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An investigation of the coordination chemistry of the ((E)-N′-(4-hydroxybenzylidene)-4-hydroxybenzohydrazide) Schiff-based ligand (HL) towards Ni(ii) acetate was performed using single crystal X-ray diffraction.

Apoyo científico y técnico del CACTI Nine potentially S,N,Npy-tridentate thiosemicarbazones (HL) derived from pyridine-2-carbaldehyde or 1-(2-pyridyl)ethanone have been prepared and fully characterized. The X-ray crystal structures of six of them and two hydrochlorides were determined and analyzed. The reaction of the [ReX(CH3CN)2(CO)3]/[ReX(CO)5] (X = Cl and Br) precursors with these ligands yielded different kinds of compounds: the adducts [ReX(HL)(CO)3], in which the ligands were S,N-bidentate; the trinuclear species [Re3Cl2(L23)(HL23)(CO)9]; and the thiosemicarbazonate compounds [Re(L)(CO)3], where the ligand is S,N,Npy-tridentate. Besides, the reaction in methanol or ethanol of the thiosemicarbazones derived from aldehydes yielded S,N,Npy-tridentate hemiaminal cationic [Re(HLOR)(CO)3]X and neutral [Re(LOMe)(CO)3] complexes after the coordinated ligand underwent addition of the alcohol group to the imine bond. The reactivity of the complex [ReX(HL)(CO)3] in MeOH and NEt3 led to the formation of dinuclear [Re2(L)2(CO)6], where the thiosemicarbazonate is again S,N-bidentate. The influence that the substituents on the thiosemicarbazone ligands have on the stability of the complexes and the effect of the reaction medium on the resulting compounds have been analyzed. Agencia Estatal de Investigación | Ref. PID2019-110218RB-I00 Universidade de Vigo/CISUG

Nine potentially S,N,N

Financiado para publicación en acceso aberto: Universidade de Vigo/CISUG Apoyo científico y técnico del CACTI Four acyl-hydrazones derived from 5-hydroxypicolinohydrazide and 4-hydroxybenzaldehyde (HL11), 2-fluoro-4-hydroxybenzaldehyde (HL12), 2,4-dihydroxybenzaldehyde (HL13) or 2-pyridinecarboxaldehyde (HL14) and two hydrazones derived from 2-hydrazino pyridine and 4-dimethylaminobenzaldehyde (HL21) or 4-diethylamino-2-hydroxybenzaldehyde (HL22) were synthesized and their X-ray structures determined. Twelve rhenium(I) complexes of formula [ReX(HLn)(CO)3] (X = Cl, Br) were obtained by treating these ligands with [ReX(CH3CN)2(CO)3], and the structures of some representative compounds were determined by X-ray diffraction. The coordination geometry around rhenium(I) can be described as octahedral, with three carbon atoms in a fac configuration, the halogen atom and two nitrogen atoms from the hydrazone chain and the pyridine group, respectively. The carbonyl group of the acyl-hydrazone ligands does not participate in coordination in any of complexes HL11–HL14. The coordination mode of the ligands in all complexes could be established by comparing the IR and 1H NMR spectra. Formation of the hydrazonate complexes only proved possible with the derivatives of HL22. A study of the corresponding single crystal showed the presence of the dimer [Re2(L22)2(CO)6], in which the phenolate group of the ligand of the dimer partner coordinates to rhenium after deprotonation. This same group is used to bind to the rhenium atom of the dimer partner at the position released by the halide. Agencia Estatal de Investigación | Ref. PID2019-110218RB-I00 Universidade de Vigo/CISUG

We present here ten coordination compounds isolated from reactions of divalent metal ions (CuII, NiII and ZnII) with the Schiff base ligand H2L derived from salicylaldehyde and ω-hydroxy carbonic acid hydrazide. Protonation levels of the ligand has played significant roles in affecting the coordination conformations of the metallosupramolecular compounds in solid state. Four kinds of complexes have been obtained: monomeric [M(HL)2] and dimeric [M2(HL)2(X)2]/[M2(HL)2](X)2 (X = anion) containing monodeprotonated ligand, and polymeric ∞1M(L) and dimeric [Zn2L2] compounds with the doubly deprotonated form of the ligand. The structures of the free ligand H2L and its complexes [Zn(HL)(H2L)]·(NO3)·EtOH (Zn-1a), [Cu2(HL)2(NO3)2] (Cu-3a), [Cu2(HL)2(SiF6)] (Cu-3b) and [Ni2(HL)2(EtOH)(H2O)](NO3)2(Ni-3a) were elucidated by single-crystal X-ray diffraction. The reactivity of [Ni(HL)2] complex in the presence of a competitive ligand was investigated.

