2H 2O Research Articles

Iron(III), chromium(III) and cobalt(II) complexes with squarate: Synthesis, crystal structure and magnetic properties

The preparation and variable temperature-magnetic investigation of three squarate-containing complexes of formula [Fe 2(OH) 2(C 4O 4) 2(H 2O) 4]·2H 2O ( 1) [Cr 2(OH) 2(C 4O 4) 2(H 2O) 4]·2H 2O ( 2) and [Co(C 4O 4)(H 2O) 4] n ( 3) [H 2C 4O 4 = 3.4-dihydroxycyclobutene-1,2-dione (squaric acid)] together with the crystal structures of 1 and 3 are reported. Complex 1 contains discrete centrosymmetric [Fe 2(OH) 2(C 4O 4) 2(H 2O) 4] diiron(II) units where the iron pairs are joined by a di-μ-hydroxo bridge and two squarate ligands acting as bridging groups through adjacent oxygen atoms. Two coordinated water molecules in cis position complete the octahedral environment at each iron atom in 1. The iron–iron distance with the dinuclear unit is 3.0722(6) Å and the angle at the hydroxo bridge is 99.99(7)°, values which compare well with the corresponding ones in the isostructural compound 2 (2.998 Å and 99.47°) whose structure was reported previously. The crystal structure of 3 contains neutral chains of squarato- O 1, O 3-bridged cobalt(II) ions where four coordinated water molecules complete the six-coordination at each cobalt atom. The cobalt–cobalt separation across the squarate bridge is 8.0595(4) Å. A relatively important intramolecular antiferromagnetic coupling occurs in 1 whereas it is very weak in 2, the exchange pathway being the same [ J = −14.4 ( 1) and −0.07 cm −1 ( 2), the spin Hamiltonian being defined as H ^ = - J S ^ 1 · S ^ 2 ]. A weak intrachain antiferromagnetic interaction between the high-spin cobalt(II) ions occurs in 3 ( J = −0.30 cm −1). The magnitude and nature of these magnetic interactions are discussed in the light of their respective structures and they are compared with those reported for related systems.

Synthesis, crystal structure and thermal properties of two new hybrid octamolybdates supported nickel complexes

Two new organic–inorganic hybrid compounds based on polyoxometallates, [Ni(im) 6][Him] 2[(im) 2Mo 8O 26]·2DMF·2H 2O ( 1) and [Ni(im) 4(DMF) 2] 2[(im) 2Mo 8O 26]·2DMF·3H 2O ( 2) (im = imidazole, DMF = N,N-dimethylformamide), have been synthesized and characterized by single crystal X-ray analysis, elemental analysis and IR spectra. The thermal properties were studied by TG analysis. Both of the two compounds consist of imidazole coordinated γ-octamolybdate anions, which firstly link to one-dimensional chains via hydrogen bonding. Then, the metal complex cations link the 1D hydrogen bonding chains to 3D frameworks by abundant hydrogen bondings.

Synthesis, structure, catalytic and calculated non-linear optical properties of cis- and trans-, mer-chlorobis(triphenyl phosphine/triphenyl arsine)-dipicolinato ruthenium III complexes

The new mononuclear Ru III complexes cis-, mer-[Ru( k 3-dipic)(EPh 3) 2Cl]·2H 2O (E = P ( 1), As ( 2)), (L = 2,6-pyridyldicarboxylate; dipic) have been synthesized and characterized. The X-ray crystal structure of 1 reveals that the coordination geometry around the Ru III center is distorted octahedral in which three sites are occupied by tridentate dipic ligand and remaining three sites are occupied by two mutually cis triphenyl phosphine ligands and one chloride ions. In chloroform solvent, cis-, mer-[Ru( k 3-dipic)(EPh 3) 2Cl]·2H 2O (E = P ( 1), As ( 2)) complexes undergoes thermal rearrangement to more stable trans-, mer-[Ru( k 3-dipic)(EPh 3) 2Cl] (E = P( 3), As( 4)) complexes. Complexes 1 and 2 show rhombic EPR spectral features, while complex 3 and 4 show tetragonal distortion. The new Ru III complexes 1 and 2 display both Ru III–Ru II reduction and Ru III–Ru IV oxidation processes. These geometric isomers exhibit textbook differences both in spectroscopic as well as structural properties in the solid state. The new complexes 1 and 2 were found to catalyze the oxidation of alcohols to carbonyl derivatives using N-methyl morpholine- N-oxide as co-oxidant. The first static hyperpolarizability ( β) for all of the complexes have been investigated by density functional theory (DFT) which suggests β value increases from trans to cis form. Also, the solvent-induced effects on the non-linear optical properties (NLO) were studied by using self-consistent reaction field (SCRF) method. As the solvent polarity increases, the β value increases monotonically. The electronic absorption bands of 1 have been assigned by time dependent density functional theory (TD-DFT).

