Search

An interesting dicarboxyl-pyridyl functionalized difluoroboron dipyrromethene dye probe (2,6-diCO2H-BODIPY), showing molecular packing in a 3D microporous supramolecular framework with 1D channels, is successfully fabricated and characterized, exhibiting a remarkable dual-responsive fluorescence sensitivity for recognizing both Hg2+ and Cu2+ ions based on the ion-induced H-aggregation.

Two new complexes, [Zn(tp)(RdmB)(H2O)] (I) and [Cd(tp)(RdmB)] (II) (tp = terephthalate, RdmB = rhodamine B), are obtained by similar hydrothermal synthesis reactions. X-ray crystallography reveals that both compounds are one-dimensional (1D) polymeric solids, in which I (C36H36N2O8Zn) ascribes to monoclinic C2/m space group, Z = 4 (a = 18.834(5) A, b = 16.859(5) A, c = 10.111(3) A, β = 97.638(4)°), while II (C108H102N6O21Cd3) crystallizes in monoclinic P21/n, 4 (a = 12.2309(1) A, b = 61.5661(7) A, c = 12.5852(1) A, β = 93.951(1)°). Owing to the difference in the coordination sphere around the metal center, four-coordinated zinc centers for I bridged by linear tp molecules associated with RdmB ligands result in an interesting 1D infinite zigzag tape-like structure, whereas six-/seven-coordinated cadmium centers for II bridged by the same ligands generate a novel 1D infinite biserrated edge ribbon structure with a 2,3,3-linked {62.10}{63}{6} network or a simplified 2,4-linked {43.62.8}{4} topological networ...

A hydrated triaminotriptycene solid, [(tatp)4·17H2O]n (1) (tatp = 2,6,12-triaminotriptycene), has been obtained by solution phase crystal growth techniques. The structure established through X-ray structural analysis shows that this hydrated solid, ascribed to cubic Fd3 space group, Z = 8 (a = 25.56(2) A, V = 16699(3) A3), crystallizes in a sodalite-like tatp porous supramolecular architecture that captures a bigger-sized heptadecameric water cluster guest. This hydrated solid is rather stable, even with removal of its guest waters in ambient temperature, and exhibits an interesting light response behavior with the crystal color converting from pale yellow to brown under a xenon lamp or sunlight irradiation.

X-ray crystallography reveals four isostructural lanthanide polymeric solids, [Ln2(atp)3(H2O)2]·dmf·4H2O (atp = 2-aminoterephthalate; dmf = N,N′-dimethylformamide; Ln = La (1), Ce (2), Pr (3) and Nd (4), respectively) that are obtained from the solvothermal synthesis which are crystallized in an interesting 3D polymeric framework with a (4,4,6)-linked {42·84}{44·62}2{48·66·8}2 fsy net topology. Upon excitation at 350 nm, they all show the solid state ligand-centered luminescences but both 2 and 3 also exhibit the weak lanthanide-based characteristic emissions in the visible region at room temperature. The cyclic voltammetric investigation indicates that 2 exhibits appreciable electrochemical activity for formaldehyde.

A convenient colorimetric molecular system constructed by the zinc viologen-carboxylate framework is developed for naked eye detection of instantaneous UV exposure levels. Only narrow-band absorption in UV regions and a unique interpenetrated structure of its colorless crystal enable the system to give a fast response toward UV irradiance with intensity as low as 0.001 mw/cm2.

A series of boron dipyrromethene (BODIPY) dyes (B1–B5) having H atoms at 2,6-positions or heavy-atom I at 2-/2,6-positions, and an ortho- or a para-COOH substituted phenyl moiety at the 8-position on the BODIPY core were synthesized and characterized. These organic dyes were applied for investigating the relationship between the BODIPY structure and the effectiveness of homogeneous and heterogeneous visible-light-driven hydrogen production as well as dye-sensitized solar cells (DSSCs). For the homogeneous photocatalytic hydrogen production systems with a cobaloxime catalyst, the efficiency of hydrogen production could be tuned by substituting with heavy atoms and varying carboxyl group orientations of BODIPYs. As a result, B5 containing two I atoms and an ortho-COOH anchoring group was the most active one (TONs = 197). The activity of hydrogen generation followed the order B5 > B3 > B2 > B1 = B4 = 0. An interesting “ortho-position effect” was observed in the present homogeneous systems, i.e., substitution groups were located at the ortho-position and higher hydrogen production activities were obtained. For the heterogeneous hydrogen production systems with a platinized TiO2 catalyst, the effectiveness of hydrogen evolution was highly influenced by the intersystem crossing efficiency, molar absorptivity and positions of the anchoring group of dyes. Thus, B3 having two core iodine atoms and a para-COOH group with TONs of 70 excelled other BODIPYs and the TONs of hydrogen generation showed the trend of B3 > B5 > B2 > B1 = B4 = 0. The results demonstrate that the present photocatalytic H2 production proceeds with higher efficiency and stability in the homogeneity than in the heterogeneity. In the case of DSSCs, the overall cell performance of BODIPY chromophores was highly dependent on both the absence or the presence of iodine atoms on the BODIPY core and –COOH anchoring positions. The B1–TiO2 system showed the best cell performance, because the most effective surface binding mode is allowed with this structure. This is also in contrast with the case of dye-sensitized solar H2 generation, in which B3 was the most efficient chromophore. The differences between dye-sensitized hydrogen-generating systems and DSSCs may be due to rates of electron transfer and the dye aggregation tendency.

