Polyoxometalate-templated lanthanide-organic hybrid layers based on 6(3)-honeycomb-like 2D nets

The reaction of a double-betaine-containing ligand with LnPMo(12)O(40)·nH(2)O (Ln = Dy, Tb and Er) led to the isolation of new polyoxometalate-templated lanthanide-organic hybrid layers with the molecular formula [Ln(L)(1.5)(H(2)O)(5)][PMo(12)O(40)]·1.5CH(3)CN·2H(2)O (Ln = Dy (1), Tb (2) and Er (3); L = 1,4-bis(pyridinil-4-carboxylato)-l,4-dimethylbenzene). All compounds were characterized by elemental analyses, TG analyses, IR and the single-crystal X-ray diffraction. Compounds 1-3 are isostructural and possess a 2D undulating cationic network [Ln(L)(1.5)(H(2)O)(5)](n)(3n+) with the honeycomb-like cavities. Interestingly, the interval 2D networks are further connected by the H-bonds to form a 3D supramolecular framework. Moreover, two of such identical supramolecular frameworks are 2-fold interpenetrated with each other and encapsulate the α-Keggin-type [PMo(12)O(40)](3-) anionic templates and the solvent molecules. These composite compounds display both luminescent properties (induced by organic ligands and/or lanthanide ions) and electrocatalytic activities towards the reduction of nitrite.     

Large cluster formation through multiple substitution with lanthanide cations (La, Ce, Nd, Sm, Eu, and Gd) of the polyoxoanion

Several new large polyoxotungstates have been synthesized by reaction of lanthanide cations with the well-known "As(4)W(40)" anion, [(B-alpha-AsO(3)W(9)O(30))(4)(WO(2))(4)](28-) (1). The heteropolyanions [(H(2)O)(11)Ln(III)(Ln(III)(2)OH)(B-alpha-AsO(3)W(9)O(30))(4)(WO(2))(4)](20)(-) (Ln = Ce, Nd, Sm, Gd) (2-4) (Ln(3)As(4)W(40)) and [M(m)()(H(2)O)(10)(Ln(III)(2)OH)(2)(B-alpha-AsO(3)W(9)O(30))(4)(WO(2))(4)]((18-m)(-)) (Ln = La, Ce, Gd and M = Ba, K, none) (5-7) (Ln(4)As(4)W(40)) have been isolated as alkali metal and ammonium salts, respectively, and characterized by single-crystal X-ray analysis, elemental analysis, and IR and (183)W-NMR spectroscopy. The X-ray analyses revealed interanionic W-O-Ln bonds between adjacent Ln(x)()As(4)W(40) units forming a "dimer" for x = 3 and chains for x = 4. Upon dissolving in water these bonds hydrolyze and the monomeric species form. The straightforward syntheses which require the use of concentrated NaCl solutions (1-4 M) and the addition of stoichiometric amounts of Ba(2+) or K(+) reemphasize the importance of the presence of appropriate countercations for the assembly of large polyoxometalate structures.     

Synthesis,Properties and Crystal Structure of A New 12-Molybdogermanic Salt of Lanthanum Coordinated to N -Methyl-2-Pyrrolidone

A new compound [La(NMP) 4 (H 2 O) 4 ][HGeMo 12 O 40 ]·2NMP·3H 2 O (NMP = N -methyl-2-pyrrolidone), 1 , was synthesized and characterized. The compound crystallizes in the monoclinic space group P 2 1 / c with a = 17.3428(4), b = 18.3258(5), c = 23.0387(7) Å, g = 107.088(1)°, V = 6998.9(3) Å 3 and Z = 4. The structure was characterized crystallographically with final R 1 = 0.0589, wR 2 = 0.1596. The crystal structure contains [GeMo 12 O 40 ] 4 m anions combining with [La(NMP) 4 (H 2 O) 4 ] 3+ cations through hydrogen bonds. The La 3+ ion exhibits eight-coordination with four water molecules and four carbonyl oxygen atoms of the organic ligands. Hydrogen bonds are formed between [GeMo 12 O 40 ] 4 m anions and coordinated water molecules, coordinating to water molecules. The anti-tumor activity of 1 was estimated against Hela and P c -3m cancer cells.     

