Project description:Complexes of type [M(tpt)2]X2 (M2+ = Fe2+, Co2+, Ni2+; tpt = 2,4,6-tri{pyrazol-1-yl}-1,3,5-triazine; X- = BF4 - or ClO4 -) crystallize in a cubic lattice, with the metal ion and ligand conformation showing unusual symmetry-imposed disorder. Addition of 1 equiv AgX to the corresponding preformed [M(tpt)2]X2 salt in concentrated MeNO2 solution affords thixotropic gels. Gelation was not observed in analogous reactions using [Mn(tpt)2][ClO4]2, or from reactions in other, more donating solvents. Scanning electron microscopy (SEM) images from dilute solutions of the reagents confirmed the fibrous microstructure of the gels and their homogeneous elemental composition. However, energy-dispersive X-ray data show a reduced Fe/Ag ratio compared to the Co/Ag and Ni/Ag gels, where a 1:1 ratio of metals is evident. More concentrated gels decomposed to silver nanoparticles during SEM sample preparation. Mass spectrometry and 1H NMR indicate that silver induces partial ligand displacement reactions in [Fe(tpt)2]2+ and [Co(tpt)2]2+, but not in [Ni(tpt)2]2+. Hence, the strength of the gels, which follows the order M = Mn (no gel) < Fe < Co < Ni, correlates with the stability of octahedral [M(tpt)2]2+ under gelation conditions. Iron(II) complexes of the related ligands 2,4,6-tri{pyrazol-1-yl}pyridine (tpp) and 2,4,6-tri{pyrazol-1-yl}pyrimidine (tpym) did not undergo gelation with silver salts under the above conditions. The unique properties of tpt as a gelator in this work may reflect the crystallographically observed ability of metal-coordinated tpt to chelate to exogenous silver ions, through its pendant pyrazolyl group and triazinyl N donors. In contrast, the pendant azolyl substituents in silver complexes of the nongelators tpp and tpym only bind exogenous silver in monodentate fashion.
Project description:Coinage metal(I)···metal(I) interactions are widely of interest in fields such as supramolecular assembly and unique luminescent properties, etc. Only two types of polynuclear silver(I) pyrazolato complexes have been reported, however, and no detailed spectroscopic characterizations have been reported. An unexpected synthetic method yielded a polynuclear silver(I) complex [Ag(μ-L1Clpz)]n (L1Clpz- = 4-chloride-3,5-diisopropyl-1-pyrazolate anion) by the reaction of {[Ag(μ-L1Clpz)]3}2 with (nBu4N)[Ag(CN)2]. The obtained structure was compared with the known hexanuclear silver(I) complex {[Ag(μ-L1Clpz)]3}2. The Ag···Ag distances in [Ag(μ-L1Clpz)]n are slightly shorter than twice Bondi's van der Waals radius, indicating some Ag···Ag argentophilic interactions. Two Ag-N distances in [Ag(μ-L1Clpz)]n were found: 2.0760(13) and 2.0716(13) Å, and their N-Ag-N bond angles of 180.00(7)° and 179.83(5)° indicate that each silver(I) ion is coordinated by two pyrazolyl nitrogen atoms with an almost linear coordination. Every five pyrazoles point in the same direction to form a 1-D zig-zag structure. Some spectroscopic properties of [Ag(μ-L1Clpz)]n in the solid-state are different from those of {[Ag(μ-L1Clpz)]3}2 (especially in the absorption and emission spectra), presumably attributable to this zig-zag structure having longer but differently arranged intramolecular Ag···Ag interactions of 3.39171(17) Å. This result clearly demonstrates the different physicochemical properties in the solid-state between 1-D coordination polymer and metalacyclic trinuclear (hexanuclear) or tetranuclear silver(I) pyrazolate complexes.