Polymorphism is a common phenomenon in crystalline materials but it has barely been studied in the field of metal organic frameworks. The study of polymorphism is useful to investigate structure–property relationships and control over the synthesis of particular polymorphs could be an effective way to fine-tune the physical properties of materials. We report here the preparation and characterization of three polymorphs of a copper(I) coordination polymer 2∞CuCl(4bpytm), 4bpytm = bis(4-pyridylthio)methane. The structural and thermal properties of these compounds were studied to obtain a detailed knowledge of the differences between the three polymorphic forms.

The reaction of fac-[ReX(CH3CN)2(CO)3] (X = Cl, Br) with N-phenyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HLA) or N-4-methoxybenzyl-[4-(dimethylamino)benzaldehyde] thiosemicarbazone (HLB...

Aim: Obtain radioimages of amyloid-β fibers using 99mTc-complexes. Methodology: Tridentate thiosemicarbazone and thiocarbonohydrazone ligands containing fragments (stilbene, azobenzene, benzothiazole or benzoxazole) with affinity for amyloid-ß fibers and its Re(I) complexes have been prepared. The molecular structures of several ligands and complexes were determined by x-ray diffraction. Binding affinity studies toward Aß1-42 fibers were performed for the ligands and Re(I) complexes. The ability of formation of some 99mTc(I) complexes, their biodistribution and in vivo stability have been established. Results & conclusion: Complexes of stilbene and benzothiazole thiosemicarbazonates show similar affinity for amyloid-β fibers to the free ligand. These 99mTc complexes present a reasonable in vivo stability and a low capability to cross the blood–brain barrier although not sufficient to brain amyloid imaging.

The reaction of CuCO3·Cu(OH)₂ with three different α-hydroxyacids (H2L′) and the nitrogen donor coligand 2,2′-dipyridylamine (dipyam) has produced five new discrete copper(II) complexes. Two kind of compounds have been isolated: neutral complexes of formula [Cu(H2L′)2(dipyam)] and cationic [Cu(H2L′)(dipyam)2](H2L′) complexes. Four of these compounds have been studied by single-crystal X-ray diffraction and the analysis of their molecular crystal structures were also performed by the analysis of their Hirshfeld surfaces. The thermal behaviour has also been investigated.

The present work assesses the ability of two flexible bis-tetrazole organosulfur ligands to build up different metallosupramolecular compounds based on the analysis of the different supramolecular interactions. The reaction of copper(II) chloride dihydrate with the N,N&rsquo, donor dithioether ligands bis(1-methyl-1H-tetrazole-5-ylthio)methane (BMTTM) and 1,2-bis(1-methyl-1H-tetrazole-5-ylthio)ethane (BMTTE) was investigated using different synthetic methods. Four compounds have been obtained as single crystals: two pseudopolymorphic 1D Cu(II) coordination polymers with the ligand BMTTM, a 2D Cu(II) coordination polymer and a discrete Cu(I) tetramer with the BMTTE ligand. The effects of the weak interactions on the crystal packing and the Hirshfeld surfaces of the structures were analyzed to clarify the nature of the intermolecular interactions.

Nine thiosemicarbazone ligands (H2Ln, n = 1–9) containing benzothiazole or benzoxazole groups at the C(2) atom of the thiosemicarbazone have been prepared and characterized. A crystal structure study was performed on six of these free ligands and the role of the π–π interactions in the molecular association was analyzed. The coordination behavior of the thiosemicarbazones towards the {Re(CO)3}+ fragment was investigated and three types of complexes were obtained: mononuclear fac-[ReX(H2Ln)(CO)3], X = Cl or Br, with bidentate ligands, dinuclear [Re2(HLn)2(CO)6] with monodeprotonated bridging thiosemicarbazonates yielding Re2S2 cores and tetranuclear [Re4(L2)2(CO)12(EtOH)2] with an unusual bideprotonated thiosemicarbazonate ligand. The intermolecular interactions before and after metal coordination were analyzed. In the dinuclear complexes, two different approximate symmetries were observed depending on the relative orientation of the thiosemicarbazonate ligands with respect to the Re2S2 diamond. The intramolecular interactions in the dimers and their relationship with the two possible symmetric dispositions were analyzed. The findings, in conjunction with theoretical calculations, allowed the main stabilizing factors for each type of symmetry to be elucidated.