Three-dimensional architectures based on lanthanide-substituted double-Keggin-type polyoxometalates and lanthanide cations or lanthanide-organic complexes

A family of three-dimensional (3D) architectures based on lanthanide-substituted polyoxometaloborate building blocks, [LnK(H(2)O)(12)][Ln(H(2)O)(6)](2)[(H(2)O)(4)LnBW(11)O(39)H](2)·20H(2)O (Ln = Ce 1, Nd 2), H(2)K(2)(H(2)O)(n)[(C(6)NO(2)H(5))Ln(H(2)O)(5)](2)[(H(2)O)(4)LnBW(11)O(39)H](2)·18H(2)O (Ln = Ce n = 8 3, Nd n = 9 4, C(6)NO(2)H(5) = pyridine-4-carboxylic acid), have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric (TG) analysis, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1 and 2 are isostructural, and are built up of lanthanide-substituted double-Keggin-type polyoxoanions [{(H(2)O)(4)Ln(BW(11)O(39)H)}(2)](10-) linked by Ln(3+) cations to form a 3D open framework with one-dimensional (1D) channels. The polyoxoanion [{(H(2)O)(4)Ln(BW(11)O(39)H)}(2)](10-) consists of two α(1)-type mono-Ln-substituted Keggin anions, constituted by two [BW(11)O(39)H](8-) polyoxoanions and two lanthanide cations. When pyridine-4-carboxylic acid ligand was added to the reaction system of 1, 2, compounds 3, 4 were obtained. Isostructural compounds 3 and 4 are constructed from the lanthanide-substituted double-Keggin-type polyoxoanions [{(H(2)O)(4)Ln(BW(11)O(39)H)}(2)](10-) linked by the [Ln(C(6)NO(2)H(5))](3+) bridges to form a 3D channel framework. From the topological point of view, the 3D nets of compounds 1-4 are binodal with three- and six-connected nodes and exhibit a rutile topology. Compounds 1-4 represent the examples of 3D architectures based on lanthanide-substituted polyoxometalates. The magnetic properties of compounds 1-4 have been studied by measuring their magnetic susceptibility in the temperature range 2-300 K.     

Lanthanide-transition-metal carbonyl complexes: new [Co4(CO)11]2- clusters and lanthanide(II) isocarbonyl polymeric arrays

Two types of Ln(II)-Co(4) isocarbonyl polymeric arrays, [(Et(2)O)(3)(-)(x)()(THF)(x)()Ln[Co(4)(CO)(11)]]( infinity ) (1-3; x = 0, 1) and [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4), were prepared and structurally characterized. Transmetalation involving Ln(0) and Hg[Co(CO)(4)](2) in Et(2)O yields [(Et(2)O)(3)Ln[Co(4)(CO)(11)]]( infinity ) (1, Ln = Yb; 2, Ln = Eu). Dissolution of the solvent-separated ion pairs [Ln(THF)(x)()][Co(CO)(4)](2) (Ln = Yb, x = 6; Ln = Eu) in Et(2)O affords [(Et(2)O)(2)(THF)Yb[Co(4)(CO)(11)]]( infinity ) (3) and [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4). In these reactions, oxidation and condensation of the [Co(CO)(4)](-) anions result in formation of the new tetrahedral cluster [Co(4)(CO)(11)](2)(-). The two types of Ln(II)-Co(4) compounds contain different isomers of [Co(4)(CO)(11)](2)(-), and, consequently, the structures of the infinite isocarbonyl networks are distinct. The cluster in [(Et(2)O)(3)(-)(x)()(THF)(x)()Ln[Co(4)(CO)(11)]]( infinity ) (1-3) possesses pseudo C(3)(v)() symmetry (an apical Co, three basal Co atoms; one face-bridging, three edge-bridging, seven terminal carbonyls) and connects to Ln(II) centers through eta(2),micro(4)- and eta(2),micro(3)-carbonyls to generate a 2-D puckered sheet. In contrast, [(THF)(5)Eu[Co(4)(CO)(11)]]( infinity ) (4) incorporates a C(2)(v)() symmetric cluster (two unique Co environments; two face-bridging, one edge-bridging, eight terminal carbonyls), and isocarbonyl linkages (eta(2),micro(4)-carbonyls) to Eu(II) atoms create a 1-D zigzag chain. Complexes 1-4 contain the first reported eta(2),micro(4)-CO bridges between a Ln and a transition-metal carbonyl cluster. Infrared spectroscopic studies revealed that the isocarbonyl associations to Ln(II) persist in solution. The solution structure and dynamic behavior of the [Co(4)(CO)(11)](2)(-) cluster in 1 was investigated by variable-temperature (59)Co and (13)C NMR spectroscopies.     

