Inorganic Chemistry Communications (v.42, #C)

Contents List (iii-v).

A new fluorescent chemosensor based on diaza-18-crown-6 ether, which was appended with dual coumarins, exhibited high selectivity and anti-disturbance for Fe3 + among environmentally and biologically relevant metal cations. Fe3 + sensing was performed via the complexation of Fe3 + ions with the chemosensor. In addition, the detection limit of the fluorescence response of the sensor to Fe3 + was 0.31 μM with a rapid response of less than 10 s.A new fluorescent chemosensor based on diaza-18-crown-6 ether, which was appended with dual coumarins, exhibited high selectivity and anti-disturbance for Fep3 + among environmentally and biologically relevant metal cations. The detection limit was 0.31 μM with a rapid response of less than 10 s.Display Omitted
Keywords: Coumarin; Diaza-18-crown-6; Fluorescent chemosensor; Fe3 +; Detection;

Oxidation of K3[WIII 2Cl9] in the mixture of concentrated hydrochloric acid and pyridine in the presence of hydrazinium dichloride afforded (PyH)5[WVOCl4(H2O)]3Cl2 (PyH+  = pyridinium cation, C5H5NH+) (1), obtained as emerald green needle-shaped crystals. The compound contains mononuclear octahedrally shaped [WOCl4(H2O)] ions. In contrast to its molybdenum analog, 1 shows a marked instability in the air. Solvothermal reaction of a tetrabutylammonium salt of the [WOCl4(H2O)] ion with pyridine at 115 °C afforded a small amount of orange crystals of [WV 8WVI 2O26(Py)8]·Py (2) (Py = pyridine, C5H5N). The WV centers can be clearly distinguished from the WVI sites, namely they are grouped into four metal–metal bonded {WV 2O4}2 + cores. The structure of the cluster is virtually identical with the analogous molybdenum complex, [Mo10O26(Py)8]. The isolation of [W10O26(Py)8]·Py (2) confirms that the {W2O4}2 + core forms from the [WOCl4(H2O)] ions upon the substitution of the labile ligands.W10O26(Py)8, a decanuclear WVWVI cluster.Display Omitted
Keywords: Tungsten(V) coordination compounds; Clusters; Mixed-valence species; {WV 2O4}2 + structural unit; Crystal structure;

A novel 3D metal–organic framework constructed from monosubstituted Keggin chains and metal–carboxylate chains by Xiuli Wang; Na Han; Hongyan Lin; Jian Luan; Aixiang Tian; Danna Liu (10-14).
A novel monosubstituted Keggin-type polyoxometalate (POM)-based metal–organic framework [Cu4 IICu2 I(pzca)6(HPCuMo11O39)(H2O)6]·2H2O (1) (pzca = 2-pyrazinecarboxylic acid) has been hydrothermally synthesized and characterized by IR, elemental analysis, TGA and single crystal X-ray diffraction analysis. Compound 1 shows a (2,3,4,7)-connected three-dimensional framework with {4 · 62  · 9 · 102}{4 · 92}{42  · 69  · 87  · 103}{6 · 9 · 10}2{9}2 topology, which is constructed from the monosubstituted Keggin chains [HPCuMo11O39]n 4n − and metal–carboxylate chains [Cu6(pzca)6]n 4n +. The electrochemical behavior and photocatalytic activity of compound 1 have been investigated.A novel 3D metal-organic framework (MOF), [Cu4 IICu2 I(pzca)6(HPCuMo11O39)(H2O)6]•2H2O (1) (pzca = 2-pyrazinecarboxylicacid) was obtained, which represents the first compound constructed by the monosubstituted Keggin chains and metal–carboxylate chains. The electrochemical and photocatalytic properties also have been investigated.Display Omitted
Keywords: Monosubstituted polyoxometalate; Metal–organic framework; 2-Pyrazinecarboxylic acid; Electrochemical property; Photocatalytic property;