Two new metal–terephthalate polymeric solids, {[Ph4P]2[Cd2(tp)2(Htp)2(H2O)]·3H2O}n (1) and {[Ph4P][Zn(tp)(Htp)]·2H2O}n (2) (tp = terephthalate, [Ph4P] = tetraphenylphosphonium), are obtained from similar hydrothermal synthesis reactions. Upon the template effect of large bulky [Ph4P]+ cation, the d10 transition metal centers are bridged by tp ligands to form an interesting 2D undulating lamellar host network for 1 and a 2D square-grid lamellar host network for 2, respectively. Both compounds exhibit intense fluorescent emission bands at 434 nm (λexc = 333 nm) for 1 and 420 nm (λexc = 350 nm) for 2 in the solid state at room temperature.

Ce/Sm ions are covalently grafted to a Keggin polyoxomolybdate cluster [PMo12O40]3− to yield interesting fluorescent-photodarkening molecular systems. Their photoresponce processes are observed to be activated via energy transfer from luminescent fragments to photocoloration components.

An investigation into the relationship between structures of three D–A supramolecular systems and their photoresponsive characteristics is presented. Compound 1 [H2CPBPY]·[H2BTEC] and compound 2 [HCPBPY]2·[H2BTEC]·5H2O are prepared with the same starting materials at different pH values and characterized by single crystal X-ray diffraction, powder X-ray diffraction, UV-vis, IR and ESR spectra. Electron-deficient CPBPY moieties and electron-donating BTEC units are linked by hydrogen-bonds and π–π stacking interactions to form the donor–acceptor systems. Under light irradiation, photoactivated electrons can transfer from the donor to the acceptor units in both 1 and 2, giving rise to a long-lived charge-separated state and accompanying an interesting color changing phenomenon. Crystals of 2 allowed to dehydrate at elevated temperature undergo single-crystal to single-crystal transformation to yield 3 [HCPBPY]2·[H2BTEC], accompanied by a drastic change in structural arrangements. For the photocoloration character, compound 1 shows a faster photoresponsive rate than 2 and 3. For the fluorescence properties, compound 1 and 2 both exhibit photoluminescence emission centered at 400 nm, whereas 3 exhibits photoluminescence emission at 520 nm, showing a significant red shift of 120 nm. Their different photoactive characters can be attributed to the connecting, packing modes and the valence states of the functional D–A moieties.

Two sandwich-like frameworks with Ag(I) and mixed ligands, [Ag3(bpp)3(ctc)·16H2O]n (1) and [Ag3(bpe)3(btc)·12H2O]n (2) (where bpp = 1,3-bis(4-pyridyl)propane, H3ctc = 1,3,5-cyclohexanetricarboxylic acid, bpe = 1,2-bis(4-pyridyl)ethane, and H3btc = 1,2,4-benzenetricarboxylic acid), have been synthesized and structurally characterized. Fully deprotonated tricarboxylate ctc3 − in 1 or btc3 − in 2, serves as anionic template driving more water molecules to aggregate into different morphologies of polymeric clusters. In 1, the hydrogen-bonding association of sixteen lattice water molecules leads to the formation of 2D layered water, which is composed of three kinds of units including planar (H2O)4, ladder-like (H2O)8 and windmill-shaped (H2O)20 cluster. One novel 1D double-comb-like water aggregate constructed from alternating (H2O)22 cluster and water dimmer exists in 2. The present observations suggest that anionic templates with more carboxylate groups have high tendency of being hydrated and make polymeric clusters possible.

A novel 2D cobalt(II) coordination polymer comprising left- and right-handed helical chains, {[H2bpp][Co2(bpp)2(Hbtec)2(H2O)4]·(H2O)5}n (1) (bpp = 1,3-bis(4-pyridyl)-propane and H4btec = 1,2,4,5-benzenetetracarboxylate), was prepared under hydrothermal conditions and characterized by single-crystal X-ray diffraction method. Complex 1 provides suitable hydrophilic channel in which lattice water molecules accumulate, forming a (H2O)5 helicate, stabilized by anchoring to the host structure through hydrogen-bonding interactions involving alternating water molecules and the carboxylate oxygen atoms of Hbtec3− ligands.

