Cation-cation complexes of pentavalent uranyl: from disproportionation intermediates to stable clusters

Three new cation-cation complexes of pentavalent uranyl, stable with respect to the disproportionation reaction, have been prepared from the reaction of the precursor [(UO(2)py(5))(KI(2)py(2))](n) (1) with the Schiff base ligands salen(2-), acacen(2-), and salophen(2-) (H(2)salen = N,N'-ethylene-bis(salicylideneimine), H(2)acacen = N,N'-ethylenebis(acetylacetoneimine), H(2)salophen = N,N'-phenylene-bis(salicylideneimine)). The preparation of stable complexes requires a careful choice of counter ions and reaction conditions. Notably the reaction of 1 with salophen(2-) in pyridine leads to immediate disproportionation, but in the presence of [18]crown-6 ([18]C-6) a stable complex forms. The solid-state structure of the four tetranuclear complexes, {[UO(2)(acacen)](4)[μ(8)-](2)[K([18]C-6)(py)](2)} (3) and {[UO(2)(acacen)](4)[μ(8)-]}?2?[K([222])(py)] (4), {[UO(2)(salophen)](4)[μ(8)-K](2)[μ(5)-KI](2)[(K([18]C-6)]}?2?[K([18]C-6)(thf)(2)]?2?I (5), and {[UO(2)(salen)(4)][μ(8)-Rb](2)[Rb([18]C-6)](2)} (9) ([222] = [222]cryptand, py = pyridine), presenting a T-shaped cation-cation interaction has been determined by X-ray crystallographic studies. NMR spectroscopic and UV/Vis studies show that the tetranuclear structure is maintained in pyridine solution for the salen and acacen complexes. Stable mononuclear complexes of pentavalent uranyl are also obtained by reduction of the hexavalent uranyl Schiff base complexes with cobaltocene in pyridine in the absence of coordinating cations. The reactivity of the complex [U(V)O(2)(salen)(py)][Cp*(2)Co] with different alkali ions demonstrates the crucial effect of coordinating cations on the stability of cation-cation complexes. The nature of the cation plays a key role in the preparation of stable cation-cation complexes. Stable tetranuclear complexes form in the presence of K(+) and Rb(+), whereas Li(+) leads to disproportionation. A new uranyl-oxo cluster was isolated from this reaction. The reaction of [U(V)O(2)(salen)(py)][Cp*(2)Co] (Cp* = pentamethylcyclopentadienyl) with its U(VI) analogue yields the oxo-functionalized dimer [UO(2)(salen)(py)](2)[Cp*(2)Co] (8). The reaction of the {[UO(2)(salen)(4)][μ(8)-K](2)[K([18]C-6)](2)} tetramer with protons leads to disproportionation to U(IV) and U(VI) species and H(2)O confirming the crucial role of the proton in the U(V) disproportionation.     

Structural Diversity and Thermochromic Properties of Iodobismuthate Materials Containing d-Metal Coordination Cations: Observation of a High Symmetry [Bi(3)I(11)](2-) Anion and of Isolated I(-) Anions

Six new inorganic-organic salts, all containing iodobismuthate anions and d-metal coordination cations, were synthesized solvothermally from reactions of bismuth iodide, a transition metal (M) nitrate salt (M = Co, Fe or Zn), and a heterocyclic, chelating organic ligand: 1,10-phenanthroline (1,10-phen), 3,4,7,8-tetramethyl-1,10-phenanthroline (TMphen), or 2,2':6',2'-terpyridine (tpy). All six compounds were structurally analyzed by single crystal X-ray diffraction, including variable temperature crystallographic analysis to monitor for structural changes. Furthermore, those containing novel anions and achieved in high yield were additionally characterized by solid-state UV visible spectroscopy at room temperature. [Co(1,10-phen)(3)][Bi(3)I(11)] (1), [Fe(1,10-phen)(3)][Bi(3)I(11)] (2), and [Zn(1,10-phen)(3)][Bi(3)I(11)] (3) are isostructural. They crystallize in the monoclinic space group P2(1)/n and contain the unprecedented iodobismuthate anion, [Bi(3)I(11)](2-), which exhibits near D(3h) symmetry and has an unusual arrangement of three cis face-sharing BiI(6) octahedra. [Co(TMPhen)(3)](2)[Bi(2)I(9)][I] (4), which crystallizes in the trigonal space group P-31c, and [Co(tpy)(2)](2)[Bi(2)I(9)][I] (5) and [Zn(tpy)(2)](2)[Bi(2)I(9)][I] (6), which are isostructural and crystallize in the monoclinic space group C2/c, contain the discrete binuclear [Bi(2)I(9)](3-) anion, common in previously reported iodobismuthate compounds. In addition they contain unusual isolated I(-) anions, which are rarely encountered in iodobismuthate phases. Compounds 1-6 show constitutional similarities while utilizing different organic ligands and illustrate the sensitive dependence of reaction conditions on the identity of the halometalate anion formed. Additionally, all six compounds and the starting material BiI(3) are thermochromic; the origin of this behavior is spectroscopically and crystallographically investigated.     

