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A series of novel thymidine dithiocarbamate derivatives (DTC-TdR) were successfully synthesized and then radiolabelled using [99mTc(CO)3]+ core with high yields. The chemical characterizations of 99mTc(CO)3-labelled dithiocarbamate derivatives have been carried out by preparing their corresponding rhenium complexes. The radiotracers were stable in vitro, and the partition coefficient results indicated that they were lipophilic. The cell uptake studies showed the uptakes of these 99mTc(CO)3-labelled thymidine derivatives were mediated by nucleoside transporters. Biodistribution of the complexes in mice bearing tumor showed that they had high tumor uptake and good tumor/muscle ratio. A clear SPECT imaging of the tumor location was obtained in mice bearing S180 tumor with one of radiotracers, suggesting they would be potential tumor imaging agents.

Nine representative [Ru(S2CNEt2)2(diphos)] complexes were prepared in almost quantitative yields (91–97%) from [RuCl2(p-cymene)]2, sodium diethyldithiocarbamate trihydrate, and a diphosphine (dppm, dppe, dppp, dppb, dpppe, dppen, dppbz, dppf, or DPEphos), using a novel, straightforward, one-pot procedure. The recourse to a monomodal microwave reactor was instrumental in reaching the thermodynamic equilibria favoring the targeted monometallic trichelates. All the products were fully characterized by using various analytical techniques and the molecular structures of seven of them were determined by X-ray crystallography. NMR, XRD, and IR spectroscopies evidenced a significant contribution of the thioureide resonance form Et2N+=CS22– to the electronic structure of the 1,1-dithiolate ligand. MS/MS spectrometry showed the formation of phosphine-free [Ru(S2CNEt2)2]+ cations in the gas phase, except when starting from [Ru(S2CNEt2)2(dppbz)]. The activity of the nine complexes was probed in three different catalytic processes, viz., the cyclopropanation of styrene with ethyl diazoacetate, the synthesis of vinyl esters from benzoic acid and 1-hexyne, and the atom transfer radical addition (ATRA) of carbon tetrachloride and methyl methacrylate. In the first two reactions, the saturated trichelates were poorly efficient. This was most likely due to their high stability, which prevented the formation of coordinatively unsaturated species. Contrastingly, with a turnover number of 2000 and an initial turnover frequency of 2080 h–1 for a 0.05 mol% catalyst loading, the [Ru(S2CNEt2)2(dppm)] complex emerged as a very robust, latent ATRA initiator, whose activity matched or outperformed those displayed by the most efficient ruthenium catalysts described so far.

The syntheses, spectroscopic data and crystal structures of (H2NCOCH2CH2-C)(R2NCS2-S,S′)3Sn (1), (H2NCOCH2CH2-C,O)2SnCl2 (triclinic polymorph) (2), (H2NCOCH2CH2-C,O)(2-H2NCOC6H4S-O,S)SnCl2 (3) and Sn(C11H9N2O2)Cl3 (4) are reported. The tin atom in compound 1 (R = Et) is coordinated by three chelating dithiocarbamate anions and a C-bound non-chelating amidoethyl ligand to generate a SnS6C pentagonal-bipyramidal coordination polyhedron. Compound 2, which features SnC2O2Cl2 octahedra, was crystallised from mixed solvents (ethanol and water) and complements the two known monoclinic forms. Compound 3 arose unexpectedly due to ligand disproportionation of the tin starting material and a “trans-esterification” reaction of the starting ligand: distorted SnCSO2Cl2 octahedra are seen in the crystal structure. Compound 4 arose from another ligand disproportionation reaction and features neutral complex molecules with N2OCl3 donor sets coordinating to the octahedral tin atoms.

The reaction of [Cl 2 Sn(CH 2 CH 2 CO 2 Me) 2 ] with sodium pyrrolidinodithiocarbamate (NaPDTC) in CHCl 3 afforded [Sn(PDTC) 2 (CH 2 CH 2 CO 2 Me) 2 ], (1) . Transesterification reactions of (1) with different alcohols in the presence of dmso yielded [Sn(PDTC) 2 (CH 2 CH 2 CO 2 Et) 2 ], (2) , [Sn(PDTC) 2 (CH 2 CH 2 CO 2 Pr) 2 ], (3) , and [Sn(PDTC) 2 (CH 2 CH 2 CO 2 Bu) 2 ], (4) . All complexes were characterized by elemental analysis, FTIR, and 1 H, 13 C{ 1 H} and 119 Sn{ 1 H} NMR spectroscopy. In addition, the crystal structures of (1) , (2) and (4) , determined by single-crystal X-ray diffraction, confirmed the presence of two different ester groups in each product, namely a free C O group and a C O⋯Sn chelating system. For (1) , (2) and (4) , the Sn-C bonds occupy the apical positions of a distorted pentagonal bipyramid, whereas the five equatorial positions are taken by the S donor centres of the unsymmetrically bonded dithiocarbamate ligands and the C O⋯Sn contact. Complexes (1) and (4) display 1D chain networks, while (2) exhibits a 2D supramolecular structure. The supramolecular networks in all complexes are held by intermolecular C-H⋯O and C-H⋯S contacts.

Metal-directed self assembly of ferrocenyl based pyridyl functionalized dithiocarbamates afforded the novel macrocyclic metal-organic coordination polymers, [M(L)2]∞ (M = Zn(II), L = L2 (N-ferrocenylmethyl-N-pyridin-4-ylmethyl) dithiocarbamate 2, M = Cd(II), L = L1 (N-ferrocenylmethyl-N-pyridin-3-ylmethyl) dithiocarbamate 3); dimers [M(L1)2]2 (M = Zn(II) 1, Hg(II) 4) and a mononuclear [Cd(L2)(phen)], (phen = 1,10-phenanthroline) complex 5. These complexes have been characterised by elemental analysis, IR, UV–Vis., 1H and 13C NMR spectroscopy and their structures have been investigated by X-ray crystallography. In 2 and 3 the metal ions are six-coordinate with two bidentate dithiocarbamate ligands L1 and L2 in an equatorial plane and axially bonded by two Py(N) of the dithiocarbamate ligands on neighbouring molecules thus establishing distorted octahedral geometry (MS4N2) in 2-D polymeric structures. In L1 where the Py(N) is in the 3-position, a centrosymmetric dinuclear complex 1 is formed in which the metal ions adopt square pyramidal geometry. In 1–4, the dithiocarbamate ligands are uniquely bonded to the metal centres in a μ2, κ3-N, S, S bridging-chelating manner. In all the complexes the supramolecular structures are sustained via C H … π (MS2C, chelate) interactions. These unusual interactions have been supported by theoretical calculations. All the complexes show luminescent emissions in the solid phase.

