Self-assembly of polymer and sheet structures from palladium(II) complexes by hydrogen bonding between carboxamide substituents

Isostructural coordination polymers of the tethering naphthalene anchored bis(2-methylpyridinecarboxamide) ligand: single crystal, XPS, EDS and theoretical studies

Interesting correlation between various analytical techniques has been made in this work concerning new isostructural CPs.

Triboelectrification-Induced Self-Assembly of Macro-Sized Polymer Beads on a Nanostructured Surface for Self-Powered Patterning

Here we report an electrostatic-templated self-assembly (ETSA) method for arbitrarily patterning millimeter-sized polymer beads on a nanostructured surface without using an extra voltage source. A patterned electrode underneath an electrification layer generates "potential wells" of the corresponding pattern at predefined window sites, which capture and anchor the beads within the window sites by electrostatic force. Analytical calculation is combined with numerical modeling to derive the electrostatic force acting on the beads, which is in great agreement with experimentally measured values. The generated pattern is solely determined by the predefined underlying electrode, making it arbitrarily switchable by using different electrode patterns. By transferring the assembled beads into an elastomer matrix, possible applications of the ETSA in fabricating optical and flexible displays are demonstrated.

Chiral nanostructuring of multivalent macrocycles in solution and on surfaces

We describe the design and synthesis of a novel functionality-rich, homochiral macrocycle, possessing the overall molecular D2 symmetry, in which multivalency is introduced into the covalent framework by means of four suitably positioned pyridine moieties. The macrocycle synthesis is carried out with functionalized, enantiopure 1,1'-binaphthyl synthons as the source of chirality by means of a room temperature esterification reaction as the cyclization procedure. Upon addition of Pd(2+), coordination of the pyridine moieties occurs both intra and intermolecularly, to afford chiral ordered mono and dimeric macrocycles or multimeric aggregates depending on the solvents and conditions used. The metal binding event takes place in combination with a significant macrocyclic conformational rearrangement detected by circular dichroism spectroscopy. When in combination with a third component (C60), the macrocycle-Pd(2+) hybrid undergoes surface-confined nanostructuring into chiral nanofibres.

A novel one-dimensional manganese(II) coordination polymer containing both dicyanamide and pyrazinamide ligands: synthesis, spectroscopic investigations, X-ray studies and evaluation of biological activities

A novel 1D coordination polymer {[Mn(μ1,5-dca)2(PZA)2](PZA)2}n, 1, has been synthesized and characterized by single crystal X-ray crystallography. The coordination mode of dicyanamide (dca) and pyrazinamide (PZA) ligands was inferred by IR spectroscopy. The compound 1 was evaluated for in vitro antimycobacterial and antitumor activities. It demonstrated better in vitro activity against Mycobacterium tuberculosis than pyrazinamide and its MIC value was determined. Complex 1 was also screened for its in vitro antitumor activity towards LM3 and LP07 murine cancer cell lines. In addition, the antibacterial activity of complex 1 has been tested against Gram(+) and Gram(-) bacteria and it has shown promising broad range anti-bacterial activity.

Design and synthesis of a novel trinuclear palladium(ii) complex containing an oxime chelate ligand: determining the interaction mechanism with the DNA groove and BSA site I by spectroscopic and molecular dynamics simulation approaches

The trinuclear Pd(II) complex containing an oxime ligand showed significant interaction with both CT-DNA and BSA.

Synthesis, chiroptical and SHG properties of polarizable push–pull dyes built on π-extended binaphthyls

Novel binaphthyl push–pull dyes extend their π-bridge and incorporate as acceptors pyridine units, useful for further supramolecular polarization.

cis-(2,2'-Bipyridine-κ(2)N,N')bis-(isonicotinamide-κN(1))palladium(II) bis-(hexa-fluoridophosphate)

In the title salt, [Pd(C₁₀H₈N₂)(C₆H₆NO)₂](PF₆)₂, the Pd^II atom is in a slightly distorted square-planar coordination environment by N atoms derived from two 4-pyridine­carboxamide ligands, in a cis disposition, and a chelating 2,2′-bipyridine mol­ecule. The monodentate ligands are nearly orthogonal to each other [dihedral angle = 85.7 (5)°] and to the PdN₄ plane [dihedral angles = 79.3 (3) and 78.7 (3)°]. The amide O atoms lie to opposite sides of the PdN₄ plane. The most notable feature of the crystal packing is a linear supra­molecular chain orientated approximately along [310] and formed via 16-membered {⋯HNCO}₄ motifs. These are connected into a three-dimensional network by amide–H⋯O, F inter­actions. Both PF₆⁻ anions are disordered over two positions of equal occupancy in respect of the F atoms.

Synthesis, crystal structure, DNA-binding and cytotoxicity in vitro of novel cis-Pt(II) and trans-Pd(II) pyridine carboxamide complexes

In an attempt to establish fundamental structure-activity relationships (SAR) of Pt/Pd-based anti-tumour compounds, we have recently designed monodentate pyridyl amide ligand containing central amide units which possess external metal co-ordinating pyridyl group and internal amide functionality. It was prepared in one step from commercially available compounds in moderate to good yield. Surprisingly, treatment of K(2)[MCl(4)] [M=Pt(II), Pd(II)] with ligand N-(4-chlorophenyl)-3-pyridinecarboxamide (L) in the same reaction condition affords two different hydrogen-bonded polymers: cis-[PtL(2)Cl(2)]·CH(3)OH·DMF (1) and trans-[PdL(2)Cl(2)]·2DMF (2). Fluorescence analysis indicates that the two complexes can bind to fish sperm DNA (FS-DNA) and gel electrophoresis assay demonstrates the ability of the complexes to cleave the pBR322 plasmid DNA. The two complexes exhibit cytotoxic specificity and significant cancer cell inhibitory rate. Furthermore, cytotoxicity values are higher in the case of cis-Pt(II) complex than trans-Pd(II) complex in four different cancer cell lines.

Antimycobacterial and antitumor activities of palladium(II) complexes containing isonicotinamide (isn): X-ray structure of trans-[Pd(N3)2(isn)(2)]

Complexes of the type trans-[PdX(2)(isn)(2)] {X = Cl (1), N(3) (2), SCN (3), NCO (4); isn = isonicotinamide} were synthesized and evaluated for in vitro antimycobacterial and antitumor activities. The coordination mode of the isonicotinamide and the pseudohalide ligands was inferred by IR spectroscopy. Single crystal X-ray diffraction determination on 2 showed that coordination geometry around Pd(II) is nearly square planar, with the ligands in a trans configuration. All the compounds demonstrated better in vitro activity against Mycobacterium tuberculosis than isonicotinamide and pyrazinamide. Among the complexes, compound 2 was found to be the most active with MIC of 35.89 μM. Complexes 1-4 were also screened for their in vitro antitumor activity towards LM3 and LP07 murine cancer cell lines.

2-Chloro-pyridine-3-carboxamide

In the crystal structure of the title compound, C(6)H(5)ClN(2)O, the dihedral angle between the pyridine ring and the carboxamine group is 63.88 (8)°. Inter-molecular N-H⋯N and N-H⋯O hydrogen bonds link the mol-ecules into a two-dimensional network.