Construction of polyoxometalates-based coordination polymers through direct incorporation between polyoxometalates and the voids in a 2D network

A series of polyoxometalates (POMs)-based coordination polymers, namely, {[Cu(2,3-Me2pz)(2,5-Me2pz)0.5]4(SiW12O40)(2,5-Me2pz)}n (2,3-Me2pz = 2,3-dimethylpyrazine; 2,5-Me2pz = 2,5-dimethylpyrazine; 1), {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(H2O)18}n (4,4'-bipy = 4,4'-bipyridine; 2), {[Cu(2-Mepz)1.5]3(PMo12O40)(H2O)3.5}n (2-Mepz = 2-methylpyrazine; 3), {[Ag(2,3-Me2pz)1.5]4(SiW12O40}n (4), {[Cu(pz)1.5]4(SiW12O40)(H2O)3}n (pz = pyrazine; 5), {[Cu(2,3-Me2pz)1.5]4(SiW12O40)}n (6), {[Cu(4,4'-bipy)1.75]4(SiW12O40)(H2O)2}n (7), and {[Cu2(4,4'-bipy)4(H2O)4](SiW12O40)(4,4'-bipy)2(H2O)4}n (8), were synthesized through direct incorporation between POMs and the voids of the 2D network. Crystal structural analysis reveals that the relationship between the size of the void of the 2D network and that of POMs is of key importance for successful synthesis of POMs-based open metal-organic frameworks. Guest replacement shows that the pore size of the framework constructed through direct incorporation between POMs and the voids of the 2D network is very sensitive to guest molecules.     

A series of new copper iodobismuthates: structural relationships, optical band gaps affected by dimensionality, and distinct thermal stabilities

Three new copper iodobismuthates, red tetranuclear [n-Bu(4)N][Cu(2)(CH(3)CN)(2)Bi(2)I(10)] (1), dark-red infinite linear [Et(4)N](2n)[Cu(2)Bi(2)I(10)](n) (2), and black polymeric ladderlike [Cu(CH(3)CN)(4)](2n)[Cu(2)Bi(2)I(10)](n) (3), crystallize from solutions of BiI3 and CuI in the presence of different cations. A regular structural relationship from 0-D (1) to 1-D linear anion chains (2) to 1-D ladderlike anion chains (3) is observed. The self-assembly of the basic building unit Cu(2)Bi(2)I(10) as altered by different cations is proposed to be the driving force for their formation. The optical band gaps exhibit a structure-related decrease from 1 to 2/3, in agreement with their color changes and the density functional theory (DFT) calculation results. The electronic structures and the relationship with corresponding monobismuth analogues and the Ag-Bi isotypes are discussed on the basis of DFT calculations. In spite of their structural similarities, the compounds are distinctive thermally: 2 is stable to 230 degrees C, 1 undergoes a solvent loss at 85 degrees C to form a new phase that is thermally stable to 230 degrees C, and 3 releases a solvent molecule and decomposes at 80 degrees C into BiI(3) and CuI. The essential reasons for these differences are discussed.     

Construction of a porous homochiral coordination polymer with two types of Cu(n)I(n) alternating units linked by quinine: a solvothermal and a mechanochemical approach

The polymer network: The reaction of quinine (QN) with CuI under solvothermal, as well as liquid-assisted grinding, conditions afforded a unique 1D homochiral coordination polymer {[Cu(4)(μ(3)-I)(4)(QN)(2)][Cu(3)(μ(3)-I)(2)(μ(2)-I)(QN)(2)](2)}(n), containing both triangular Cu(3)I(3) and cubane Cu(4)I(4) clusters as connecting nodes (see scheme). Van der Waals interactions between the adjacent 1D polymer chains lead to an extended quasi-honeycomb homochiral pillared 3D network with solvent-free 1D channels.     

