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.

From Operando Raman Mechanochemistry to "NMR Crystallography": Understanding the Structures and Interconversion of Zn-Terephthalate Networks Using Selective 17O-Labeling

The description of the formation, structure, and reactivity of coordination networks and metal-organic frameworks (MOFs) remains a real challenge in a number of cases. This is notably true for compounds composed of Zn2+ ions and terephthalate ligands (benzene-1,4-dicarboxylate, BDC) because of the difficulties in isolating them as pure phases and/or because of the presence of structural defects. Here, using mechanochemistry in combination with operando Raman spectroscopy, the observation of the formation of various zinc terephthalate compounds was rendered possible, allowing the distinction and isolation of three intermediates during the ball-milling synthesis of Zn3(OH)4(BDC). An "NMR crystallography" approach was then used, combining solid-state NMR (1H, 13C, and 17O) and density functional theory (DFT) calculations to refine the poorly described crystallographic structures of these phases. Particularly noteworthy are the high-resolution 17O NMR analyses, which were made possible in a highly efficient and cost-effective way, thanks to the selective 17O-enrichment of either hydroxyl or terephthalate groups by ball-milling. This allowed the presence of defect sites to be identified for the first time in one of the phases, and the nature of the H-bonding network of the hydroxyls to be established in another. Lastly, the possibility of using deuterated precursors (e.g., D2O and d 4-BDC) during ball-milling is also introduced as a means for observing specific transformations during operando Raman spectroscopy studies, which would not have been possible with hydrogenated equivalents. Overall, the synthetic and spectroscopic approaches developed herein are expected to push forward the understanding of the structure and reactivity of other complex coordination networks and MOFs.

Synthesis and structural properties of a 2D Zn(II) dodecahydroxy-closo-dodecaborate coordination polymer

In this work, we discuss the synthesis and characterization of a 2D coordination polymer composed of a dianionic perhydroxylated boron cluster, [B12(OH)12]2-, coordinated to Zn(II)—the first example of a transition...

Heterometallic MOFs constructed from thiophene and furandicarboxylate ligands for heavy metal luminescence sensing

A series of heterometallic porous MOFs were rationally designed from preorganized molecular complexes for heavy metal cation luminescence detection.

Structure of a Luminescent MOF-2 Derivative with a Core of Zn(II)-Terephthalate-Isoquinoline and Its Application in Sensing of Xylenes

A new blue photoluminescent 2D metal–organic framework, 1, with formula {[Zn2(μ2-BDC)2(iQ)2]}∞ has been synthesized in a high yield under solvothermal conditions by reacting Zn(II) ions with 1,4-benzenedicarboxylic acid (H2BDC) and isoquinoline (iQ) in DMF. Compound 1 was thoroughly characterized by single-crystal X-ray diffraction, solid-state cross-polarization magic-angle spinning 13C NMR, X-ray powder diffraction, scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS), and thermoanalysis. The crystal structure of 1 showed interpenetrated 2D frameworks consisting of dinuclear paddle-wheel cores Zn2; moreover, this material possessed thermostability up to 310 °C. The CPMAS 13C-NMR spectrum of 1 is consistent with the symmetry of the crystal structure. Luminescence studies showed that 1 strongly enhances its fluorescence emission in the presence of xylene isomers with a pronounced selectivity to p-xylene.

A luminescent Eu coordination polymer with near-visible excitation for sensing and its homologues constructed from 1,4-benzenedicarboxylate and 1H-imidazo[4,5-f][1,10]-phenanthroline

Ln-CPs were constructed to achieve luminescent Eu-CP excited at a wide excitation band including the visible region for sensing.

Fluorescent metal–organic frameworks based on mixed organic ligands: new candidates for highly sensitive detection of TNP

Novel metal–organic frameworks have been constructed based on fluorescent mixed ligands, which can be employed as efficient sensors.

