Phenolic nitroaromatics detection by fluorinated metal-organic frameworks: Barrier elimination for selective sensing of specific group of nitroaromatics.

Many piesce of research have been performed to detect nitroaromatic-compounds (NACs) by metal-organic frameworks (MOFs). Despite extensive studies, there are still significant challenges like selective detection of specific NAC group in presence of other NACs. Here, we have integrated two functionalization strategies through decoration of pore-walls of the MOFs with trifluoromethyl groups and extension in π-conjugated system.

Size-Selective Urea-Containing Metal-Organic Frameworks as Receptors for Anions.

Anion recognition by neutral hosts that function in aqueous solution is an emerging area of interest in supramolecular chemistry. The design of neutral architectures for anion recognition still remains a challenge. Among neutral anion receptor systems, urea and its derivatives are considered as "privileged groups" in supramolecular anion recognition, since they have two proximate polarized N-H bonds exploitable for anion recognition.

Ultrasonic assisted synthesis of two urea functionalized metal organic frameworks for phenol sensing: A comparative study.

Two pillared metal-organic frameworks containing urea functional groups were synthesized by a sonochemical method and characterized by scanning electron microscopy, X-ray powder diffraction, IR spectroscopy and elemental analysis. The time of sonication and concentration of starting materials have been optimized to synthesize nanoparticles of TMU-31 and TMU-32. These two frameworks are interesting candidates for a comparative fluorescence study.

Ultrasound-assisted synthesis of nano-structured Zinc(II)-based metal-organic frameworks as precursors for the synthesis of ZnO nano-structures.

A 3D, porous Zn(II)-based metal-organic framework {[Zn(oba)(4-bpmn)]·(DMF)} (TMU-21), (4-bpmn=N,N'-Bis-pyridin-4-ylmethylene-naphtalene-1,5-diamine, Hoba=4,4'-oxybis(benzoic acid)) with nano-rods morphology under ultrasonic irradiation at ambient temperature and atmospheric pressure was prepared and characterized by scanning electron microscopy. Sonication time and concentration of initial reagents effects on the size and morphology of nano-structured MOFs were studied. Also {[Zn(oba)(4-bpmn)] (TMU-21) and {[Zn(oba)(4-bpmb)] (TMU-6), 4-bpmb=N,N'-(1,4-phenylene)bis(1-(pyridin-4-yl)methanimine) were easily prepared by mechanochemical synthesis.

Urea Metal-Organic Frameworks for Nitro-Substituted Compounds Sensing.

Urea groups are known to form strong hydrogen bonds with molecules containing atom(s) that can act as hydrogen bond acceptor(s). Thus, urea is a particularly interesting building block for designing receptors for neutral or charged guests. In the quest for new sensors with enhanced performance for the detection of nitro-substituted compounds, two pillared metal-organic frameworks containing urea functional groups were synthesized and structurally characterized.

Lanthanide metal-organic frameworks as selective microporous materials for adsorption of heavy metal ions.

Four microporous lanthanide metal-organic frameworks (MOFs), namely Ln(BTC)(H2O)(DMF)1.1 (Ln = Tb, Dy, Er and Yb, DMF = dimethylformamide, H3BTC = benzene-1,3,5-tricarboxylic acid), have been used for selective adsorption of Pb(ii) and Cu(ii). Among these MOFs, the Dy-based MOF shows better adsorption property and selectivity toward Pb(ii) and Cu(ii) ions.

Ultrasonic-assisted synthesis and structural characterization of two new nano-structured Hg(II) coordination polymers.

Two new Hg(II) coordination polymers containing N,N'-Bis-pyridin-3-ylmethylene-naphtalene-1,5-diamine ligand were synthesized by conventional and sonochemical methods, characterized by spectroscopic techniques (FT-IR and elemental analysis), and their X-ray crystallographic structures were determined. The crystal packing and supramolecular features of these coordination polymers were studied using geometrical analysis and Hirshfeld surface analysis. The crystal structure analysis revealed that H⋯H contacts, C-H⋯π and C-H⋯X (X = Cl for 1 and X = Br for 2) hydrogen bonding interactions are strong enough to govern the supramolecular architecture.