A series of mono- and polynuclear ferrocenylthiosemicarbazone complexes were prepared via nucleophilic substitution reactions of various amine scaffolds with a ferrocenyl dithiocarbamate. The dithiocarbamate was prepared via a Schiff base condensation reaction. The compounds were characterised using various spectroscopic and analytical techniques including Nuclear Magnetic Resonance (NMR) and Infrared (IR) spectroscopy, mass spectrometry and elemental analysis. The ferrocenyl dithiocarbamate and thiosemicarbazone compounds were screened for their preliminary antimicrobial activity against the H37Rv strain of Mycobacterium tuberculosis and the chloroquine-sensitive (CQS) NF54 strain of Plasmodium falciparum. Against M. tuberculosis, the compounds displayed moderate to low activity. The mononuclear and octanuclear complexes were the most active, exhibiting similar MIC values. All compounds displayed moderate activity in the antiplasmodial screening. The mononuclear and trinuclear complexes exhibited enhanced activity compared to the complexes with higher nuclearity.

A straightforward single pot reaction of N-methylaryl-N-methylferrocenyl amine (L1-L3), CS2 and M(OAc)2 in Et3N at room temperature led to the formation of [M{κ2S,S–S2CN(CH2R)CH2Fc}n] {M = CoIII, R = 1-naphthyl, (1), 3-pyridyl (2), 2-furyl (3); M = NiII, R = 1-naphthyl, (4), 3-pyridyl (5), 2-furyl (6); M = CuII, R = 1-naphthyl, (7), 2-furyl (8); M = ZnII, R = R = 1-naphthyl, (9); n = 3 for 1–3 and n = 2 for 4–9}. L1-L3 and 1–9 were characterized by microanalysis and standard spectroscopic methods viz. MS, IR, 1H, 13C, DEPT 135 NMR, UV–vis. absorption and emission spectroscopy. Single crystal X-ray diffraction technique was used to detect a new polymorphic form of 8, sustained by significant S/lp⋯π and C–H…π intermolecular interactions. All the compounds were screened against a panel of microbes viz. Staphylococus aureus, Bacillus subtilis, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Remarkably, L1, 4 and 8 were found to have better antibacterial activity against S. aureus than Ciprofloxacin, while compound 5 was found to be as good an antifungal agent as Flucanazole against C. albicans. All the compounds display a single quasi-reversible cyclic voltammograms and formal redox potentials in the range of 407 to 224 mV vs Ag/Ag+ (CH3CN).

Five new organotin(IV) dithiocarbamate complexes of the form R2SnL2 (R = nBu, L = L1, (4-phenylpiperazine-1-dithiocarbamate) 1, L2, (N-benzyl-N′-methyl-4-pyridyldithiocarbamate) 2; Ph, L3, (N-benzyl-N′-methyl-3-pyridyldithiocarbamate) 3) and Ph3SnL (L = L4, (N,N′-di(methyl-3-pyridyldithiocarbamate)) 4, L5, (4-ethoxycarbonylpiperidine-1-dithiocarbamate) 5) have been synthesized and characterized by elemental analysis, spectroscopy (IR, UV–Vis., 1H, 13C and 119Sn NMR) and their structures have been investigated by single crystal X-ray crystallography. In (1,2) the structure has C2 symmetry with the tin atom in a highly distorted octahedral six-coordinate geometry in which the bidentate ligands are asymmetrically bonded and the two nBu groups subtend an angle at the metal of 140.7(1), 141.4(3)°. By contrast 3, also with C2 symmetry, with phenyl substituents, is closely octahedral. In 3 the Py(N) on the dtc backbone interacts with the H37 on the adjacent molecule via unconventional C–H⋯N hydrogen bonding forming a six membered benzene like (C2H2N2) structure. In 4 and 5 five coordinate TBP geometry is established; 4 contains two molecules in the asymmetric unit (4A and 4B). In 4 the Py(N) on the dithiocarbamate unit uniquely interacts with the tin atom on the neighbouring molecule with Sn⋯N contacts at 3.11 A. The C–H⋯π (CG) interactions between CG of 4A and H34 of 4B are also observed. These interactions have been supported by theoretical calculations. All the complexes luminesce in CH2Cl2 solution at room temperature except for 1; the strongest luminescent behaviour is found in 4. TGA analysis of 3 and 5 show a double and single step decomposition respectively.

The combination of bis-dithiocarbamate ligands derived from N,N′-dibenzylcyclohexane-trans-1,4-diamine with dimethyl- and di-n-butyltin(IV) dichloride provided two discrete dinuclear complexes of the composition [(Me2SnCl)2(bis-dtc)]·2CHCl3 (1) and [(nBu2SnCl)2(bis-dtc)] (2) with bis-dtc = N,N′-dibenzylcyclohexane-trans-1,4-diamine-bisdithiocarbamate. Additionally, single crystals of the composition [(nBu2SnCl)(mono-dtc)]·[nBu2SnCl2]2 (3) with mono-dtc = N,N′-dibenzylcyclohexane-trans-1,4-diamine-monodithiocarbamate were isolated. Within the crystal structures of the three complexes, a varied number of common (C–H⋯S, C–H⋯Cl and N–H⋯Cl) and less common (S⋯S, S⋯Cl, Cl⋯Cl, Cl⋯N and Cl⋯Sn) secondary interactions were observed and analyzed. The supramolecular solid-state organization of [(Me2SnCl)2(bis-dtc)]·2CHCl3 revealed the presence of channels, which were filled with chloroform molecules. In the crystal structure of [(nBu2SnCl)(mono-dtc)]·[nBu2SnCl2]2, the di-n-butyltin dichloride units are arranged in form of a so far unknown dimeric aggregate of the composition [(nBu2SnCl)(μ-Cl)2(ClSnnBu2)]. The latter assembly represents thus a rare example for a two-component co-crystalline assembly, in which a relatively large non-solvent molecule with unusual molecular structure is stored and stabilized.

