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Three new polynuclear complexes, [Co7(bm)12]·(ClO4)2·13H2O (1), [Co4(bm)4Cl4(C3H7OH)4] (2), and [Co4(bm)4(μ-HCO2)2(μ2-HCO2)2(C3H7OH)2] (3) (Hbm = (1H-Benzimidazol)-methanol), have been synthesized and characterized by elemental analysis, IR, powder X-ray diffraction and X-ray single-crystal diffraction. Compound 1features a centrosymmetric wheel-like heptanuclear Co(ii) cluster. Compound 2having a I41/aspace group exhibits a tetranuclear Co(ii) cluster with a cubane topology in which the central Co(ii) ion and oxygen atoms from bm occupy the alternate vertices of the cube. However, compound 3has a tetranuclear Co(ii) cluster with a C2/cspace group different from that of compound 2. These results show that the geometries and sizes of the corresponding anions as well as their coordinating and hydrogen-bonding properties are essential in determining the final structures of the assemblies. Magnetic properties of 1–3in the 2–300 K have also been discussed. The {Co7} (1) and {Co4} (2) cores display dominant ferromagnetic interactions while the {Co4} (3) core displays dominant anti-ferromagnetic interactions. [ABSTRACT FROM AUTHOR]

Abstract: A new hexanuclear cadmium(II) complex of Cd6(pyim)4(Hpyim)6(sal)4 (Hpyim=2-pyridylbenzimidazole, H2sal=salicylic acid) (1) has been synthesized under hydrothermal condition and characterized by element analysis, FT-IR spectroscopy and luminescent analysis. X-ray crystallographic studies reveal that complex 1 displays a novel hexanuclear unit in which six cadmium ions are bridged by deprotonated salicylic and pyridylbenzimidazole ligands. In 1, the hexanuclear units are further assembled into a 3D supramolecular framework by hydrogen bonding, π–π and C−H⋯π stacking interactions. In the solid state, complex 1 shows blue photoluminescent property at room temperature. [Copyright &y& Elsevier]

The silver and acid hydrogen atoms in the crystal structure of [Ag(pa)(Hpa)]n (Hpa = 3-(1H-benzimidazol-2-yl) propionic acid-N) both lie on special positions of -1 site symmetry; the silver atom shows linear coordination [Ag-N = 2.109(3) Å, N-Ag-N = 180°]. The 'acid hydrogen' links molecules into a linear chain, and hydrogen bonds between the nitrogen-bound hydrogen atom and the carbonyl oxygen atom of an adjacent chain furnish a three-dimensional supramolecular structure. The compound, C20H19AgN4O4, belongs to the triclinic space group P1 [a = 6.536(7), b = 8.127(9), c = 9.051(1) Å; α = 81.692(2), β = 82.819(2), γ = 87.229(2)°], and there is one formula unit in the unit cell. [ABSTRACT FROM AUTHOR]

The asymmetric unit of the title compound, C7H6Br2O2·0.5H2O, contains two independent 3,5-dibromo­salicyl alcohol mol­ecules and one water mol­ecule. The salicyl alcohol mol­ecules inter­act with each other and with the water mol­ecule through O—H⋯O hydrogen bonding, giving rise to a layer structure. [ABSTRACT FROM AUTHOR]

The title compound, [Zn(NO3)(C8H8N2O)2]NO3·H2O, consists of a tris-chelated zinc cation and a nitrate anion, along with an uncoordinated water mol­ecule. These inter­act through O—H⋯O and N—H⋯O hydrogen bonds, giving rise to a three-dimensional network structure. The ZnII ion has an octa­hedral coordination. [ABSTRACT FROM AUTHOR]

The two chromen-3-yl substituents at the 2- and 3-positions of the 1,4-dihydroxy­benzene in the title dimethyl­formamide (DMF) tris­olvate, C24H14O10·3C3H7NO, are aligned at 67.1 (1) and 69.8 (1)° with respect to the central aromatic ring. The 1-hydr­oxy group serves as a hydrogen-bond donor to a DMF whereas the substituent at the 3-position functions as a hydrogen-bond donor to two DMF mol­ecules. The other three hydr­oxy groups inter­act with donor sites of adjacent mol­ecules, generating a three-dimensional network architecture. [ABSTRACT FROM AUTHOR]

