Lanthanide(III) Nitrate Complexes of Two 17 Membered N3O2-Donor Macrocycles

The interaction of lanthanide(III) ions with two N₃O₃-macrocycles, L¹ and L², derived from 2,6-bis(2-formylphenoxymethyl)pyridine and 1,2-diaminoethane has been investigated. Schiff-base macrocyclic lanthanide(III) complexes LnL¹(NO₃)₃ · xH₂O (Ln = Nd, Sm, Eu or Lu) have been prepared by direct reaction of L¹ and the appropriate hydrated lanthanide nitrate. The direct reaction between the diamine macrocycle L² and the hydrated lanthanide(III) nitrates yields complexes LnL²(NO₃)₃· H₂O only for Ln = Dy or Lu. The reduction of the Schiff-base macrocycle decreases the complexation capacity of the ligand towards the Ln(III) ions. The complexes have been characterised by elemental analysis, molar conductivity data, FAB mass spectrometry, IR and, in the case of the lutetium complexes, ¹H NMR spectroscopy.     

Coordination Reaction of Alanine with Neodymium(III) and Erbium(III) Nitrate. Thermochemical study

The solid-state coordination reaction: Nd(NO₃)₃·6H₂O(s)+4Ala(s) → Nd(Ala)₄(NO₃)₃·H₂O(s)+5H₂O(_l) and Er(NO₃)₃·6H₂O(s)+4Ala(s) → Er(Ala)₄(NO₃)₃·H₂O(s)+5H₂O(l) have been studied by classical solution calorimetry. The molar dissolution enthalpies of the reactants and the products in 2 mol L^–1 HCl solvent of these two solid-solid coordination reactions have been measured using a calorimeter. From the results and other auxiliary quantities, the standard molar formation enthalpies of [Nd(Ala)₄(NO₃)₃·H₂O, s, 298.2 K] and[Er(Ala)₄(NO₃)₃·H₂O, s,298.2 K] at 298.2 K have been determined to be Δ_f H _m ⁰ [Nd(Ala)₄(NO₃)₃·H₂O,s, 298.2 K]=–3867.2 kJ mol^–1, and Δ_f H _m ⁰ [Er(Ala)₄(NO₃)₃·H₂O, s, 298.2 K]=–3821.5 kJ mol^–1. This revised version was published online in August 2006 with corrections to the Cover Date.     

Identification of the Structural Boundary between [Ln(18‐crown‐6)(NO3)3] and [Ln(NO3)3(H2O)3] · 18‐crown‐6 Motifs in the Lanthanide Series

Recrystallization of Ln(NO₃)₃ (Ln = Sm, Eu, Yb) in the presence of 18‐crown‐6 under aqueous conditions yielded [Ln(NO₃)₃(H₂O)₃] · 18‐crown‐6. X‐ray crystallography revealed isomorphous structures for each of the lanthanide complexes where [Ln(NO₃)₃(H₂O)₃] is involved in hydrogen bonding interactions with 18‐crown‐6. The transition point where the structural motif changes from [Ln(18‐crown‐6)(NO₃)₃] (with the metal residing in the crown cavity) to [Ln(NO₃)₃(H₂O)₃] · 18‐crown‐6 has been identified as at the Nd/Sm interface. A similar investigation involving [Ln(tos)₃(H₂O)₆] (tos = p‐toluenesulfonate) and 18‐crown‐6 were resistant to crown incorporation. X‐ray studies show extensive intra‐ and intermolecular hydrogen bonding is present.     

Self-assembly of a Co(II) dimer through H-bonding of water molecules to a 3D open-framework structure

Reaction of pyridine-2,4,6-tricarboxylic acid (ptcH₃) with Co(NO₃)2.6H₂O in presence of 4,4′-bipyridine (4,4′-bpy) in water at room temperature results in the formation of [Co₂(ptcH)₂(4,4′-bpy) (H₂O)4]·2H₂O, (1). The solid-state structure reveals that the compound is a dimeric Co(II) complex assembled to a 3D architecture via an intricate intra- and inter-molecular hydrogen-bonding interactions involving water molecules and carboxylate oxygens of the ligand ptcH^2-. Crystal data: monoclinic, spacegroup P2 ₁/c, a = 11·441(5) ?,b = 20·212(2) ?,c = 7·020(5) ?, Β = 103·77(5)°,V= 1576-7(1) ?³,Z = 2,R1 = 00363,wR2 = 0·0856,S = 1·000.     

Synthesis and characterization of novel heteronuclear complexes of Ln(III)-Cu(II) with non-cyclic polyether Schiff base

Nine novel heteronuclear complexes of Ln(III)-Cu(II) with salicylidene tetraethylene glycol diamine (SALTTA) have been synthesized and characterized. They have the general formulae [L_nC_u2(SALTTA)₂(NO₃)₃](NO₃)₄·3H₂O (Ln=La, Pr, Nd, Sm) and [LnCu₃(SALTTA)₃(NO₃)₅]-(NO₃)₄·4H₂O (Ln=Gd, Tb, Er, Yb, Y). The IR spectra show that v_C=N in the Ln(III)-Cu(II) heteronuclear complexes are splitted up into two peaks with a far distance. It has been confirmed that oxygen atoms in oxyethylene of the ligand are not all coordinated to the central metal ions by both IR and NMR methods.     