Achiral glycolic acid and chelating aromatic diamine ligands were employed at room temperature to prepare five 1D copper(II) coordination polymers which were structurally characterized. The polymers ∞1{[Cu(HG)(dipyam)](HG)} (1) (dipyam = 2,2′-dipyridylamine) and ∞1[Cu(HG)(ClO4)(NN)] (NN = 2,2′-bipyridine (2), NN = 1,10-phenanthroline (3)) adopt homochiral helical structures in the crystal state and undergo spontaneous chiral resolution in the solid state. On the other hand, the polymers containing bidepronated glycolato ligand G, ∞1{[Cu(G)(dipyam)]·H2O} (1a), obtained from a solution of 1 in MeOH/iPrOH and ∞1{[Cu2(μ-G)(ClO4)(H2O)(dipyam)2](ClO4)(H2O)2} (4b) are achirals. Crystals of 4b have been obtained together with crystals of the molecular complex [Cu(HG)(H2O)(dipyam)](ClO4) (4a). Analysis by Hirshfeld surface generation and two-dimensional fingerprinting was carried out to study the nature of the interactions and their contributions towards the crystal packing.

Mol­ecules of the complex fac-[ReCl(4-pyOH)2(CO)3] (4-pyOH is 4-hy­droxy­pyridine) and 4-pyridone are associated in ladder chains by hydrogen and coordination bonds., The asymmetric unit of the title compound, [ReCl(C5H5NO)2(CO)3]·C5H5NO, contains one mol­ecule of the complex fac-[ReCl(4-pyOH)2(CO)3] (where 4-pyOH represents 4-hy­droxy­pyridine) and one mol­ecule of pyridin-4(1H)-one (4-HpyO). In the mol­ecule of the complex, the Re atom is coordinated to two N atoms of the two 4-pyOH ligands, three carbonyl C atoms, in a facial configuration, and the Cl atom. The resulting geometry is slightly distorted octa­hedral. In the crystal structure, both fragments are associated by hydrogen bonds; two 4-HpyO mol­ecules bridge between two mol­ecules of the complex using the O=C group as acceptor for two different HO– groups of coordinated 4-pyOH from two neighbouring metal complexes. The resulting square arrangements are extented into infinite chains by hydrogen bonds involving the N—H groups of the 4-HpyO mol­ecule and the chloride ligands. The chains are further stabilized by π-stacking inter­actions.

We report design and structural characterization of six new coordination polymers fabricated from PbCl2 and a series of closely related bis-pyridyl ligands LI and HLII–HLVI, namely, [Pb2(LI)Cl4]n, [Pb(HLII)Cl2]n·nMeOH, [Pb(HLIII)Cl2]n·0.5 nMeOH, [Pb2(LIV)Cl3]n, [Pb(HLV)Cl2]n, and [Pb3(LVI)2Cl4]n·nMeOH. The topology of the obtained networks is dictated by the geometry of the organic ligand. The structure of [Pb2(LI)Cl4]n is constructed from the [PbCl2]n two-dimensional (2D) sheets, linked through organic linkers into a three-dimensional framework, which exhibits a unique binodal 4,7-connected three-periodic topology named by us as sda1. Topological analysis of the 2D metal–organic sheet in [Pb(HLII)Cl2]n·nMeOH discloses a binodal 3,4-connected layer topology, regardless of the presence of tetrel bonds. A one-dimensional (1D) coordination polymer [Pb(HLIII)Cl2]n·0.5 nMeOH is considered as a uninodal 2-connected chain. The overall structure of [Pb2(LIV)Cl3]n is constructed from dimeric tetranuclear [Pb4(μ3-L...

A supramolecular synthesis process in methanol of a combination of several resorcinol-thiosemicarbazones (TSC) and two N,N′-divergent bipyridines (BP) led to the isolation of 14 cocrystals, some of which contained solvent in the crystal lattice. The main hydrogen bonded motifs have been identified, and some key structural factors have been analyzed by theoretical calculations. Structurally, the 14 cocrystals can be grouped into two main types. The first type is characterized by the formation of TSC/BP cyclic arrangements involving a solvent and also by the absence of the intramolecular O–H···N, S(6), interaction in the TSC component. The second type is characterized by TSC/BP acyclic associations, in most cases without the inclusion of solvent, and the usual intramolecular O–H···N, S(6), interaction is maintained in the TSC component.