A one-dimensional manganese(II) complex, [Mn( L 2 )] n ( 1 , HL = 4-pyridyl- NH -1,2,3-triazole), has been hydrothermally synthesized at 120 °C. In the structure of 1 , the Mn(II) ions are octahedral coordinated and further bridged by L − ligands, forming a rigid 1D ribbon coordination chain. Varieties of supramolecular interactions, such as hydrogen bonds and C H ⋯ π interactions, play an important role on the stabilization of the structures. As revealed by magnetic measurement, complex 1 displays weak antiferromagnetic interaction with θ = –4.83 K, the best fit using Fisher's 1D Heisenberg model gives the intrachain magnetic coupling constant J = –0.21 cm − 1 above 30 K due to the neighboring Mn(N–N) 2 Mn rings twisted in the angle of almost 90°. [ABSTRACT FROM AUTHOR]

An unprecedented Schiff base gelator with ultra-low molecular weight (Mw=188) was facilely prepared from readily available starting materials in a single step. The gelator was found to possess a strong gelation ability with the critical gelation concentration down to 0.45 wt% in dichloromethane (DCM). FT-IR NMR, XRD, SEM, theoretical calculation, and control experiment were combined to elucidate the assembly mechanism of gelator leading to gel. It was revealed that the hydrogen bonding associated with the triazole NH moiety plays a crucial role in the formation of the fibrillar gel network. This supramolecular gel demonstrated multiple-stimulus responsive (temperature, pH, metal ion) gel-sol phase transition behavior, particularly interesting aspect is that only 0.13 eq. F- is required to collapse the gel, representing the most sensitive supramolecular gel to F- anion up to now and endowing it with great potential as F- detector. The newly found Schiff base gelator reported here would offer prospects for the future design of more intelligent materials based on simple but versatile molecular scaffolds. A simple but versatile Schiff base gelator was facilely prepared from readily available materials and demonstrated multiple-stimulus responsive properties. [Display omitted] • Facile synthesis in a single step from readily available starting materials. • One of the smallest organogelator up to now (Mw=188). • Having a strong gelation ability with the critical gelation concentration down to 0.45 wt%. • Multiple stimulus-responsive properties, particularly for F- detection. [ABSTRACT FROM AUTHOR]

Abstract: One novel 1D chain of {[Zn2(L)3(H2O)(NO3)]·2.5H2O} n (HL =1-methyl-2-(3H-[1, 2, 3]triazol-4-yl)-1H-benzoimidazole) has been hydrothermally constructed from in situ generated 1-methyl-2-(3H-[1, 2, 3]triazol-4-yl)-1H-benzoimidazole ligand at 160°C. Compound 1 exhibits a 1D butterfly-like chain architecture, which is further assembled into a 3D supermolecular network by interchain hydrogen bonds. TGA studies show that compound 1 is highly thermally stable. The fluorescent property in the solid state is also explored, and the emission spectrum shows a blue shift of 62nm compared with that of HL, which may be assigned to ligand-to-metal charge transfer. [Copyright &y& Elsevier]

In the title compound, C16H11NO3, the quinolin-8-yl­oxy and 2-carboxy­phenyl groups are linked through an ether O atom, the angle at this atom being 116.4 (1)° in one mol­ecule and 114.8 (1)° in the other independent mol­ecule. In both mol­ecules, the carboxylic acid group inter­acts with the heterocyclic moiety through an intra­molecular hydrogen bond. [ABSTRACT FROM AUTHOR]

In the crystal structure of the title compound, C16H16N4O22+·2NO3−, the cation, which lies on a twofold rotation axis, inter­acts with the nitrate anions, giving rise to a hydrogen-bonded layer structure. [ABSTRACT FROM AUTHOR]