT)X]n (M=Pd or Pt; DMDT=Me2NCS2−; X=Cl or Br) species have been reacted with various amines (Py, pyridine; Pra, n-propylamine; Cba, cyclobutylamine; Dap, 1,3-diaminopropane; En, ethylenediamine) in dichloromethane with the aim of obtaining mixed complexes of various stoichiometries. Along with the neutral complexes M(DMDT)(L)X (L=Py, Pra or Cba), the ionic species [M(DMDT)(L2)]X, [M(DMDT)(En)]X and [M(DMDT)(Dap)]X have been isolated, which have been characterised by IR and proton NMR spectroscopy. Thermogravimetric data suggest a particular behaviour for the palladium–Pra and palladium–Cba derivatives, with formation of low-stoichiometry intermediates of formula Pd2(DMDT)2AmX2. The behaviour of the prepared complexes in various solvents has been described on the basis of the proton NMR spectra. All complexes have been tested for in vitro cytostatic activity against KB cells.

Synthesis, characterisation and X-ray crystal structures of diorganotin(IV) complexes with 2-mercaptopyridine derivatives

Abstract By reaction of diorganotin(IV) dihalides with esters of 2-mercapto-pyridine-5-carboxylic acid ( R = Et, HTNEE; R = i Pr, HTNIPE ) the complexes R2SnX(L) and R2Sn(L)2 (L = TNEE or TNIPE; R = Me, Et, Bu or Ph) have been prepared and characterised by IR, NMR, and Mossbauer spectroscopies. The structures of Et2SnBr(TNIPE) and Me2SnCl(TNEE) have been determined by an X-ray single crystal diffraction study. Both ligands behave as bidentate chelating groups forming a four-member ring with very similar and small NSnS bite angles. The tin atom is pentacoordinated in a severely distorted trigonal bipyramidal geometry with apical XSnN angles of 151.9(2)° for Et2SnBr(TNIPE) and 154.9(1)° for Me2SnCl(TNEE) and equatorial CSnZ angles of 127.4(6)° and 129.8(2)° respectively. On the basis of 119Sn Mossbauer data, analogous structure are proposed for all the complexes.

The behaviour of dithiocarbamic ester palladium(II) and platinum(II) complexes in dimethyl sulfoxide

Abstract The complexes [M(MeS 2 CNMe 2 )X 2 ] (M=Pd or Pt; X=Cl or Br) decompose in dimethyl sulfoxide, yielding species which contain the dimethyldithiocarbamato moiety. In order to clarify the degradation pathway, the mixed species [M(S 2 CNMe 2 )(Me 2 SO)X] have been prepared and characterized by infrared and 1 H NMR spectroscopy and by thermal analysis (TG, DTG and DTA). Although all square planar mixed complexes contain S-bound dimethyl sulfoxide, the platinum derivatives are stabler than the palladium analogues, which release easily the Me 2 SO molecule either on heating or in solution to form the [Pd(S 2 CNMe 2 )X] n species. Accordingly Me 2 SO interaction with the [M(MeS 2 CNMe 2 )X 2 ] complexes depends on the different solvent to metal donor ability. The nature of the interaction products is discussed on the basis of proton NMR spectra in deuterated dimethyl sulfoxide.