Two polyoxometalate-templated organic–inorganic hybrid porous frameworks, namely, [Cu2(H2O)2(bpp)2Cl][PM12O40]·∼20H2O (for 1, M = W; for 2, M = Mo; bpp = 1,3-bis(4-pyridyl)propane), were self-assembly obtained and structurally determined by elemental analyses, inductively coupled plasma analyses, infrared spectroscopy, and single-crystal X-ray diffraction analyses. Single-crystal X-ray analysis of these crystals revealed that both of the structures are constructed from eight-connected three-dimensional coordination polymer hosts [Cu2(H2O)2(bpp)2Cl]n3n+ and ball-shaped Keggin-type guests [PM12O40]n3n− as templates. The polymer hosts resulted from a bcc-type framework with nanotubes, and the nanotubes can be regarded as a tetra-stranded helix structure. Furthermore, compounds 1 and 2 exhibit photoluminescent properties at ambient temperature, and the compound 2 bulk-modified carbon paste electrode (2-CPE) displays good electrocatalytic activity toward the reduction of nitrite.

Self-assembly of organic-inorganic hybrid materials constructed from eight-connected coordination polymer hosts with nanotube channels and polyoxometalate guests as templates.

Four organic compounds based on substituted coumarin derivatives (1–4) have been synthesized and characterized by X-ray structural studies with a detailed analysis of Hirshfeld surface and fingerprint plots facilitating a comparison of intermolecular interactions in building different supramolecular architectures. The X-ray study reveals that in the molecular packing C–H···O, π···π, and carbonyl (lone pair)···π interactions cooperatively take part. The recurring feature of the self-assembly in all the compounds is the appearance of the molecular ribbon through weak hydrogen bonding. These hydrogen bonded ribbons further stacked into molecular layers by π···π forces. The mode of cooperativity of the weak C–H···O and π···π forces is such that they operate in mutually perpendicular directions — hydrogen bonding in the plane of the molecule at their edges and π-stacking perpendicular to the molecular plane. Investigation of intermolecular interactions and crystal packing via Hirshfeld surface analyses reveals...

On the Possibility of Tuning Molecular Edges To Direct Supramolecular Self-Assembly in Coumarin Derivatives through Cooperative Weak Forces: Crystallographic and Hirshfeld Surface Analyses

Hexamethylenetetramine: An old new building block for design of coordination polymers

Self-Assembly of a Nanoscopic Prism via a New Organometallic Pt3 Acceptor and Its Fluorescent Detection of Nitroaromatics

Four new metal-organic polymers with SCN–/N3– anion bridges and flexible long spacers L {L = bim [1,2-bis(imidazol-1-yl)ethane] and bte [1,2-bis(1,2,4-triazol-1-yl)ethane]}, [Co(SCN)2(bim)] (1-Co), [Co(SCN)2(bte)] (2-Co), [Mn(N3)2(bte)] (3-Mn), and [Mn(N3)2(bim)] (4-Mn), were synthesized and characterized by single-crystal X-ray diffraction studies and their magnetic properties were investigated. Complex 1-Co is a triple-bridging chain complex with double end-to-end SCN– anions and single gauche-bim spacers as bridges. Complexes 2-Co and 3-Mn both contain 1D chains bridged by double end-to-end SCN– or N3– anions and these chains are further extended to 2D (4,4) layers by the anti-bte spacers. Complex 4-Mn has a topological 3D diamond structure constructed through 1D double end-on azide-bridged MnII chains and extended through the anti-bim spacers. Magnetic measurements reveal that 1-Co and 3-Mn remain paramagnetic; the dominant magnetic coupling between CoII is weak ferromagnetic and that between MnII is strong antiferromagnetic. As for 2-Co and 4-Mn, they show metamagnetic behavior below TN = 2.9 and 3.0 K, respectively. Our results show that a combination of the short anion bridges (SCN–/N3–) and flexible bidentate long spacers can be used to construct coordination polymers with novel topologies and interesting magnetic properties. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Extended Networks of Co2+ and Mn2+ Bridged by NCS–/N3– Anions and Flexible Long Spacers: Syntheses, Structures, and Magnetic Properties

Higher dimensional networks of Mn(II) azide/cyanate using flexible N-donor ligands: Synthesis, crystal structure and magnetic properties

A new zinc-based two-dimensional coordination polymer, [Zn(5-AIP)(Ald-4)]·H2O (5-AIP = 5-amino isophthalate, Ald-4 = aldrithiol-4), 1, has been synthesized at room temperature by the layer diffusion technique. Single-crystal X-ray diffraction analysis of 1 showed a two-dimensional bilayer structure. An aqueous suspension of 1 upon excitation at 300 nm displayed an intense blue emission at 403 nm. The luminescence spectra were interestingly responsive and selective to Al3+, Cr3+ and Fe3+ ions even in the presence of other interfering ions. The calculated detection limits for Al3+, Cr3+ and Fe3+ were 0.35 μM (8.43 ppb), 0.46 μM (22.6 ppb) and 0.30 μM (15.85 ppb), respectively. Notably, with the cumulative addition of Al3+ ions, the luminescence intensity at 403 nm decreased steadily with a gradual red shift up to 427 nm. Afterward, this red shifted peak showed a turn-on effect upon further addition of Al3+ ions. On the other hand, for Cr3+ and Fe3+ ions, there was only drastic luminescence quenching and a large red shift up to 434 nm. This indicated the formation of a complex between 1 and these metal ions, which was also supported by the UV-Visible absorption spectra of 1 that showed the appearance of a new band at 280 nm in the presence of these three metal ions. The FTIR spectra revealed that these ions interacted with the carboxylate oxygen atom of 5-AIP and the nitrogen atom of the Ald-4 ligand in the structure. The luminescence lifetime decay analysis manifested that a charge-transfer type complex was formed between 1 and Cr3+ and Fe3+ ions that resulted in huge luminescence quenching due to the efficient charge transfer involving the vacant d-orbitals, whereas for Al3+ ions having no vacant d-orbital, turn-on of luminescence occurred because of the increased rigidity of 1 upon complexation.

Response of a Zn(II)-based metal-organic coordination polymer towards trivalent metal ions (Al3+, Fe3+ and Cr3+) probed by spectroscopic methods.

3D supramolecular networks of Co(II)/Fe(II) using the croconate dianion and a bipyridyl spacer: Synthesis, crystal structure and thermal study

Synthesis, crystal structure and thermal analysis of supramolecular architectures of copper(II)(2,2′-biimidazole) complexes using dicarboxylate as a coligand

Ananta Kumar Ghosh

Papers

Higher dimensional networks of Mn(II) azide/cyanate using flexible N-donor ligands: Synthesis, crystal structure and magnetic properties

Response of a Zn(II)-based metal-organic coordination polymer towards trivalent metal ions (Al3+, Fe3+ and Cr3+) probed by spectroscopic methods.

3D supramolecular networks of Co(II)/Fe(II) using the croconate dianion and a bipyridyl spacer: Synthesis, crystal structure and thermal study

Synthesis, crystal structure and thermal analysis of supramolecular architectures of copper(II)(2,2′-biimidazole) complexes using dicarboxylate as a coligand