Bimetallic single-source precursors [M(NH 3) 4][Co(C 2O 4) 2(H 2O) 2]·2H 2O (M = Pd, Pt) for the one run synthesis of CoPd and CoPt magnetic nanoalloys

All the steps of the proposed technique, from the synthesis of single-source precursors to the preparation of CoPd and CoPt nanoalloys, are described. The double complex salts (DCS) [M(NH 3) 4][Co(C 2O 4) 2(H 2O) 2]·2H 2O (M = Pd, Pt), which were synthesized by mixing solutions containing [M(NH 3) 4] 2+ cations and [Co(C 2O 4) 2(H 2O) 2] 2− anions, have been used as precursors. The salts obtained were characterized by IR spectroscopy, thermal analysis, XRD and single crystal X-ray diffraction. The prepared compounds crystallize in the monoclinic (space group I2/ m, M = Pd) and orthorhombic (space group I222, M = Pt) crystal systems. Thermal decomposition of the salts in helium or hydrogen atmosphere at 200–600 °C results in the formation of nanoalloys powders (random solid solution Co 0.50Pd 0.50 and chemically ordered CoPt). The size of the bimetallic particles varied from 5 to 20 nm. Order–disorder structural transformations in Co 0.50Pt 0.50 nanoalloys were studied. The magnetic properties of both chemically disordered Co 0.50Pd 0.50 and ordered CoPt clusters have also been measured.

New open-framework phosphate and phosphite compounds of gallium

Five new open-framework compounds of gallium have been synthesized by hydrothermal methods and their structures determined by single crystal X-ray diffraction studies. The compounds, [C 8N 4H 26][Ga 6F 4(PO 4) 6], I, [C 5N 3H 11][Ga 3F 2(PO 4) 3]·H 2O, II, [C 6N 3H 19][Ga 4(C 2O 4)(PO 4) 4(H 2PO 4)]·2H 2O, III, [Ga 2F 3(HPO 4)(PO 4)]·2H 3O, IV, and [C 3N 2H 5] 2[Ga 4(H 2O) 3(HPO 3) 7], V, possess three-dimensional structures. All the compounds are formed by the connectivity between the Ga polyhedra and phosphite/phosphate units. The observation of SBU-6 ( I and II) and spiro-5 ( IV) secondary building units (SBUs) are noteworthy. The flexibility of the formation of gallium phosphate frameworks has been established by the isolation of two related structures ( I and II) from the same SBU units but different organic amines. Some of the present structures have close resemblance to the gallium phosphate phases known earlier. The compounds have been characterized by CHN analysis, powder XRD, IR, and TGA.

Crystal structure of Kuzel's salt 3CaO·Al 2O 3·1/2CaSO 4·1/2CaCl 2·11H 2O determined by synchrotron powder diffraction

The crystal structure of Kuzel's salt has been successfully determined by synchrotron powder diffraction. It crystallizes in the rhombohedral R3̅ symmetry with a = 5.7508 (2) Å, c = 50.418 (3) Å, V = 1444.04 (11) Å 3. Joint Rietveld refinement was realized using three X-ray powder patterns recorded with a unique wavelength and three different sample-to-detector distances. Kuzel's salt is the chloro-sulfoaluminate AFm phase and belongs to the layered double hydroxide (LDH) large family. Its structure is composed of positively charged main layer [Ca 2Al(OH) 6] + and negatively charged interlayer [Cl 0.50·(SO 4) 0.25·2.5H 2O] −. Chloride and sulfate anions are ordered into two independent crystallographic sites and fill successive interlayer leading to the formation of a second-stage compound. The two kinds of interlayer have the compositions [Cl·2H 2O] − and [(SO 4) 0.5·3H 2O] −. The crystal structure explains why chloride and sulfate anions are not substituted and why the formation of extended solid solution in the chloro-sulfate AFm system does not occur.