固态配位聚合物{[Ag 2 (bpp) 2 (H 2 O) 2 ](chd)·9H 2 O} n ( 1 ) (bpp=1,3-二(4-吡啶基)丙烷、H 2 chd=1,4-环己烷二羧酸)是通过溶液相超声波合成技术获得的, 建立在X射线结构分析技术基础上的结构(单斜晶系 C 2/ c 空间群, Z =4; 晶胞参数 a =30.37(2) A, b =9.271(5) A, c =18.89(1) A; β =128.47o; V =4164(4) A 3 )展现出该化合物捕捉了一条有趣的、由“三叉星”笼状五聚体及 D 2 h 构型四聚体水簇交替构成的一维水带, 该化合物之所以新奇在于其代表了被认为是不太稳定的笼状水五聚体团簇的晶体学范例. 第一性原理的密度涵理论(DFT)计算表明, 笼状五聚体及 D 2 h 构型四聚体水簇的相互连接对于此类欠稳定水簇的稳定性是有益的.

A mixed-ligand Ag(I) coordination polymer {[Ag2(bpe)2(H2O)2](chd)·5H2O}n (1) (bpe = 4,4′-bipyridylethylene, H2chd = 1,4-cyclohexanedicarboxylic acid), has been synthesized and structurally characterized. Complex 1 exhibits a three-dimensional (3-D) supramolecular sandwich architecture that is composed of cationic chains of Ag(I) ions and bpe ligands, alternating with anionic sheets in which uncoordinated chd2 − anions and water molecules form a 2-D hydrogen-bonded network. An odd-numbered (H2O)7 cluster is trapped inside the water-chd aggregation. The discrete water heptamer consists of a puckered pentameric core and two pendent water molecules and structurally shows similarity to the simple hydrocarbon (1,1)-dimethylcyclopentane.

A new three-dimensional (3D) silver(I) metal–organic framework (MOF) formulated as [Ag(sub)0.5(bpp)]n·5nH2O (1) was prepared by the ultrasonic reaction of Ag2O with H2sub (H2sub = suberic acid) in the presence of dipyridyl-containing ligand bpp (bpp = 1,3-bis(4-pyridyl)propane) and structurally characterized by single crystal X-ray diffraction. Topologically, when argentophilic interactions are taken into account, the resultant 3D Ag(I) MOF can alternatively be simplified to the irl (42 · 63 · 8) topology. A self-assembled T5(0)A(2) water tape is confined in the channel of the framework and has been analyzed in comparison with known 1D water tapes constructed from pentameric water clusters. Moreover, photoluminescence property of 1 was investigated.

A discrete centrosymmetric (H2O)20(CH3OH)4 binary cluster was confined in the cavity of a metal-ligand hybrid [Ag4(bpda)2(bpp)4·14H2O·2CH3OH]n (1) (where bpp = 1,3-bis(4-pyridyl)propane and H2bpda = 2,2′-biphenyldicarboxylic acid). The novel mixed water-methanol cluster consists of one grail-shaped hexadecameric cluster, four dangling water and four hanging methanol molecules. The (H2O)16 cluster is composed of two pairs of edge-sharing (H2O)5 rings attached to one (H2O)4 core with twenty hydrogen bonds. Alternatively, the (H2O)16 cluster is structurally similar to a complicated hydrocarbon generated by undergoing [2+2] cycloaddition of 1,2,3,4,5,6-hexahydropentalene, which reveals the resemblance between water clusters and organic compounds.

An octameric water moiety which consists of a chairlike water hexamer and two pendent water molecules in the 1,4-diaxial positions and shows a similar structure to the hydrocarbon (1r,4r)-1,4-dimethylcyclohexane, is unambiguously trapped in a 2D Cu(II) mixed-ligand coordination polymer, {[Cu2(bpp)2(H2O)2(bpda)2]·6H2O} n (1) (bpp = 1,3-bis(4-pyridyl)propane and H2bpda = 2,2′-biphenyldicarboxylic acid). The water octamer can be extended into a hybrid carboxylate-water decamer when carboxylic oxygen atoms from bpda2− are involved. Interestingly, the present hybrid decamer bears a similar structural topology to a butterfly (H2O)10 cluster. The reversible dehydration/hydration of 1 is determined by X-ray powder diffraction studies.

The ultrasonic reaction of Ag2O, 1,3-bis(4-pyridyl)propane (bpp) and Na2B4O5(OH)4·8H2O (borax) under ammoniacal medium gave rise to an unexpected 3D Ag(I) supramolecular sandwich lamellar framework, {[Ag2(bpp)2(H2O)2]·[(H3BO3)3(CO3)·2H2O]}n (1), which consists of 2D silver-bpp cationic host and water–borate–carbonate anionic guest layers. The present 2D anionic layer is formed by fused H2O–H3BO3–CO32 − anionic rosette ribbons, in which H3BO3 is obtained via in situ hydrolysis of borax and CO32 − derived from absorption of CO2 in air. Interestingly, an unprecedented [CO32 −·3(H3BO3)] hydrogen-bonding aggregate having the shape of one concave three-leaved propeller is found in the anionic rosette ribbon.

