Synthesis, spectral and thermal studies on dicarboxylate-bridged palladium(II) coordination polymers. Part I

The synthesis and thermal behavior of the new [Pd(fum)(bipy)] _n ·2nH₂O (1), [Pd(fum)(bpe)] _n ·nH₂O (2) and [Pd(fum)(pz)] _n ·3nH₂O (3) {bipy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethene and pz = pyrazine} fumarate complexes are described in this work as well their characterization by IR and ¹³C CPMAS NMR spectroscopies. TG curves showed that the compounds released organic ligands and lattice water molecules in the temperature range of 46–491 °C. In all the cases, metallic palladium was identified as the final residue.     

Synthesis,spectral and thermal studies on pyrazolatebridged palladium(II) coordination polymers

Synthesis, spectroscopic characterization and thermal behavior of pyrazolate-bridged palladium complexes [Pd(μ-Pz)₂]_n (1), [Pd(μ-mPz)₂]_n (2), [Pd(μ-dmPz)₂]_n (3), [Pd(μ-IPz)₂]_n (4) {pyrazolate (Pz^–), 4-methylpyrazolate (mPz^–), 3,5-dimethylpyrazolate (dmPz^–), 4-iodopyrazolate (IPz^–)} have been described in this work. The exobidentate coordination mode of pyrazolato ligands in 1–4 was inferred on basis of IR spectroscopic evidences. TG investigations indicated that the introduction of substituents at the 4 position in the pyrazolyl moiety into coordination polymers do not affect significantly their thermal stability, whereas at the 3 and 5 position reduced the stability of the main chain. Metal palladium was the final product of the thermal decompositions, which was identified by X-ray powder diffraction.     

Synthesis,crystal structures,and thermal and thermodynamic properties of dimorphic copper(I) coordination polymers

A second modification of the literature-known copper(I) coordination polymer CuCl(pyridazine) was prepared by the reaction of CuCl with pyridazine in acetonitrile. The crystal structure of catena[CuCl(mu(2)-pyridazine-N,N)] is built up of CuCl chains of which each two are connected by the pyridazine ligands to form double chains that are directed parallel to the crystallographic a-axis. In the literature known form LI (CuCl)(2) dimers occur that are connected to chains by the pyridazine ligand. On heating, compound I and LI lose half of the pyridazine ligands and transform to the new 2:1 coordination polymer poly[(CuCl)(2)(pyridazine-N,N)] (II), which transforms at higher temperatures to CuCl. The crystal structure of II is composed of discrete CuCl tetra-chains that are linked by the pyridazine ligands to sheets parallel to (010). The same thermal reactivity is found for the literature-known compound CuBr(pyridazine) (LII), which is isotypic to LI. On heating LII a transformation into the new 2:1 compound poly[(CuBr)(2)(pyridazine-N,N)] (III) is observed, which is isotypic to II. The thermal reactivity of all compounds and the transformation behavior as well as the range of thermodynamic stability of the dimorphic modifications were studied using DTA-TG-MS and DSC measurements, temperature dependent X-ray powder investigations, and crystallization experiments.     

Electronic structure and properties of camphorimine Cu(I) coordination polymers

The first Cu(I) coordination polymer with an aromatic‐substituted camphorimine ligand [(CuCl)(μ‐Cl) (Cu(H₂NC₆H₄NC₁₀H₁₄O)]_n was obtained from reaction of CuCl with 3‐(4‐aminophenylimino)‐1,7,7‐trimethylbicyclo[2.2.1]heptan‐2‐one (H₂NC₆H₄NC₁₀H₁₄O). The electronic and the surface properties (studied by X‐ray photoelectron spectroscopy) are consistent with two distinct coordination environments for the copper(I) atoms—tetrahedral and linear—for the polymer family [(CuCl)(μ‐Cl){Cu(YNC₁₀H₁₄O)}]_n. DFT band calculations reveal that the highest energy bands are more localized on the copper(I) tetrahedral sites than on the copper(I) linear sites. The redox properties of [(CuCl)(μ‐Cl){Cu(YNC₁₀H₁₄O)}]_n [Y = NMe₂ ( 2b ), NH₂, and H₂NC₆H₄NC₁₀H₁₄O ( 2a )] studied by cyclic voltammetry show that the oxidation potentials of the two copper centers are in fact indistinguishable. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012     