Project description:The 2D heterometallic sodium-palladium(II) coordination polymers with 2-halonicotinates [2-chloropyridine-3-carboxylate (2-chloronicotinate), 2-Clnic- and 2-bromopyridine-3-carboxylate (2-bromonicotinate), 2-Brnic-], {[Na2(H2O)2(μ-H2O)4PdCl2(μ-2-Clnic-N:O')2]}n (1), and {[Na2(H2O)2(μ-H2O)4PdBr2(μ-2-Brnic-N:O')2]·2H2O}n (2) were prepared in aqueous solutions under the presence of NaHCO3, while palladium(II) monomers with the neutral 2-chloronicotinic and 2-bromonicotinic acid ligands, [PdCl2(2-ClnicH-N)2]·2DMF (3) and [PdCl2(2-BrnicH-N)2]·2DMF (4), were prepared in DMF/water mixtures (DMF = N,N'-dimethylformamide). The zigzag chains of water-bridged sodium ions are in turn bridged by [PdCl2(2-Clnic)2]2- moieties in 1 or by [PdBr2(2-Brnic)2]2- moieties in 2, leading to the formation of the infinite 2D coordination networks of 1 or 2. The DFT calculations showed the halosubstituents type (Cl vs Br) does not have an influence on the formation of either trans or cis isomers. The trans isomers were found in all reported compounds; being more stable for about 10 to 15 kJ mol-1. The 2D coordination networks 1 and 2 are more stabilized by the formation of Na-Ocarboxylate bonds, comparing to the stabilization of palladium(II) monomers 3 and 4 by hydrogen-bonding with DMF molecules. The difference in DFT calculated energy stabilization for 1 and 2 is ascribed to the type of halosubstituents and to the presence/absence of lattice water molecules in 1 and 2. The compounds show no antibacterial activity toward reference strains of Escherichia coli and Staphylococcus aureus bacteria and no antiproliferative activity toward bladder (T24) and lung (A549) cancer cell lines.
Project description:The reaction of hydroxyl-amine hydro-chloride with isatin in ethanol, catalysed with HCl and neutralized with Na(2)CO(3), yielded the one-dimensional coordination polymer, catena-poly[[[aqua-sodium]-di-μ-aqua-[aqua-sodium]-bis-(μ-2-oxoindoline-2,3-dione 3-oximato)] tetra-kis-(oxoindoline-2,3-dione 3-oxime)], {[Na(C(8)H(5)N(2)O(2))(H(2)O)(2)]·2C(8)H(6)N(2)O(2)}(n). The Na(I) atom has a six-coordinate distorted-octa-hedral environment. Isatine-3-oximate O atoms and water mol-ecules bridge adjacent Na atoms, forming a one-dimensional polymeric structure parallel to [100]. Each isatine-3-oxime dimerizes through N-H⋯O interactions and in addition each oxime is linked to a coordination polymer. Thus, coordination polymers are linked by O-H⋯O and O-H⋯N interactions from isatine-3-oxime dimers, building a two-dimensional network parallel to [110].
Project description:The title compound catena-poly[aqua-sodium-μ(2)-aqua-μ(3)-2-nitro-cinnamato], [Na(C(9)H(6)NO(4))(H(2)O)(2)](n), the sodium salt of trans-2-nitro-cinnamic acid, is a one-dimensional coordination polymer based on six-coordinate octa-hedral NaO(6) centres, comprising three facially related monodentate carboxyl-ate O-atom donors from separate ligands (all bridging) [Na-O = 2.4370 (13)-2.5046 (13) Å], and three water mol-ecules (two bridging and one monodentate) [Na-O = 2.3782 (13)-2.4404 (17) Å]. The structure is also stabilized by intra-chain water-carboxyl-ate and water-nitro O-H⋯O hydrogen bonds.