The ultrasonic reaction of Ag2O, bipy and H2aze gave rise to a novel Ag(I) mixed-ligand coordination polymer, namely [Ag(aze)(bipy)]·(H2O)3 (1) (bipy = 4,4′-bipyridine, H2aze = azelaic acid). In 1, Ag(I) ions are linked by bipy and aze ligands to form a single two-dimensional (2D) undulated net with a (6,3) topology, incorporating Ag6(bipy)4(aze)2 windows of 22.58 × 11.06 A based on Ag⋯Ag distances. A pair of identical 2D single nets are interconnected via π⋯π stacking and unsupported Ag⋯Ag interactions to generate a 2D double-layered net. A discrete water hexamer composed of a new planar tetrameric water ring and two pendent water molecules is perpendicularly located in each hydrophilic cavity of the 2D bilayer and acts as a ‘glue’ to assemble adjacent 2D double-layered nets into a three-dimensional (3D) structure.

The Sr3Tl5 phase was prepared by high temperature synthesis techniques through reaction of the high purity elements in the welded Nb tubes. The structure established through X-ray structural analysis shows the compound is a good hypoelectronic trielide example of the Pu3Pd5 structural type in which skeletal electron count is lower than in a traditional Zintl phase (Cmcm, Z = 4; a = 10.604(2) A, b = 8.675(2) A, and c = 10.985(2) A; V = 1010.5(3) A3). The strontium size and the compound's polarity appear responsible for this thallium phase crystallization in the Pu3Pd5 family type rather than the isoelectronic Sr3In5 version. A first-principle electronic structure calculation (LMTO) demonstrates that the strontium atoms participate substantially in Sr-Tl bonding in the structure.

Two mixed-ligand Ag(I) coordination polymers (CPs), [Ag2(bpp)2(suc)·12H2O]n (1) and [Ag2(bpe)2(suc)·9H2O]n (2) (where bpp = 1,3-bis(4-pyridyl)propane, bpe = 1,3-bis(4-pyridyl)ethane, and H2suc = succinic acid), have been synthesized and structurally characterized. Both structures consist of cationic layers with Ag···π interacted chains of alternating metal and bis(pyridyl) ligands. The noncoordinated succinate (suc2−) in 1 or 2 serves as an anionic template driving surrounding water molecules to aggregate into an ordered 2D water-suc anionic layer. The interlamellar anions and cationic layers are stacked through weak electrostatic interaction and hydrogen bonds. One novel 1D water chain constructed from alternating water tetramer with uudd configuration and rare octamer exists in the anionic layer of 1. Each octameric water cluster consists of a pair of fused hexameric water clusters, and each water hexamer assumes a rare bag-shaped conformation. A discrete spirocyclic nonameric water cluster featuring tw...

National Natural Science Foundation of China[50971063, 21071118]; Natural Science Foundation of Fujian Province[2003F006, 2010J01042]; Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry of China; Huaqiao University[10BS210]

A unique zero-dimensional (0D) discrete (H2O)14 cluster containing a rare hanging-ladder-like water octamer and an infinite one-dimensional (1D) loose-string-like water chain, respectively, was observed in the coordination polymeric solids {[Cu(bpp)2(H2O)2](tp)·7H2O} (1) and {[Cu(bpp)2(H2O)](ip)·7H2O} (2) (bpp = 1,3-bis(4-pyridyl)propane, tp = terephthalate, and ip = isophthalate), obtained by similar solution phase ultrasonic synthesis techniques, in which 1 (C34H50CuN4O13) crystallized in the monoclinic P21/n space group, Z = 4 (a = 12.824(3) A, b = 16.867(3) A, c = 17.660(4) A; β = 94.50(3)°; V = 3808(1) A3) and 2 (C34H48CuN4O12) was attributed to the monoclinic P21 chiral space group, Z = 2 (a = 10.439(2) A, b = 16.863(3) A, c = 11.302(2) A; β = 107.84(3)°; V = 1893.9(6) A3), respectively. Of particular interest, the shapes of water clusters have been obviously well-tuned by modulating different relative orientations of carboxylate groups based on the tp2− and ip2− dianions, demonstrating that water a...