Three metallamacrocycles and one coordination polymer were obtained by using coordination driven self-assembly of the HgI2 salt with four different ligands: 2,2′-butan-1,4-diylbis(oxy)dianiline (L1), 1,4-bis(2′-formylphenyl)-1,4-dioxabutane bis(isonicotinoylhydrazone) (L2), (E)-N′-(pyridin-3-ylmethylene)isonicotinohydrazide (L3) and (E)-1-(pyridin-3-yl)-N-(pyridin-3-ylmethyl)methanimine (L4). The coordination compounds were studied by elemental analysis, FT-IR spectroscopy and single-crystal X-ray diffraction analyses. Reaction of the HgI2 salt with L1, L2 and L3 yields metallamacrocycles of formula [(HgI2)2(μ-L1)2] (1), [(HgI2)2(μ-L2)2] (2), [HgI2(μ-L3)]4 (3). In contrast, the reaction with L4 under the same conditions yields a coordination polymer of formula [{HgI2(L4)}]n (4). In addition, the X-ray structure of L2 is also reported. The influence of the flexibility of the ligand on the final shape and nuclearity of the macrocycle is also analysed. Hirshfeld surface analysis and fingerprint plots facilitate a comparison of intermolecular interactions in all compounds, which are crucial in the construction of the supramolecular architectures. Finally, some noncovalent interactions have been evaluated energetically using DFT calculations and characterized using Bader's theory of atoms-in-molecules.

Five thiosemicarbazones (H2Ln) derived from 4,6-diacetylresorcinol (n = 1–4) and salicylaldehyde (n = 5) have been synthesized and spectroscopically characterized. Single crystal X-ray diffraction studies on some of the complexes show that the molecular structure is dominated by intramolecular hydrogen bonds involving the O(1)–H group of the resorcinol/salicylaldehyde group and the azomethinic nitrogen atom and sulfur atom of the thiosemicarbazone arm. All of the ligands react with fac-[ReCl(CO)3(CH3CN)2] in the presence of NEt3 to form the stable anionic complexes [NHEt3][fac-[Re(Ln)(CO)3] (1–5). The thiosemicarbazonate ligand, as suggested by spectroscopic data and confirmed by X-ray diffraction, acts as a tridentate S,N,O system. The complexes are stable in solution for weeks, although other dimeric species were also detected by X-ray diffraction analysis. The reaction of fac-[99mTc(CO)3(H2O)3]+ with the appropriate ligand at 100 °C for 30 min yielded the complexes [fac-[99mTc(Ln)(CO)3]− (Tc1–Tc5). The radiochemical yield and purity were determined by HPLC and their chemical identity was ascertained by comparing their radiochromatogram with the chromatogram of the rhenium congeners (1–5). The results of biodistribution studies in mice on the five technetium compounds showed rapid blood clearance and fast liver uptake that slowly cleared into the intestines, a finding that indicates the hepatobiliary tract as the major excretory pathway. HPLC analysis of urine and blood serum samples from mice injected with the 99mTc complexes confirmed their in vivo stability since the predominant radiochemical species had the same retention time as the corresponding injected compound.

New copper(II) metal–organic compounds with the formulae [Cu3Cl(HCO2)5(SCS)3(H2O)2]·8H2O·EtOH (1) and [Cu3(HCO2)4(SCS)4(H2O)2](NO3)2·9H2O (2) (SCS=bis(4-pyridylthio)methane) have been synthesized after a careful study of the reaction of the SCS ligand with copper(II) formate. The compounds were obtained in the presence of sodium chloride and nitrate salts under microwave irradiation. The influence of the anion at different metal/anion ratios on the final architecture has been studied. The new chloride-MOF 1 has been characterized by electron paramagnetic resonance (EPR), magnetic properties and single crystal X-ray diffraction studies. The thermal stability and topological analysis have also been investigated.

The imine ligand L1 was prepared by the reaction of 4-amino-4′-(dimethylamino)stilbene and 2-pyridinecarbaldehyde. The amine ligand L2 was obtained in good yield by the reduction of L1 with NaBH4. The complexes [ReX(CO)3(Ln)] (1a: X = Cl, n = 1; 1b: X = Br, n = 1; 2a: X = Cl, n = 2; 2b: X = Br, n = 2) were prepared through the reactions of equimolar solutions of the corresponding ligand and [ReX(CO)3(CH3CN)2]. The complexes were characterized spectroscopically, and the structures of 1a and 1b were established by X-ray diffraction. A configurational and conformational study of the amine complex 2b in dimethyl sulfoxide (DMSO) solution was performed through molecular modeling and with the experimental NMR spectroscopy data. The transformations of 2a and 2b into 1a and 1b, respectively, were also monitored by UV/Vis and NMR spectroscopy.

Six new nickel(II) complexes have been synthesized by the reaction of the nitrogen donor coligand 2,2′-dipyridylamine (dipyam) and three different α-hydroxyacids (H2L′) with different levels of bulkiness, namely lactic, 2-methyllactic and mandelic acids. Two types of compounds have been obtained: neutral complexes of formula [Ni(HL′)2(dipyam)] and the cationic metal complexes of general formula [Ni(HL′)(dipyam)2](HL′). The structures of the cationic metal complexes have been elucidated by single-crystal X-ray diffraction. The role of the second coordination sphere in the metallosupramolecular organization through different hydrogen-bonding patterns has been analysed. The thermal behaviour of all new compounds has been investigated.