Two series of novel rare earth complexes with dicyanamide [Ln(dca)2(phen)2(H2O)3][dca].(phen), (Ln = Pr, Gd, and Sm) and [Ln(dca)3(2,2'-bipy)2(H2O)]n, (Ln = Gd, Sm, and La): syntheses, crystal structures, and magnetic properties

Two series of novel complexes, [Ln(dca)(2)(Phen)(2)(H(2)O)(3)](dca).(phen) (Ln = Pr (1), Gd (2), and Sm (3), dca = N(CN)(-), phen = 1,10-phenanthroline) and [Ln(dca)(3)(2,2'-bipy)(2)(H(2)O)](n), (Ln = Gd (4), Sm (5), and La (6), 2,2'-bipy = 2,2'-bipydine), have been synthesized and structurally characterized by X-ray crystallography. The crystal structures of the first series (1-3) are isomorphous and consist of discrete [Ln(dca)(2)(Phen)(2)(H(2)O)(3)]+ cations, dca anions, and lattice phen molecules; whereas the structures of the second series (4-6) are characterized by infinite chains [Ln(dca)(3)(2,2'-bipy)(2)(H(2)O)](n). The Ln(III) atoms in all complexes are nine-coordinated and form a distorted tricapped trigonal prism environment. The three-dimensional frameworks of 1-6 are constructed by intermolecular hydrogen bond interactions. Variable-temperature magnetic susceptibility measurements for complexes 1, 2, 4, and 5 indicate a Curie-Weiss paramagnetic behavior over 5-300 K.     

Lanthanoid-containing open Wells-Dawson silicotungstates: synthesis, crystal structures, and properties

Five novel lanthanoid-containing silicotungstates with polymeric crystal structures [Ln(2)(H(2)O)(7)Si(2)W(18)O(66)](n)(10n-) [Ln = Gd(III) (Gd-1 and Gd-2), Tb(III), Ho(III)] and [Dy(2)(H(2)O)(6.5)(C(2)H(4)O(2))(0.5)Si(2)W(18)O(66)](n)(10n-) were obtained from the one-step reaction of Na(10)[SiW(9)O(34)]·nH(2)O with Ln(NO(3))(3)·nH(2)O in a sodium acetate buffer. The compounds were characterized by single-crystal X-ray diffraction and a wide range of analytical methods, including FT-IR, UV/vis, and photoluminescence spectroscopy as well as electrochemistry and thermogravimetric analysis. This new polyoxotungstate series is the first example of lanthanoids embedded in the open Wells-Dawson silicotungstate anion [α-Si(2)W(18)O(66)](16-). The lanthanoid-containing Wells-Dawson-type polyoxoanions [Ln(2)(H(2)O)(7)Si(2)W(18)O(66)](10-) [Ln = Gd(III) (Gd-1 and Gd-2), Tb(III), Ho(III)] and [Dy(2)(H(2)O)(6.5)(C(2)H(4)O(2))(0.5)Si(2)W(18)O(66)](10-) are linked by Ln(3+) cations to form 3D architectures for Gd-1 or 2D frameworks for the isostructural compounds Tb-2, Dy-2, Ho-2, and Gd-2. The structure-directing influence of the lanthanoid cation on the local structure of the dimeric building blocks and on the crystal packing motifs is investigated in detail. The photoluminescence properties of Tb-2 and Dy-2 were investigated at room temperature, and Ho-2 exhibits an interesting photochromic behavior. The magnetic susceptibility of Gd-1 and Gd-2 was studied in the temperature range between 2 and 300 K for its effective magnetic moment.     

Synthesis, crystal structure of α-Keggin heteropolymolybdates with pyridine-2,6-dicarboxylate based frameworks, and associated RhB photocatalytic degradation and 2D-IR COS tests