Three new linear gold(I) complexes of the formulas [(Ipr)Au(S2CN(CH3)2)] (1), [(Ipr)Au (S2CN(C2H5)2)] (2) and [(Ipr)Au(S2CN(C7H7)2)] (3) [where Ipr = 1,3-bis(2,6-di-isopropylphenyl)imidazol-2-ylidenegold] have been prepared by the reaction of equimolar amounts of 1,3–bis(2,6-di-isopropylphenyl)imidazol-2-ylidenegold(I)chloride, [(Ipr)Au(Cl)] with sodium dimethyldithiocarbamate monohydrate, sodium diethyl dithiocarbamatetrihydrate and dibenzyl dithiocarbamate, respectively. The structures of the complexes have been determined by single X-ray crystallography. All gold(I) complexes (1–3) are iso-structural i.e. linear geometry. The complex (1) crystallizes in monoclinic space group ‘P21/a’, while the complexes (2) and (3) crystallize in orthorhombic space group ‘Pna21’. The IR spectra and 1H as well as 13C NMR measurements of the Au(I) complexes (1–3) corroborate well with their single crystal X-ray structure analysis. These gold(I) complexes show moderate potential anti-cancer activities against A549 (human lung carcinoma), HCT15 (human colon cancer), and HeLa (human cervical cancer) cell lines.

Eleven mixed-ligand organotellurium(IV) compounds of composition R2Te(dtc)(dtp) have been prepared employing two different dithiocarbamate (dtc) and dithiophosphate (dtp) ligands: 1, R2 = C4H8, dtc = S2CNEt2, dtp = S2P(OCH2)2CEt2; 2, R2 = C8H8, dtc = S2CNEt2, dtp = S2P(OCH2)2CEt2; 3, R2 = C4H8O, dtc = S2CNEt2, dtp = S2P(OCH2)2CEt2; 4, R2 = C5H10, dtc = S2CNEt2, dtp = S2P(OCH2)2CEt2; 5, R2 = C4H8, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CEt2; 6, R2 = C8H8, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CEt2; 7, R2 = C4H8O, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CEt2; 8, R2 = C5H10, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CEt2; 9, R2 = C4H8, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CMenPr; 10, R2 = C8H8, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CMenPr; 11, R2 = C4H8O, dtc = S2CN(CH2)4, dtp = S2P(OCH2)2CMenPr. 1–11 were characterized by mass spectrometry, IR spectroscopy and multinuclear NMR (1H, 13C, 31P, 125Te) spectroscopy. The molecular structures of 2, 4 and 6, of which 2 crystallized in form of two different polymorphs (2a and 2b), were analyzed by single-crystal X-ray diffraction analysis. This analysis showed that the coordination mode of both ligand types is anisobidentate. When considering only covalent Te–C and Te–S bonds, the coordination geometry of the tellurium atoms is distorted Ψ-trigonal-bipyramidal, since the lone pair is stereochemically active and occupies an equatorial position together with the carbon atoms of the tellurocycles. If secondary Te⋯S interactions are considered also, the coordination sphere around tellurium is best described as bicapped Ψ-trigonal-bipyramidal for the complexes with two intramolecular Te⋯S secondary bonds and monomeric molecular structures, and pentagonal-bipyramidal for the complexes in which neighboring molecules in the crystal lattice are linked through additional weak intermolecular Te⋯S secondary bonds to form dimeric supramolecular aggregates.

Two series of di and trinuclear chlorodiorganotin(IV) complexes derived from bis- and tris-dithiocarbamate ligands have been prepared and structurally characterized. The dinuclear complexes 1–2 of the composition {(R2SnCl)2(bis-dtc)} (1, R = Me; 2, R = nBu) have been obtained from R2SnCl2 (R = Me, nBu) and the triethylammonium salt of N,N′-dibenzyl-1,2-ethylene-bis(dithiocarbamate). The trinuclear complexes 3–9 with the general formula {(R2SnCl)3(tris-dtc)} 3, R = Me, tris-dtc = tris-dtc-Me; 4, R = Me, tris-dtc = tris-dtc-iPr; 5, R = Me, tris-dtc = tris-dtc-Bn; 6, R = nBu, tris-dtc = tris-dtc-Me; 7, R = nBu, tris-dtc = tris-dtc- iPr; 8, R = nBu, tris-dtc = tris-dtc-Bn; 9, R = tBu, tris-dtc = tris-dtc-Me) were prepared from R2SnCl2 (R = Me, nBu, tBu) and the potassium dithiocarbamate salts of (tris[2-(methylamino)ethyl]amine) (tris-dtc-Me), (tris[2-(isopropylamino)ethyl]amine) (=tris-dtc-iPr) and (tris[2-(benzylamino)ethyl]amine) (=tris-dtc-Bn). Compounds 1–9 have been analyzed as far as possible by elemental analysis, FAB+ mass spectrometry, IR and NMR (1H, 13C, 119Sn) spectroscopy, and single-crystal X-ray diffraction analysis. The solid state and solution studies showed that the dtc ligands are coordinated to the tin atoms in the anisobidentate manner. In all cases the metal centers are five-coordinate. The coordination geometry is intermediate between square-pyramidal and trigonal-bipyramidal coordination polyhedra with τ-values in the range of 0.32–0.53. For the members of each series characterized in the solid state by X-ray diffraction analysis, different molecular conformations were found. The crystal structures show the presence of C–H⋯Cl, C–H⋯S, C–H⋯π, S⋯Cl, S⋯S, Cl⋯Sn and S⋯Sn contacts.