A new 3D complex, {[Cd3(HL)2(H2L)(H2O)4]·2H2O}n (1) (H4L = 1,1′-(1,4-phenylenebis(methylene))bis(1H-imidazole-4,5-dicarboxylic acid), has been hydrothermally synthesized and characterized by elemental analyses, IR, TG, and X-ray single-crystal diffraction. Complex 1 is the first framework based on CdII ion and semi-rigid bis-IDC ligand. The (6,6)-net architecture of 1 is built from H2L2 − ligands linking 1D chain-like [Cd3(HL)2]n SBUs, which formed by HL3 − anions bridging two kinds of metal centers. In addition, complex 1 was demonstrated to display strong blue-violet fluorescence emission in the solid state at room temperature.A new complex based on the designed H3IDC derivative ligand with two IDC groups has been successfully synthesized under hydrothermal condition. Complex 1 exhibits a 3D 6-connected framework constructed from H2L2 – ligands linking chain-like SBUs formed by HL3− ligands bridging two different metal nodes. Moreover, the thermostability and luminescent properties complex 1 have been investigated.Display Omitted
Keywords: Hydrothermal reaction; CdII complex; Bis(imidazole-4,5-dicarboxylate) ligand; SBUs; Topology;

Unprecedented 4/5-methylimidazole linkage isomerism within a binuclear copper(II) complex molecule by Hanan El Bakkali; Alicia Domínguez-Martín; Duane Choquesillo-Lazarte; Esther Vílchez-Rodríguez; Josefa María González-Pérez; Alfonso Castiñeiras; Juan Niclós-Gutiérrez (20-22).
A new dinuclear copper(II) complex namely [Cu22-1,4-CDTA)(H4Meim)(H5Meim)(H2O)2]·2H2O (1,4-CDTA = Trans-14-cyclohexanediaminotetraacetate(4-) ion, H4Meim/H5Meim = 4/5-methylimidazole) has been synthesized and characterized by elemental analysis, thermo-gravimetry (TG), FT-IR and electronic (diffuse reflectance) spectroscopy. Single-crystal X-ray diffraction analysis reveals that in the dinuclear copper(II) complex molecule each tautomer (4-methylimidazole or 5-methylimidazole) is linked to a different metallic center within the same molecule. The results are briefly discussed on the basis of the previous literature. Attention is paid to the driving forces of this unusual reported structure in order to deepen on the factors that influence the linkage isomerism.The linkage isomerism of 4-methyl- and 5-methyl-imidazole tautomers has never been reported for two different coordination centers within the same binuclear copper(II) complex.Display Omitted
Keywords: Linkage isomerism; 4/5-Methylimidazole; Copper(II); Crystal structure; Trans-1,4-CDTA;

A pair of bibenzo[d]imidazole-based cistrans positional isomers have been obtained via the condensation between biphenyl-3,3′,4,4′-tetraamine and 3,5-dichloro-2-hydroxybenzaldehyde, and they can be isolated by the following spontaneous crystallization in N,N-dimethylformamide (DMF) and manual separation. Halogen substituent effects are believed to be responsible for the successful isolation of cis and trans isomers, which could be further supported by density function theory (DFT) calculations. To our knowledge, this is the first structural report on the cistrans isomerism for this family of compounds.A pair of bibenzo[d]imidazole-based cistrans position isomers have been obtained via the condensation between biphenyl-3,3′,4,4′-tetraamine and 3,5-dichloro-2-hydroxybenzaldehyde and they can be isolated by the spontaneous conglomerate crystallization in DMF.Display Omitted
Keywords: Cistrans isomers; Bibenzo[d]imidazoles; Crystal structures; DFT computations;

