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Reaction of CoSO4 and 4-hydroxybenzhydrazide in water/methanol solution resulted in polymeric complex with C O and NH2 groups of organic ligand, two water molecules and two oxygen atoms of two sulfate anions in metal coordination sphere. The X-ray analysis revealed that the complex is in the form of polymer chain of the helical structure formed due to sulfate bridge geometry and intra-chain hydrogen bonds. The variety of coordinated ligands is reflected in the vibrational spectra where six different metal–ligand modes were found. The bands related to stretching and bending vibrations of NH2, NH, OH groups as well as water molecules were located with help of hydrogen–deuterium substitution. For proposed band assignment the animation of DFT calculated normal modes was employed.

This article presents the electronic spectral characteristics enhanced with the structural, IR and magnetic data of the copper(II) acetate complex with 3-methyl-4-nitropyridine-N-oxide. The complex of the formula, [Cu2(OAc)4(3-mnpn)2], belongs to the group of the ‘paddle wheel’ type species with a very short (2.58 A) metal–metal distance. In the electronic spectra, new bands were found at 16,000 and 24,000 cm−1, which have been tentatively assigned to the metal–metal interactions and solid state effects, respectively. The complex show fast kinetic exchange of the apical ligand, i.e. 3-methyl-4-nitropyridine-N-oxide.

The structure of known copper(II) complex with 4-hydroxybenzoic acid hydrazide has been corrected on the basis of a new X-ray analysis. It has been found, that the sulfate(VI) ion is bonded in apical position of Cu(II) coordination pyramid having two organic ligands at the base. Two water molecules are not coordinated as has been postulated before, but stabilizes the sulfate(VI) group orientation and link the layers of complex molecules by strong hydrogen bonds. The detailed interpretation of the measured IR and Raman spectra has been performed with aid of both: quantum calculations as well as H/D and 63Cu–65Cu isotope substitution.

The vibrations of crystalline 4-hydroxybenzhydrazide were investigated by IR and Raman spectroscopy. Spectral changes resulting from O,N-deuteration together with DFT calculations were employed for band assignment presented in terms of potential energy distribution. The characteristic absorptions of the hydrazide group were located at 1623 (C O stretching), 1588 (NH2 bending) and 1532 cm−1 (NH bending). The greatest contributions of the N N and C N stretching vibrations were found in the 1208 and 1109 cm−1 modes, respectively. The predominant contribution of the C O stretching vibration was observed for the 1282 cm−1 absorption. The computations at the B3LYP level with 6-311++G(d,p) basis set were based on structural parameters taken from refined single crystal X-ray investigations. The details of hydrogen bonding and crystal packing are also presented.

Structure and magnetic properties of CoII complexes with N-phosphorylthiourea derivatives {RC(S)NHP(O)(OiPr)2} (HL) [Co{Et2NC(S)NP(O)(OiPr)2}2] (1), [Co{iPrNHC(S)NP(O)(OiPr)2}2] (2), [Co{[tBuNHC(S)NP(O)(OiPr)2}2] (3), [Co{p-MeOC6H4NHC(S)NP(O)(OiPr)2}2] (4), [Co{p-BrC6H4NHC(S)NP(O)(OiPr)2}2] (5) were investigated. Paramagnetic shifts in the 1H NMR spectrum were observed for high-spin CoII complexes with HL, incorporating amidophosphate moiety C(S)NP(O). The thermal dependence of the magnetic susceptibility has shown that the extended materials 2, 3 and 5 show ferromagnetic exchange between distorted tetrahedral metal atoms, while in complex 4 antiferromagnetic behavior takes place. Compound 1 behaves as a spin-canted ferromagnet, an antiferromagnetic ordering taking place below a critical temperature, Tc = 175 K. Complex 2 was investigated by single crystal X-ray diffraction. The cobalt(II) atom in complex 2 is in distorted tetrahedral CoO2S2 environment formed by the C=S sulfur atoms and the P=O oxygen atoms of two deprotonated ligands.