Six novel monosubstituted dithiocarbamate compounds containing organotellurium(IV) heterocycles, C4H8OTeI[S2CN(CH2CH3)2] (1), C5H10TeI[S2CN(CH2CH3)2] (2), C4H8TeI[S2CN(CH2CH2)2] (3), C8H8TeI[S2CN(CH2CH2)2] (4), C4H8OTeI[S2CN(CH2CH2)2] (5) and C5H10TeI[S2CN(CH2CH2)2] (6) were synthesized. The compounds were characterized by common spectroscopic methods; IR, EI-MS and multinuclear NMR (1H, 13C and 125Te). The structure of compounds 2, 3, 5 and 6 was uniequivocally established by single-crystal X-ray diffraction studies. Compounds 3, 4 and 5 exhibit dimeric arrangements achieved through secondary bonding (Te···S) and in the case of 2, an additional Te···S interaction resulted in the formation of a self-assembled chain. Furthermore, the geometrical arrangement displayed in the tellurium atoms of all the compounds corresponds to a distorted octahedron while the coordination mode for the dithiocarbamate ligands is considered anisobidentate in all cases.

Metallacyclic palladium(II) complexes [Pd(L)(R3P)Cl], L = TIQDTC (1,2,3,4-tetrahydroisoquinolinedithiocarbamate), 4MpipDTC (4-methylpipradinedithiocarbamate), MPizDTC (N-methylpiperazinedithiocarbamate), R3P = Ph3P, (o-tolyl)3P, Ph2ClP, were synthesized in a 1:1 molar metal–ligand ratio. These complexes were characterized by elemental analyses, FT-IR, multinuclear (1H, 13C and 31P) NMR. The X-ray crystal structures of [Pd(TIQDTC)(Ph3P)Cl] and [Pd(TIQDTC)((o-tolyl)3P)Cl] show a slightly distorted square planar environment around the Pd(II) ion with S–Pd–S and P–Pd–Cl average bond angles of 74.51 and 92.41, respectively. These complexes were screened for cytotoxic, antifungal, anti-inflammatory and antibacterial activity. Some complexes exhibit a significant activity against fungi.

The title compounds were prepared in good yield by treatment of Re(CO)5Cl or [Re(CO)3(H2O)3]Br with sodium dimethyldithiocarbamate hydrate (NaS2CNMe2·H2O) and a neutral ligand yielding eight Re(CO)3(S2CNMe2)(L) derivatives: L = NH3 1, pyridine (py) 2, imidazole (im) 3, pyrazole (pz) 4, triphenylphospine (PPh3) 5, 1,3,5-triaza-7-phosphaadamantane (PTA) 6, t-butyl isocyanide (t-BuNC) 7, and cyclohexyl isocyanide (CyNC) 8. The resulting new complexes were characterized by 1H and 13C NMR and infrared spectroscopy. Each was also structurally elucidated by X-ray crystallography. General structural features in all eight compounds were similar. The orientation of the three single-faced ligands, py, im and pz, demonstrates an interaction with the filled π orbital of the dithiocarbamate. Compounds were tested for stability under conditions that mimic physiological conditions; 1–4 quickly decomposed, 7 and 8 decomposed over 24 h while 5 and 6 were stable.

Reactions of [Ru(PPh3)3Cl2] with ROCS2K in THF at room temperature and at reflux gave the kinetic products trans-[Ru(PPh3)2(S2COR)2] (R = nPr 1, iPr 2) and the thermodynamic products cis-[Ru(PPh3)2(S2COR)2] (R = nPr 3, iPr 4), respectively. Treatment of [RuHCl(CO)(PPh3)3] with ROCS2K in THF afforded [RuH(CO)-(S2COR)(PPh3)2] (R = nPr 5, iPr 6) as the sole isolable products. Reaction of [RuCl2(PPh3)3] with tetramethylthiuram disulfide [Me2NCS2]2 gave a Ru(III) dithiocarbamate complex, [Ru(PPh3)2(S2CNMe2)Cl2] (7). This reaction involved oxidation of ruthenium(II) to ruthenium(III) by the disulfide group in [Me2NCS2]2. Treatment of 7 with 1 equiv. of [M(MeCN)4][ClO4] (M = Cu, Ag) gave the stable cationic ruthenium(III)–alkyl complexes [Ru{C(NMe2)QC(NMe2)S}(S2CNMe2)(PPh3)2][ClO4] (Q = O 8, S 9) with ruthenium–carbon bonds. The crystal structures of complexes 1, 2, 4·CH2Cl2, 6, 7·2CH2Cl2, 8, and 9·2CH2Cl2 have been determined by single-crystal X-ray diffraction. The ruthenium atom in each of the above complexes adopts a pseudo-octahedral geometry in an electron-rich sulfur coordination environment. The 1,1′-dithiolate ligands bind to ruthenium with bite S–Ru–S angles in the range of 70.14(4)–71.62(4)°. In 4·CH2Cl2, the P–Ru–P angle for the mutually cis PPh3 ligands is 103.13(3)°, the P–Ru–P angles for other complexes with mutually trans PPh3 ligands are in the range of 169.41(4)–180.00(6)°. The alkylcarbamate [C(NMe2)QC(NMe2)S]− (Q = O, S) ligands in 8 and 9 are planar and bind to the ruthenium centers via the sulfur and carbon atoms from the C S and N C double bonds, respectively. The Ru–C bond lengths are 1.975(5) and 2.018(3) A for 8 and 9·2CH2Cl2, respectively, which are typical for ruthenium(III)–alkyl complexes. Spectroscopic properties along with electrochemistry of all complexes are also reported in the paper.