Three α-Keggin heteropolymolybdates with the formula [(C(5)H(4)NH)COOH](3)[PMo(12)O(40)] 1, {[Sm(H(2)O)(4)(pdc)](3)}{[Sm(H(2)O)(3)(pdc)]}[SiMo(12)O(40)]·3H(2)O 2 and {[La(H(2)O)(4)(pdc)](4)}[PMo(12)O(40)]F 3 (H(2)pdc = pyridine-2,6-dicarboxylate), have been synthesized under hydrothermal condition and characterized by single crystal X-ray diffraction analyses, elemental analyses, inductively coupled plasma atomic emission spectroscopy (ICP-AES), IR, thermal gravimetric analyses, thermal infrared spectrum analyses and powder X-ray diffraction (PXRD) analyses. Single crystal X-ray diffraction indicates all three compounds comprise ball-shaped Keggin type [XMo(12)O(40)](n-) polyoxometalates (POMs) (n = 3, X = P; n = 4, X = Si, respectively) with different types of carboxylic ligands derived from H(2)pdc, and these cluster anions are isostructural. In order to explore structural characteristics, Rhodamine B photocatalytic (RhB) degradation and two-dimensional infrared correlation spectroscopy (2D-IR COS) tests, are investigated for 1, 2 and 3. In RhB degradation, all compounds show good photocatalytic activity. For 1, the activity mainly comes from POMs. While in 2 and 3, POMs' photocatalytic activity is enhanced by the Ln(iii)-pdc metal-organic frameworks. Structural properties like POM's stability and magnetic sensitivity are discussed by 2D-IR COS under thermal/magnetic perturbations.     

Structures and properties of porous coordination polymers based on lanthanide carboxylate building units

A series of 3-D lanthanide porous coordination polymers, [Ln(6)(BDC)(9)(DMF)(6)(H(2)O)(3)·3DMF](n) [Ln = La, 1; Ce, 2; Nd, 3], [Ln(2)(BDC)(3)(DMF)(2)(H(2)O)(2)](n) [Ln = Y, 4; Dy, 5; Eu, 6], [Ln(2)(ADB)(3)(DMSO)(4)·6DMSO·8H(2)O](n) [Ln = Ce, 7; Sm, 8; Eu, 9; Gd, 10], {[Ce(3)(ADB)(3)(HADB)(3)]·30DMSO·29H(2)O}(n) (11), and [Ce(2)(ADB)(3)(H(2)O)(3)](n) (12) (H(2)BDC = benzene-1,4-dicarboxylic acid and H(2)ADB = 4,4'-azodibenzoic acid), have been synthesized and characterized. In 1-3, the adjacent Ln(III) ions are intraconnected to form 1-D metal-carboxylate oxygen chain-shaped building units, [Ln(4)(CO(2))(12)](n), that constructed a 3-D framework with 4 × 7 ? rhombic channels. In 4-6, the dimeric Ln(III) ions are interlinked to yield scaffolds with 3-D interconnecting tunnels. Compounds 7-10 are all 3-D interpenetrating structures with the CaB6-type topology structure. Compound 11 is constructed by ADB spacers and trinulcear Ce nodes with a NaCl-type topology structure and a 1.9-nm open channel system. In 12, the adjacent Ce(III) ions are intraconnected to form 1-D metal-carboxylate oxygen chain-shaped building units, [Ln(4)(CO(2))(12)](n), and give rise to a 3-D framework. Moreover, 6 exhibits characteristic red luminescence properties of Eu(III) complexes. The magnetic susceptibilities, over a temperature range of 1.8-300 K, of 3, 6, and 7 have also been investigated; the results show paramagnetic properties.     

Syntheses, structures, and magnetic properties of mixed-valent diruthenium(II,III) diphosphonates with discrete and one-dimensional structures

Four mixed-valent ruthenium diphosphonates, namely, Na(4)[Ru(2)(hedp)(2)X]x16H(2)O [X = Cl (1), Br (2)], K(3)[Ru(2)(hedp)(2)(H(2)O)(2)]x6H(2)O (3), and Na(7)[Ru(2)(hedp)(2)Fe(CN)(6)]x24H(2)O (4), where hedp represents 1-hydroxyethylidenediphosphonate [CH(3)C(OH)(PO(3))(2)](4-), were synthesized and structurally characterized. Compounds 1, 2, and 4 show linear chain structures in which the mixed-valent [Ru(2)(hedp)(2)](3-) dimers are linked by X(-) or [Fe(CN)(6)](4-) bridges. Compound 3 contains discrete species of [Ru(2)(hedp)(2)(H(2)O)(2)](3-) where the axial positions of [Ru(2)(hedp)(2)](3-) paddlewheel are terminated by water molecules. Magnetic studies show that significant antiferromagnetic exchanges are mediated between the [Ru(2)(hedp)(2)](3-) (S = 3/2) units through halide bridges in compounds 1 and 2.     