Improved two-step anodization technique for ordered porous anodic aluminum membranes

We report on an improved two-step anodization technique through combining the first hard anodization in C 2H 2O 4 with the second mild anodization in H 3PO 4, which successfully overcome the drawbacks of irregular top surfaces in the conventional two-step hard anodization in C 2H 2O 4 and disordered pore arrays in the two-step mild anodization in H 3PO 4. The key success of our method is the strong guidance effect of the first hard anodization on the second mild anodization. Highly-ordered (both top and bottom surfaces) porous anodic aluminum (PAA) membranes with interpore spacing from 220 to 350 nm have been realized under anodizing voltages from 100 to 150 V. The interpore spacing is only determined by the first anodizing voltage, while the pore diameter can be manipulated in the second step by adding ethanol in the H 3PO 4 electrolyte, changing the H 3PO 4 bath temperature, and altering the second anodizing voltage. The bath temperature for the steady growth of ordered structures can be expanded up to 20 °C, from which the average activation energy can be yielded. The present novel two-step anodization approach is simple, efficient, and cost-effective. It expands the self-ordering regime of PAA membranes, which is of great value for applications in diverse areas of nanotechnology.

Layered and self-penetrated cadmium isophthalate and 5-methylisophthalate coordination polymers containing bis(4-pyridylformyl)piperazine or bis(4-pyridylmethyl)homopiperazine ligands

Hydrothermal synthesis has afforded divalent cadmium coordination polymers containing isophthalate (ip) or 5-methylisophthalate (mip) dicarboxylate ligands and bis(4-pyridylformyl)piperazine (4-bpfp) or bis(4-pyridylmethyl)homopiperazine (4-bpmh) tethers. {[Cd 2(ip) 2(H 2O) 2(4-bpfp)]·7H 2O} n ( 1) displays a (4,4) grid topology based on {Cd 2O 2} dimeric clusters, along with “infinite” water molecule tapes with rare T4(0)A(1) classification. {[Cd(mip)(H 2O)(4-bpfp)]·3H 2O} n ( 2) also exhibits (4,4) grid layers but with 2D + 2D → 3D mutual inclined interpenetration instead of parallel stacking. [Cd 4(ip) 4(4-bpmh) 2] n ( 3) has tetrameric {Cd 4(ip) 4} cluster units linked by ip and 4-bpmh ligands into a unique self-penetrated 3,5,5,5-connected tetranodal net with (4.8 2)(4 36 28 5)(4 46 48 2)(4.5 64 8) topology. {[Cd 2(mip) 2(H 2O) 2(4-bpmh)]·2H 2O} n ( 4) possesses a structure similar to that of 1, without the aggregated water molecule tapes. All four materials emit visible light upon ultraviolet excitation, ascribed to ligand-based electronic transitions.

Spectroscopic and structural studies of 6-(1-methylbenzimidazol-2-yl)-1 H-pyridin-2-one and of an unusual T4(2)7(2)6(2)7(2) water tape stabilized by the copper(II) coordination polymer

The solid-state structures of 6-(1-methylbenzimidazol-2-yl)-1 H-pyridin-2-one ( HL) and the copper(II) complex [Cu( L − ) 2(OH 2)]·2H 2O ( 1) are established by X-ray crystallography and also by means of physicochemical and spectroscopic methods. The molecules of HL form a self-complementary head-to-tail hydrogen-bonded dimer through C–H⋯N and C–H⋯O contacts to give an infinite 1D chain. The copper(II) complex ( 1) is five-coordinate with distorted trigonal-bipyramidal (TBP) geometry of the N 4O donor atoms. The electronic and EPR data are in agreement with the X-ray structure of 1, showing that HL coordinates to copper(II) centre as a mono-anionic ligand through deprotonated pyridone N atom and the tertiary benzimidazole nitrogen atom to form a neutral complex in which the water molecule occupies the fifth position. The 1D water tape, T4(2)7(2)6(2)7(2) is anchored to the host through hydrogen bonds between coordinated water molecule [O(3w)] as acting double H-donor, pyridone carbonyl groups [O(2) and O(1)] as double H-acceptor and the lattice water molecules [O(4w) and O(5w)] as double H-donor and single H-acceptor).