Synthesis,spectral and thermal studies on dicarboxylate-bridged palladium(II) coordination polymers. Part II

The synthesis and thermal behavior of the new [Pd(fum)(bipy)] _n ·2nH₂O (1), [Pd(fum)(bpe)] _n ·nH₂O (2) and [Pd(fum)(pz)] _n ·3nH₂O (3) {bipy = 4,4′-bipyridine, bpe = 1,2-bis(4-pyridyl)ethene and pz = pyrazine} fumarate complexes are described in this work as well their characterization by IR and ¹³C CPMAS NMR spectroscopies. TG curves showed that the compounds released organic ligands and lattice water molecules in the temperature range of 46–491 °C. In all the cases, metallic palladium was identified as the final residue.     

Synthesis and coordination behavior of Cu(I) bis(phosphaethenyl)pyridine complexes

Cu(I) complexes bearing BPEP as a PNP-pincer type phosphaalkene ligand undergo effective bonding interactions with SbF(6)(-) and PF(6)(-) as non-coordinating anions to give [Cu(SbF(6))(BPEP)] and [Cu(2)(BPEP)(2)(μ-PF(6))](+), respectively [BPEP = 2,6-bis(1-phenyl-2-phosphaethenyl)pyridine]. NMR and theoretical studies indicate a reduced anionic charge of the μ-PF(6) ligand, which is induced by the strong π-accepting ability of BPEP.     

Synthesis, crystal structure, thermal and luminescence properties of CuX(2,3-dimethylpyrazine) (X=Cl, Br, I) coordination polymers

Three new coordination polymers based on CuI and 2,3-dimethylpyrazine (2,3-dmpyz) were prepared, structurally characterized and investigated for their thermal and luminescence properties. In the ligand rich 2:3 compound [(CuI)2(2,3-dmpyz)3] (CuI)2 dimers are found, which are connected by the N-donor ligands into chains, whereas in the structure of the 1:1 intermediate [(CuI)(2,3-dmpyz)] (CuI)4 tetramers are found, which are also connected into chains. The crystal structure of the ligand deficient 2:1 compound [(CuI)2(2,3-dmpyz)] is built up of CuI double chains, which are connected by the 2,3-dmpyz ligands into layers. Thermal decomposition of results in its direct transformation into the ligand deficient compound , without the formation of the 1:1 compound as an intermediate. A similar thermal reactivity is found for compound , which transforms into on heating. Stirring of a crystalline suspension of pure or in acetonitrile, always leads to a transformation into the ligand deficient compound indicating that compound is the most stable of all the coordination polymers, whereas compounds and are metastable. The luminescence properties of the CuCl and CuI coordination polymers were investigated at 298 and 77K. It was observed that the emission maxima strongly depends on the nature of the halide atom and the composition and structure of the coordination polymers. In addition, several of these compounds show luminescence thermochromism. These results are compared with those obtained for the previously reported CuCl and CuBr(2,3-dimethylpyrazine) coordination polymers.     

Synthesis,spectral, thermal,DNA interaction and antimicrobial properties of novel Cu(II) heterochelates

Novel dimeric Cu(II) heterochelates were synthesized using 1‐cyclopropyl‐6‐fluoro‐4‐oxo‐7‐piperazin‐1‐yl‐1,4‐dihydro‐quinoline‐3‐carboxylic acid (Cpf) and eight different neutral bidentate ligands. All ligands were characterized by elemental analyses, melting point and IR, ¹H NMR and ¹³C NMR spectra, while heterochelates were characterized by elemental analyses, IR spectra, reflectance spectra, magnetic measurements and thermogravimetric analyses. The DNA interaction and cleavage behaviors of the ligands and corresponding heterochelates were studied by UV–vis absorption titration and gel electrophoresis technique, respectively. The results indicate that heterochelates show larger DNA interaction and cleavage affinity than the ligands. The antimicrobial activities of heterochelates, ligands, cupric nitrate and standard drugs against six bacteria and three fungi were tested. Copyright © 2007 John Wiley & Sons, Ltd.     