Lanthanide-based metal–peptide frameworks prepared by ionothermal method: Anion direct effect, DFT calculation and luminescence property by Wen-xian Chen; Li Tan; Qiu-ping Liu; Ying Zhou; Yong-xian Fan; Gen-rong Qiang; Gui-lin Zhuang (29-32).
A series of new isomorphic lanthanide-based metal–peptide frameworks, [Ln(PODC)(H2O)2]Br (Ln = La(1), Nd(2), Eu(3), Tb(4), H2PODC = 2, 5-piperazinedione-1, 4-diacetic acid), were synthesized under the ionic liquid medium. Crystal structure measure results exhibit that they are new three-dimensional frameworks, where bromine anions of ionic liquid are enveloped in the pore. Interestingly, it is found that bromine anions can effectively counteract the effects of lanthanide ions (e.g. lanthanide contraction). Via the first-principles DFT calculation, it is obtained that bromine anions of ion liquid influence the electronic properties of PODC2 − ligand and thereby directly control the structure. Luminescence analysis demonstrates that compounds 3 and 4 have good fluorescence properties, where the emission peaks can be ascribed to the transitions of 5D0  →  7FJ (J = 0, 1, 2, 3, 4) for 3 and 5D4  →  7FJ (J = 6, 5, 4, 3) for 4.Four lanthanide-based metal–peptide frameworks under ionothermal condition exhibit new three-dimensional framework and further reveal that anion of ion liquid plays an important role in structure by DFT calculation.Display Omitted
Keywords: Metal–organic framework; Ionothermal; Luminescence; DFT;

By using a macrocyclic vanadium(IV)-oxo complex ligand VOL (H2L = 2,3-dioxo-5,6:13,14-dibenzo-7,12-diphenyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as a precursor, two new trinuclear complexes [(VOL)2Co(C2H5OH)2](ClO4)2·2C2H5OH (1) and [(VOL)2Ni(CH3OH)2](ClO4)2 (2) have been synthesized and characterized by elemental analyses, IR spectroscopy, and power and single-crystal X-ray diffraction. In the two complexes, the central ions cobalt(II) and nickel(II) are connected with two VOL fragments via exo-cis oxamido bridge. Magnetic susceptibility measurements indicate that both complexes 1 and 2 show weak ferromagnetic interactions.By using a macrocyclic vanadium(IV)-oxo complex ligand VOL (H2L = 2,3-dioxo-5,6:13,14-dibenzo-7,12-diphenyl-1,4,8,11-tetraazacyclo-tetradeca-7,12-diene) as a precursor, two new trinuclear complexes [(VOL)2Co(C2H5OH)2](ClO4)2·2C2H5OH (1) and [(VOL)2Ni(CH3OH)2](ClO4)2 (2) have been synthesized and structurally characterized by X-ray crystallography. Magnetic susceptibility measurements indicate that weak ferromagnetic interactions exist in the two complexes.Display Omitted
Keywords: Trinuclear complex; Vanadium-oxo; Crystal structure; Magnetic properties;

MnII and CoII salts reacting with 4-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine (4-Hcptpy) in DMF/H2O afford two complexes, [Mn(4-cptpy)(DMF)(H2O)2] n ·n(4-cptpy)·nDMF (1) and [Co(4-cptpy)2(H2O)2] n (2). Complex 1 is a 1D ribbon coordination polymer assembled by Mn2 dimer and tridentate 4-cptpy ligand. The guest 4-cptpy anion is embedded in 3D supramolecular architecture with strong hydrogen bonds. Complex 2 is a 1D linear chain coordination polymer with quadrangled pores. The complex 1 releases H2O and DMF in 87–150 °C, and the anhydrous [Mn(4-cptpy)] n ·n(4-cptpy) remains thermally stable until 403 °C. Variable temperature magnetic susceptibility study in 2–300 K proves that a weak antiferromagnetic interaction exists in the (μ-O2CR)2Mn2 core.Two MnII/CoII 1D coordination polymers were constructed from 4-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine. [Mn(4-cptpy)(DMF)(H2O)2] n ·n(4-cptpy)·nDMF displays interesting supramolecular framework in which uncoordinated 4-cptpy exists as guest molecule. Its magnetic properties and thermal stability have been studied.Display Omitted
Keywords: Coordination polymer; 4-(4-carboxyphenyl)-4,2′:6′,4″-terpyridine; Crystal structure; Thermal stability; Magnetism;