The binding affinities towards estrogen receptors (ERs) α and β of a set of thiosemicarbazone ligands (HL n ) and their rhenium(I) carbonyl complexes [ReX(HL n )(CO) 3 ] (X = Cl, Br) were determined by a competitive standard radiometric assay with [ 3 H]-estradiol. The ability of the coordinated thiosemicarbazone ligands to undergo deprotonation and the lability of the Re X bond were used as a synthetic strategy to obtain [Re(hpy)(L n )(CO) 3 ] (hpy = 3- or 4-hydroxypyridine). The inclusion of the additional hpy ligand endows the new thiosemicarbazonate complexes with an improved affinity towards the estrogen receptors and, consequently, the values of the inhibition constant (K i ) could be determined for some of them. In general, the values of K i for both ER subtypes suggest an appreciable selectivity towards ERα.

The mol­ecular and crystal structures of a monoclinic polymorph of 1,2-bis­[(1-methyl-1H-tetra­zol-5-yl)sulfan­yl]ethane (BMTTE) are described., The synthesis and crystal structure of a monoclinic (P21/c) polymorph of the title compound, C6H10S2N8, are reported. The mol­ecule has pseudo-twofold rotational symmetry, with the tetra­zole rings being inclined to one another by 5.50 (6)°. In the crystal, mol­ecules are linked by C—H⋯N hydrogen bonds, forming chains propagating along [101] and enclosing R 2 2(20) ring motifs. The chains are linked by offset π–π inter­actions involving the tetra­zole rings [inter­centroid distances vary from 3.3567 (7) to 3.4227 (7) Å], forming layers parallel to the ac plane. The crystal structure of the triclinic polymorph (P ) has been described previously [Li et al. (2011 ▸). Acta Cryst. E67, o1669].

We report design and structural characterization of six new coordination polymers fabricated from PbCl

The dynamics of probability (modulus) and phase (current) components of general electronic states is used to determine the temporal evolution of the overall descriptors of the information (determinicity) and entropy (indeterminicity) content of complex molecular states. These resultant information-theoretic concepts combine the classical (probability) contributions of Fisher and Shannon, and the corresponding nonclassical supplements due to the state phase/current. The total time derivatives of such overall measures of the gradient information and complex entropy are determined from Schrodinger’s equation using the chainrule transformations. These overall productions of the gradient information and complex entropy are shown to be of a purely nonclassical origin, thus identically vanishing in real electronic states, e.g., the nondegenerate ground state of a molecule.

Four new coordination compounds have been obtained by the reaction of copper(II) acetate with SCS [bis(4-pyridylthio)methane], namely, [Cu2(AcO)4(SCS)] (1), [Cu2(AcO)4(SCS)]·solv (2), [Cu4(AcO)8(SCS)5(H2O)6]·4H2O (3), and [Cu4(OH)2(AcO)6(SCS)2]·10H2O (4). Structural diversity is achieved by the copper acetate moiety in combination with the flexibility of the SCS ligand. X-ray structural analysis revealed that the compounds have different structural motifs: linear chains in 1, zigzag chains in 2, undulated tetramers in 3, and ladder-like chains in 4. The structures are further connected through hydrogen-bonding interactions with trapped solvent molecules in the crystal lattices (2–4). Guest molecules have a decisive influence on the final crystal system for 2–4. Compound 2 exhibits a temperature-induced single-crystal to single-crystal (SC–SC) transformation, and phase transitions from 2 and 3 to 1 have been found in an irreversible desolvation or recrystallization process.

Three Schiff bases derived from of 2,4-dihydroxybenzaldehyde or 2,4-dihydroxyacetophenone and esters of tyrosine and histidine have been synthesized and the crystal and molecular structures determined by single crystal X-ray diffraction. The molecular structures of the three compounds are dominated by short intramolecular hydrogen bonds with distances N⋯O ranging from 2.536(2) to 2.588(2) A and the hydrogen atom is bonded to the nitrogen. In the solid state, the structures are characterized by the keto-amine tautomer, whereas in the solution the phenol-imine form was detected by 1H NMR spectroscopy. Intermolecular interactions influencing crystal packing are discussed.