Reaction of ZnCl2 and 2-thiophenecarboxylic hydrazide (tch), in ethanol resulted in the crystalline product [Zn(tch)3][ZnCl4] · 2EtOH, which slowly decomposes losing solvent molecules. The structure of the first compound has been determined by the single crystal X-ray method. Analysing the IR spectra of both compounds it has been found that the complex [Zn(tch)3]2+ cation and [ZnCl4]2− anion are preserved after crystal decomposition. Vibrational spectra of the obtained substances were interpreted with the assistance of DFT calculations and metal isotope as well as deuterium replacement.

A crystal of the title complex [Pt(DMSO)(GT)] (1a), where H2GT = glyoxylic acid thiosemicarbazone, has been characterized by X-ray crystallography and its structure has been compared with that of the recently described cytotoxic complex [Pt(DMSO)(GT)]·DMSO (1). The crystal of 1a is monoclinic; space group P 21/n; unit cell dimensions: a = 7.3270(10), b = 10.313(2), c = 13.706(3) A, β = 101.92(3)°; V = 1013.3(3) A3; Z = 4. The Pt(II) ion is approximately planar tetragonal coordinated by the carboxylato oxygen, azomethine nitrogen and thiolato sulfur atom of the doubly deprotonated H2GT molecule, and the sulfur atom of DMSO. The two five membered chelate rings are almost coplanar. In distinct with 1, the sulfoxide oxygen atom and thiolato sulfur atom are in gauche position. A system of hydrogen bonds of the type N–H···O involving the amino, carboxylato and sulfoxide groups links the complex molecules within the unit cells. The π -π stacking pattern between the chelate rings in 1a involves centrosymmetric pairs of complex molecules and differs from that in 1. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The X-ray single crystal investigation revealed that Pd 2+ ion is bonded to tch ligands only via amine nitrogen atoms, forming with two chloride ions a quasi-square metal environment. The crystal slowly looses dmf molecules transforming into complex which can also be obtained by mixing the PdCl 2 and tch water solutions. Both compounds, together with their bromo derivatives, have been intensively investigated by vibrational spectroscopy methods employing the palladium isotope substitution, deuteration and theoretical calculations on the DFT level. All those attempts resulted in complete assignment of the observed bands, in terms of potential energy distribution.

The reaction of PdBr2 and the 2-hydrazino-2-imidazoline (hi) hydrobromide in H2O–dmf solution yielded the [Pd(hi)2]Br2 crystals suitable for X-ray analysis. The complex cation shows the quasi-planar, centrosymmetric structure with hi acting as bidentate chelating ligand offering the NH2 and imidazoline nitrogen atoms for metal bonding. The structure of the complex is reflected in vibrational spectra where metal ligand bands were localized by 104Pd–110Pd substitution and N-deuteration. Both isotope effects were reproduced in density functional calculations (DFT) supporting the theoretical band assignment presented in terms of potential energy distribution.

Green crystals of the [Cu(taa)2(dmf)]2 (where taa denotes 2-thiopheneacetate anion) complex crystallize from the dmf solution of another polymeric [Cu2(taa)4]n complex. Obtained compound was investigated by X-ray diffraction methods, which revealed that the complex consists of centrosymmetric dimers where the bidentate 2-thiopheneacetate anions form syn, syn bridges between copper(II) ions. The coordination polyhedron of each metal ion is completed by the dmf molecule. The complex structure is well reflected in the infrared spectrum, where the assignment of the bands originating from the Cu–COO and Cu–dmf vibrations was confirmed with the aid of metal isotope substitution.

The crystal structure of a novel polymeric copper(II) complex with 2-thiopheneacetic acid is presented and the vibrational spectra are discussed. The copper(II) atoms and coordinating carboxylate oxygen atoms form the [Cu2O8] dinuclear units typical for other carboxylates of this metal. The units are directly linked via two, relatively short Cu–O interactions and form polymeric chains along the b axis. A structural two- and threefold disorder has been found for the thiophene rings. The IR and Raman spectra of the title complex and free ligand are interpreted with help from literature data and deuteration effects. The absorption bands that are related to Cu–Cu core vibrations have been localized by a 63Cu–65Cu labelling technique.