Solvent-dependent dynamics of the MQ*-->ReII excited-state electron transfer in [Re(MQ+)(CO)3(dmb)]2+

The Re-->MQ(+) MLCT excited state of [Re(MQ(+))(CO)(3)(dmb)](2+) (MQ(+) = N-methyl-4,4'-bipyridinium, dmb = 4,4'-dimethyl-2,2'-bipyridine), which is populated upon 400-nm irradiation, was characterized by picosecond time-resolved IR and resonance Raman spectroscopy, which indicate large structural differences relative to the ground state. The Re-->MQ(+) MLCT excited state can be formulated as [Re(II)(MQ*)(CO)(3)(dmb)](2+). It decays to the ground state by a MQ*-->Re(II) back-electron transfer, whose time constant is moderately dependent on the molecular nature of the solvent, instead of its bulk parameters: formamides approximately DMSO approximately MeOH (1.2-2.2 ns) < THF, aliphatic nitriles (3.2-3.9 ns) < ethylene-glycol approximately 2-ethoxyethanol (4.2-4.8 ns) < pyridine (5.7 ns) < MeOCH(2)CH(2)OMe (6.9 ns) < PhCN (7.5 ns) < MeNO(2) (8.6 ns) < CH(2)Cl(2), ClCH(2)CH(2)Cl (25.9-28.9 ns). An approximate correlation was found between the back-reaction rate constant and the Gutmann donor number. Temperature dependence of the decay rate measured in CH(2)Cl(2), MeOH, and BuCN indicates that the inverted MQ*-->Re(II) back-electron transfer populates a manifold of higher vibrational levels of the ground state. The solvent dependence of the electron transfer rate is explained by solvent effects on inner reorganization energy and on frequencies of electron-accepting vibrations, by interactions between the positively charged MQ(+) pyridinium ring and solvent molecules in the electron-transfer product, that is the [Re(MQ(+))(CO)(3)(dmb)](2+) ground state.     

Photochromic metal complexes of N-methyl-4,4'-bipyridinium: mechanism and influence of halogen atoms

Photochromism of N-methyl-4,4'-bipyridinium (MQ(+)) salts and their metal complexes has never been reported. A series of MQ(+) coordinated halozinc complexes [(MQ)ZnX(3)] (X = Cl (1), Br (2), I (3)) and [(MQ)ZnCl(1.53)I(1.47)](2)(MQ)ZnCl(1.68)I(1.32) (4), with better physicochemical stability than halide salts of the MQ(+) cation, have been found to exhibit different photochromic behaviors. Compounds 1-3 are isostructural, but only 1 and 2 show photochromism. Introduction of partial Cl atoms to nonphotochromic compound 3 yields compound 4, which also displays photochromism. The photochromic response of 1, 2, and 4 indicates the presence of their long-lived charge separation states, which originate from X → MQ(+) electron transfer according to ESR and XPS measurements. Studies on the influence of different coordinated halogen atoms demonstrate that the Cl atom may be a more suitable electron donor than Br and I atoms to design redox photochromic metal complexes.     

Isolation of (CO)1- and (CO2)1- radical complexes of rare earths via Ln(NR2)3/K reduction and [K2(18-crown-6)2]2+ oligomerization

Deep-blue solutions of Y(2+) formed from Y(NR(2))(3) (R = SiMe(3)) and excess potassium in the presence of 18-crown-6 at -45 °C under vacuum in diethyl ether react with CO at -78 °C to form colorless crystals of the (CO)(1-) radical complex, {[(R(2)N)(3)Y(μ-CO)(2)][K(2)(18-crown-6)(2)]}(n), 1. The polymeric structure contains trigonal bipyramidal [(R(2)N)(3)Y(μ-CO)(2)](2-) units with axial (CO)(1-) ligands linked by [K(2)(18-crown-6)(2)](2+) dications. Byproducts such as the ynediolate, [(R(2)N)(3)Y](2)(μ-OC≡CO){[K(18-crown-6)](2)(18-crown-6)}, 2, in which two (CO)(1-) anions are coupled to form (OC≡CO)(2-), and the insertion/rearrangement product, {(R(2)N)(2)Y[OC(═CH(2))Si(Me(2))NSiMe(3)]}[K(18-crown-6)], 3, are common in these reactions that give variable results depending on the specific reaction conditions. The CO reduction in the presence of THF forms a solvated variant of 2, the ynediolate [(R(2)N)(3)Y](2)(μ-OC≡CO)[K(18-crown-6)(THF)(2)](2), 2a. CO(2) reacts analogously with Y(2+) to form the (CO(2))(1-) radical complex, {[(R(2)N)(3)Y(μ-CO(2))(2)][K(2)(18-crown-6)(2)]}(n), 4, that has a structure similar to that of 1. Analogous (CO)(1-) and (OC≡CO)(2-) complexes of lutetium were isolated using Lu(NR(2))(3)/K/18-crown-6: {[(R(2)N)(3)Lu(μ-CO)(2)][K(2)(18-crown-6)(2)]}(n), 5, [(R(2)N)(3)Lu](2)(μ-OC≡CO){[K(18-crown-6)](2)(18-crown-6)}, 6, and [(R(2)N)(3)Lu](2)(μ-OC≡CO)[K(18-crown-6)(Et(2)O)(2)](2), 6a.     