New neutral tricarbonylrhenium(I) complexes with bidentate thiosemicarbazone ligands derived from resorcinol have been prepared. Ligands were obtained by condensation reactions of 2,4-dihydroxybenzaldehyde (dhb) and 2,4-dihydroxyacetophenone (dha) with thiosemicarbazide derivatives. The metal complexes have been characterized by elemental analysis, mass spectrometry, spectroscopic methods (IR, 1 H NMR) and the crystal structures for eight of these compounds have been elucidated. The Re(I) metal centers are coordinated through the azomethine nitrogen and the sulfur atoms establishing five-membered chelate rings (κ- S , N (3)). The deprotonation of the ligand HL 6 and the labilization of the halogen produces the formation of the dimeric complex [Re 2 (L 6 ) 2 (CO) 6 ] by Re–S–Re bridges, where S is the thiolate sulfur atom from a κ- S , N (3)-bidentate thiosemicarbazonate ligand.

The reaction of the ditopic bis(benzoylhydrazone) of isophthalaldehyde (H2L) with copper(II) acetate in methanol under aerobic conditions afforded a green solid that contains the tetranuclear complex [Cu4L*2(OCH3)2] (1). The ligand L*, a bis(benzoylhydrazone) of 2,6-diformylphenol, resulted from hydroxylation of the corresponding isophthalaldehyde derivative. H2L and 1 were characterized by different spectroscopic techniques, and their molecular structures were confirmed by single-crystal X-ray diffraction. The reaction of H2L with copper(II) under argon, on the other hand, resulted in a brown diamagnetic solid [Cu2L]·H2O (2) containing copper(I), which was readily transformed into 1 when exposed to air. In contrast, the reaction with [Cu(CH3CN)4][BF4] afforded a mononuclear complex [Cu(H2L)][BF4]·H2O (3), and single crystals of [Cu(H2L)2][BF4] (4) were isolated from its dichloromethane solution. H2L cleaved plasmid DNA in the presence of copper(II) independently of any reducing agent, but more efficiently when ascorbate was present. The cleavage process is likely oxidative because the enzyme catalase, which decomposes hydrogen peroxide, quenched the reaction. In the absence of ascorbate, the ligand H2L presumably acts as the reductant in the redox reaction, as exploited also in the synthesis of 1. As a consequence, a variety of reactive oxygen species were generated, eventually also leading to the cleavage of DNA (“self-activating” chemical nuclease).

This review focuses on the coordination chemistry of α-hydroxycarboxylates with first-row transition cations. It takes in both mono- and polycarboxylates, surveying their bonding modes in these complexes (with and without other ligands) and summarizing important chemical and physical properties of these metal compounds. © 2013 Elsevier B.V.

The neutral α-hydroxycarboxylate complexes [Pd(bpy)(GLYO)]·3H2O (1), [Pd(bpy)(MANO)]·4H2O (2) and [Pd(GLYO)(phen)]·5H2O (3), together with the palladium(II) complexes [Pd(phen)2](NO3)2 (4) and [Pd(CH2COCH3)(bpy)(Cl)] (5) (where GLYO and MANO are the glycolate and mandelate dianions, respectively, and bpy and phen, 2,2′-bipyridine and 1,10-phenantrholine, respectively), have been prepared by reaction of [Pd(bpy)Cl2] or [PdI2(phen)] with salts of α-hydroxycarboxylic acids in water. These compounds were characterized by elemental analysis, mass spectrometry, 1H and 13C NMR, UV–Vis, IR spectroscopy, TG analysis and single crystal X-ray diffraction. The aforementioned studies confirmed the formation of a variety of square-planar mononuclear compounds (1–3) where the α,α′-diimine ligands exhibit a rather simple bidentate chelating role and the α-hydroxycarboxylate ligands are dianionic. A variety of ligand distortions, hydrogen-bonding and stacking interactions were found and these were thoroughly analyzed. In compounds 1 and 3, the complex molecules are stacked in such a way that the coordination planes are parallel to one another. The Pd⋯Pd distances between the nearest stacked neighbors are 3.8043(6) and 3.302(2)/3.475(1) A, respectively. Compounds 1–3 have been tested in vitro for cytotoxicity on HeLa-299 human tumor cell lines.

Materials based on the cationic copper(II) hexanuclear 18-membered metallacrown [18-MCCuII-N(2ph) -6] (2phH=2-piconyl hydrazide) and tetrafluoroborate, perchlorate, nitrate, sulfate, and perrhenate anions were prepared by an easy method in aqueous medium. Single-crystal X-ray characterization of six members of this new family of complexes showed that the anions are attached to the metallacrown by direct coordination to a copper cation or by hydrogen-bonding interaction with the center of the hexamer. The stable cationic nature of the complexes and their ability to bind different anions allows them to adsorb and immobilize environmentally relevant anions such as MO (M=Tc, Re). The MO trapping capacities suggest that these materials would be useful in the treatment of oxoanionic contaminants in water., Financial support from ERDF (EU), Ministerio de Ciencia e Innovación (Spain), and the Xunta de Galicia (Spain) under research projects CTQ2010-19386/BQU and 10TMT314002PR is gratefully acknowledged. A.B.L. thanks the Xunta de Galicia for a postdoctoral contract under the “Ángeles Alvariño” program.