The synthesis, structure, and bonding of BaTl(4) are described [C2/m, Z = 4, a = 12.408(3), b = 5.351(1), c = 10.383(2) Å, β = 116.00(3)°]. Pairs of edge-sharing Tl pentagons are condensed to generate a network of pentagonal biprisms along b that encapsulate Ba atoms. Alternating levels of prisms along c afford six more bifunctional Tl atoms about the waists of the biprisms, giving Ba a coordination number of 16. Each Tl atom is bonded to five to seven other Tl atoms and to three to five Ba atoms. There is also strong evidence that Hg substitutes preferentially in the shared edges of the Tl biprisms in BaHg(0.80)Tl(3.20) to generate more strongly bound Hg(2) dimers. Cations that are too small relative to the dimensions of the surrounding polyanionic network make this BaTl(4) structure (and for SrIn(4) and perhaps EuIn(4) as well) one stable alternative to tetragonal BaAl(4)-type structures in which cations are bound in larger hexagon-faced nets, as for BaIn(4) and SrGa(4). Characteristic condensation and augmentation of cation-centered prismatic units is common among many relatively cation- and electron-poor, polar derivatives of Zintl phases gain stability. At the other extreme, the large family of Frank-Kasper phases in which the elements exhibit larger numbers of bonded neighbors are sometimes referred to as orbitally rich.

The three-dimensional (3D) chiral helical framework of the new polymeric solid, Zn[Htma][ddm] (1) (tma = trimesate, ddm = p,p′-diamino-diphenyl-methane), has been prepared by the hydrothermal reaction of zinc acetate dihydrate, H3tma, and ddm. X-ray single-crystal structural analysis reveals that 1 (C22H18N2O6Zn) crystallizes in the orthorhombic P212121 space group, Z = 4 (a = 5.4533(3) A, b = 17.593(1) A, c = 20.542(1) A, V = 1970.8(2) A3). Tetrahedrally coordinated zinc centers in 1 bridged by the rigid trigonal tectonic tma ligands with Δ-configuration plus the flexible ddm molecules give rise to an interesting 3D chiral helical diamondoid network single enantiomer that has been confirmed by solid-state circular dichroism spectra. 1 is stable up to about 297 °C in the ambient environment and exhibits an intense fluorescent emission band at 420 nm upon excitation at 326 nm and the band gap semiconducing character. The theoretical calculations reveal that 1 is a potential nonlinear optical-active material.

High yields of the novel BaHg(2)Tl(2) are achieved from reactions of the appropriate cast alloys at approximately 400 degrees C. (Isotypic SrHg(2)Tl(2) also exists.) The tetragonal barium structure (P4(2)/mnm, a = 10.606 A, c = 5.159 A) was refined from both single-crystal X-ray and neutron powder diffraction data in order to ensure the atom site assignments although distances and calculated atom site population also support the results. The Hg and Tl network atoms are distinctive in their functions and bonding. Parallel chains of Hg hexagons and of Tl tetrahedra along c are constructed from polyhedra that share opposed like edges, and these are in turn interconnected by Hg-Tl bonds. Overall, the number of Tl-Tl bonds per cell exceeds the Hg-Hg type by 20:12, but these are approximately 1:2 each in bonding according to their average -ICOHP values (related to overlap populations). Barium is bound within a close 15-atom polyhedron, 12 atoms of which are the more electronegative Hg. LMTO-ASA calculations show that scalar relativistic effects are particularly important for Hg 5d-6s mixing in Hg-Hg and Hg-Tl bonding, whereas relatively separate Tl 6s and 6p states are more important in Tl-Tl interactions. The 6p states of Hg and Tl and 5d of Ba define a dominant conduction band around E(F), and the phase is metallic and Pauli-like paramagnetic. The thallium characteristics here are close to those in numerous alkali-metal-Tl cluster systems. Other active metal-mercury phases that have been studied theoretically are all distinctly electron-richer and more reduced, and without appreciable net 5d, 6s contributions to Hg-Hg bonding.

Two new compounds, [Cd(tp)(H2O)3] · 4H2O (1) and [Ph4P][Cd (tp)0.5Cl2] · H2O (2) (tp = terephthalate, [Ph4P] = tetraphenylphosphonium), are metal-polycarboxylate coordination polymers prepared by similar hydrothermal synthesis techniques. Both compounds crystallize in the 1D chain-like architectures. 1 (C8H18CdO11) is orthorhombic Pcca, Z = 4 (a = 7.3018(1) A, b = 9.9975(3) A, c = 19.9695(5) A, V = 1457.77(6) A3). 2 (C28H24CdCl2O3P) is triclinic P−1, Z = 2 (a = 9.5028(4) A, b = 12.3130(5) A, c = 12.7343(6) A, α = 68.380(1)°, β = 73.723(1)°, γ = 89.624(1)°, V = 1321.8(1) A3). Transition metal cadmium centers bridged by rigid linear tp ligands give rise to a 1D infinite zigzag chain polymer for 1 and a simple 1D infinite stepped chain polymer for 2. 1 presents an interesting plywood-like packing network while 2 shows a simple parallel rod-like stacking network. An intense fluorescent emission at 412 nm (λexc = 338 nm) for 1 in the solid state at room temperature is observed. Polymeric compounds [Cd(tp)(H2O)3] · 4H2O (1) and [Ph4P][Cd (tp)0.5Cl2] · H2O (2) crystallize in two remarkable 1D chain-like architectures prepared by similar hydrothermal synthesis techniques, showing an interesting plywood-like packing network in 1 and a simple parallel rod-like stacking network in 2, respectively. An intense fluorescent emission at 412 nm (λexc = 338 nm) for 1 in the solid state at room temperature is observed.