Preparation and characterization of novel inorganic-organic hybrid materials containing rare, mixed-halide anions of bismuth(III)

Three new hybrid inorganic-organic salts containing novel mixed haloanions of bismuth were synthesized by the solvothermal reaction of bismuth iodide with a haloacid, HX (X = Cl or Br), and the alkylamine 4,4'-trimethylenedipiperidine (TMDP). All three compounds were structurally characterized by single-crystal X-ray diffraction. Reaction of TMDP and BiI(3) with HCl yielded two crystalline products: [H(2)TMDP](2)[(Bi(2)I(9))(BiCl(2)I(2))] (1, major yield) and [H(2)TMDP](2)[Bi(2)Cl(10-x)I(x)] (2, x = 3.83, minor yield). Compound 1 crystallizes in the monoclinic space group Cc (a = 22.8586(11) A, b = 15.5878(7) A, c = 17.6793(9) A, beta = 118.7010(10) degrees , Z = 4) and contains the mononuclear mixed-halide anion BiCl(2)I(2)(-) in addition to a face-sharing bioctahedral Bi(2)I(9)(3)(-) anion and two independent H(2)TMDP(2+) cations. The BiCl(2)I(2)(-) anion has a sawhorse geometry (equatorially vacant trigonal bipyramidal geometry) that is not commonly observed in bismuth chemistry. Compound 2 crystallizes in the monoclinic space group P2(1)/c (a = 14.9471(7) A, b = 12.7622(6) A, c = 13.3381(7) A, beta = 116.1030(10) degrees , Z = 2) and contains an edge-sharing bioctahedral mixed-halide anion in which iodide occupies one and chloride occupies two of the five crystallographically independent halide sites. The remaining two sites have mixed-chloride and -iodide occupancy. Reaction of TMDP and BiI(3) with HBr yielded the crystalline product [H(2)TMDP][BiBr(5-x)I(x)] (3, x = 0.99), which contains, in addition to the organic cation, a polymeric, mixed-haloanion of bismuth(III). Compound 3 crystallizes in the chiral, orthorhombic space group P2(1)2(1)2(1) (a = 8.5189(5) A, b = 14.8988(9) A, c = 17.9984(11) A, Z = 4) and consists of an H(2)TMDP(2+) cation in addition to the anion, which is built up of corner-sharing BiX(6) octahedra. Of the five crystallographically independent halide sites in this anion, two are occupied solely by Br and the remaining three have mixed-bromide and -iodide occupancy. Other anion stoichiometries have been observed crystallographically for 3, as the specific stoichiometry is dependent on the relative concentration of the haloacid starting material used.     

Heterobimetallic chalcogenidometallate strands: synthesis, structure, magnetism, and conductivity

Two salts with one-dimensional, SiS(2)-type telluridostannate chain anions {[MSnTe(4)](2-)}(n), Rb(2)[HgSnTe(4)] (2) and (NMe(4))(2)[MnSnTe(4)] (3), were prepared by the reactions of [SnTe](4-) anions with Hg(2+) or Mn(2+) ions in solution. We present the crystal structures of 2 and 3, as well as the magnetic properties of the previously reported Cs(+) analogue Cs(2)[MnSnTe(4)] (1).     

A series of new organic-inorganic molybdenum arsenate complexes based on [(ZnO6)(As3O3)2Mo6O18]4- and [HxAs2Mo6O26](6-x)- clusters as SBUs