Cobalt-lanthanide coordination polymers constructed with metalloligands: a ferromagnetic coupled quasi-1D Dy3+ chain showing slow relaxation

Four types of cobalt-lanthanide heterometallic compounds based on metalloligand Co(2,5-pydc)(3) (3-) (2,5-H(2)pydc=pyridine-2,5-dicarboxylate acid), [Ln(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n) 2n H(2)O (1) (Ln=Tb, Dy for 1 a, 1 b respectively), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(4)](n)3n H(2)O (2), [Tb(2)Co(2)(2,5-pydc)(6)(H(2)O)(9)](n)4n H(2)O (3), and [LaCo(2,5-pydc)(3)(H(2)O)(2)](n)2n H(2)O (4) have been synthesized. Compound 1 has a layer structure with well-isolated carboxylate-bridged Ln(3+) chains, compound 2 is a three-dimensional (3D) porous network with Tb(3+) chains that are also well isolated and carboxylate bridged, 3 is a layer structure based on dinuclear units, and 4 is a 3D network with boron nitride (BN) topology. DC magnetic studies reveal ferromagnetic coupling in all the carboxylate-bridged Ln(3+) chains in 1 a, 1 b, and 2. Compared to the silence of the out-of-phase ac susceptibility of 2, above 1.9 K the magnetic relaxation behavior of both 1 a and 1 b is slow like that of a single-chain magnet.     

Magnetic ordering in the rare earth molecule-based magnets,Ln(TCNE)(3) (Ln = Gd,Dy; TCNE = tetracyanoethylene)

The reaction of LnI(3) x xMeCN (Ln = Gd, Dy) and TCNE (tetracyanoethylene) in acetonitrile forms Ln(2)[C(4)(CN)(8)](3) x xMeCN. These paramagnetic light-colored solids contain the S = 0 octacyanobutandiide dianion, [C(4)(CN)(8)](2-), which upon desolvation of these products forms dark green Ln(TCNE)(3). In these compounds the central C[bond]C sigma bond in [C(4)(CN)(8)](2-) is broken, re-forming S = 1/2 [TCNE]*(-). as evidenced by the color change and the infrared spectra. Ln(TCNE)(3) exhibit coupling between Ln(3+) and [TCNE]*(-) and magnetically order as ferrimagnets at 8.5 (Dy) and 3.5 (Gd) K.     

Lanthanide coordination with alpha-amino acids under near physiological pH conditions: polymetallic complexes containing the cubane-like [Ln4(mu3-OH)4]8+ cluster core

Tetranuclear lanthanide-hydroxo complexes of the general formula [Ln(4)(mu(3)-OH)(4)(AA)(x)(H(2)O)(y)](8+) (1, Ln = Sm, AA = Gly, x = 5, y = 11; 2, Ln = Nd, AA = Ala, x = 6, y = 10; 3, Ln = Er, AA = Val, x = 5, y = 10) have been prepared by alpha-amino acid controlled hydrolysis of lanthanide ions under near physiological pH conditions (pH 6-7). The core component of these compounds is a cationic cluster [Ln(4)(mu(3)-OH)(4)](8+) whose constituent lanthanide ions and triply bridging hydroxo groups occupy the alternate vertexes of a distorted cube. The amino acid ligands coordinate the lanthanide ions via bridging carboxylate groups. Utilizing L-glutamic acid as the supporting ligand, a cationic cluster complex (4) formulated as [Er(4)(mu(3)-OH)(4)(Glu)(3)(H(2)O)(8)](5+) has been obtained. Its extended solid-state structure is composed of the cubane-like [Er(4)(mu(3)-OH)(4)](8+) cluster building units interlinked by the carboxylate groups of the glutamate ligands. All compounds are characterized by using a combination of spectroscopic techniques and microanalysis (CHN and metal). Infrared spectra of the complexes suggest the coordinated amino acids to be zwitterionic. The presence of mass (MALDI-TOF) envelopes corresponding to the [Ln(4)(mu(3)-OH)(4)](8+) (Ln = trivalent Sm, Nd, or Er) core containing fragments manifests the integrity of the cubane-like cluster unit. Magnetic studies using Evans' method suggest that exchange interactions between the lanthanide ions are insignificant at ambient temperature. The structural identities of all four compounds have been established crystallographically. The tetranuclear cluster core has been demonstrated to be a common structural motif in these complexes. A mechanism responsible for its self-assembly is postulated.     

