Optimized Synthesis of Tetrafluoroterephthalic Acid: A Versatile Linking Ligand for the Construction of New Coordination Polymers and Metal-Organic Frameworks

Pure 2,3,5,6-tetrafluoroterephthalic acid (H(2)tfBDC) is obtained in high yields (95%) by reacting 1,2,4,5-tetrafluorobenzene with a surplus (>2 equiv) of n-butyllithium in tetrahydrofuran (THF) and subsequent carbonation with CO2 without any extensive purification procedure. A single crystal X-ray structure analysis of H2tfBDC (1) confirms former data obtained for a deuterated sample (P (1) over bar, Z = 1). Recrystallization from water/acetone leads to single crystals of H(2)tfBDC center dot 2H(2)O (2, P2(1)/c, Z. 2), where an extensive hydrogen bonding network is found. By reacting H2tfBDC with an aqueous ammonia solution, single crystals of (NH4)(2)tfBDC (3, C2/m, Z. 2) are obtained. 3 is thermally stable up to 250 degrees C and shows an enhanced solubility in water compared to H(2)tfBDC. Monosubstituted 2,3,5,6-tetrafluorobenzoic acid (H(2)tfBC, 4) is obtained by reacting 1,2,4,5-tetrafluorobenzene with stoichiometric amounts (1 equiv) of n-butyllithium in THF. Its crystal structure (Fdd2, Z = 16) shows dimeric units as characteristic structural feature

Supplementary Information from Unexpected formation of polymeric silver(I) complexes of azine-type ligand via self-assembly of Ag-salts with isatin oxamohydrazide

Isatin oxamohydrazide (<b>L</b>) reacted with the aqueous solution of silver nitrate at room temperature afforded the polymeric silver(I) nitrato complex, [Ag₂L′(NO₃)₂]<i>_n</i>, <b>(1)</b> of the azine ligand (<b>L′</b>). Similarly, the reaction of <b>L</b> with silver(I) perchlorate gave the [Ag₂L′₂(ClO₄)₂]<i>_n</i>, <b>(2)</b> coordination polymer. Careful inspection of the crystals from the nitrato complex preparation showed the presence of another crystalline product which is found to be [Ag(Isatin-3-hydrazone)NO₃], <b>(3)</b> suggesting that the reaction between silver(I) nitrate and <b>L</b> proceeds first by the hydrolysis of <b>L</b> to the isatin hydrazone which attacks another molecule of <b>L</b> to afford <b>L′</b>. Testing metal salts such as Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺ and Cd²⁺ did not undergo any reaction with <b>L</b> either under the same reaction conditions or with heating under reflux up to 24 h. Treatment of the warm alcoholic solution of <b>L</b> with few drops of 1 : 1 (<i>v</i>/<i>v</i>) hydrochloric acid gave the free ligand (<b>L′</b>) in good yield. The [Ag₂L′(NO₃)₂]<i>_n</i> complex forms a two-dimensional infinite coordination polymer, while the [Ag₂L′₂(ClO₄)₂]<i>_n</i> forms one-dimensional infinite chains with an alternating silver-azine backbone. Quantitative analysis of the intermolecular interactions in their crystals is made using Hirshfeld surface analysis. Density functional theory studies were performed to investigate the coordination bonding in the studied complexes

Supplementary Information from Unexpected formation of polymeric silver(I) complexes of azine-type ligand via self-assembly of Ag-salts with isatin oxamohydrazide

Isatin oxamohydrazide (<b>L</b>) reacted with the aqueous solution of silver nitrate at room temperature afforded the polymeric silver(I) nitrato complex, [Ag₂L′(NO₃)₂]<i>_n</i>, <b>(1)</b> of the azine ligand (<b>L′</b>). Similarly, the reaction of <b>L</b> with silver(I) perchlorate gave the [Ag₂L′₂(ClO₄)₂]<i>_n</i>, <b>(2)</b> coordination polymer. Careful inspection of the crystals from the nitrato complex preparation showed the presence of another crystalline product which is found to be [Ag(Isatin-3-hydrazone)NO₃], <b>(3)</b> suggesting that the reaction between silver(I) nitrate and <b>L</b> proceeds first by the hydrolysis of <b>L</b> to the isatin hydrazone which attacks another molecule of <b>L</b> to afford <b>L′</b>. Testing metal salts such as Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺ and Cd²⁺ did not undergo any reaction with <b>L</b> either under the same reaction conditions or with heating under reflux up to 24 h. Treatment of the warm alcoholic solution of <b>L</b> with few drops of 1 : 1 (<i>v</i>/<i>v</i>) hydrochloric acid gave the free ligand (<b>L′</b>) in good yield. The [Ag₂L′(NO₃)₂]<i>_n</i> complex forms a two-dimensional infinite coordination polymer, while the [Ag₂L′₂(ClO₄)₂]<i>_n</i> forms one-dimensional infinite chains with an alternating silver-azine backbone. Quantitative analysis of the intermolecular interactions in their crystals is made using Hirshfeld surface analysis. Density functional theory studies were performed to investigate the coordination bonding in the studied complexes