By synthesizing the novel molybdenum arsenate complexes, we have obtained eight new structures, namely, (4,4'-bipy)[Zn(4,4'-bipy)2(H2O)2]2[(ZnO6)(AsIII3O3)2Mo6O18].7H2O, 1, [Zn(phen)2(H2O)]2[(ZnO6)(AsIII3O3)2Mo6O18].4H2O, 2, [Zn(2,2'-bipy)2(H2O)]2[(ZnO6)(AsIII3O3)2Mo6O18].4H2O, 3, [Zn(H4,4'-bipy)2(H2O)4][(ZnO6)(AsIII3O3)2Mo6O18].8H2O, 4, (H24,4'-bipy)[CuI(4,4'-bipy)]2[H2AsV2Mo6O26].H2O, 5, (H24,4'-bipy)3[AsV2Mo6O26].4H2O, 6, (H24,4'-bipy)3[AsV2Mo6O26(H2O)].4H2O, 7, and (H24,4'-bipy)2.5(H3O)[AsV2Mo6O26(H2O)].1.25H2O, 8 (4,4'-bipy = 4,4'-bipyridine, 2,2'-bipy = 2,2'-bipyridine, phen = 1,10-phenanthroline). These structures were determined by single-crystal X-ray diffraction analysis and were further characterized by elemental analysis, IR, XPS spectroscopy, and TG analysis. The structure of 1 is constructed from two-dimensional square gridlike sheets linked by the polyanions [(ZnO6)(AsIII3O3)2Mo6O18]4- via hydrogen-bonding interactions to form a three-dimensional supramolecular framework with two types of channels. Compounds 2 and 3 display similar bisupported structures. Compound 4 features a three-dimensional supramolecular architecture. Compound 5 possesses a 1D infinite ladderlike ribbon. Compounds 6-8 are discrete structures exhibiting three isomeric forms of [HxAs2Mo6O26](6-x)-. Furthermore, compound 8 represents a new isomer B'-[As2Mo6O26(H2O)]6-. In addition, the fluorescent properties of compounds 1-3 are reported.     

Syntheses, structures, and characterizations of four new lead(II) 5-sulfosalicylate complexes with both chelating and bridging neutral ligands

Four structurally diverse complexes, {[Pb(Hssal)(2,2'-bipy)](4,4'-bipy)0.5}n (1), [Pb2(Hssal)2(2,2'-bipy)2(4,4'-bipy)(H2O)2] (2), [Pb(Hssal)(phen)(4,4'-bipy)0.5]n (3), and [Pb(Hssal)(2,2'-bipy)(bpe)0.5]n (4), have been synthesized and characterized by elemental analyses, IR, thermogravimetric analyses, fluorescent spectra, and single-crystal X-ray analyses, where Hssal2- is doubly deprotonated 5-sulfosalicylate, 2,2'-bipy is 2,2'-bipyridine, phen is 1,10-phenanthroline, 4,4'-bipy is 4,4'-bipyridine, and bpe is trans-1,2-bis(4-pyridyl)ethylene. The structure of complex 1 possesses a one-dimensional ladderlike chain with guest 4,4'-bipy molecules, while the molecular structure of complex 2 is a dimeric species with a coordinating 4,4'-bipy ligand. Complex 3 consists of a one-dimensional ladderlike chain with monodentate 4,4'-bipyridine but somewhat different from that of complex 1. Complex 4 is a two-dimensional layer structure. In 1-4, all 5-sulfosalicylates are doubly deprotonated, and all carboxylate groups of Hssal2- chelate to PbII ions; however, the coordination modes of sulfonyl groups are different: syn-syn bridging in 1, noncoordinating in 2, syn-skew bridging in 3, and one-atom bridging in 4. The noncoordinating mode of sulfonate in PbII complexes containing 5-sulfosalicylate is first reported in this presentation. The 4,4'-bipy ligands act as guest molecules in 1, dimeric linkers in 2, and monodentates in 3. The pi-pi stacking interactions can be observed in complexes 1-3, whereas there is no such interaction in complex 4. The coordination spheres of PbII ions in 1-4 are controlled by three factors: the activity of a lone pair of electrons, weak Pb-O interactions, and pi-pi stacking interactions. The PbII lone pair in 4 is inactive, whereas in 1-3, they are stereochemically active. The thermal stability and fluorescent property of complexes 1-4 are different from those of PbII complexes only containing chelating ligands, [Pb(Hssal)(2,2'-bipy)(DMF)]n (5), and [Pb(Hssal)(2,2'-bipy)(H2O)]n (6), and [Pb(Hssal)(phen)(DMF)]n (7).     

