A series of 3d-4f heterometallic three-dimensional coordination polymers: syntheses, structures and magnetic properties

Seven lanthanide-cobalt heterometallic three-dimensional coordination polymers: {[Ln(3)Co(2)(BPDC)(5)(HBPDC)(H(2)O)(5)](ClO(4))(2)·mH(2)O}(n) (Ln = Eu (1, m = 10.25), Gd (2, m = 8), Tb (3, m = 9.5), Dy (4, m = 11), Ho (5, m = 10.5), Tm (6, m = 11), Lu (7, m = 10.25); BPDC = 5,5'-dicarboxylate-2,2'-dipyridine anion) were structurally and magnetically characterized. Compounds 1-7 crystallize in the orthorhombic space group Pbca, featuring a 3D sandwich framework. Magnetic properties of 2-6 have been investigated by using DC (direct current) and AC (alternating current) susceptibility measurements. Among these compounds, only compound 4 displays significant frequency dependence, albeit without reaching the characteristic maxima above 2 K, implying slow magnetic relaxation behavior in 4. After the application of a DC field, good peak shapes of AC signals were obtained and the energy barrier ΔE/k(B) = 62.89 K and the preexponential factor τ(0) = 6.16 × 10(-8) s. To our knowledge, 4 has the highest energy barrier in Ln-Co SMM systems hitherto.     

Three-dimensional 3d-4f heterometallic coordination polymers: synthesis, structures, and magnetic properties

Three new 3d-4f heterometallic coordination polymers, [Ln(2)(H(2)O)(4)M(2)(H(2)O)(2)(QA)(5)].nH(2)O (H(2)QA = quinolinic acid; Ln = Gd, M = Ni, n = 7 (1); Ln = Gd, M = Co, n = 6.5 (2); Ln = Dy, M = Co, n = 6.5 (3)), have been synthesized through hydrothermal pretreatment and cooling-down crystallization. These compounds possess the isostructural 3D frameworks with 1D chairlike channels along the c axis, which are occupied by noncoordinating water molecules. Crystal data: for 1, C(35)H(41)Gd(2)Ni(2)N(5)O(33), orthorhombic, space group Pna2(1), with a = 28.567(6) A, b = 14.498(3) A, c = 12.250(2) A, and Z = 4; for 2, C(35)H(40)Gd(2)Co(2)N(5)O(32.5), orthorhombic, space group Pna2(1), with a = 28.843(3) A, b = 14.4325(13) A, c = 12.2275(9) A, and Z = 4; for 3, C(35)H(40)Dy(2)Co(2)N(5)O(32.5), orthorhombic, space group Pna2(1), with a = 28.8471(14) A, b = 14.4534(10) A, c = 12.2520(7) A, and Z = 4. The magnetic behaviors for the three compounds have been investigated.     

Three-dimensional 3d-4f polymers containing heterometallic rings: syntheses, structures, and magnetic properties

Two novel three-dimensional (3D) 3d-4f mixed complexes [Ln(H(2)O)(4)][Ni(2)TTHA(SCN)(2)].H(3)O+ [Ln = Pr (1), Ce (2); H(6)TTHA = triethylenetetraaminehexaacetic acid], based on the building blocks of [Ni(2)TTHA(SCN)(2)](4-), were synthesized and characterized by X-ray crystal diffraction and magnetic properties. The single-crystal structures show that these complexes form a 3D framework, comprised of an unusual infinite one-dimensional chain based on heterometallic Ln2Ni2 rings. The temperature-dependent magnetic susceptibilities were analyzed by an approximate model, leading to g = 2.06. Delta = 2.83, zJ' = -0.6 cm-1 for complex 1 and g = 2.07, Delta = 1.00, zJ' = -0.5 cm(-1) for complex 2.     