Two compounds H[Mn(cyclam)(pyridine-2,6-dicarboxylate)2] · H2O (1) and [MnIII(cyclam)Cl2]ClO4 (2) (where cyclam=1,4,8,11-tetraazacyclotetradecane) have been synthesized and structurally characterized. The complex 1 crystallizes in the monoclinic space group P2(1)/c with a=11.4328(11), b=14.4275(14), c=8.5782(9) A, V=1343.1(2) A 3 , Z=2, R=0.0453. Complex 1 is octahedral in which [Mn(cyclam)]3+ unit occupies the basal plane having two pyridine-2,6-dicarboxylate anions in the axial positions. Molecular packing of the crystal is dominated by string of molecules along the b-axis. The strings are held together by extensive intermolecular hydrogen bonds involving N–H ⋯ O, N–H ⋯ N and O–H ⋯ O which impart it an infinite 1D chain. Complex 2 on the other hand crystallizes in the space group P212121 (No. 19) of the orthorhombic system. Mn(III) ions occupy the center of a distorted octahedron and two chloride ions occupy the axial positions. The packing diagram of 2 reveals that the complex is percholrate-bridged hydrogen bonded 1D chain along a-axis. Cyclic voltammogram of complex 1 shows a reduction wave at −0.25 V coupled to an oxidation wave at −0.05 V versus SCE in aqueous solution. The complex 2 is characterized by an irreversible reduction wave at −0.11 V versus SCE and is identical to that observed for [MnIII(cyclam)Cl2]Cl · 5H2O. The magnetic measurements in the temperature range 1.9–300 K have been carried out for complex 1 which exhibits a very weak ferromagnetic interaction at low temperature. Complex 2 shows room temperature magnetic moment value of 4.92 BM consistent with the high spin d4 electronic configuration.

Co(NO3)2·6H2O reacts with N,N-bis(1–methylbenzimidazol-2–ylmethyl)methylamine (Me2L) in MeOH/ Et2O solution at ca. 5°C, yielding a novel, penta-coordinate complex, formulated as [Co(NO3)2(Me2L)], which was characterized by means of structural, spectroscopic and magnetic measurements. The Co atom is coordinated in distorted trigonal bipyramidal geometry by three N and two O atoms. The ligand Me2L is coordinated in a facial mode and two coordinated O atoms from the nitrato ligands are in cis-positions.

The crystal structure of the complex [CuL][ClO4]2(L = 3-{[2-diaminomethyleneamino)thiazol-4-yl]methylsulfanyl}-N2-sulfamoylpropionamidine, famotidine) has been determined. It provides a full description of the metal binding sites and reveals the impact of metal co-ordination on the conformation of the drug molecule. Even metal ion binding is not able to change some conformational features of famotidine, which could be an important factor biologically. Potentiometric and spectroscopic data were obtained for the ternary species in the Cu2+–famotidine–histidine system and show that famotidine is a very competitive chelating agent even in the presence of the strongly co-ordinating amino acid.

The reaction product of Co(II) chloride and the title ligand L, formulated as CoLCl2·CH3OH, was prepared and characterized by means of structural and spectroscopic measurements. The violet crystals are orthorhombic, (space groupP212121) witha=8.093(2),b=14.883(3),c=16.831(3) A, andZ=4. The structure consists of discrete molecules with pseudo-, noncrystallographic twofold symmetry in which the Co atom is coordinated in trigonal bipyramidal geometry by three nitrogen and two chlorine atoms. The ligand L is coordinated to the Co atom in afac mode and two chlorine atoms are incis-positions. The structure was confirmed by IR-spectra.

[Pt Cl 4 (C 5 H 8 N 2 ) 2 ] cristallise dans P2 1 /n avec a=12,749, b=9,217, c=14,898 A, β=110,06°, Z=4; affinement jusqu'a R=0,036. Le complexe comprend des mailles mononucleaires Pt Cl 4 (1-ethylimidazole) 2 . La coordination autour de Pt (IV) est octaedrique avec les deux coordinats 1-ethylimidazole mutuellement cis. Les distances Pt-N sont de 2,007 et 2,055 A. Les distances Pt−CL (de 2,304 a 2,326 A) sont typiques des complexes de Pt(IX)