Three novel Cd(II) coordination polymers: Synthesis,crystal structures,fluorescence and thermal properties

Three novel Cd(II) coordination polymers, {[Cd(C₄BIm)(N₃)(OAc)]·C₂H₅OH}_n (1), [Cd(C₄BIm)(H₂O)₃(SO₄)]_n (2) (C₄BIm = 1,4-bis(benzimidazolyl)butane) and [Cd(bbbm)_1.5(NO₃)₂]_n (3) (bbbm = 1,1′-(1,4-butanediy)bis-1H-benzimidazole) have been prepared and characterized spectroscopically and crystallographically. In polymer 1, C₄BIm–Cd chains and N₃–Cd chains criss-cross to a layer structure. Polymer 2 possesses a concave–convex chain structure. Polymer 3 exhibits a two-dimensional (2-D) rhomboid grid network, the dimensions of the grid is 25.807 × 13.771 Å, and the diagonal-to-diagonal distances are 28.608 × 21.145 Å. The fluorescence properties and the thermal stabilities of the three polymers were investigated.     

Cobalt(III) tetrabenzoporphyrin: Synthesis,spectral and coordination properties

Comparison of tetrabenzoporphyrin complexation reactions and transmetalation of cadmium(II) tetrabenzoporphyrinate with cobalt(II) acetate and chloride in dimethylformamide (DMF) has been carried out Cobalt(III) tetrabenzoporphyrinate has been prepared and identified. Acido ligands displacement in Co(III) tetrabenzoporphyrinate by pyridine, imidazole, and quinuclidine molecules has been studied.     

Synthesis,crystal structure,and electrochemical properties of Cu(I) coordination polymers with two new (NS)2 Schiff-base ligands containing long flexible spacers

Two new (NS)₂ Schiff bases, (4-NO₂Ph)₂dapte (N,N′-di-(4-nitrobenzaldimine)-1,2-di(o-aminophenylthio)ethane) (1) and (thio)₂daptx (N,N′-di-(thiophenedimine)-1,4-di(o-aminophenylthio)xylene) (2), and their 1-D copper(I) coordination polymers [Cu₂(μ-Br)₂(μ-(4-NO₂Ph)₂dapte)] _n (3), [Cu₂(μ-I)₂(μ-(4-NO₂Ph)₂dapte)] _n (4), and [Cu₂(μ-I)₂(μ-(thio)₂daptx)] _n (5) have been synthesized and characterized by elemental analyses and IR, UV-Vis, and ¹H NMR spectroscopy. The structures of 4 and 5 have been determined by X-ray crystallography and were shown to consist of Cu₂(μ-I)₂ secondary building units (SBUs) bridged by (4-NO₂Ph)₂dapte or (thio)₂daptx ligands. The CuNSI₂ coordination sphere is a distorted tetrahedral in both cases. Both (4-NO₂Ph)₂dapte and (thio)₂daptx are N₂S₂-bis-bidentate chelating ligands with the two imine nitrogens and two thioether sulfurs in a trans configuration generating dinuclear [Cu₂(μ-(4-NO₂Ph)₂dapte)] and [Cu₂(μ-(thio)₂daptx)]. These units are connected by two bridging iodides to form 1-D copper(I) coordination polymers. The electrochemical properties of 3–5 are also reported and discussed.     

Solvothermal syntheses,crystal structure,and photoluminescent properties of two Cu(I) coordination polymers constructed by bisimidazole ligands

Journal of Structural Chemistry - Two Cu(I) coordination polymers {[Cu2(bibp)2]·bdc·3H2O} n (1) and {[Cu3(bib)3]·btc·5H2O} n (2), where bibp =...     

The structures of Cu(I) and Ag(I) coordination polymers using the tricyanofluoroborate anion

The anion BF(CN)3-forms isomorphous network polymers with Cu(I) and Ag(I) that exhibit one-dimensional channels along the b axis and demonstrate stability to air and light respectively.     