Synthesis, crystal structure, and magnetic properties of two 3d-4f heterometallic coordination polymers

Two new 4f-3d heterometallic coordination polymers, [Gd₂^IIICo^II(pydc)₃(ox)(H₂O)₄)·2H₂O] (1) and [Dy^IIICu^II(pydc)₂(ox)_1/2(H₂O)₂·H₂O] (2) (pydc = pyridine-2,5-dicarboxylate anion, ox = oxalate dianion) were successfully synthesized under hydrothermal condition. Structure and magnetism of the two coordination polymers were characterized by single crystal X-ray diffraction and Quantum Design (MPMS) SQUID magnetometer. In both compounds, metal centers were connected by double ligand bridges. In 1 the gadolinium ions were linked in sheets by OCO ligand bridges and these sheets were connected by separated cobalt coordination spheres to generate the overall 2-D structure. In 2 the dysprosium centers were constructed into one dimensional chain by OCO bridges from pydc ligand bridges and these chains were linked by oxalate bridges to form sheets and different sheets were connected by copper coordination planes. The copper centers in 2 were linked in chain by elongated OCO brides and the chains were connected by hydrogen bond to generate 3-D structure. Magnetic properties of the two complexes were investigated by variable temperature magnetic susceptibility. The magnetic data suggest that overall antiferromagnetic interactions are present in the two compounds.     

Self-assembly of silver polymers based on flexible isonicotinate ligand at different pH values: syntheses, structures and photoluminescent properties

Two interesting coordination polymers, [Ag₈(IN)₆(NO₃)₂] 1 and [Ag(IN)(HIN)]_1/2 [Ag(IN)] 2 (HIN=isonicotinic acid) have been synthesized hydrothermally at different pH values. 1 crystallizes in the triclinic space group P-1, with , , , α=75.87(3)°, β=80.87(3)°, γ=76.50(3)°, and Z=2. Compound 1 is the first example of a bilayer framework, in which both single layers are connected by the bond interactions (Ag-O) between Ag from two two-dimensional (2D) single layers generated by the A building block and O atoms from one-dimensional (1D) chain constructed by the B building block, in which coordination modes of IN were reported for the first time. 2 crystallizes in the monoclinic space group P2(1)/c, with , , , β=92.90(3)°, V=1185.0(4) and Z=4. Compound 2 exhibits a 2D plywood-like structure assembled by hydrogen bonds and weak Ag-O interactions.     

Novel heterometallic 3d-4f metal-azido complex of mixed ligands with unprecedented structure type: synthesis, structure, and magnetic properties

A novel heterometallic 3d-4f metal-azido complex of mixed ligands, showing unprecedented structure type and interesting magnetic properties, has been hydrothermally synthesized and characterized.     

Construction of 1-D 4f and 3d-4f coordination polymers with flexible Schiff base ligands

Three new lanthanide 1-D coordination polymers ({[Ln(2)(H(2)L)(OAc)(6)]·EtOH·2H(2)O}(n) (Ln = Eu (1), Er (2)) and {YbNiLCl(OAc)(2)(H(2)O)}(n) (3)) and a heterobinuclear complex [YbNiLCl(3)(H(2)O)(3)] (4) are reported which are formed from salen type Schiff-base ligands H(2)L (H(2)L = N,N'-bis(3-methoxysalicylidene)butane-1,4-diamine). The polymeric structures are formed by bridging H(2)L units in the case of 1 and 2, and by acetate groups in 3. The structures of 1-4 were determined by single crystal X-ray crystallographic studies and their luminescence properties in MeCN solution were determined.     

A series of three-dimensional 3d–4f heterometallic coordination frameworks based on pyridinedicarboxylic acid

Four new 3d–4f heterometallic coordination polymers [Cu₃Eu₂(2,5-pydc)₆(H₂O)₁₂]·4(H₂O) (1), [Zn₂Eu₂(2,5-pydc)₅(H₂O)₂]·3(H₂O) (2), and [Co₃Ln₂(2,6-pydc)₆(H₂O)₆]·4(H₂O) (Ln = Eu, 3; Dy, 4) (H₂pydc = pyridinedicarboxylic acid) have been synthesized and characterized. All of these compounds have extended 3D coordination frameworks containing supramolecular 1D channels, in which lattice water molecules are located. Hydrogen bonds stabilize the 3D frameworks. Additionally, a study of their fluorescence properties has indicated that compounds 1 and 2 show the characteristic transitions of Eu³⁺. Weak antiferromagnetic interactions are observed in compound 3.     

Two coordination polymers based on mixed 1,4-bis(benzimidazo-1-yl)benzene and O-donor linker ligands: syntheses,crystal structures and properties

Transition Metal Chemistry - Two coordination polymers based on 1,4-bis(benzimidazo-1-ly)benzene (L) and O-donor linking co-ligands, namely {[ZnL(mipa)(H2O)]}n (1) and {[Cd2L2(sdba)Cl2]}n (2)...     