Seven new mono- and dinuclear Cu(II) complexes containing various methyl substituted 4-nitropyridine N-oxides as ligands were isolated and characterized physicochemically and biologically. The characterization included elemental analysis, magnetic and spectroscopic methods (diffuse reflectance and UV-visible absorption, IR, FIR). A single crystal X-ray diffraction analysis was performed for the complex with 2,5-dimethyl-4-nitropyridine N-oxide. Trans- and cis-square planar configuration around Cu ion was established for mono- and dinuclear species, respectively. In methanolic solutions the dinuclear species decompose into mononuclear ones with increasing 4 → 6 coordination number with attachment of two solvent molecules. The IR spectra showed that the strength of the Cu-ligand bond gauged by the degree of N–O elongation changed irregularly with position and number of methyl groups. Cytotoxic studies on the MCF-7 human breast cancer line revealed a structure-activity relationship: double blocking of the NO2 group with two CH3 groups rendered the complex completely inactive.

Rh(Hdmg)2(PPh3)Cl (Hdmg=monoanion of dimethylglyoxime) undergoes reduction with zinc amalgam to give the tetranuclear bimetallic compound [Rh(Hdmg)(ClZndmg)(PPh3)]2, characterized by elemental analysis, electronic, IR and NMR spectroscopy and X-ray crystallography. It crystallizes in the triclinic space group P1 with: a=14.262(4), b=14.675(4), c=14.698(4) A, α=82.15(4), β=87.57(4), γ=65.89(3)°, Z=2. The structure was refined up to R=0.13 for 4704 reflections. The molecule consists of two [Rh(dmg)(Hdmg)(PPh3)] subunits linked by an [Rh(II)(II)] bond of length equal to 2.852(3) A and by two Zn ions bridging the oxygens of the equatorial ligands. The binding with zinc relieves the equivalence among the atoms of each subunit.

This paper describes the synthesis and properties of two new palladium(II) complexes with 2,6-dimethyl-4-nitro-pyridine (dmnp): mononuclear [Pd(dmnp) 2 Cl 2 ] and dinuclear [Pd 2 (dmnp) 2 Cl 4 ]. Complexes were characterized on the basis of chemical and chromatographic analyses, MS and conductometric measurements, as well as by IR and NMR ( 1 H and 13 C) spectral studies. The crystal structures of ligand and mononuclear complex, trans -dichlorobis(2,6-dimethyl-4-nitro-pyridine)palladium(II), were determined by three-dimensional X-ray methods. The crystals of both compounds are monoclinic, space groups P 2 1 / c with a =19.075(4), b =5.419(1), c =15.045(3) A and β =108.15(3)° for (dmnp), and a =7.544(2), b =14.509(3), c =8.032(2) A and β =90.32(3)° for [Pd(dmnp) 2 Cl 2 ]. In the (dmnp) there are two crystallographically independent molecules in the unit cell. The nitro groups and methyl C atoms are coplanar with the ring plane. The hydrogen bond of the type C–H⋯O links the molecules into pairs around center of symmetry. These dimers are held together by contacts of the van der Waals type. In the crystal structure of [Pd(dmnp) 2 Cl 2 ] the Pd atom lies on an inversion center and is four-coordinated by two pyridine N atoms and by two Cl atoms in trans positions. The coordination geometry is square-planar, with Pd–N and Pd–Cl distances of 2.033(2) and 2.311(1) A, respectively. The two pyridine rings are mutually parallel, but they are twisted from the PdN2Cl2 coordination plane by about 88.5°. The preliminary assessments of anti-tumor properties of both complexes and ligand were evaluated as in vitro anti-proliferative activity in four human cancer cell lines: SW707 (adenocarcinoma of the rectum), T47D (breast cancer), HCV (bladder cancer) and A549 (non-small cell lung carcinoma). The [Pd(dmnp) 2 Cl 2 ] exhibits strong cytotoxic activity against all cell lines whereas the free ligand and dinuclear [Pd 2 (dmnp) 2 Cl 4 ] are only moderate active.

A new platinum complex of 1-methyl-5-nitroimidazole has been obtained and characterized by elemental analysis, i.r. and n.m.r. spectroscopy. The structure of [PtI2-(C4 H5N3O2)2] has been determined by single-crystal X-ray diffraction. The crystals are triclinic: P1, a = 15.640(3), b = 12.617(2), c = 6.701(1) A, α = 102.77(5), β = 101.15(5), γ = 100.71(5)°, V = 1228.6(3) A3, Z = 3, Dx = 2.851(6) Mg m−3, λ(MoKα) = 0.71069 A, μ = 12.85 mm−, F(000) = 948, final R = 0.038 for 2859 reflections. The complex consists of monomeric PtI2(1-methyl-5-nitroimidazole)2 units. The coordination geometry is square-planar. The two 1-methyl-5-nitroimidazole ligands are trans coordinated to platinum.