Diversity of lanthanide(III)-organic extended frameworks with a 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid ligand: syntheses, structures, and magnetic and luminescent properties

A sulfonate-carboxylate ligand, 4,8-disulfonyl-2,6-naphthalenedicarboxylic acid (H(4)-DSNDA), and eight new lanthanide coordination polymers {[Pr(4)(OH)(4)(DSNDA)(2)(H(2)O)(12)](H(2)O)(10)}(n) (1), [Ln(H(2)-DSNDA)(0.5)(DSNDA)(0.5)(H(2)O)(5)](n) (Ln = La(2), Nd(3), Sm(4), Eu(5), Gd(6), and Dy(7)), and {[Er(H-DSNDA)(H(2)O)(4)](H(2)O)}(n) (8) have been synthesized. Detailed crystal structures of these compounds have been investigated. Compound 1 has a 3D framework featuring the unique cubane-shaped [Pr(4)(μ(3)-OH)(4)] clusters and is a binodal 4,8-connected network with (4(16)·6(12))(4(4)·6(2))(2) topology. Compounds 2-7 are isostructural and have 2D layered structures. Compound 8 is also a 2D layer but belongs to different structural types. The luminescence behavior of compound Eu(5) shows that the π-rich aromatic organic ligands efficiently transfer the absorbed light energy to the Eu(III) ions, thus enhancing the overall luminescent properties of compound Eu(5). The magnetic properties of all compounds except for the diamagnetic La(2) compound have been investigated. In addition, elemental analysis, IR spectra, and thermogravimetric analysis of these compounds are also described.     

Diversity of lanthanide(iii)-2,5-dihydroxy-1,4-benzenedicarboxylate extended frameworks: syntheses, structures, and magnetic properties

Six lanthanide(iii)-2,5-dihydroxy-1,4-benzenedicarboxylate frameworks, namely, [Ln(H(2)-DHBDC)(1.5)(H(2)O)(2)](n) (Ln = La (1) and Pr (2); H(4)-DHBDC = 2,5-dihydroxy-1,4-benzenedicarboxylic acid), {[Nd(H(2)-DHBDC)(1.5)(H(2)O)(3)](H(2)O)}(n) (3), {[Eu(H(2)-DHBDC)(NO(3))(H(2)O)(4)](H(2)O)(2)}(n) (4), and {[Ln(2)(H(2)-DHBDC)(2)(DHBDC)(0.5)(H(2)O)(3)](H(2)O)(4)}(n) (Ln = Gd (5) and Dy (6)), with four different structural types ranging from 1D chain, 2D layer to 3D networks have been synthesized and structurally characterized. Compounds La (1) and Pr (2) are isomorphous and exhibit 3D frameworks with the unique 1D tubular channels. Compounds Nd (3) and Eu (4) are 2D layer and 1D zigzag chain, respectively, which are further extended to 3D supramolecular frameworks through extensive hydrogen bonds. Isomorphous compounds of Gd (5) and Dy (6) are 3D frameworks constructed from secondary infinite rod-shaped metal-carboxylate/hydroxyl building blocks. While the hydroxyl groups as secondary functional groups in the 1D chain of Eu (4) and 2D layer of Nd (3) are not bonded to the lanthanide centers, the hydroxyl groups in the 3D frameworks of La (1), Pr (2), Gd (5), and Dy (6) participate in coordinating to lanthanide centers and thus modify the structural types of theses compounds. The magnetic data of compounds Pr (2), Nd (3), Gd (5), and Dy (6) have been investigated in detail. In addition, elemental analysis, IR spectra, powder X-ray diffraction (PXRD) patterns and thermogravimetric analysis of these compounds are described.     

Cationic assembly of metal complex aggregates: structural diversity,solution stability,and magnetic properties