The role of weak hydrogen and halogen bonding interactions in the assembly of a series of Hg(II) coordination polymers.

A series of eight new Hg(II) complexes based on the L4-X ligands, where L is (E) -4-halo-N-(pyridin-4-ylmethylene)aniline, were synthesized and characterized and their supramolecular crystal structures were studied by different geometrical and theoretical methods. Our study reveals the role of weak intermolecular interactions involving halogens, such as C–H∙∙∙X hydrogen bonds (in the cases of 1, 2, 3, 5, 6 and 7) and C–X∙∙∙X′–M halogen bonds (in the cases of 4 and 8), in the structural changes of supramolecular assemblies of coordination compounds. Complexes 1–8 were also synthesized by sonochemical irradiation and the morphology of the prepared complexes was investigated using FE-SEM.

Influence of halogen bonding interaction on supramolecular assembly of coordination compounds; head-to-tail N···X synthon repetitivity.

In this study, N-(3-halophenyl)-2-pyrazinecarboxamide ligands, L(3-F), L(3-Cl), L(3-Br), and L(3-I), carrying a different halogen atom on the phenyl meta-position and N-phenyl-2-pyrazinecarboxamide ligand, L(H), have been employed for the synthesis of 12 mercury(II) complexes, [HgCl2(L(H))]n, 1, [HgCl2(L(3-Cl))]n, 2, [Hg2Cl4(L(3-Br))2], 3, [Hg2Cl4(L(3-I))2], 4, [Hg2Br4(L(H))2], 5, [HgBr2(L(3-F))], 6, [HgBr2(L(3-Cl))], 7, [HgBr2(L(3-Br))], 8, [HgBr2(L(3-I))], 9, [Hg2I4(L(H))2], 10, [HgI2(L(3-Br))], 11, and [HgI2(L(3-I))]n, 12. Interestingly, structural analysis clearly shows that, by the replacing of coordinated anions from chloride with bromide and iodide in each series containing the same ligand, the coordination geometry and structural motif of the resulting compounds have been dramatically affected. One of the common features in the crystal structures of these complexes is that there is a strong tendency to form halogen bonding synthons between adjacent halophenyl and pyrazine rings.

2-Phenyl-1H-imidazole.

In the title compound, C(9)H(8)N(2), a mirror plane lies perpendicular to the phenyl and imidazole rings and passes through the bridging C-C bond, so that the imidazole ring is disordered over two sites about the mirror plane with the equal site occupancy; the asymmetric unit contains one half-mol-ecule. In the crystal, adjacent mol-ecules are linked via N-H⋯N hydrogen bonds.

catena-Poly[[bis-(pyrazine-2-carbox-amide)mercury(II)]-di-μ-chlorido].

In the polymeric title compound, [HgCl(2)(C(5)H(5)N(3)O)(2)](n), the Hg(II) atom (site symmetry ) adopts a distorted trans-HgN(2)Cl(4) octa-hedral coordination geometry. In the crystal, adjacent mercury ions are bridged by pairs of chloride ions, generating infinite [100] chains, and N-H⋯O and N-H⋯(N,N) hydrogen bonds help to consolidate the packing.

catena-Poly[[bis-(pyrazine-2-carbox-amide-κN)mercury(II)]-di-μ-bromido].

In the crystal structure of the title compound, [HgBr(2)(C(5)H(5)N(3)O)(2)](n), the Hg(II) cation is located on an inversion center and is coordinated by two N atoms from the pyrazine rings and four bridging Br(-) anions in a distorted octa-hedral geometry. The Br(-) anions bridge the Hg(II) cations with significantly different Hg-Br bond distances of 2.4775 (8) and 3.