Supplementary Information from Unexpected formation of polymeric silver(I) complexes of azine-type ligand via self-assembly of Ag-salts with isatin oxamohydrazide

Isatin oxamohydrazide (<b>L</b>) reacted with the aqueous solution of silver nitrate at room temperature afforded the polymeric silver(I) nitrato complex, [Ag₂L′(NO₃)₂]<i>_n</i>, <b>(1)</b> of the azine ligand (<b>L′</b>). Similarly, the reaction of <b>L</b> with silver(I) perchlorate gave the [Ag₂L′₂(ClO₄)₂]<i>_n</i>, <b>(2)</b> coordination polymer. Careful inspection of the crystals from the nitrato complex preparation showed the presence of another crystalline product which is found to be [Ag(Isatin-3-hydrazone)NO₃], <b>(3)</b> suggesting that the reaction between silver(I) nitrate and <b>L</b> proceeds first by the hydrolysis of <b>L</b> to the isatin hydrazone which attacks another molecule of <b>L</b> to afford <b>L′</b>. Testing metal salts such as Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺ and Cd²⁺ did not undergo any reaction with <b>L</b> either under the same reaction conditions or with heating under reflux up to 24 h. Treatment of the warm alcoholic solution of <b>L</b> with few drops of 1 : 1 (<i>v</i>/<i>v</i>) hydrochloric acid gave the free ligand (<b>L′</b>) in good yield. The [Ag₂L′(NO₃)₂]<i>_n</i> complex forms a two-dimensional infinite coordination polymer, while the [Ag₂L′₂(ClO₄)₂]<i>_n</i> forms one-dimensional infinite chains with an alternating silver-azine backbone. Quantitative analysis of the intermolecular interactions in their crystals is made using Hirshfeld surface analysis. Density functional theory studies were performed to investigate the coordination bonding in the studied complexes

Supplementary Information from Unexpected formation of polymeric silver(I) complexes of azine-type ligand via self-assembly of Ag-salts with isatin oxamohydrazide

Isatin oxamohydrazide (<b>L</b>) reacted with the aqueous solution of silver nitrate at room temperature afforded the polymeric silver(I) nitrato complex, [Ag₂L′(NO₃)₂]<i>_n</i>, <b>(1)</b> of the azine ligand (<b>L′</b>). Similarly, the reaction of <b>L</b> with silver(I) perchlorate gave the [Ag₂L′₂(ClO₄)₂]<i>_n</i>, <b>(2)</b> coordination polymer. Careful inspection of the crystals from the nitrato complex preparation showed the presence of another crystalline product which is found to be [Ag(Isatin-3-hydrazone)NO₃], <b>(3)</b> suggesting that the reaction between silver(I) nitrate and <b>L</b> proceeds first by the hydrolysis of <b>L</b> to the isatin hydrazone which attacks another molecule of <b>L</b> to afford <b>L′</b>. Testing metal salts such as Ni²⁺, Co²⁺, Mn²⁺, Cu²⁺ and Cd²⁺ did not undergo any reaction with <b>L</b> either under the same reaction conditions or with heating under reflux up to 24 h. Treatment of the warm alcoholic solution of <b>L</b> with few drops of 1 : 1 (<i>v</i>/<i>v</i>) hydrochloric acid gave the free ligand (<b>L′</b>) in good yield. The [Ag₂L′(NO₃)₂]<i>_n</i> complex forms a two-dimensional infinite coordination polymer, while the [Ag₂L′₂(ClO₄)₂]<i>_n</i> forms one-dimensional infinite chains with an alternating silver-azine backbone. Quantitative analysis of the intermolecular interactions in their crystals is made using Hirshfeld surface analysis. Density functional theory studies were performed to investigate the coordination bonding in the studied complexes