Synthesis and Crystal Structure of a Three-dimensional Manganese(Ⅱ)Complex Constructed via Covalent and Hydrogen Bonds

1INTRODUCTIONCrystalengineeringofone-,two-andthree-dimensionalsupramolecularcomplexesiscurrentlyofgreatinterestowingtothefascinatingstructuraldiversityandpotentialapplicationsinmaterials,suchaselectricconductivity,magnetism,host-guestapplication,molecularrecognitionandcatalysis[1,2].Severaltypesofinteractions,suchascoordinationcovalentbond,hydrogenbond,p-pstackingandelectrostaticinteractionscanbeusedtoconstructextendedsupramolecularframeworks[3~6],butcoordinationbondingandhydrogenbondingin…     

Novel aggregation of [Ni(thiolato)2(amine)2]-type square planes assisted by silver(I) ions

Treatment of [Ni(L)][L =((-)SCH(2)CH(2)NH[double bond, length as m-dash]C(CH(3))-)(2)] with Ag(+) in water gave a pinwheel-like S-bridged Ni(II)(3)Ag(I)(2) structure in [Ag(2)[Ni(L)](3)](2+), which further reacted with [Ni(L)] to produce a Ni(II)(4)Ag(I)(2) structure in [Ag(2)[Ni(L)](4)](2+) and a Ni(II)(7)Ag(I)(4) structure in [Ag(4)[Ni(L)](7)](4+).     

Self-assembly of D-penicillaminato M6M'8 (M = Ni(II), Pd(II), Pt(II); M' = Cu(I), Ag(I)) clusters and their organization into extended La(III)M6M'8 supramolecular structures

A series of chiral M(6)M'(8) cluster compounds having twelve free carboxylate groups, [M(6)M'(8)(D-pen-N,S)(12)X](5-) (M/M'/X = Pd(II)/Ag(I)/Cl(-) ([1](5-)), Pd(II)/Ag(I)/Br(-) ([2](5-)), Pd(II)/Ag(I)/I(-) ([3](5-)), Ni(II)/Ag(I)/Cl(-) ([4](5-)), Pt(II)/Ag(I)/Cl(-) ([5](5-)), Pd(II)/Cu(I)/Cl(-) ([6](5-)); D-H(2)pen = D-penicillamine), in which six cis-[M(D-pen-N,S)(2)](2-) square-planar units are bound to a [M'(8)X](7+) cubic core through sulfur-bridges, was synthesized by the reactions of cis-[M(D-pen-N,S)(2)](2-) with M' in water in the presence of halide ions. These M(6)M'(8) clusters readily reacted with La(3+) in aqueous buffer to form La(III)(2)M(6)M'(8) heterotrimetallic compounds, La(2)[1](CH(3)COO), La(2)[2](CH(3)COO), La(2)[3](CH(3)COO), La(2)[4](CH(3)COO), La(2)[5](CH(3)COO) and La(2)[6]Cl, in which the M(6)M'(8) cluster units are linked by La(3+) ions through carboxylate groups in a 1?:?2 ratio. While the La(III)(2)M(6)Ag(I)(8) compounds derived from [1](5-), [2](5-), [3](5-), [4](5-) and [5](5-) have a 1D helix supramolecular structure with a right-handedness, the La(III)(2)Pd(II)(6)Cu(I)(8) compound derived from [6](5-) has a 2D sheet-like structure with a triangular grid of the Pd(II)(6)Cu(I)(8) cluster units. When aqueous HCl was added to the reaction solution of [6](5-) and La(3+), another La(III)(2)Pd(II)(6)Cu(I)(8) heterotrimetallic compound, La(2)[6]Cl·HCl, in which the Pd(II)(6)Cu(I)(8) cluster units are linked by La(3+) ions to form a 2D structure with a rectangular grid, was produced. The solid-state structures of these La(III)(2)M(6)M'(8) compounds, determined by single-crystal X-ray crystallography, along with the spectroscopic properties of the M(6)M'(8) cluster compounds in solution, are described.     

Lanthanide-tungstobismuthate clusters based on [BiW9O33]9- building units: synthesis, crystal structures, luminescent and magnetic properties

The reaction of Na(12)[Bi(2)W(22)O(74)(OH)(2)]·44H(2)O, Na(9)[BiW(9)O(33)]·16H(2)O, lanthanide chloride and Na(2)CO(3) in aqueous solution at a pH value of about 7.0 resulted in the three unprecedented giant lanthanide-tungstobismuthate clusters Na(x)H(22-x)[(BiW(9)O(33))(4)(WO(3)){Bi(6)(μ(3)-O)(4)(μ(2)-OH)(3)}(Ln(3)(H(2)O)(6)CO(3))]·nH(2)O {Ln = Pr(3+) (1), Nd(3+) (2), La(3+) (3), x = 22 (1), 22 (2), 20 (3), n = 95 (1), 91 (2), 73 (3)}. These three complexes represent the first examples of lanthanide ions encapsulated in polyoxotungstobismuthates and the largest polytungstobismuthates so far. Furthermore, a [{Bi(6)(μ(3)-O)(4)(μ(2)-OH)(3)}](7+) polyoxo cation was incorporated into the structure of these compounds. All complexes are characterized by single-crystal X-ray diffraction, IR spectra, electronic spectroscopy, thermogravimetric and elemental analysis. Magnetic investigation revealed that the progressive depopulation of excited Stark sublevels of the lanthanide ions at low temperature and the weak antiferromagnetic interaction between the neighboring metal centres are responsible for the magnetic properties of 1 and 2. The original synthesis strategy in this work may open a gateway to assembly of large lanthanide-tungstobismuthates clusters and novel multifunctional solid materials in aqueous solution under mild conditions.     