The title compounds were synthesized via high-temperature reactions of the elements in welded Ta tubes and characterized by single-crystal X-ray diffraction analyses and band structure calculations. SrAu{sub 3.76(2)}In{sub 4.24} crystallizes in the YCo{sub 5}In{sub 3} structure type with two of eight network sites occupied by mixtures of Au and In: Pnma, Z = 4, a = 13.946(7), b = 4.458(2), c = 12.921(6) {angstrom}. Its phase breadth appears to be small. Sr{sub 4}Au{sub 9}In{sub 13} exhibits a new structure type, P{sub 6}m2, Z = 1, a = 12.701(2), c = 4.4350(9) {angstrom}. The Sr atoms in both compounds center hexagonal prisms of nominally alternating In and Au atoms and also have nine augmenting (outer) Au + In atoms around their waists so as to define 21-vertex Sr{at}Au{sub 9}M{sub 4}In{sub 8} (M = Au/In) and Sr{at}Au{sub 9}In{sub 12} polyhedra, respectively. The relatively larger Sr content in the second phase also leads to condensation of some of the ideal building units into trefoil-like cages with edge-shared six-member rings. One overall driving force for the formation of these structures can be viewed as the need for each Sr cation to have as many close neighbors as possible in the more anionic Au-In network.more » The results also depend on the cation size as well as on the flexibility of the anionic network and an efficient intercluster condensation mode as all clusters are shared. Band structure calculations (LMTO-ASA) emphasize the greater strengths (overlap populations) of the Au-In bonds and confirm expectations that both compounds are metallic.« less

The compounds BaAu(0.40(2))Tl(1.60(7)) (1), BaAu(0.36(4))In(1.64(4)) (2), and BaHg(0.92(2))In(1.08(2)) (3) have been prepared by high-temperature techniques. Single-crystal X-ray diffraction shows that these have the orthorhombic CeCu(2)-type structure, Imma, Z = 4 (a = 5.140(1), 5.104(1), 5.145(1) A; b = 8.317(2), 8.461(2), 8.373(2) A; c = 8.809(2), 8.580(2), 8.715(2) A, respectively). The structure consists of a four-linked honeycomblike polyanion (4(2)6(3)8) of infinity3[Tr2]2- (Tr = In or Tl) with encapsulated Ba2+ cations. The Au or Hg randomly replace Tr in a single type of site. The two gold phases exhibit appreciable nonstoichiometry ranges. Band calculations (EHTB) demonstrate that the three compounds are electron-poor and metallic, and the latter has been confirmed for 1 through resistivity and magnetic susceptibility measurements. The orthorhombic structure of 1 contrasts with the hexagonal structure of BaTl2 (CaIn2-type, P6(3)/mmc), a change that appears to be driven by substitution of the smaller Au atoms into the polyanion network. Relativistic effects for the heavier Au and Hg are evidently responsible for decreases in lattice parameters and bond lengths from BaIn2 to those in isostructural 2 and 3.

Four novel compounds, [Cd(tp)(bpp)]n (1), [Cd(tp)(bpy)]n (2), [{Cd4(bpa)4(bpy)6}·(bpy)0.5·7H2O]n (3) and [Cd2{(Htp)(tp)1.5}(bpe)]n (4) [tp = terephthalate, bpp = 1,3-bis(4-pyridyl)propane, bpy = 4,4′- bipyridine, bpa = 4,4′-biphenyldicarboxylate, bpe = 1,2-bis(4-pyridyl)ethane], of cadmium(II) polycarboxylate coordination polymers based on mixed ligands were obtained by a hydrothermal method. Complex 1 (C21H18CdN2O4) crystallizes in the orthorhombic Pbca space group [a = 11.9401(0) A, b = 16.8148(3) A, c = 20.2743(3) A, and Z = 8]. Complex 2 (C18H12CdN2O4) belongs to the monoclinic C2/m space group [a = 20.299(3) A, b = 10.720(1) A, c = 11.764(2) A, β = 110.944(2)°, and Z = 6]. Complex 3 (C121H98Cd4N13O23) belongs to the monoclinic P21/c space group [a = 23.2208(0) A, b = 11.8103(1) A, c = 45.4670(6) A, β = 104.516(1)°, and Z = 4]. Complex 4 (C32H23Cd2N2O10) belongs to the monoclinic P21/n space group [a = 6.9896(1) A, b = 22.6294(1) A, c = 19.7738(3)A, β = 99.380(1)°, and Z = 4].The CdII centers in the four compounds are bridged by mixed polycarboxylate ligands with bpy and related species to form the twofold parallel interpenetration topology of an undulating 2D 44 net for 1, a twofold interpenetration topology of a 3D α-Po net for 2, a fourfold interpenetration topology of a 3D 5-connected borazone 4664 net for 3 and an interesting 3D spiral pipe-like structure with a bolt for 4. These four compounds exhibit strong fluorescent emissions at 549 and 582 nm (λex = 532 nm) for 1, 493 nm (λex = 360 nm) for 2, 413 and 424 nm (λex = 315 nm) for 3 and 350 nm (λex = 220 nm) for 4 in the solid state at room temperature. These are novel structural topologies and could be significant in the field of photoactive materials. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)