A novel anagostic C [sbnd]H⋯Cu interaction and clustered water molecules in copper(II)–pyridine-2,5-dicarboxylate complex

In this study, a new mononuclear Cu(II)–pyridine-2,5-dicarboxylate complex with N,N-diethylethylenediamine (deen), [Cu(pydc)(deen)(H 2O)]·2H 2O ( 1) (pydc = pyridine-2,5-dicarboxylic acid or isocinchomeronic acid), has been synthesized. Elemental, thermal analysis and IR spectroscopic study have been performed to characterize the complex. The molecular structure of the complex has been determined by single crystal X-ray diffraction. In 1, the Cu(II) ion is coordinated by pyridine nitrogen and carboxylate oxygen atoms from pydc. The square pyramidal geometry around Cu(II) is completed by two N atoms from deen and aqua ligands. One of the interesting structural features of 1 is the presence of obvious C H⋯M anagostic interactions between the Cu(II) ion and the H atom of ethyl group.

Aqua bridge cleavage and metal ion extrusion by thiocyanate anions in a dicopper complex

Reaction of the imidazolidinyl phenolate-based ligand, H 3L [(2-(2′-hydroxyphenyl)-1,3-bis[4-(2-hydroxyphenyl)-3-azabut-3-enyl]-1,3-imidazolidine)] with Cu(ClO 4) 2·6H 2O produces an aqua-bridged cationic reactant complex [Cu 2(μ-H 2O)(μ-L)][ClO 4]·1.5H 2O ( 1·1.5H 2O). Solution phase interaction of 1·1.5H 2O with SCN − anions in 1:1 molar ratio leads to [Cu 2(μ-L)(NCS)]·2H 2O ( 2·2H 2O) that does not possess anymore the reactive aqua bridge but instead a terminal SCN − anion coordinated only to one Cu II ion. Whereas in 1:2 molar ratio, partial extrusion of the Cu II ions takes place to generate in situ [Cu(NCS) 3(OH 2)] − anions. These complex anions then quantitatively replace ClO 4 - anions in 1·1.5H 2O via ‘anion metathesis’ and concurrently remove the aqua bridge by coordination of linear MeCN to one of the Cu II ions to give [Cu 2(μ-L)(CH 3CN)][Cu(NCS) 3(OH 2)] ( 3). The literature unknown [Cu(NCS) 3(OH 2)] − anion forms an intimate H-bonded assembly with the cationic part of 3 to yield a novel [Cu 3] isosceles triangle. The precursor complex is known as antiferromagnetic whereas in 2·2H 2O, the Cu II ( S = 1/2) ions in a dinuclear entity exhibit ferromagnetic interactions ( J/k B = +15.0 K and g = 2.22) to yield an S T = 1 spin ground state in good agreement with the M versus H data below 8 K.

New Cu(II) 4 and Zn(II) 4 complexes: Synthesis, characterization and magnetic and biological studies

Two new isomorphous tetranuclear complexes [Cu 4L 2(4,4′-bipy) 2]·(ClO 4) 4·2CH 3CN·2H 2O ( 1) and [Zn 4L 2(4,4′-bipy) 2]·(ClO 4) 3·CH 3O·4H 2O ( 2) have been obtained and fully characterized (where bipy = bipyridine, H 2L = macrocycle is the [2+2] condensation product of 2,6-diformyl-4-fluoro-phenol and 1,4-diaminobutane). They exhibit wheel-like configuration in which two 4,4′-bipy molecules connect two dinuclear [M 2L] 2+ units. The interactions of the complexes with calf thymus DNA were studied by UV–Vis and CD spectroscopic techniques. The binding constants of 1 and 2 are 2.27 × 10 6 and 3.89 × 10 5 M −1, respectively. The magnetic measurement of 1 reveals that there are strong antiferromagnetic coupling ( J = –272.6 cm −1) between two Cu(II) ions in the macrocyclic unit and ferromagnetic interaction ( j′ = 41.7) between the Cu(II) ions in two adjacent macrocyclic units. Furthermore, the cyclic voltammogram of 1 shows that it undergoes two quasi-reversible processes with the half wave potentials –0.232 and –0.606 V, respectively.