Five new hetero-organotellurium (IV) dithiocarbamates O[Si(CH 3 ) 2 CH 2 ] 2 TeIS 2 CN(CH 2 CH 2 ) 2 ( 1 ), O[Si(CH 3 ) 2 CH 2 ] 2 TeIS 2 CN(CH 2 CH) 2 ( 2 ), O[Si(CH 3 ) 2 CH 2 ] 2 TeIS 2 CN(CH 2 CH 2 ) 2 O ( 3 ), O[Si(CH 3 ) 2 CH 2 ] 2 -TeIS 2 CN(CH 2 CH 2 ) 2 S ( 4 ) and O[Si(CH 3 ) 2 CH 2 ] 2 TeIS 2 CN(CH 2 CH 2 ) 2 CH 2 ( 5 ) were prepared from the 2,2,6,6-tetramethyl-1-oxa-4,4-diiodo-4-tellura-2,6-disilacyclohexane and the corresponding dithiocarbamate (dtc) sodium salts in ethanol. The compounds were characterized by means of Elemental Analyses, FAB MS, IR, 1 H, 13 C, 125 Te NMR spectroscopy. The crystal structures of 1 , 3 and 4 were determined. Dithiocarbamate ligands display an anisobidentate chelating coordination mode on interacting with the tellurium center in all compounds. The Te(IV) immediate environment can be described as that of a sawhorse structure in which the lone pair is apparently stereochemically active and occupying an equatorial position in a distorted trigonal bipyramid. The two methylene groups occupy the other equatorial positions with a sulfur atom of the dithiocarbamate group and the iodine atom occupying the axial positions. The solid state structures of 3 and 4 exhibit important intermolecular interaction Te⋯S(2B). This interaction results in the formation of a dimer, which is better described as a distorted octahedron with an apparently inactive lone pair.

Heating cis-[Ru(S2CNMe2)(2)(CO)(2)] and [Ru-3(CO)(12)] in xylene affords octanuclear [Ru-8(mu(5)-S)(2)(mu(4)-S)(mu(3)-S)(mu-CNMe2)(2)(mu-CO)(CO)(15)] resulting from the double carbon-sulfur bond cleavage of two dithiocarbarnate ligands. The structure consists of a tri-edge-bridged square of ruthenium atoms with a further ruthenium atom being bound only to the central bridging atom. Studies suggest that it may be formed via the pentanuclear intermediate [Ru-5(mu(4)-S)(2)(mu-CNMe2)(2)(CO)(11)] which is formed in trace amounts. (c) 2007 Elsevier B.V. All rights reserved.

Six palladium(II) dithiocarbamates of general formula Pd(AmDTC) 2 , where HAmDTC = aminedithiocarbamic acid, [Pd(II) piperidinedithiocarbamate ( 1 ), Pd(II) 4-methylpiperidinedithiocarbamate ( 2 ), Pd(II) N -methylbenzyldithiocarbamate ( 3 ), Pd(II) dibenzyldithiocarbamate ( 4 ), Pd(II) dicyclohexyldithiocarbamate ( 5 ), Pd(II) N -cyclohexyl- N -methyldithiocarbamate ( 6) ] have been synthesized and characterized by elemental analyses, FT-IR, 1 H and 13 C NMR. The X-ray structure of Pd(II), compounds 3 and 4 , showed that the ligands are chelated by both sulfur atoms with bond angles S1–Pd–S4 = 179.24(2)° and S2–Pd–S3 = 179.09(5)°, with a distorted square planar geometry around Pd. All these complexes were screened for cytotoxic and antibacterial effects and showed significant antibacterial activity and no substantial in vitro cytotoxicity indicating specificity of the compounds.

Trans-[RuCl2(CO)2(PEt3)2] reacts with two equivalents of a series of 1,1-dithiolate ligands to form the bis(dithiolate) complexes, cis-[Ru(CO)(PEt3)(S2X)2] (X = CNMe2, CNEt2, COEt, P(OEt)2, PPh2). Two intermediates have been isolated; trans-[Ru(PEt3)2Cl(CO){S2P(OEt)2}] and trans-[Ru(PEt3)2(CO)(η1-S2COEt)(η2-S2COEt)], allowing a simple reaction scheme to be postulated involving three steps; (i) initial replacement of cis carbonyl and chloride ligands, (ii) substitution of the second chloride, (iii) loss of a phosphine. Thermolysis of cis-[Ru(CO)(PEt3)(S2CNMe2)2] with Ru3(CO)12 in xylene affords trinuclear [Ru3(μ3-S)2(PEt3)(CO)8] as a result of dithiocarbamate degradation. Crystal structures of cis-[Ru(CO)(PEt3)(S2X)2] (X = NMe2, COEt), trans-[Ru(PEt3)2Cl(CO){S2P(OEt)2}], trans-[Ru(PEt3)2(CO)(η1-S2COEt)(η2-S2COEt)] and [Ru3(μ3-S)2(PEt3)(CO)8] are reported.

“2 + 1” Dithiocarbamate (DTC)–isocyanide (ISO) system was studied to label amino acids and model peptides with 99 m Tc ( CO ) 3 + fragment. Two ways were used: (i) conjugation via free carboxy group of bifunctional DTC [ S 2 CNMe 2 - (L3), S2CNHCH2COO2− (L1) and S2C(C4H7N)COO2− (L2)] using pre-labeling procedure and (ii) conjugation via isocyanide ligand [tert-BuNC (L4), EtOC(O)CH2NHC(O)CH2NC (L5), and gly-gly-gly-CH2NHC(O)CH2NC (L6)]. Complexes M(CO)3L2L4− (1a, 1b), M(CO)3L3L4− (2a, 2b) and bioconjugates M(CO)3L1L5 (5a, 5b), and M(CO)3L1L6 (6b) (a, M = Re; b, 99mTc) were synthesized. Bioconjugates 4a and 4b were prepared by reaction of histidine methyl ester with 2a and 2b, respectively. All rhenium complexes were characterized by 1H and 13C NMR, IR, and MS spectroscopy and complexes with 99mTc, by HPLC using rhenium analogs as references.