Syntheses, structures, and properties of five coordination polymers containing fluorescent whitener

Fluorescent whitener (4,4'-bis(2-sulfonatostiryl)biphenyl) was incorporated with M/4,4'-bipy (M=Cd, Co; 4,4'-bipy=4,4'-bipyridine) 2D frameworks, Mn/4,4'-bipyH fragment, and the [Zn2(Im)2(ImH)4]2+ (ImH=imidazole) chain under hydrothermal conditions to obtain seven new coordination polymers: [Cd(4,4'-bipy)(L)(H2O)2] (1), [Co(4,4'-bipy)2(L)].2H2O (2), [Co(4,4'-bipy)2(H2O)2](4,4'-bipy)(L).2H2O (3), [Mn(4,4'-bipyH)2(L)2(H2O)2].4H2O (4), and [Zn2(Im)2(ImH)4](L) (5). Their structures were determined by single-crystal X-ray diffraction. In 1, binuclear [Cd2] units are bridged by 4,4'-bipys into a 2D cationic framework, which is further penetrated by L anions. 2 has an organic-inorganic hybrid layer consisting of [Co(4,4'-bipy)2] squarelike motifs and L anions. 3 features a pcu-like 3D cationic framework with the inclusion of L anions. In 4, the [Mn(4,4'-bipyH)2(H2O)2]4+ cationic fragment is sandwiched by L anions into a sandwichlike hybrid layer. 5 exhibits a 3D honeycomb-like structure with each nanotube encapsulating two parallel L anionic chains. TGA and PXRD indicate solids 1, 4, and 5 are thermally stable up to 280, 200, and 250 degrees C under an air atmosphere, respectively. 1 has bright blue-green luminescence with a peak maximum band at about 470 nm. 4 exhibits tunable emission between dark-red and weak-green under the excitation of 500 and 280 nm, respectively. 5 displays a bright blue-green emission with a peak band at 454 nm and a shoulder peak at 473 nm. It is attractive that the luminescent properties of solids 1, 4, and 5 are almost retained after heat treatment at 200, 200, and 250 degrees C for 2 h under an air atmosphere, respectively.     

Systematic structural control of multichromic platinum(II)-diimine complexes ranging from ionic solid to coordination polymer

Reactions of a Pt(II)-diimine-based metalloligand Na(2)[Pt(CN)(2)(4,4'-dcbpy)] (4,4'-H(2)dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) with alkaline-earth metal salts Mg(NO(3))(2)·6H(2)O, CaCl(2), SrCl(2)·6H(2)O, and BaBr(2)·2H(2)O in aqueous solution gave luminescent complexes formulated as [Mg(H(2)O)(5)][Pt(CN)(2)(4,4'-dcbpy)]·4H(2)O (MgPt-4·9H(2)O), {[Ca(H(2)O)(3)][Pt(CN)(2)(4,4'-dcbpy)]·3H(2)O}(∞) (CaPt-4·6H(2)O), {[Sr(H(2)O)(2)][Pt(CN)(2)(4,4'-dcbpy)]·H(2)O}(∞) (SrPt-4·3H(2)O), and {[Ba(H(2)O)(2)][Pt(CN)(2)(4,4'-dcbpy)]·3H(2)O}(∞) (BaPt-4·5H(2)O), respectively. The crystal structures of all MPt-4 complexes were determined by X-ray crystallography. In these structures, the alkaline-earth metal ions are commonly coordinated to the carboxyl groups of the [Pt(CN)(2)(4,4'-dcbpy)](2-) metalloligand. In the case of MgPt-4·9H(2)O, the Mg(II) ion is bound by five water molecules and one oxygen atom of a carboxyl group to form a neutral complex molecule [Mg(H(2)O)(5)][Pt(CN)(2)(4,4'-dcbpy)]. In contrast, the alkaline-earth metal ion and metalloligand form two-dimensional (CaPt-4·6H(2)O) and three-dimensional (SrPt-4·3H(2)O and BaPt-4·5H(2)O) coordination networks, respectively. All fully hydrated complexes exhibited a strong phosphorescence from the triplet π-π* transition state. Luminescence spectroscopy revealed that MgPt-4·9H(2)O exhibited interesting multichromic (i.e., thermo-, mechano-, and vapochromic) luminescence, whereas CaPt-4·6H(2)O showed only thermochromic luminescence. The other two complexes did not exhibit any chromic behaviour. Combination analysis of powder X-ray diffraction, thermogravimetry, and IR spectroscopy suggests that the dimensionality of the coordination network contributes considerably to both the structural flexibility and luminescence properties; that is, the low-dimensional flexible coordination network formed in MPt-4 complexes with smaller alkaline-earth metal ions enables a structural rearrangement induced by thermal and mechanical stimuli and vapour adsorption, resulting in the observed multichromic behaviour.     