Hydrothermal syntheses,structural characterization,and photoluminescent properties of five lanthanide coordination polymers

Five mixed-ligand coordination polymers, [Ln₂(PTCP)₂(m-BDC)₃] _n ?·?nH₂O (Ln?=?Pr (1), Sm (2), Eu (3), Tb (4), Dy (5); m-BDC?=?1,3-benzenedicarboxylate; PTCP?=?2-phenyl-1H-1,3,7,8-tetraazacyclopenta[l]phenanthrene), were synthesized and characterized by IR spectra, elemental analyses, thermogravimetric analyses, single-crystal X-ray diffraction, and solid-state photoluminescent spectra. X-ray crystallographic analyses reveal that the five complexes are 1-D structures based on dinuclear [Ln₂O₁₂N₄] units and further assembled into 3-D supramolecular networks by hydrogen bonds and π···π stacking interactions. The solids possess high thermal stabilities, with 3 and 4 exhibiting strong pure red and green characteristic emissions of Eu(III) and Tb(III) at room temperature.     

Syntheses and structures of 3d–4d heterometallic coordination polymers based on 4-amino-1,2,4-triazole

Three heterometallic coordination polymers based on 4-amino-1,2,4-triazole (atrz), Cd_2.98Fe_2.02(atrz)₆(SCN)₁₀·2H₂O (1), Cd_2.86Co_2.14(atrz)₆(SCN)₁₀·2H₂O (2), and Cd_2.02Ni_2.98(atrz)₆(SCN)₁₀·2H₂O (3), were synthesized. Crystal structures of the polymers were determined by single-crystal X-ray diffraction, X-ray powder diffraction, and infrared analysis. The complexes exhibit a 3-D structure and are isostructural, but entail different durations for transformation from a 1-D polymer to a 3-D structure. The results of vibrating sample magnetometry for 1 indicate that the complex exhibits weak paramagnetism.     

Synthesis and structural characterization of a novel two-dimensional 3d-4f heterometallic coordination framework based on pentanuclear lanthanide cluster

A novel 3d-4f heterometallic coordination polymer, {[Tm₅(μ₃-OH)₂(BDC)₆(IN)₂Cu(H₂O)₂]·(H₂O)₃}_n (1) [BDC = benzene-1,2-dicarboxylate, IN = isonicotinate], has been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction, FTIR, elemental analysis, powder X-ray diffraction and thermogravimetric analysis. The compound crystallizes in monoclinic system, space group P2₁/c (No. 14), a = 13.7302(5) Å, b = 23.5428(3) Å, c = 21.5789(2) Å, β = 91.491(3)°, V = 6973.0(3) ų, and Z = 4. The structure exhibits unusual two-dimensional Tm-carboxylate layer, which is constructed from the expansion of novel pentanuclear {Tm₅} clusters. More interestingly, the heterometallic Cu(I) ions were successfully planted into such Ln-carboxylate layer by the bifunctional IN bridging ligands, resulting in the formation of an unprecedented 2D heterometallic lanthanide-transition-metal framework.     

Stepwise assembly of two 3d-4d heterometallic coordination polymers based on a hexanuclear silver(I) metalloligand

Two novel 3d-4d heterometallic coordination polymers {[Cu(3)(bipy)(3)(H(2)O)(5)][Ag(6)(mna)(6)]·11.5H(2)O}(n) (1) and {[Zn(3)(eda)(3)(H(2)O)(4)][Ag(6)(mna)(6)]·8H(2)O}(n) (2) were synthesized based on a hexanuclear silver(I) metalloligand by a three-step synthetic method (bipy = 2, 2'-bipyridine, eda = ethylenediamine and H(2)mna = 2-mercaptonicotinic acid). The photoluminescence behaviors of 1 and 2 were also discussed.     

A series of heterometallic 3d-4f polyoxometalates as single-molecule magnets

Three sandwich-like [Ln₂Fe₂(B-α-FeW₉O₃₄)₂]^10? clusters (Ln₂Fe₄, Ln = Dy (1), Ho (2), and Y (3)) were obtained by reacting Na₉[B-α-SbW₉O₃₃], Ln₂O₃, FeCl₃·6H₂O and KH₂PO₄. The [B-α-FeW₉O₃₄]^11? units were formed via the in situ conversion of lacunary polyoxometalates (POM) [B-α-SbW₉O₃₃]^9? and the Ln³⁺ ions were generated from the slow dissolution of Ln₂O₃, both of which play important roles in the synthesis of Ln₂Fe₄. Ln₂Fe₄ is the first 3d-4f cluster assembled from d-metal heteroatom-containing POM. The Dy₂Fe₄ cluster exhibits single-molecule magnet properties with an 80 K energy barrier in an optimal DC field. Cyclic voltammetry tests and controlled-potential coulometry experiments show that the polyoxometalate Fe heteroatom in clusters 1–3 is also electrochemically active.     