Two forms of [Pd(hypy)2]Cl2 complex have been prepared. The reaction of PdCl2 with 2-hydrazinopyridine (hypy) ligand carried out in DMF solution produces the title complex 1, whereas its recrystallization from methanol gives [Pd(hypy)2]Cl2·2MeOH 2. The latter compound was the subject of full, single-crystal X-ray analysis, which revealed the planar structure of the metal vicinity and trans-orientation of the ligands, chelating the metal through amine and pyridine nitrogen atoms. The vibrations of the complex cation [Pd(hypy)2]2+ were investigated using IR spectroscopy and DFT modelling employing the B3LYP functional and LanL2DZ basis set. The vibrations of the hydrazine moiety and palladium(ii) environment, detected by N-deuteration and 104Pd/110Pd stable isotope labelling, were also reproduced in the calculations.

A compound of the type 2:1 2-amino-1,3-thiazoline hydrochlorideCuCl 2 was prepared and characterized by means of X-ray and spectroscopic measurements. Crystals of the complex (ATH) 2 CuCl 4 (ATH + = 2-amino-1,3-thiazoline cation) are monoclinic, space group C2/c, with a = 27.772(13) A, b = 7.811(4) A, c = 15.609(7) A, β = 112.09(5)° and Z = 8. The structure was solved by the heavy atom technique and refined by full-matrix least-squares calculations to a final R = 0.042 for 2356 counter reflections. The crystal consists of a CuCl 2− 4 anion and two ATH + cations. There is no direct bonding between the metal atom and the ATH molecule. The CuCl 2− 4 ion shows a slight tetrahedral distortion with two large ClCuCl angles (131.9 and 141.1(6)°. The CuCl distances range from 2.221 to 2.271(1) A . The ATH + cations are linked to CuCl 2− 4 units through hydrogen bonding involving the amino nitrogen atoms. Both 2-amino-1,3-thiazoline molecules have a similar conformation. This conformation is different from that of 2-amino-1,3-thiazoline hydrochloride. The spectroscopic studies have shown that in methanol solution the direct metal-2-amino-1,3-thiazoline bond is formed via heterocyclic nitrogen. The Cu(AT) +2 2 complex is formed as a major species.

X-ray evidence for the lysyl lateral amine group coordination to cupric ion is presented for the Cu(II) complex with L-lysyl-L-tyrosyl dipeptide. The dipeptide molecule is coordinated to the metal ion via all its functions. The α-amine, N− and COO- donors bind the metal ion forming two small chelate rings while ϵ-NH2 is coordinated to the other copper ion related by the screw axis and the polymeric complex is formed.

IR, NMR and X-ray studies have shown that in the Pt(II) or Pd(II)S-methyl-L-cysteine sulfoxide (SOMC) complexes the ligand molecule coordinates to the metal ion via the sulfur and amine donors. Two isomers are found in solution which differ by the ligand conformation on the sulfur center. Crystals of dichloro-[(S-methyl-L-cysteine)sulfoxided]palladium(II) monohydrate are orthorhombic, space group P2 1 2 1 2 1 with a = 17.858(4), b = 8.690(3), c = 7.008 (2) A and Z = 4. The structure was solved by the heavy-atom technique and refined by full-matrix least-squares calculations to a final R = 0.061 for 942 counter reflections. Coordination around palladium is slightly distorted square-planar and involves the sulfur and the nitrogen atoms of the amino acid molecule and two chlorine atoms. The five-membered chelate ring has a λ conformation. The R, S absolute configuration of the ligand is confirmed in this study. Only one of the SOMCPd isomers was found to be present in the studied crystals.

Le compose du titre cristallise dans le systeme monoclinique avec le groupe d'espace P2 1 /a. Affinement de la structure jusqu'a 0,038. La geometrie de coordination est octaedrique