Europium(II) compounds: simple synthesis of a molecular complex in water and coordination polymers with 2,2'-bipyrimidine-mediated ferromagnetic interactions

Reaction between EuCl(2) and 2,2'-bipyrimidine (bpm) in de-oxygenated water afforded a cationic molecular complex [EuCl(bpm)(2)(H(2)O)(4)][Cl]·H(2)O (1). When performed in an organic solvent such as THF or methanol, the same reaction yielded a 3-dimensional coordination polymer of formula [EuCl(2)(bpm)(MeOH)(0.5)](∞) (2) in which both bpm and the chloride ions act as linkers between the Eu(II) ions. Upon replacing Cl(-) by I(-), two coordination polymers of formula {[Eu(bpm)(2)(H(2)O)(3)][I](2)·0.5bpm}(∞) (3) and {[Eu(I)(bpm)(MeOH)][I]}(∞) (4) were obtained from reaction in water and methanol, respectively. All these compounds were characterized by X-ray crystallography. Investigations of the magnetic properties revealed a weak antiferromagnetic coupling in 2, while 3 and 4 showed a weak ferromagnetic coupling at low temperature.     

Novel hydrogen-bonded three-dimensional networks encapsulating one-dimensional covalent chains: [M(4,4'-bipy)(H2O)(4)](4-abs)(2).nH2O (4,4'-bipy = 4,4'-bipyridine; 4-abs = 4-aminobenzenesulfonate) (M = Co,n = 1; M = Mn,n = 2)

Two novel compounds, [Co(4,4'-bipy)(H(2)O)(4)](4-abs)(2).H(2)O (1) and [Mn(4,4'-bipy)(H(2)O)(4)](4-abs)(2).2H(2)O (2) (4,4'-bipy = 4,4'-bipyridine; 4-abs = 4-aminobenzenesulfonate), have been synthesized in aqueous solution and characterized by single-crystal X-ray diffraction, elemental analyses, UV-vis and IR spectra, and TG analysis. X-ray structural analysis revealed that 1 and 2 both possess unusual hydrogen-bonded three-dimensional (3-D) networks encapsulating one-dimensional (1-D) covalently bonded infinite [M(4,4'-bipy)(H(2)O)(4)](2+) (M = Co, Mn) chains. The 4-abs anions in 1 form 1-D zigzag chains through hydrogen bonds. These chains are further extended through crystallization water molecules into 3-D hydrogen-bonded networks with 1-D channels, in which the [Co(4,4'-bipy)(H(2)O)(4)](2+) linear covalently bonded chains are located. Crystal data for 1: C(22)H(30)CoN(4)O(11)S(2), monoclinic P2(1), a = 11.380(2) A, b = 8.0274(16) A, c = 15.670(3) A, alpha = gamma = 90 degrees, beta = 92.82(3) degrees, Z = 2. Compound 2 contains interesting two-dimensional (2-D) honeycomb-like networks formed by 4-abs anions and lattice water molecules via hydrogen bonding, which are extended through other crystallization water molecules into three dimensions with 1-D hexagonal channels. The [Mn(4,4'-bipy)(H(2)O)(4)](2+) linear covalent chains exist in these channels. Crystal data for 2: C(22)H(32)MnN(4)O(12)S(2), monoclinic P2(1)/c, a = 15.0833(14) A, b = 8.2887(4) A, c = 23.2228(15) A, alpha = gamma = 90 degrees, beta = 95.186(3) degrees, Z = 4.