Solvothermal syntheses,crystal structure,and photoluminescent properties of two Cu(I) coordination polymers constructed by bisimidazole ligands

Journal of Structural Chemistry - Two Cu(I) coordination polymers {[Cu2(bibp)2]·bdc·3H2O} n (1) and {[Cu3(bib)3]·btc·5H2O} n (2), where bibp =...     

New heterometallic coordination polymers based on zinc(II) complexes with Schiff-base ligands and dicyanometallates: synthesis,crystal structures,and luminescent properties

Four new d¹⁰ heterometallic coordination polymers have been obtained using three Schiff-base ligands, zinc(II) nitrate, and dicyanometallates: ₁^∞[{Zn₃(Salen)₂}{μ-Au(CN)₂}₂] (1); ₁^∞[Zn(Saldmen){μ-Ag(CN)₂}]·2H₂O (2); ₁^∞[Zn(Salampy){μ-Ag(CN)₂}] (3); ₁^∞[Zn(Salampy){μ-Au(CN)₂}] (4). The Schiff bases are obtained from condensation of salicylaldehyde with ethylenediamine (H₂Salen); N,N-dimethyl-ethylenediamine (HSaldmen) and, respectively, 2-aminomethyl-pyridine (HSalampy). The dicyanometallates are K[Ag(CN)₂] and K[Au(CN)₂]. The compounds were characterized by X-ray single-crystal diffraction, infrared spectroscopy, UV–vis spectroscopy, and elemental analysis. In compound 1, the homotrimetallic units, {Zn₃(salen)₂}²⁺, are connected by two [Au(CN)₂]^? bridges, forming a 1-D double chain. In compounds 2–4, the crystal structures show polymeric zigzag chains generated by the mononuclear zinc(II) nodes and [M(CN)₂]^? spacers. The luminescence properties of the new heterometallic polymers have also been investigated.     

Syntheses,structures, and properties of two- and three-dimensional coordination polymers based on bis(imidazole) and glutarate ligands

Two new coordination polymers, [Zn(bix)_0.5(glu)]_n (1) and {[Co(bix)(glu)]·4H₂O}_n (2), were synthesized (bix = 1,4-bis(2-methylimidazol-1-ylmethyl)benzene, glu = glutarate). In 1, each Zn(II) is connected by four glu ligands and extend to form a [Zn(glu)]_n 2-D network. Adjacent [Zn(glu)]_n 2-D networks are bridged by bix ligands to construct a 6-connected 3-D network based on the Zn₂ unit. 2 shows an undulated 2-D (4,4) network. The interesting structural feature of 2 is that there are 1-D water chains. The O–H···O hydrogen bond interactions link the 2-D coordination networks and construct the 3-D supramolecular architecture in 2. The glu ligands are bis-(bidentate) bridges in 1 and bis-(monodentate) bridges in 2. The luminescence of 1 and thermal stability of 1 and 2 were investigated.     

Tetrazoleacetic acid templated 3d-4f heterometallic-organic frameworks constructed from different ligands: structures,luminescence, magnetism and photocatalytic properties

A series of 3-D lanthanide-transition 3d-4f heterometallic complexes have been synthesized by hydrothermal route from mixtures of 2,2′-bipyridyl-5,5′-dicarboxylic acid (H₂bpdc) and acetic acid (HAc) with tetrazoleacetic acid as template. The single-crystal X-ray analysis shows that nine CdLn(H₂O)₂Cl₂(bpdc)Ac complexes (Ln = La for 1, Pr for 2, Nd for 3, Sm for 4, Eu for 5, Gd for 6, Dy for 7, Ho for 8, Er for 9) crystallized in the space group P-1 and featured three-nodal (3, 4, 6)-three connected topological frameworks. The photocatalytic behaviors imply that 1–9 have significant photocatalytic activities for degradation of RhB.