Ruthenium(II) carboxylate and dithiocarbamate complexes containing 1,1′-bis(diphenylphosphino)ferrocene (dppf) were synthesized by displacement of triphenylphosphine in Ru(RCOO) 2 (PPh 3 ) 2 (R=Me, Et, Ph) and Ru(SC(S)NEt 2 ) 2 (PPh 3 ) 2 with dppf. The complexes Ru(RCOO) 2 (dppf) ( 1a : R=Me, 1b : R=Et, 1c : R=Ph) and Ru(SC(S)NEt 2 ) 2 (dppf) ( 3 ) were obtained in yields of 78–93%. The crystal structures of these complexes show coordination of the phosphorus atoms of dppf and four oxygen/sulphur atoms of carboxylate/dithiocarbamate ligands to a Ru(II) centre with axial-bond-distorted octahedral geometry. Two pseudo-polymorphic forms of 1c were isolated and crystallographically characterized. VT- 1 H- and 31 P{ 1 H}-NMR spectral studies of 1a – c and 3 demonstrate mono- and bidentate exchange behaviour of the carboxylate or dithiocarbamate ligands, together with concerted twisting of the Cp rings of the dppf ligand. Complex 1c in CH 3 CN at room temperature gives Ru(PhCOO) 2 (dppf)(CH 3 CN)(H 2 O) ( 2 ), the crystal structure of which reveals two monodentate benzoate ligands around octahedral ruthenium and intramolecular inter-ligand H-bonding interaction between the coordinated H 2 O and the pendant carboxylate oxygen atoms. The interrelationship of crystallographic properties, structural dynamics, ligand mobility and chemical instability of these complexes will be described.

The structures of first dithiocarbamate chromium(0) complex [Et4N][Cr(η2-S2CNC5H10)(CO)4] (1) and the diethyldithiophosphate tungsten(0) complex [Et4N][W{η2-S2P(OEt)2(CO)4] (2) have been determined by X-ray diffraction analyses. Crystal data for 1: space group, P21 with a=10.240(2) A, b=12.705(4) A, c=9.888(2) A, β=117.26(2)°, V=1143.6(4) A3, and Z=2. The structure was refined to R=0.027 and Rw=0.028; Crystal data for 2: space group, C2/c with a=13.054 (6) A, b=16.220 (4) A, c=11.417 (3) A, β=93.73 (3)°, V=2412.3 (14) A3, and Z=4. The structure was refined to R=0.026 and Rw=0.019. The geometry around the metal atom in the anion of these two complexes is a distorted octahedron. The dithiocarbamato and diethyldithiophosphato ligands, respectively, coordinate to the Cr and W metal center through the two sulfur atoms. The short CN bond length of 1.335(4) A in 1 indicates a considerable partial double bond character. The allyl dithiophosphate tungsten complex [W(CH3CN)(η3-C3H5)(CO)2{η2-S2P(OEt)2}] (3) can be obtained from the reaction of [W(CH3CN)2(η3-C3H5)(CO)2Br] and (EtO)2PS2NH4 in CH3CN at room temperature but decomposed in the reaction of 2 with allyl bromide. Complex 3 reacted with dppe in CH2Cl2 at room temperature to give a mixture of complex [W(η3-C3H5)(CO)2{η2-S2P(OEt)2}]2(μ-dppe) (4) and [W(η3-C3H5)(CO)2{η2-S2P(OEt)2(η1-dppe)] (5).

Reactions of (ring)MoCl3 [ring=cyclopentadienyl, η5-C5H5 (Cp) and indenyl η5-C9H7 (Ind)] with salts of the N,N-diethyldithiocarbamate (S2CNEt2)−, O,O′-diethyldithiophosphate [S2P(OEt)2]−, N,N′-diphenylformamidinate [CH(NPh)2]−, acetate (O2CCH3)− and acetylacetonate [CH3COCH(O)CH3]− (acac)− anions yield the molybdenum(IV) complexes of the type (ring)MoCl2X. Characterisation of new compounds by elemental analysis, IR and 1H-NMR spectroscopy and magnetic susceptibility measurements is discussed.

Reaction of [Fe2(μ-CS)(μ-CSMe)Cp2(CO)2]+ (1) with sodium N,N-dimethyldithiocarbamate [Me2dtc]Na affords a mixture of the dithiocarbene [Fe Fe(μ-CS){μ-C(SMe)S C(S)NMe2}Cp(CO)] (2) and the thiocarbyne [Fe2(μ-CS)(μ-CSMe)(μ-S2CNMe2)Cp2] (3). Complex 2 is quantitatively converted into 3 by photochemical irradiation. The X-ray molecular structure of 3 demonstrates the presence of three bridging ligands and exhibits the shortest FeFe interaction found in similar systems [2.453(1) A]. Complex 3 can also be obtained by reacting [Me2dtc]− with the di-solvento thiocarbyne [Fe2(μ-CS)(μ-CSMe)(NCMe)2Cp2]+ (1a). By contrast no stable addition product has been isolated in analogous reactions involving the thiocarbyne [Fe2(μ-CO)(μ-CSMe)Cp2(CO)2]+ (1b). The [Me2dtc]− nucleophilic addition at the μ-C to form [Fe2(μ-CO){μ-C(CN)SC(S)NMe2}Cp2(CO)2] (4a) is obtained starting from [Fe2(μ-CO){μ-C(CN)(SMe2)}Cp2(CO)2]SO3CF3 (1d). Photochemical reaction of the cyanocarbene 4a causes intramolecular ring closure affording [Fe Fe(μ-CO){μ-C(CN)S C(S)NMe2}Cp2(CO)] (5a).

Two dithiocarbamate derivatives of stannolane, 2-nbutyl-2-(dimethyldithiocarbamate)-1,3,2-oxathiastannolane and 2-nbutyl-2-(piperidyldithiocarbamate)-1,3,2-oxathiastannolane have been obtained and full characterized. The X-ray single crystal diffraction studies show the presence of a dimer arrangement, through the formation of an inorganic ring. The bond lengths between the tin and all the S and O atoms are in the middle of covalent and secondary bonds, with a remarkable preference toward oxygen atoms. Both oxathiastannolane units present in solid state an equilibrium between conformations, while the arrangement of the three fused rings (oxathiastannolane–distannoxane–oxathiastannolane) is almost planar.