Four mixed-ligand complexes, {Na2[Cd2(Htma)2(ox)(H2O)2]}n(1) (tma=trimesate, ox=oxalate), {[Cd2(2,2′-bipyridine)2(ox)2] · 2H2O}n (2), {Cd3(4,4′-trimethylenedipyridine)3(ox)3}n (3), and {Na2[Cd4(isonicotinate)4(ox)3]}n (4) were synthesized by hydrothermal reactions. The structures of 1, 2, 3 and 4 consist of 1D ladder-like chains, 1D zigzag chains, a 2D square network and a 3D framework, respectively, featuring dinuclear (for 1 and 2), trinuclear (for 3) and tetranuclear (for 4) units. The TGA experiments showed that these four complexes were quite thermally stable.

Hydrothermal reactions of CdII, CoII, and MnII with the mixed ligands 3,4-pyridinedicarboxylate (pydc), 1,3-bis(4-pyridyl)propane (bpp), or 1,2-bis(4-pyridyl)ethane (bpe) gave crystals of {[Cd(pydc)(bpp)]·0.5H2O}n (1), {[Co(pydc)(H2O)(bpe)0.5]·0.5H2O}n (2), and {[Mn(pydc)(H2O)(bpe)0.5]· 0.5H2O}n (3), respectively. Single-crystal X-ray analyses reveal that these are all three-dimensional non-interpenetrating coordination polymers. Their structures alter markedly with the conformation and the function of the ligands. In 1, the 3,4-pyridinedicarboxylate acted as a three-connector, a coordination topology of the type (3,5) [containing 3 and 5 connected centers] being generated through self-assembly, while in 2 and 3, with the help of the four-connector 3,4-pyridinedicarboxylate and the terminal ligand water molecule, another three-dimensional framework with a coordination topology of the type (4, 5) was obtained. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)

The interdigitation of the lateral tma ligands from two adjacent 44 nets via aromatic π-π interactions and host–guest molecular recognition gives rise to a novel 2D bilayer supramolecular architecture formed by the {[Cd(Htma)(bpy)(H2O)]·(H2tp)0.5·2H2O}n polymer. An interested parallel/parallel interpenetration of the 44 net appears in this bilayer supramolecular architecture through other 2D H-bonded 44 nets formed by tma molecules that H-bond with water molecules. This compound, obtained from a hydrothermal reaction, crystallizes in the triclinic P-1 space group and exhibits a broad intense fluorescent emission upon photoexcitation at 311 nm.

Five novel heptanuclear trigonal-prismatic polyhedra, Na4[PrNi6(Gly)9(mu 3-OH)3(H2O)6].(ClO4)7 (1), Na2[PrNi6(Gly)8(mu 3-OH)3(mu 2-OH2)-(H2O)6].(ClO4)6.(H2O)2 (2), Na[DyNi6(Gly)7(mu 3-OH)3(mu 2-OH2)2(H2O)6].(ClO4)6.H2O (3), [SmNi6(Gly)6-(mu 3-OH)3Cl3(H2O)6].Cl3.(H2O)9 (4), and [ErNi6(Gly)6(mu 3-OH)3Cl3(H2O)6].Cl3.(H2O)9 (5), were synthesized through self-assembly and characterized by X-ray structure analysis. Complex 1 crystallizes in the trigonal P3 space group (a = b = 18.1121(2), c = 11.987(0) A, and Z = 2). Complex 2 belongs to the triclinic P1 space group (a = 16.0145(3), b = 20.58650(10), c = 20.8452(3) A, alpha = 78.0590(10), beta = 67.9200(10), gamma = 68.1540(10) degrees, and Z = 4). Complex 3 belongs to the monoclinic P2(1)/m space group (a = 14.9863(3), b = 13.533, c = 15.6171(3) A, beta = 116.8970(10) degrees, and Z = 2). Complexes 4 and 5 are isomorphous (4: trigonal, P3; a = b = 11.8661(4), c = 18.2034(10) A, Z = 2; 5: a = b = 11.9001(5), c = 18.1229(11) A, Z = 2). A Ln3+ ion is in the center of the prism formed by six nickel atoms. It coordinates to nine oxygen atoms. Its coordination polyhedron may be best described as a tricapped trigonal prism. The five complexes all have a core of [LnNi6(Gly)6-(mu 3-OH)3(H2O)6]6+ and were obtained through the edge-ligand exchange of the three mu 2-OH2 ligands of [LnNi6(Gly)6-(mu 3-OH)3(H2O)6(mu 2-OH2)3]6+ partly or wholly by glycine or Cl-. Magnetic measurements reveal that 1 and 4 exhibit antiferromagnetic interaction, while 5 exhibits a ferromagnetic interaction.