Chemical delithiation and exfoliation of LixCoO2

AbstractProgressive chemical .delithiation of commercially available lithium cobalt oxide (LiCoO2) showed consecutive changes in the crystal properties. Rietveld refinement of high resolution X-ray and neutron diffraction revealed an increased lattice parameter c and a reduced lattice parameter a for chemically delithiated samples. Using electron microscopy we have also followed the changes in the texture of the samples towards what we have found is a critical layer stoichiometry of about LixCoO2 with x=1/3 that causes the grains to exfoliate. The pattern of etches by delithiation suggests that unrelieved strain fields may produce chemical activity

Fe(III) Complexes Based on Mono- and Bis-pyrazolyl-s-triazine Ligands: Synthesis, Molecular Structure, Hirshfeld, and Antimicrobial Evaluations

The self-assembly of iron(III) chloride with three pyrazolyl-s-triazine ligands, namely 2,4-bis(3,5-dimethyl-1H-pyrazol-1-yl)-6-(piperidin-1-yl)-1,3,5-triazine (PipBPT), 4-(4,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazin-2-yl)morpholine (MorphBPT), and 4,4&rsquo;-(6-(3,5-dimethyl-1H-pyrazol-1-yl)-1,3,5-triazine-2,4-diyl)dimorpholine (bisMorphPT) afforded [Fe(PipBPT)Cl2][FeCl4] (1), [Fe(MorphBPT)Cl2][FeCl4] (2), and [H(bisMorphPT)][FeCl4]. bisMorphPT.2H2O (3), respectively, in good yield. In complexes 1 and 2, the Fe(III) is pentacoordinated with three Fe-N interactions from the pincer ligand and two coordinated chloride anions in the inner sphere, and FeCl4&macr; in the outer sphere. Complex 3 is comprised of one protonated ligand as cationic part, one FeCl4&macr; anion, and one neutral bisMorphPT molecule in addition to two crystallized water molecules. Analysis of molecular packing using Hirshfeld calculations indicated that H&hellip;H and Cl&hellip;H are the most important in the molecular packing. They comprised 40.1% and 37.4%, respectively in 1 and 32.4% and 37.8%, respectively in 2. Complex 1 exhibited the most bioactivity against the tested microbes while 3 had the lowest bioactivity. The bisMorphPT and MorphBPT were inactive towards the tested microbes while PipBPT was active. As a whole, the Fe(III) complexes have enhanced antibacterial and antifungal activities as compared to the free ligands

Synthesis, X-ray crystal structure and DFT studies of two octahedral cobalt(II) complexes with <i>N,N,N</i>-tridentate triazine-type ligand

<p>Two new Co(II) complexes, [CoL₂]X₂∙2H₂O, with <i>N,N,N</i>-tridentate triazine type ligand (<b>L</b>) and X = Cl⁻ (<b>1</b>) or NO₃⁻ (<b>2</b>) are synthesized and characterized using elemental analysis, FTIR spectra, and single-crystal X-ray diffraction. Complexes <b>1</b> and <b>2</b> are crystallized in the centrosymmetric space groups <i>P-1</i> and <i>C2/c</i>, respectively. The Co atoms are surrounded by two neutral tridentate ligands coordinated via nitrogen atoms, thus forming a distorted octahedral coordination sphere. Hirshfeld topology analyses of the molecular packing revealed that the polar Cl⋯H, O⋯H and N⋯H contacts are the most important intermolecular interactions while the nonpolar C⋯H and C⋯C (<i>π</i>–<i>π</i> stacking) contacts are weak and insignificant, respectively. DFT calculations indicated that the high-spin state is energetically more favored than the low-spin case. The Co(II) center transfers its spin density to the ligand donor atoms via the spin delocalization mechanism. Based on the atoms in molecules (AIM) results, all Co–N interactions have a predominant covalent character. The strength of the Co–N interactions decreases in the order Co–N_(hydrazone) > Co–N_(triazine) > Co–N_(amine). The metal anti-bonding natural orbitals involved in the Co–N interactions have high and s-orbital characters. Both complexes showed good thermal stability up to 276°C and 250°C for complexes <b>1</b> and <b>2</b>, respectively.</p