Structural variation within uranium VI heterocyclic carboxylates: Solid and solution states studies

The solution chemistry and solid-state structures of two new uranium VI metal–organic compounds, (tataH) 2[(UO 2) 2(pdtc) 2(μ-OH) 2]·2H 2O ( 1) and (AcrH) 2[(UO 2)(pydc) 2] ( 2), [where tata = 1,3,5-triazine-2,4,6-triamine, Acr = acridine, pydc = pyridine-2,6-dicarboxylate and pdtc = pyridine-2,6-bis(monothiocarboxylate)] have been investigated. These compounds were obtained via proton-transfer methodology by reacting UO 2 2+ with the preformed proton-transfer systems (tataH) 2(pdtc) and (AcrH) 2(pydc), respectively, in aqueous solution, after evaporation of the solvent. Our results show that noncovalent interactions such as hydrogen bonds, sulfur···sulfur, and π···π interactions, when acting cooperatively, are driving forces for the selection of different structures. The protonation constants of Acr, tata, pdtcH 2, and pydcH 2, the building blocks of the proton-transfer systems (tataH) 2(pdtc) and (AcrH) 2(pydc), and the stability constants of these systems were determined by potentiometric studies in a dioxane/H 2O (1:1 v/v) mixture. The stoichiometry and the formation stability constants of complexes formed on reacting pydcH 2/Acr or pdtcH 2/tata 1:1 molar mixtures with the UO 2 2+ ion in dioxane/H 2O (1:1 v/v) were investigated by potentiometric pH titration methods. The stoichiometries of the complex species formed in solution were compared with those observed for the crystalline metal ion complexes 1 and 2.

Measuring protein synthesis using metabolic 2H labeling, high-resolution mass spectrometry, and an algorithm

We recently developed a method for estimating protein dynamics in vivo with heavy water ( 2H 2O) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI–TOF MS) [16], and we confirmed that 2H labeling of many hepatic free amino acids rapidly equilibrated with body water. Although this is a reliable method, it required modest sample purification and necessitated the determination of tissue-specific amino acid labeling. Another approach for quantifying protein kinetics is to measure the 2H enrichments of body water (precursor) and protein-bound amino acid or proteolytic peptide (product) and to estimate how many copies of deuterium are incorporated into a product. In the current study, we used nanospray linear trap Fourier transform ion cyclotron resonance mass spectrometry (LTQ FT–ICR MS) to simultaneously measure the isotopic enrichment of peptides and protein-bound amino acids. A mathematical algorithm was developed to aid the data processing. The most notable improvement centers on the fact that the precursor/product labeling ratio can be obtained by measuring the labeling of water and a protein (or peptide) of interest, thereby minimizing the need to measure the amino acid labeling. As a proof of principle, we demonstrate that this approach can detect the effect of nutritional status on albumin synthesis in rats given 2H 2O.

Building block approach to a series of substituted Keggin-type inorganic–organic hybrids

A series of polyoxotungstates based on monovacant Keggin-type anions have been synthesized via a step-by-step assembly process. Reaction of trivacant Keggin-type polyoxotungstate precursors with cupric sulfate at pH ≈ 5 in the presence of 1,2-ethylenediamine (abbreviated as en) led to the isolation of a inorganic–organic hybrid compound, [Cu(en) 2][Cu(en) 2H 2O] 2[SiW 11CuO 39]·5H 2O ( 1). Compound 1 exhibits a 1D chain structure constructed from mono-copper-substituted Keggin silicotungstate grafted by {Cu(en) 2} groups. When lanthanide ions were introduced into the present system, H 14[Cu(en) 2] 4[Ce(PW 11O 39) 2] 2·2en·21H 2O ( 2), H 14[Cu(en) 2] 4[Pr(PW 11O 39) 2] 2·11H 2O ( 3) and H 8[Cu(en) 2H 2O] 4[Cu(en) 2]{[Cu(en) 2][Pr(PW 11O 39) 2]} 2·2en·12H 2O ( 4) have been successfully synthesized, which all show 1D chain structures constructed from {Ln(PW 11O 39) 2} and {Cu(en) 2} moieties. Magnetic study of 1 reveals weak ferromagnetic interactions exist in it. The cyclic voltammetry behaviors of compounds 2– 4 have also been investigated.