Supramolecular Assembly of a Zn(II)-Based 1D Coordination Polymer through Hydrogen Bonding and π···π Interactions: Crystal Structure and Device Applications

A new mixed-ligand divalent one-dimensional coordination polymer (1D CP) [Zn(adc)(4-nvp)₂(H₂O)₂] _n , (1) [H₂adc = acetylenedicarboxylic acid and 4-nvp = 4-(1-naphthylvinyl)pyridine] has been synthesized and well characterized by elemental analysis, infrared spectrum, single-crystal X-ray crystallography, powder X-ray diffraction pattern, and thermogravimetric analysis. The compound 1 constructs a 3D supramolecular network by the combination of hydrogen bonding, C-H···π, and π···π interactions. Interestingly, the material shows Schottky behavior which is exclusively analyzed with the help of thermionic emission and space charge-limited current theory. In addition, the Schottky barrier diode parameters for compound 1 demonstrate better device performance after light soaking. Hence, the compound has applicability in the fabrication of optoelectronic devices.

Five Co(ii) coordination polymers with different counter anions based on [3,5-di(4H-1,2,4-triazol-4-yl)benzoato]− ligand: directed synthesis, structures and magnetic properties

Five cobalt(ii) coordination polymers were synthesized by reactions of HL with varied cobalt(ii) salts and different templates under solvothermal conditions.

A combined continuous wave electron paramagnetic resonance and DFT calculations of copper-doped 3∞[Cd0.98Cu0.02(prz-trz-ia)] metal–organic framework

Successful combination of EPR and DFT was applied for investigation the novel heteronuclear MOF compounds.

Hydrothermal synthesis and structural characterization of metal-organic frameworks based on new tetradentate ligands

The hydrothermal reaction of two new tetradentate ligands with different metal salts of cadmium nitrate, zinc chloride, cobalt nitrate and deprotonated terephthalic acid (H2tp), isophthalic acid (H2ip), 4,4'-oxybisbenzoic acid (H2obba) in H2O/DMF or H2O/methanol gave three metal-organic frameworks (MOFs): {[Zn2(L1)(tp)(formate)2]·H2O}n (), {[Cd2(L2)(ip)2]·2H2O}n (), {[Co2(L2)(obba)2]}n () (L1 = 1,2-bis {2,6-bis [(1H-imidazol-1-yl) methyl]-4-methylphenoxy} ethane, L2 = 1,3-bis {2,6-bis [(1H-imidazol-1-yl) methyl]-4-methylphenoxy} propane). The structures of the frameworks are established by single-crystal X-ray diffraction. Compound is a three-dimensional (3D) framework with a 2-fold interpenetrated form, which exhibits a 2-nodal (3,4)-connected fsh-3,4-P21/c net with a {8(3)}2{8(5)·10} topology. Compound has a 2-nodal (4,8)-connected 3D framework where the dinuclear cadmium cluster secondary building units (SBUs) assemble with isophthalate and ligand L2 to construct a rare topological type sqc22 net with a {3(2)·5(4)}{3(4)·4(4)·5(10)·6(10)} topology. Whereas, Compound can be extended to a 2D interlocked (4,4)-connected 4,4 L28 net with the point symbol {4·6(4)·8}2{4(2)·6(4)}. L1 and L2 are tetradentate ligands with diverse linkers and display different coordination modes. In addition, the thermal stability and photochemical properties of the frameworks are also investigated.

Crystal structures, topological analysis and luminescence properties of three coordination polymers based on a semi-rigid ligand and N-donor ligand linkers

Three new mixed-ligand coordination polymers have been synthesized based on 3,3′-(anthracene-9,10-diyl)diacrylate acid and different N-donor ligands. Complex 2 displays rapid and selective sensing of Fe³⁺.

Multidimensional transition metal complexes based on 3-amino-1H-1,2,4-triazole-5-carboxylic acid: from discrete mononuclear complexes to layered materials

The synthesis and structural characterization of five transition metal complexes with different dimensionality and incorporating residues of 3-amino-1H-1,2,4-triazole-5-carboxylic acid (H₂atrc) is reported: [Zn(Hatrc)₂(H₂O)] (1), [Mn(Hatrc)₂(H₂O)₂]·2H₂O (2), [Fe₂(Hatrc)₄(OH)₂]·6H₂O (3), [Cd(Hatrc)₂(H₂O)]_n (4), and [Mn(atrc)(H₂O)]_n·nH₂O (5). These materials could be prepared from solution (1–3), diffusion (4), or hydrothermal reactions (5) with various anions and L:M ratios. Structural details were revealed by single crystal X-ray diffraction. The discrete units composing compounds 1–3, the polymeric 1D chain of 4 and the 2D layer of 5 are further extended into 3D supramolecular architectures through the formation of hydrogen bonds.