Cyanoscorpionates: synthesis and crystallographic characterization of one-dimensional Cu(I) coordination polymers

A new cyanoscorpionate ligand, hydrotris(3- t-butyl-4-cyanopyrazolyl)borate (Tp ( t-Bu,4CN )) is reported. Both Tp ( t-Bu,4CN ) and hydrotris(4-cyano-3-phenylpyrazolyl)borate (Tp (Ph,4CN)) form one-dimensional coordination polymers with Cu(I). The polymeric chains align to form channels which, in the case of Tp ( t-Bu,4CN ), can encapsulate solvent molecules, as evidenced by the characterization of one such polymer with encapsulated acetonitrile molecules.     

Synthesis,spectral, magnetic,and thermal properties of Ge(IV) tetrachlorocobaltates complexes with 2-hydroxyarylaldehydes pyridinoyl(aminobenzoyl) hydrazones

The interaction in the GeCl₄–nicotinoyl(isonicotinoyl, 2-, or 4-aminobenzoyl) hydrazone of 2-hydroxybenz(2-hydroxy-1-naphth)aldehyde (H₂L)–CoCl₂–methanol systems has resulted in the formation of [Ge(L·H)₂][CoCl₄]·nCH₃OH complexes with germanium chelates [Ge(L·H)₂]²⁺ protonated at the exo chelate nitrogen atom (N_Py or NH₂) as the cation. The type of electrolytic dissociation and character of thermolysis of the complexes have been revealed. Spectral, thermal, and magnetic properties of the complexes have been studied.     

Synthesis and properties in solution of ruthenium(II) coordination polymers

Synthetic strategies are presented for the preparation of readily soluble ruthenium(II) coordination polymers of high molecular weight. The constitutional homogeneity of the polymers is proved using high-resolution NMR spectroscopy, and their molar masses are estimated from ¹H NMR spectra, viscosity data and SAXS investigations. The polymers are shown to be conformationally rigid, and to form either densely packed coils or rods. It is mainly this difference in shape which causes the very specific properties of the respective polyelectrolytes in the solid state as well as in dilute solution. Finally, the UV-vis absorption spectra of some of these materials are presented.     

Synthesis,spectral and thermal properties of macrocyclic zinc(II) complexes

The new zinc ternary complexes [Zn(cyclen)NO₃]ClO4 (I), [Zn₂(cyclen)₂(m-nic)](ClO₄)₃ (II), [Zn₂(cyclen)₂(m-pic)](ClO₄)₃ (III) (cyclen=1,4,7,10-tetraazacyclododecane; nic=nicotinic acid; pic=picolinic acid) were synthesized and their spectral and thermal properties were investigated. The compounds were characterized by elemental analysis, IR spectroscopy and TG/DTG, DTA methods. Moreover, the way of coordination of pyridinecarboxylate anions was proposed on the basis of the spectral data and consequently proved with results of X-ray structure analysis. This revised version was published online in August 2006 with corrections to the Cover Date.     

Cu(II) coordination polymers incorporating 3-aminopyridine and flexible aliphatic dicarboxylate ligands: Synthesis,structure and magnetic properties

The synthesis, structural chemistry and magnetic properties of a series of new Cu(II) polymers with α,ω-dicarboxylic acids (sebacic (H₂seb), suberic (H₂sub), succinic (H₂suc) and adipic (H₂adip)) and 3-aminopyridine (3-apy) are described: [Cu(Hsub)₂(3-apy)₂·2CH₃OH]_n (1); [Cu(Hseb)₂(3-apy)₂·4CH₃OH]_n (2); [Cu(Hsuc)₂(3-apy)₂]_n (3); [Cu(adip)(3-apy)₂]_n·n(H₂adip) (4). All four compounds feature a bis-monodentate bridging mode of the coordinated dicarboxylate moiety. Compounds 1 and 2 exhibit linear chains, whereas compound 3 shows two-dimensional structure. The 3-apy ligand acts as terminal ligand in 1–3. Compound 4 contains a doubly deprotonated adipate (adip²⁻) that connects Cu centers into linear chains. Additionally, 3-apy acts as a bridge in 4, resulting in the formation of parallel two-dimensional layers distant enough to host neutral molecules of adipic acid. Magnetic susceptibility measurements of compounds 1 and 3 show Curie law behavior indicating that the S = 1/2 Cu(II) spin carriers are magnetically well isolated by the dicarboxylate ligands.