Four hydrogen-bonded assemblies of formula [M(dpds)2(OH2)2]A2·nH2O (A = anion) are described. These assemblies result from the second-sphere coordination interactions between the 1D coordination polymers [M(dpds)2(OH2)2]2+, M = Zn(II) and Cu(II), dpds = 4,4′-dipyridyldisulfide, and the pyridine-3-sulfonate (3pySO3−) or hydrogenfumarate (Hfum−) anions. Significantly, supramolecular structural variations are observed depending on the presence of water lattice molecules, which formed discrete aggregates when the Hfum− anion was used. The effects of geometrical variations in the building blocks are also evident on using Jahn–Teller-distorted divalent Cu(II) ions or regular octahedral species based on Zn(II) ions. The second-sphere effects on the stabilization of the compounds are illustrated by TGA experiments.

A series of new zinc compounds has been prepared easily under mild synthetic conditions with the drug ibuprofen incorporated as a ligand to form different coordination polymers. The host materials have a high drug content and exhibit high stability, low cytotoxicity, good biodegradability and high biocompatibility. The ion exchange mechanism involved in the ibuprofen release process and the pH-controlled drug release have been studied. Ministerio de Educación y Ciencia (Spain) | Ref. CTQ2010-19386/BQU European Union (ERF) | Ref. CTQ2010-19386/BQU Xunta de Galicia | Ref. 10TMT314002PR

The complexes {[Cu(HGLYO)(NO3)(bpy)]·H2O}4 (1), {[Cu(HGLYO)(NO3)(phen)]·H2O}4 (2), and [Cu(HLACO)(ClO4)(phen)]4 (3) (bpy is 2,2′-bipyridine, phen is 1,10-phenanthroline, HGLYO is monoanionic glycol...

Recrystallization from dmso of the previously prepared compound [Co(chel)(H 2 O) 4 ] (chel = 4-oxo-4 H -pyran-2,6-dicarboxylate), led to the new one-dimensional coordination polymers 1a and 1b , which are linkage isomers of formula [Co(chel)(dmso)(OH 2 ) 3 ]·H 2 O. Also the recrystallization from dmso of the previously prepared [Zn(chel)(H 2 O) 2 ] allow the isolation of the one-dimensional coordination polymer [Zn(chel)(dmso) 2 ] ( 2 ). [Co(chel)(H 2 O) 4 ] was characterized by elemental analysis, IR and electronic spectroscopy, magnetic measurements at room temperature and thermogravimetric analysis. X-ray single crystal diffraction of 1a , 1b and 2 showed the coordinative behavior of the chelidonate ligand in each compound as well as the different participation of this ligand in the corresponding metallosupramolecular organization.

N-thioamide thiosemicarbazone derived from 4-(methylthio)benzaldehyde (R = H, HL1; R = Me, HL2 and R = Ph, HL3) have been prepared and their reaction with fac-[ReX(CO)3(CH3CN)2] (X = Br, Cl) in methanol gave the adducts [ReX(CO)3(HLn)] (1a X = Cl, n = 1; 1a′ X = Br, n = 1; 1b X = Cl, n = 2; 1b′ X = Br, n = 2; 1c X = Cl, n = 3; 1c′ X = Br, n = 3) in good yield. All the compounds have been characterized by elemental analysis, mass spectrometry (ESI), IR and 1H NMR spectroscopic methods. Moreover, the structures of HL2, HL3, HL3·(CH3)2SO and 1b′·H2O were also elucidated by X-ray diffraction. In 1b′, the rhenium atom is coordinated by the sulphur and the azomethine nitrogen atoms (κS,N3) forming a five-membered chelate ring, as well as three carbonyl and bromide ligands. The resulting coordination polyhedron can be described as a distorted octahedron. The structure of the dimers is based on rhenium(I) thiosemicarbazonates [Re2(L1)2(CO)6] (2a), [Re2(L2)2(CO)6] (2b) and [Re2(L3)2(CO)6] (2c) as determined by X-ray studies. Methods of synthesis were optimized to obtain amounts of these thiosemicarbazonate complexes. In these compounds the dimer structures are achieved by Re–S–Re bridges, where S is the thiolate sulphur from a κS,N3-bidentate thiosemicarbazonate ligand. Some single crystals isolated in the synthesis of 2b contain [Re(L4)(L2)(CO)3] (3b) where L4 (=2-methylamine-5-(para-methylsulfanephenyl)-1,3,4-thiadiazole) is originated in a cyclization process of the thiosemicarbazone. Furthermore, the rhenium atom is coordinate by the sulphur and the thioamidic nitrogen of the thiosemicarbazonate (κS,N2) affording a four-membered chelate ring.