Project description:A novel Ca(II) coordination polymer, [CaL(4,4'-bipyridyl)(H₂O)₄]n (L = 1,6-naphthalenedisulfonate), was synthesized by reaction of calcium perchlorate with 1,6-naphthalenedisulfonic acid disodium salt and 4,4'-bipyridyl in CH₃CH₂OH/H₂O. It was characterized by elemental analysis, IR, molar conductivity and thermogravimetric analysis. X-ray crystallography reveals that the Ca(II) coordination polymer belongs to the orthorhombic system, with space group P2₁2₁2₁. The geometry of the Ca(II) ion is a distorted CaNO₆ pengonal bipyramid, arising from its coordination by four water molecules, one nitrogen atom of 4,4'-bipyridyl molecule, and two oxygen atoms from two L ligands. The complex molecules form a helical chain by self-assembly. The antitumor activity of 1,6-naphthalenedisulfonic acid disodium salt and the Ca(II) coordination polymer against human hepatoma smmc-7721 cell line and human lung adenocarcinoma A549 cell line reveals that the Ca(II) coordination polymer inhibits cell growth of human lung adenocarcinoma A549 cell line with IC50 value of 27 μg/mL, and is more resistive to human lung adenocarcinoma A549 cell line as compared to 1,6-naphthalenedisulfonic acid disodium salt.
Project description:NaSm(PO(3))(4) has been prepared by solid state reactions. It belongs to type II of the structural family of M(I)Ln(III)(PO(3))(4) compounds (M(I) = alkali metal and Ln(III) = rare earth metal) and is composed of (∞)(PO(3))(n)](n-) polyphosphate chains with a repeating unit of four PO(4) tetra-hedra. The chains extend parallel to [100] and share O atoms with irregular SmO(8) polyhedra, forming a three-dimensional framework which delimits tunnels occupied by Na(+) cations in a distorted octa-hedral environment.
Project description:The ditopic ligand 10-[4-(pyridin-4-yl)phenyl]-9-phospha-10-silatriptycene (TRIP-Py, C29H20NPSi) binds as a pyridine donor to NiII and as a phosphatriptycene donor towards PtII. The selectivity relies entirely on the Pearson character of the donor sites and the matching hardness of the respective metal cations. The product is the one-dimensional coordination polymer catena-poly[[[dichloridonickel(II)]-bis{μ-10-[4-(pyridin-4-yl)phenyl]-9-phospha-10-silatriptycene}-bis[dichloridoplatinum(II)]-bis{μ-10-[4-(pyridin-4-yl)phenyl]-9-phospha-10-silatriptycene}] dichloromethane pentasolvate ethanol icosasolvate], {[NiPt2Cl6(TRIP-Py)4]·5CH2Cl2·20EtOH}n (1), which retains large pores due to the inherent rigidity of the ligand. This is enabled by the caged triptycene scaffold which fixes the direction of the phosphorus donor with respect to the remaining molecule and especially the pyridyl moiety. In its crystal structure, which was determined from synchrotron data, the pores of the polymer are filled with dichloromethane and ethanol molecules. Finding a suitable model for the pore content is complicated as it is too disordered to give a reasonable atomic model but too ordered to be described by an electron gas solvent mask. This article presents an in-depth description of this polymer, as well as a discussion on the use of the bypass algorithm for solvent masks.
Project description:In the title complex, [Ca2Cu(C9H3O6)2(H2O)2] n , the CaII and CuII cations are bridged by the benzene-1,3,5-tri-carboxyl-ate anions (BTC3-) to form the coordination polymer, in which each BTC3- anion bridges two CuII and five CaII cations with a μ7 coordination mode. The CuII cation, located at an inversion centre, is in a nearly square-planar geometry defined by four O atoms from four bridging BTC3- anions, while the CaII cation is in a distorted octa-hedral geometry defined by five O atoms from bridging BTC3- anions and one water mol-ecule. O-H⋯O hydrogen bonds between coordinating water mol-ecules and carboxyl groups further stabilize the structure; π-π stacking is also observed between parallel benzene rings, the centroid-to-centroid distance being 3.357 (2) Å.