Jeanne Jordanov

Synthesis and X-ray structure of tris(N,N-diethyldithiocarbamato)-hydrogensulphidomolybdenum(IV)–tetrahydrofuran (1/1)

The complex [Mo(SH)(S2CNEt2)3]·thf (thf = tetrahydrofuran) has been prepared by the reaction of [Mo(CO)2(S2CNEt2)2] with [Fe4(cp)4S6](cp =η5-cyclopentadienyl). The compound crystallizes in the space group P with a= 10.148(5), b= 14.104(4), c= 10.759(6)A, α= 72.39(3), β= 89.04(6), γ= 97.84(3)°, and Z= 2. The structure was solved by Patterson and Fourier-difference techniques and refined to R= 0.070 and R′= 0.066 for 2 774 independent reflections. The molybdenum atom is surrounded by seven sulphur atoms in a distorted pentagonal-bipyramidal co-ordination.

Interaction of cis-diaminotolueneplatinum(II) with nucleosides: evidence for guanosine O(6).N(7) chelation by platinum

The binding of the anti-tumour agent cis-[Pt(dat)Cl2)(dat = 3,4-diaminotoluene) to nucleosides is reported; adenosine and cytidine act as monodentate ligands, via N(7) or N(3), respectively, and guanosine behaves as a bidentate ligand, the Pt atom being firmly bound at N(7) and weakly via O(6).

Metal-catalysed ring opening. Reactions of 2-amino-thiazole and -thiazoline with palladium(II) and platinum(II)

[PtCl4]2– and [Pd2Cl6]2– ions condense in basic media with an amino-substituted thiazoline or thiazole to give complexes in which ring opening has been induced by C–S bond cleavage.

Reactivity of primary amines co-ordinated to palladium and platinum. Part II. Cyclometallation and rearrangement of the co-ordinated ligands

Reaction of trans-[PdCl2(NH2X)2](X = NPhR or PhCH2; R = Ph, Me, or H) with acetophenone gives the cyclo-palladated dimer [{PdCl(C6H4CMeNX)}2], the acetophenone phenyl ring being orthometallated. Reaction of [PtCl4]2– and [Pd2Cl6]2– with 2-aminothiazoline and 2-aminothiazole (L) affords in acid media the cyclic N-co-ordinated monosubstituted [NBu4][PdCl3L] and disubstituted cis-[PtCl2L2] and trans-[PdCl2L2] complexes. In basic solution, the monomeric [PdCl2L′2] and dimeric [{MCl2L′}2] species are obtained [M = PtII or PdII; L′= HS·CH2·CH2·NH·C⋮N and HS·CH:CH·NH⋮N. The combined presence of the metal and hydroxide ions appears to induce the ring opening and rearrangement of the amine ligands.

Synthesis and Characterization of [Fe4S5Cp4][MoOCl (thf)]: A “Cubane” Type Cluster with One Penta-Coordinated Fe Site

Recent findings show that natural Fe-S clusters (1) are not confined to the by now well studied species having planar 2Fe-2S and cubane-type 4Fe-4S core units. This has triggered a series of synthetic efforts to obtain new polynuclear Fe/S geometries, where one of the Fe sites is different from the others in its coordination number and/or type of ligands (2). In this paper we report the preparation and properties of a new structural Fe-S cluster type. The X-rays analysis reveals a S22− ligand bonded to three of the Fe sites, and one Fe atom is pentacoordinated. Also, EPR and Moessbauer studies indicate the presence of a [3FeIII, 1FeII] oxidation state.

Binding of cis-dichlorobis(1-methylimidazole-2-thiol)-palladium(II) and -platinum(II) to nucleosides: synthesis and hydrogen-1 and carbon-13 nuclear magnetic resonance studies

The reactions of cis-[MCl2(mit)2](M = Pd or Pt; mit = 1-methylimidazole-2-thiol) with guanosine (guo), cytidine (cyd), and adenosine (ado) have been studied in neutral solutions. Two types of complexes have been isolated, of general formula [M(mit)2L2]X2(L = guo or cyd) and [ML4]X2(L = cyd or ado) with X = Cl– and [PF6]–. By use of i.r. spectroscopy and of the chemical shifts occurring in 1H and 13C n.m.r. spectroscopy, it is possible to confirm co-ordination of Pd and Pt to N7 in guo and ado, and to N6 in cyd. The n.m.r. investigations reflect electronic modifications in the ring system of the co-ordinated nucleosides, which are discussed in terms of DNA denaturation by heavy transition-metal complexes.