Two novel coordination polymers formed by cobalt nitrate and 1,2-bis(4-pyridyl)ethane with the homologous ligands 2-aminoterephthalic acid and terephthalic acid, respectively, have been prepared. One displays a fivefold diamond-type feature while the other exhibits a twofold interpenetrating structural motif. The thermal and photoluminescence properties associated with their structures have been characterized and studied. (© Wiley-VCH Verlag GmbH, 69451 Weinheim, Germany, 2002)

We report the synthesis, single-crystal X-ray structure, IR, TGA–DTA and fluorescence of a black MOF crystal {(Mo4O12)(4,4′-bipy)2}n, which has two channels. One channel along the [001] direction was formed by a metaloxygen octatomic ring and the another one along the [010] direction was shaped by 4′4-bipy.

The 1-D complex with high-nuclearity [{La6Cu26gly18(μ 3-OH)30(H2O)24(ClO4)} (ClO4)21·26H2O] n was synthesized and characterized by X-ray diffraction analysis. The inner core of the basic unit is an octahedron with La3+ ions at its vertexes and Cu2+ ions at the meddles of the twelve edges. Two additional Cu2+ ions are connected to each La3+ vertex to form a [La6Cu24] unit, and adjacent units are interconnected by a pair [Cu(gly)2] bridges to give a polymeric chain structure.

A unique hydrothermal selective hydrogenation process is carried out effectively in a simple and friendly way without adding any precious metal catalysts and hydrogen gas from outside. The self-assembly of the hydrogenated product 3-(4-(pyridin-4-yl)piperidin-1-yl) benzoate (PYPDB) with the zinc ion produces a highly stable photoactive complex Zn(PYPDB)2 displaying interesting long range electron transfer behavior in the conjugated ring system.

Mercaptotin complexes are difficult to synthesize since they are usually transient intermediates. Here, we report the synthesis and crystal structure of two examples of stable hexamercaptotin complexes [N(CH 3 ) 4 ] 2 Sn(SH) 6 ( 1 ) and [N(C 2 H 5 ) 4 ] 2 Sn(SH) 6 ( 2 ), and discuss their stability by use of quantum chemistry method. Both the complexes 1 and 2 were obtained by hydrothermal synthesis and were crystallized in monoclinic space group, C2/m, Z =8, a =25.724(8), b =18.183(6), c =9.097(3) for 1 , and C2/c, Z =4, a =14.0733(14), b =14.4018(14), c =13.2538(13) for 2 . Single crystal X-ray diffraction analysis revealed that the Sn(IV) centers of 1 and 2 are octahedrally coordinated to six [SH] − ligands and all of the six hydrosulfuryl groups are located in terminal positions. The computational results of quantum chemistry method show that highly symmetric coordination of [SH] − ligands can be effective in stabilizing stannanethiols entities.

The nature of clay fines influences the characteristics of clay–rubber composites. This paper discusses the improvement of properties of clay–rubber composites by acid activation and surface modification of the clay. Acid-treated clays show a higher surface activity and a stronger combining ability with silane coupling agents. The silane modified clay fines reinforce the rubber by increasing the compatibility between rubber and clay.

A cadmium benzenetricarboxylate coordination polymer has been synthesized by hydrothermal reaction. It presents an interesting tri-layer structure motif featuring tri-nuclear units and exhibits intense photoluminescence as well.

Two Cd(II)-pyridinedicarboxylate polymers have been synthesized by hydrothermal reaction. They present novel structural motifs and exhibit intense fluorescent emissions upon photoexcitation.

A phosphatooxalate compound {Na2[Zn(C2O4)1.5H2PO4] · 2H2O}n 1 was synthesized under hydrothermal condition and characterized by single-crystal X-ray diffraction, IR spectroscopy, thermal gravimetric analysis (TGA) and fluorescent spectroscopy. X-ray single-crystal analysis revealed that its structure was a new mixed inorganic–organic ligand supramolecular framework building up through multilayer assembly.

The reaction of silver nitrate with 4,4′-biphenyldicarboxylate and 1,2-bis(4-pyridyl)ethane under hydrothermal conditions gives an interesting 2D bilayer containing a new kind of “T-shaped” unit. Each of these 2D frames is interlocked with the neighboring layers to form an overall three-dimensional architecture, displaying an unprecedented entanglement.

BaTl4 is synthesized by solid state reaction of the elements at 1050 °C (4 h) and subsequent annealing at 600 °C (4 d).