Fast liquid chromatography–tandem mass spectrometry for the analysis of bisphenol A-diglycidyl ether, bisphenol F-diglycidyl ether and their derivatives in canned food and beverages

In this work a fast liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) method using a C18 Fused Core™ column, was developed for the simultaneous analysis of bisphenol A diglycidyl ether (BADGE), bisphenol A (2,3-dihydroxypropyl) glycidyl ether (BADGE·H 2O), bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE·2H 2O), bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE·HCl), bisphenol A bis(3-chloro-2-hydroxypropyl) ether (BADGE·2HCl) and bisphenol A (3-chloro-2-hydroxypropyl)(2,3-dihydroxypropyl ether) (BADGE·HCl·H 2O) and bisphenol F diglycidyl ether (BFDGE), bisphenol F bis(2,3-dihydroxypropyl) ether (BFDGE·2H 2O), bisphenol F bis(3-chloro-2-hydroxypropyl) ether (BFDGE·2HCl). The LC method was coupled with a triple quadrupole mass spectrometer, using an ESI source in positive mode and using the [M+NH 4] + adduct as precursor ion for tandem mass spectrometry experiments. The method developed was applied to the determination of these compounds in canned soft drinks and canned food. OASIS HLB solid phase extraction (SPE) cartridges were used for the analysis of soft drinks, while solid canned food was extracted with ethyl acetate. Method limits of quantitation ranged from 0.13 μg L −1 to 1.6 μg L −1 in soft drinks and 1.0 μg kg −1 to 4.0 μg kg −1 in food samples. BADGE·2H 2O was detected in all the analyzed samples, while other BADGEs such as BADGE·H 2O, BADGE·HCl·H 2O, BADGE·HCl and BADGE·2HCl were also detected in canned foods.

Structural diversification of the coordination mode of divalent metals with 1,3-propanediaminetetraacetate (1,3-pdta): The missing crystal structure of the s-block metal complex [Sr 2(1,3-pdta)(H 2O) 6]·H 2O

This paper reports the synthesis and X-ray characteristics of the missing homonuclear s-block metal complex {[Sr 2(1,3-pdta)(H 2O) 6]·H 2O} n . In the title compound, the hexadentate 1,3-propanediaminetetraacetate (1,3-pdta) ligand joins to two Sr(II) centers via the diamine chain. Moreover, each Sr(II) is bridged through two carboxylate O atoms and a water molecule to two neighboring Sr(II) ions. The coordination sphere around each Sr(II) ion consists of one diamine nitrogen, four carboxylate oxygens and four water molecules. Comparison with the previously reported M(II)–1,3-pdta complexes reveals that increasing of the ion size results in the incorporation of water molecules into its first coordination sphere and consequent increase of the coordination number (C.N.) from six to seven or eight, while keeping the hexadentate coordination mode of the ligand. Further increase of the metal ion size leads to the loss of the chelating properties of the diamine and formation of a bis-tridentate complex. Associated with it is the change in the binding mode of the carboxylate groups. This forms the basis for classification of divalent metal 1,3-pdta complexes into five distinct structural classes. Additionally, in the present study X-ray powder diffraction and IR spectroscopy were used to distinguish the different structural types of M(II)–1,3-pdta complexes, including Ba[Ba(1,3-pdta)]·2H 2O which has been used for their preparation.

Three new two-dimensional metal-organic coordination polymers derived from bis(pyridinecarboxamide)-1,4-benzene ligands and 1,3-benzenedicarboxylate: Syntheses and electrochemical property