The tetradentate imino-carboxylate ligand [L](2)(-) chelates the equatorial sites of Ni(II) to give the complex [Ni(L)(MeOH)(2)] in which a Ni(II) center is bound in an octahedral coordination environment with MeOH ligands occupying the axial sites. Lanthanide (Ln) and Group II metal ions (M) template the aggregation of six [Ni(L)] fragments into the octahedral cage aggregates (M[Ni(L)](6))(x)(+) (1: M = Sr(II); x = 2,2: M = Ba(II); x = 2, 3: M = La(III); x = 3, 4: M = Ce(III); x = 3, 5: M = Pr(III); x = 3, and 6: M = Nd(III); x = 3). In the presence of Group I cations, however, aggregates composed of the alkali metal-oxide cations template various cage compounds. Thus, Na(+) forms the trigonal bipyramidal [Na(5)O](3+) core within a tricapped trigonal prismatic [Ni(L)](9) aggregate to give ((Na(5)O) subset [Ni(L)](9)(MeOH)(3))(BF(4))(2).OH.CH(3)OH, 7. Li(+) and Na(+) together form a mixed Li(+)/Na(+) core comprising distorted trigonal bipyramidal [Na(3)Li(2)O](3+) within an approximately anti-square prismatic [Ni(L)](8) cage in ((Na(3)Li(2)O) subset [Ni(L)](8)(CH(3)OH)(1.3)(BF(4))(0.7))(BF(4))(2.3).(CH(3)OH)(2.75).(C(4)H(10)O)(0.5), 8, while in the presence of Li(+), a tetrahedral [Li(4)O](2+) core within a hexanuclear open cage [Ni(L)](6) in ((Li(4)O) subset [Ni(L)](6)(CH(3)OH)(3))2ClO(4).1.85CH(3)OH, 9, is produced. In the presence of H(2)O, the Cs(+) cation induces the aggregation of the [Ni(L)(H(2)O)(2)] monomer to give the cluster Cs(2)[Ni(L)(H(2)O)(2)](6).2I.4CH(3)OH.5.25H(2)O, 10. Analysis by electronic spectroscopy and mass spectrometry indicates that in solution the trend in stability follows the order 1-6 > 7 > 8 approximately 9. Magnetic susceptibility data indicate that there is net antiferromagnetic exchange between magnetic centers within the cages.     

Synthesis, characterization, and photoresponsive properties of a series of Mo(IV)-Cu(II) complexes

Six Mo(IV)-Cu(II) complexes, [Cu(tpa)](2)[Mo(CN)(8)]·15H(2)O (1, tpa = tris(2-pyridylmethyl)amine), [Cu(tren)](2)[Mo(CN)(8)]·5.25H(2)O (2, tren = tris(2-aminoethyl)amine), [Cu(en)(2)][Cu(0.5)(en)][Cu(0.5)(en)(H(2)O)][Mo(CN)(8)]·4H(2)O (3, en = ethylenediamine), [Cu(bapa)](3)[Mo(CN)(8)](1.5)·12.5H(2)O (4, bapa = bis(3-aminopropyl)amine), [Cu(bapen)](2)[Mo(CN)(8)]·4H(2)O (5, bapen = N,N'-bis(3-aminopropyl)ethylenediamine), and [Cu(pn)(2)][Cu(pn)][Mo(CN)(8)]·3.5H(2)O (6, pn = 1,3-diaminopropane), were synthesized and characterized. Single-crystal X-ray diffraction analyses show that 1-6 have different structures varying from trinuclear clusters (1-2), a one-dimensional belt (3), two-dimensional grids (4-5), to a three-dimensional structure (6). Magnetic and ESR measurements suggest that 1-6 exhibit thermally reversible photoresponsive properties on UV light irradiation through a Mo(IV)-to-Cu(II) charge transfer mechanism. A trinuclear compound [Cu(II)(tpa)](2)[Mo(V)(CN)(8)](ClO(4)) (7) was synthesized as a model of the photoinduced intermediate.     

A series of three-dimensional architectures constructed from lanthanide-substituted polyoxometalosilicates and lanthanide cations or lanthanide-organic complexes as linkers