The reaction between PPN[AuCl4] and [Hg(mes)(2)] gives the anionic complex cis-PPN[Au(mes)(2)Cl-2] (1) and [Hg(mes)Cl] as side-product. Complex 1 is a precursor to other compounds both neutral and cationic. Removal of one chloride ligand affords the mononuclear neutral complexes cis-[Au(mes)(2)ClL] (L = PPh3 (2), P{p-tol}(3) (3), AsPh3 (4), SPPh3 (5)) by addition of a neutral ligand or, alternatively if no ligand is added, dimeric cis-[Au(mes)(2)Cl](2) (6). If both chloride groups in 1 are removed, cationic compounds can be obtained by addition of a potentially bidentate ligand affording cis-[Au(mes)(2)(L-L)]X complexes (X = ClO4, L-L = bipy (7), L-L = phen (8), L-L = dppe (9) X = SO3CF3, L-L = dppm (10)). Dithiocarbamate- or acetate salts can be added to solutions of 'Au(mes)(2)X' (obtained by removal of two chloride anions in 1) leading to the neutral compounds cis-[Au(mes),(L-L)] (L-L = S2CNR2 (R = Me (11), Et (12), Bz (13)), O2CCF3 (14)). The structures of cis-[Au(mes)(2)Cl(PPh3)] (2) and cis-[Au(mes)(2)Cl](2) (6) have been established by an X-ray diffraction study.

Reaction of the alkoxo-containing niobium complexes [NbCl3(OR)2]2 (R=Me, Et, iPr) with β-diketones R′COCH2COR′ [R′=Me (Hacac); R′=tBu (Hdpm); R′=Ph (Hdbm)] in a 1:2 molar ratio, afforded the corresponding (alkoxo)(β-diketonato) complexes [NbCl2(OR)2(O,O′-R′COCHCOR′)] (R=Me, R′=Me 1; R=Et, R′=Me 2; R=iPr, R′=Me 3; R=Me, R′=tBu 4; R=Et, R′=tBu 5; R=iPr, R′=tBu 6; R=Me, R′=Ph 7; R=Et, R′=Ph 8; R=iPr, R′=Ph 9). The molecular structure of 8 was elucidated by an X-ray diffraction study. The kinetics of the displacement reaction of 5 and 8 with Hacac to give complex 2 and the corresponding β-diketone Hdpm or Hdbm have also been studied by 1H-NMR spectroscopy. Finally, the complexes [NbCl3(OR)2]2 reacted with reagents of the type Na(S2CNR′2), in a 1:4 molar ratio, to give the corresponding (alkoxo)[dialkyl(aryl)dithiocarbamato] complexes [NbCl(OR)2(S,S′-S2CNR′)2] (R=Me, R′=Me 10; R=Me, R′=Et 11; R=Me, R′=Bz 12; R=Et, R′=Me 13; R=Et, R′=Et 14; R=Et, R′=Bz 15; R=iPr, R′=Me 16; R=iPr, R′=Et 17; R=iPr, R′=Bz 18). All complexes were characterised spectroscopically.

Three nitrogen-containing aromatic heterocycles, 2-(1′-naphthyl)pyridine, 2-phenylquinoline, and 2,3-diphenylquinoxaline, have been mercurated in the naphthyl or phenyl ring 2-position and then symmetrised to form the mercury compounds Ar2Hg (Ar=Nppy (3), Phqn (1) or Dpqx (5), respectively). These reagents are suitable for trans-metallation and reaction with MHCl(CO)(PPh3)3 affords the complexes M(η2-C,NAr)Cl(CO)(PPh3)2, (6, M=Ru, Ar=Nppy; 7, M=Os, Ar=Nppy; 8, M=Ru, Ar=Phqn; 9, M=Os, Ar=Phqn; 10, M=Ru, Ar=Dpqx; 11, M=Os, Ar=Dpqx) in which each product features an aryl ligand that forms a strongly chelated five-membered ring through coordination of the heterocyclic N atom. The chloride ligand in each of the complexes 6–11 can be replaced by dimethyl dithiocarbamate to give ultimately the mono-triphenylphosphine complexes, M(η2-Ar)(η2-S2CNMe2)(CO)(PPh3) (12, M=Ru, Ar=Nppy; 13, M=Os, Ar=Nppy; 14, M=Ru, Ar=Phqn; 15, M=Os, Ar=Phqn; 16, M=Ru, Ar=Dpqx; 17, M=Os, Ar=Dpqx). Similarly, compound 10 when treated with Na(acac) gives Ru(η2-Dpqx)(η2-acac)(CO)(PPh3) (18), while treatment with trifluoroacetic acid gives Ru(η2-Dpqx)(O2CCF3)(CO)(PPh3)2 (19). Many of these complexes were found to be very robust, making them suitable for electrophilic aromatic substitution reactions under harsh conditions. In each case, the presence of the metal had both an activating and a directing effect on the aryl ring to which it was bonded. Bromination or nitration reactions, both of which are not normally possible with organometallic substrates, were carried out successfully, giving rise to monobrominated or dinitrated products, respectively. The following compounds were characterised, M(η2-Ar-4-Br)Cl(CO)(PPh3)2 (20, M=Ru, Ar=Phqn; 21, M=Os, Ar=Phqn; 22, M=Ru, Ar=Dpqx; 24, M=Os, Ar=Dpqx), M(η2-Dpqx-4-Br)(η2-S2CNMe2)(CO)(PPh3) (23, M=Ru; 25, M=Os), Os(η2-Ar)Cl(CO)(PPh3)2 (26, Ar=Nppy-6,8-(NO2)2; 27, Ar=Phqn-4,6-(NO2)2). Crystal structures of compounds 7, 12, 15, 18, 19, 21, 23 and 25 have been determined.

Treatment of the complex Mo(Nmes)(O)Cl 2 (dme) (mes=2,4,6-trimethylphenyl; dme=1,2-dimethoxyethane) with KTp Me2 , NaCp and bipy gives the corresponding derivatives (Tp Me2 )Mo(Nmes)(O)Cl ( 1 ), CpMo(Nmes)(O)Cl ( 2 ) and Mo(Nmes)(O)Cl 2 (bipy) ( 3 ). Other oxoimido compounds of composition Mo(Nmes)(O)(S 2 CNR 2 ) 2 (R 2 =C 4 H 4 4 , C 5 H 10 5 , i Pr 2 6 ) can be obtained by reacting Mo(Nmes)(O)Cl 2 (dme) with the appropriate dithiocarbamate salt. The NMR properties of 4 – 6 are consistent with the presence of two rapidly equilibrating dithiocarbamate ligands. The reaction of Mo(Nmes)(O)Cl 2 (dme) with different Grignard reagents, Mg(R)X, produces the trialkyl imido complexes Mo(Nmes)R 3 Cl (R=Me 7 , CH 2 C(Me) 2 Ph 8 , CH 2 SiMe 3 9 ).