Three new metal-organic coordination polymers, [Co( 3- bpcb)(1,3-BDC)]·H 2O ( 1), [Co( 4- bpcb)(1,3-BDC)]·2H 2O ( 2) and [Cu( 4- bpcb)(1,3-BDC)] 2·0.5( 4- bpcb) ( 3), have been hydrothermally synthesized using N, N′-bis(3-pyridinecarboxamide)-1,4-benzene ( 3- bpcb) or N, N′-bis(4-pyridinecarboxamide)-1,4-benzene ( 4- bpcb) and 1,3-benzenedicarboxylate (1,3-H 2BDC) mixed ligands and characterized by elemental analyses, IR, TG, XRPD and single-crystal X-ray diffraction. Complexes 1– 2 exhibit the similar two-dimensional (2D) network with different undulation degrees and dimensions, owing to different N positions from the 3- bpcb and 4- bpcb ligands. 1,3-BDC ligand in complexes 1 and 2 shows two coordination modes. The adjacent 2D layers for 1– 2 are further linked by hydrogen bonding interactions to form a three-dimensional (3D) supramolecular network. Complex 3 possesses infinite 3-fold interpenetrating 2D network composed of three kinds of Cu- 4- bpcb one-dimensional (1D) chains and 1,3-BDC ligands, in which 1,3-BDC only shows one coordination mode. The 2D network is further extended into 3D supramolecular framework by hydrogen bonding interactions. The non-coordinated 4- bpcb ligands existing in the 2D network connect with adjacent 2D layers through the hydrogen bonding interactions. In addition, the electrochemical behaviors and the fluorescence property of complexes 1– 3 have been reported.

Proapoptotic activity in vitro of two novel ruthenium(II) complexes with flavanone-based ligands that overcome cisplatin resistance in human bladder carcinoma cells

In this study we examined their proapoptotic activity of cis-dichloridobis(3-imino-2-methoxyflavanone)ruthenium(II) 3H 2O ( 1) and cis-dichloridobis(3-imino-2-ethoxyflavanone)ruthenium(II) 2H 2O ( 2) towards human bladder carcinoma cell line EJ and its cisplatin resistant subline EJcisR. On the basis of the experiments we carried out, it may be concluded, that: CDDP ( c is- diammine dichlorido platinum) resistance of EJcisR cells is probably based on partial loss of apoptotic pathway activating caspase-8 and increased resistance to DNA strand breaks and/or alkali-labile sites. Increased glutathione levels, as well as activity of P-gp transporter seems to be not relevant in this case. The proapoptotic activity of the ruthenium compounds is higher than that of cisplatin. Higher proapoptotic activity of 1 and 2 when compared to CDDP may be due to the presence of large, lipophilic flavanone-based ligands that may facilitate their trans-membrane transport and their redox activity. 1 and 2 induce apoptosis apparently in more than one way. Although caspase-8 activation and DNA strand breaks and/or alkali-labile sites are caused by the compounds, their ability to cause the oxidative stress in the cells may also participate in apoptosis induction.

In situ benzene-1,4-disulfonate ligand synthesis and electric conductivities of four silver 4-sulfobenzoate or benzene-1,4-disulfonate complexes

The reaction of 4,4′-bipyridine (bipy), AgNO 3 and 4-sulfobenzoate (4-sb) led to an unprecedented complex, {[Ag 2(4,4′-bipy) 2(H 2O) 2]·(1,4-bds)·(2H 2O)} n ( 1), in which benzene-1,4-disulfonate (1,4-bds) was synthesized in situ. This does not happen in the similar 1,2-bis(4-pyridyl)ethylene (bpe) system, where the complex {[Ag 2(bpe) 2(H 2O) 2]·(4-sb)·3H 2O} n ( 2) is formed. The same in situ reaction occurred when triphenylphosphine (PPh 3) was added into the bipy and silver reaction solution, resulting in the complex [Ag 2(PPh3) 4(1,4-bds)]. 2DMF ( 3). Complex 4, {[Ag 2(Ph 3P) 2(4-sb)(H 2O)]·(H 2O)} n , was synthesized similar to the synthesis of complex 3, without the presence of 4,4′-bipyridine. Complexes 1– 4 were characterized by single-crystal X-ray analyses, elemental analyses, IR spectra, TG analyses, fluorescence studies and electric conductivity. Complexes 1 and 2 are cation–anion species. Complexes 3 and 4 are silver triphenylphosphine complexes, where the phenyl embrace interactions play important roles. In 3, the six-fold phenyl embrace (6PEs) connect the molecules into a 1- d hybrid zig-zag infinite chain. Complex 4 is a one-dimensional branch-like polymer containing a 1- d necklace-like backbone made up of an [Ag 2(4-sb)(H 2O)] unit and PPh 3 ‘‘leaves”. Two new coordination modes for the 1,4-bds ligands and one for the 4-sb ligand are observed. Complexes 1– 3 are semi-conductors, while complex 4 is an insulator.