Six 3D architectures based on lanthanide-substituted polyoxometalosilicates, KLn[(H(2)O)(6)Ln](2)[(H(2)O)(4)LnSiW(11)O(39)](2)·nH(2)O (Ln = La 1, n = 42; Ce 2, n = 40), H[(H(2)O)(6)Nd](2)[(H(2)O)(7)Nd][(H(2)O)(4)NdSiW(11)O(39)][(H(2)O)(3)NdSiW(11)O(39)]·13H(2)O (3), H(2)K(2)[(Hpic)(H(2)O)(5)Ln](2)[(H(2)O)(4)LnSiW(11)O(39)](2)·nH(2)O (Ln = La 4, n = 18.5; Ce 5, n = 35; Nd 6, n = 36; Hpic = 4-picolinic acid), have been synthesized and characterized by elemental analysis, IR and UV-vis spectroscopy, TG analysis, powder X-ray diffraction and single crystal X-ray diffraction. Compounds 1 and 2 are isostructural, built up of lanthanide-substituted polyoxoanions [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) linked by Ln(3+) cations to form a 3D open framework with 1D channels. The polyoxoanion [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) consists of two α(1)-type mono-Ln-substituted Keggin anions. When Nd(3+) ion was used instead of La(3+) or Ce(3+) ions, compound 3 with a different structure was obtained, containing two kinds of polyoxoanions [{(H(2)O)(4)Nd(SiW(11)O(39))}(2)](10-) and [{(H(2)O)(3)Nd(SiW(11)O(39))}(2)](10-) which are connected together by Nd(3+) ions to yield a 3D framework. When 4-picolinic acid was added to the reaction system of 1-3, isostructural compounds 4-6 were obtained, constructed from the polyoxoanions [{(H(2)O)(4)Ln(SiW(11)O(39))}(2)](10-) linked by picolinate-chelated lanthanide centers to form a 3D channel framework. From a topological viewpoint, the 3D nets of 1, 2, 4, 5 and 6 exhibit a (3,6)-connected rutile topology, whereas the 3D structure of 3 possesses a rare (3,3,6,10)-connected topology. The magnetic properties of 2, 3, 5 and 6 have been studied by measuring their magnetic susceptibilities in the temperature range 2-300 K.     

Complex formation of vanadium(IV) with 1,3,5-triamino-1,3,5-trideoxy-cis-inositol and related ligands

The complex formation of vanadium(IV) with 1,3,5-triamino-1,3,5-trideoxy-cis-inositol (taci) and 1,3,5-trideoxy-1,3,5-tris(dimethylamino)-cis-inositol (tdci) was studied in aqueous solution and in the solid state. The formation constants of [V(IV)O(taci)](2+), [V(IV)O(tdci)](2+), and [V(IV)(tdci)(2)](4+) and of the deprotonation product [V(IV)(tdci)(2)H(-)(1)](3+) were determined (25 degrees C, 0.1 M KNO(3)). Cyclic voltammetry measurements established a reversible one-electron transfer for the [V(IV)(tdci)(2)H(-)(m)]((4)(-)(m))/[V(III)(tdci)(2)H(-)(n)]((3)(-)(n)) couple (0 相似文献   

Modified polyoxometalates: Hydrothermal syntheses and crystal structures of three novel reduced and capped Keggin derivatives decorated by transition metal complexes

Three novel polyoxometalate derivatives decorated by transition metal complexes have been hydrothermally synthesized. Compound 1 consists of [PMo(VI)(6)Mo(V)(2)V(IV)(8)O(44)[Co (2,2'-bipy)(2)(H(2)O)](4)](3+) polyoxocations and [PMo(VI)(4-)Mo(V)(4)V(IV)(8)O(44)[Co(2,2'-bipy)(2)(H(2)O)](2)](3-) polyoxoanions, which are both built on mixed-metal tetracapped [PMo(8)V(8)O(44)] subunits covalently bonded to four or two [Co(2,2'-bpy)(2)(H(2)O)](2+) clusters via terminal oxo groups of the capping V atoms. Compound 2 is built on [PMo(VI)(8)V(IV)(6)O(42)[Cu(I)(phen)](2)](5-) clusters constructed from mixed-metal bicapped [PMo(VI)(8)V(IV)(6)O(42)](7-) subunits covalently bonded to two [Cu(phen)](+) fragments in the similar way to 1. The structure of 3 is composed of [PMo(VI)(9)Mo(V)(3)O(40)](6-) units capped by two divalent Ni atoms via four bridging oxo groups. The crystal data for these are the following: C(120)H(126)Co(6)Mo(16)N(24)O(103)P(2)V(16) (1), triclinic P1, a = 15.6727(2) A, b = 17.3155(3) A, c = 19.5445(2) A, alpha = 86.1520(1) degrees, beta = 81.2010(1) degrees, gamma = 63.5970(1) degrees, Z = 1; C(120)H(85)Cu(6-)Mo(8)N(20)O(44)PV(6) (2), triclinic P1, a = 14.565(4) A, b = 15.899(3) A, c = 16.246(4) A, alpha = 116.289(2) degrees, beta = 103.084(2) degrees, gamma = 94.796(2) degrees, Z = 1; C(60)H(40)Mo(12)N(10)Ni(3)O(40)P (3), monoclinic P2(1)/c, a = 14.804(3) A, b = 22.137(4) A, c = 25.162(5) A, alpha = 90 degrees, beta = 98.59(3) degrees, gamma = 90 degrees, Z = 4.