The air-sensitive dithiophosphate complexes [Et 4 N][M(CO) 4 {η 2 -S 2 P(OEt) 2 }] ( 1 , M=Mo; 2 , M=W) are accessible by the reaction of M(CO) 4 (pip) 2 (pip=piperidine) (M=Mo, W) with NH 4 S 2 P(OEt) 2 in refluxing acetonitrile in the presence of Et 4 NBr. Complex 1 reacts with allyl bromide in CH 3 CN to give the complex [Mo(CH 3 CN)(η 3 -C 3 H 5 )(CO) 2 {η 2 -S 2 P(OEt) 2 }] ( 3 ). The single-crystal structures of complexes 1 and 3 have been determined by X-ray diffraction analyses. Crystal data for 1 : space group, C 2/ c with a =13.088(7), b =16.271(4), c =11.366(7) A, β =93.88(5)°, V =2414.9(21) A 3 , Z =4. The structure was refined to R =0.031 and Rw =0.031; Crystal data for 3 : space group, Pna 2 1 with a =15.979(3), b =8.613(2), c =12.720(3) A, V =1750.6(6) A 3 , Z =4. The structure was refined to R =0.026 and Rw =0.028. Treatment of 3 with piperidine results in the formation of the complex [Mo(η 3 -C 3 H 5 )(CO) 2 {η 2 -S 2 P(OEt) 2 }(C 5 H 10 NH)] ( 4 ), in which the labile CH 3 CN ligand was substituted by C 5 H 10 NH. The rotational behaviors of complex 3 and 4 in solution state were detected by variable-temperature 1 H-NMR spectroscopy. The mechanism can be described as a trigonal twist, which involves the rotation of the triangular face formed by the nitrogen ligand and the two sulfur atoms relative to the face formed by the allyl and the two carbonyl groups. The 16-electron dithiocarbamate complex [Mo(η 3 -C 3 H 5 )(CO) 2 (η 2 -S 2 CNC 5 H 10 )] ( 5 ) is produced by S 2 P(OEt) 2 − ligand replacement of 4 with C 5 H 10 NC(S)SH or the insertion reaction of CS 2 into the MoN bond of 4 with releasing of the (EtO) 2 P(S)SH ligand.

Reactions of [MCp*Cl4] (M=Mo, W; Cp*=η5-C5Me5) with salts of the N,N-diethyldithiocarbamate [Et2dtc]− and O,O′-diethyldithiophosphate [Et2dtp]− anions yield the paramagnetic metal(V) complexes [MCp*Cl3(Et2dtc)] (M=Mo, W) and [MCp*Cl3(Et2dtp)] (M=Mo, W), respectively. Hydrolytic oxidation of both dithiocarbamate–molybdenum complexes with aqueous hydrogen peroxide leads to η2-coordinated peroxo compounds [MoCp*Cl(O–O)O], which were also obtained from [MoCp*Cl4]. The related complexes [MCp′Cl(O–O)O] (M=Mo, Cp′=η5-C5H5; M=W, Cp′=η5-C5Me5) were isolated in a similar way. Reduction of a THF solution of [MoCp*Cl4] with one equivalent of 10% Na/Hg followed by the addition of one equivalent of ammonium dithiophosphate gives [MoCp*Cl2(Et2dtp)] which was also obtained via the reaction of [MoCp*Cl3(Et2dtp)] with MeMgCl, whereas reduction with three equivalents of Na/Hg in the presence of CNtBu leads to the molybdenum(II) complex [MoCp*(Et2dtp)(CNtBu)2] in high yield. All these compounds were characterized by elemental analysis, IR, 1H- and 13C-NMR spectroscopy, magnetic susceptibility measurements and the molecular structures of [Mo(η5-C5H5)Cl(O–O)O] and [Mo(η5–C5Me5)Cl3{η2-S2P(OEt)2}] were determined by X-ray diffraction studies., Consiglio Nazionale delle Ricerche (Rome)

The reaction of [RuCl(PPh3)2{HB(pz)3}] (pz=pyrazol-1-yl) with 4-ethynyl toluene provides [RuCl(CCHC6H4Me-4)(PPh3){HB(pz)3}] (1a) which reacts with [Et2NH2][S2CNEt2] to give the metallacyclic alkenyl complex [Ru{C(CHC6H4Me-4)SC(NEt2)S}(PPh3){HB(pz)3}] (2). The reaction of [RuCl(PPh3)2{HB(pz)3}] with diphenylpropynol and Ag[PF6] however provides [Ru(CCCPh2)(PPh3)2{HB(pz)3}]PF6 (3) or in the absence of silver salts, the neutral complex [RuCl(CCCPh2)(PPh3){HB(pz)3}] (4). Both (3) and (4) react with Na[S2CNMe2] to give the metallacyclic allenyl complex [Ru{C(CCPh2)SC(NMe2)S}(PPh3){HB(pz)3}] (5). Treatment of [RuHCl(CO)(PPh3)3] with diphenylpropynol and Na[S2CNMe2] provides [Ru(CHCHCPh2OH)(S2CNMe2)(CO)(PPh3)2] which reacts with excess diphenylpropynol to give the alkynyl complex [Ru(CCCPh2OH)(S2CNMe2)(CO)(PPh3)2]. Protonation of this complex with HBF4 provides the allenylidene complex [Ru(CCCPh2)(S2CNMe2)(CO)(PPh3)2]BF4 (6) which reacts with Na[S2CNMe2] to give a kinetic isomer (7k) and ultimately a structurally characterised thermodynamic isomer of the metallacyclic allenyl complex [Ru{C(CCPh2)SC(NMe2)S}(S2CNMe2)(CO)(PPh3)] (7t).