A new mixed-ligand nickel(II) coordination compound [Ni(bz)2(phen)2] (1) (bz = benzilate and phen = 1,10-phenanthroline) has been synthesized by refluxing nickel(II) acetate with benzilic acid and 1,10-phenantholine. Compound 1 has been characterized by elemental analysis, IR and electronic absorption spectroscopy, magnetic measurements, thermogravimetric analysis and single-crystal X-ray diffraction The crystal of 1 belongs to monoclinic crystal system, space group C2/c and its unit cell parameters are a = 25.881(3), b = 11.1728(15), c = 17.609(2) A and β = 124.104(3)°. The effect of non-covalent interactions, such as π···π and C–H···π, on the 3D supramolecular organization of this molecular complex is analyzed. A new mixed-ligand nickel(II) coordination compound [Ni(bz)2(phen)2] (1) (bz = benzilate and phen = 1,10-phenanthroline) has been synthesized and structurally characterized, the effect of non-covalent interactions, such as π···π and C–H···π, on the 3D supramolecular organization of this molecular complex has been analyzed.

The ligand 4bpytm [4bpytm = bis(4-pyridylthio)methane] in strongly acidic media afforded H24bpytm(NO3)2. The reaction of CuCl2.2H2O with 4bpytm at low pH values afforded three supramolecular compounds: H24bpytm[CuCl4] (1) and the monomeric complexes [CuCl3(H4bpytm)(4bpytm)] (2) and [CuCl2(H4bpytm)2]·Cl2 (3). Nevertheless, the same reaction using aprotic solvents under microwave irradiation afforded the 1D coordination polymers [CuCl2(4bpytm)]·2dmf (4.dmf) and [CuCl2(4bpytm)]·2dmso (4.dmso). The 3D supramolecular organization through weak interactions has been analyzed for all of the compounds, and their thermal behavior and structural dynamics after solvent release were also investigated for 4.dmf and 4.dmso. X-ray structural analysis of these complexes showed that the synthetic conditions used represent an effective method to obtain metal−organic square grid networks with cavities.

Tricarbonylrhenium(I) and -technetium(I) halide (halide = Cl and Br) complexes of ligands derived from 4,5-diazafluoren-9-one (df) and 1,10-phenanthroline-5,6-dione (phen) derivatives of benzoic and 2-hydroxybenzoic acid hydrazides have been prepared. The complexes have been characterized by elemental analysis, MS, IR, 1 H NMR and absorption and emission UV/Vis spectroscopic methods. The metal centres (Re I and Tc I ) are coordinated through the nitrogen imine atoms and establish five-membered chelate rings, whereas the hydrazone groups stand uncoordinated. The 1 H NMR spectra suggest the same behaviour in solution on the basis of only marginal variations in the chemical shifts of the hydrazine protons.

We report herein the solid state structure of a new complex [Cu(ox)(Im)2] (II) which adopts a mononuclear 0D form in contrast to the polymeric 1D form adopted by the previously described [ Cu ( ox ) ( Im ) 2 ] ∞ 1 (I). Both compounds were obtained from an oxidative transformation of chelidonate to oxalate in the presence of Cu(II) and imidazole. The packing and weak interactions of II are analyzed and compared with those of I.

La esquistosomiasis, enfermedad tropical transmitida por molusco, ocupa el segundo lugar en enfermedades parasitarias despues de la malaria. En Cuba no existe la esquistosomiasis aunque si el riesgo a contraerla, puesto que en nuestra fauna se encuentran especies que pueden actuar como hospederos intermediarios del trematodo causante de la enfermedad. El objetivo del trabajo fue evaluar el polvo de colofonia sobre larvas de Biomphalaria havanensis para el control de vectores que propagan la esquistosomiasis, segun la metodologia desarrollada por la Organizacion Mundial para la Salud (OMS) y descrita por Mott para la evaluacion de plantas con accion molusquicida. Los resultados del estudio sugieren la accion molusquicida de colofonia obtenida de pinaceas cubanas (Pinus caribaea y Pinus tropicalis) sobre larvas de Biomphalaria havanensis en dosis letales (DL50 y DL90) son 44, 33 m·gL-1 y 141, 76 m·gL-1, respectivamente. La ecuacion de regresion correspondiente fue: Y = - 0, 412 + 1, 086 ln X con un valor del coeficiente de correlacion R 0, 99 y error estandar 0, 13. Las dosis revelan la efectividad de los componentes presentes en la colofonia, resultados comparables con publicaciones de extractos de otras especies de plantas.