Structures and magnetic properties of two series of Schiff base binuclear lanthanide complexes

Until now, although there are many examples of studying the magnetic properties of Schiff base binuclear lanthanide complexes, the relationship between the structure and magnetic properties of the complexes still is worth further investigation in order to improve the magnetic properties of Schiff base lanthanide complexes. In this work, we successfully obtained two series of binuclear Ln complexes by in situ reaction of 4-diethylaminosalicylaldehyde, benzoic hydrazide and different lanthanide salts at 80°C under solvothermal conditions, namely, [Ln₂(L)₃(NO₃)₃]·CH₃CN·CH₃OH·H₂O [Ln = Dy ( 1 ), Ho ( 2 ), Gd ( 3 ) L = deprotonated 4-diethylamino salicylaldehyde benzoylhydrazine], [Ln₂(L)₄(CH₃COO)]CH₃COO·CH₃CN [Ln = Dy ( 4 ), Ho ( 5 ), Gd ( 6 )]. The complex 1 contains three Schiff base ligands L, two Dy (III) ions, and three NO₃⁻. The ligand H₁L is formed by in situ Schiff base reaction with 4-diethylaminosalicylaldehyde and benzoic hydrazide with the participation of Ln (NO₃)₃. When replacing Ln (NO₃)₃ with Ln (OAc)₃, obtained three μ₂-OAc bridged binuclear Ln (III) complexes. The magnetic study showed that complex 4 exhibits field-induced single-molecule magnet (SMM) behavior while complex 1 does not show any SMMs behavior. In addition, we have studied the magnetocaloric effect of complexes 3 and 6 , their maximum −ΔS_m values are 21.37 J kg⁻¹ K⁻¹ and 15.32 J kg⁻¹ K⁻¹, respectively, under ΔH = 7 T and T = 2 K.     

Insights into crystal structures,supramolecular architectures and antioxidant activities of self-assembled fluorescent hetero-multinuclear [Cu (II)-Ln (III)] (Ln = La,Ce, Pr and Nd) salamo-like complexes

Newly designed hetero-dinuclear 3d–4f complex [Cu(L)La (NO₃)₂(μ-NO₃)(H₂O)]·EtOH ( 1 ), hetero-tetranuclear 3d–4f complex [Cu(L)Ce (NO₃)₂(μ-NO₃)(OAc)₂]₂·MeOH ( 2 ) and hetero-multinuclear 3d–4f complexes [{Cu(L)Ln (NO₃)₃}₂][Cu(L)Ln (NO₃)₃]₂ (Ln = Pr ( 3 ) and Nd = ( 4 )) have been self-assembled from the reaction of Cu (OAc)₂·H₂O, Ln (NO₃)₃·6H₂O (Ln = La, Ce, Pr and Nd) with an unsymmetric salamo-like bisoxime ligand H₂L (6-Methoxy-6′-ethoxy-2,2′-[ethylenedioxybis (nitrilomethylidyne)]diphenol) based on a Schiff base condensation of 2-[O-(1-ethoxyamide)]oxime-6-methoxyphenol and 3-ethoxysalicylaldehyde. The structures of complexes 1 – 4 were characterized by elemental analyses, PXRD analyses, IR, UV–Vis spectra, and single-crystal X-ray analyses. In addition, the supramolecular interactions and fluorescence properties of complexes 1 – 4 are discussed in detail. Moreover, the antioxidant activities of the complexes 1 – 4 were determined by superoxide radical-scavenging method in vitro, which indicates that the complexes 1 – 4 all show potential antioxidant properties.     

Hydroxo Bridged Dinuclear Rare Earth Complexes: Syntheses and Crystal Structures of [Ln2(phen)4(H2O)4(OH)2](NO3)4(phen)2 with Ln = Er,Lu

Reactions of phenanthroline (phen) and Er(NO₃)₃ · 5 H₂O or Lu(NO₃)₃ · H₂O in CH₃OH/H₂O yield [Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄(phen)₂ with Ln = Er ( 1 ), Lu ( 2 ). Both isostructural complex compounds crystallize in the triclinic space group P 1 (no. 2) with the cell dimensions: a = 11.257(2) Å, b = 11.467(2) Å, c = 14.069(2) Å, α = 93.93(2)°, β = 98.18(1)°, γ = 108.14(1)°, V = 1696.0(6) ų, Z = 1 for ( 1 ) and a = 11.251(1) Å, b = 11.476(1) Å, c = 14.019(1) Å, α = 93.83(1)°, β = 98.27(1)°, γ = 108.27(1)°, V = 1689.0(3) ų, Z = 1 for ( 2 ). The crystal structures consist of the hydroxo bridged dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cations, hydrogen bonded NO₃^– anions and π‐π stacking (phen)₂ dimers. The rare earth metal atoms are coordinated by four N atoms of two phen ligands and four O atoms of two H₂O molecules and two μ‐OH groups to complete tetragonal antiprisms. Via two common μ‐OH groups, two neighboring tetragonal antiprisms are condensed to a centrosymmetric dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cation. Based on π‐π stacking interactions and hydrogen bonding, the complex cations and (phen)₂ dimers form 2 D layers parallel to (1 0 1), between which the hydrogen bonded NO₃^– anions are sandwiched. The structures can be simplified into a distorted CsCl structure when {[Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄} and (phen)₂ are viewed as building units.     

Nitratkomplexe der Seltenerdelemente mit 2,2′-Bipyridin-N,N′-dioxid

Compounds ScL ₂(NO₃)₃·2 H₂O,LnL ₂(NO₃)₃·H₂O (Ln=Pr, Sm, Eu, Gd, Tb),LnL ₂(NO₃)₃·3 H₂O (Ln=Nd, Dy, Ho, Er),LnL ₃(NO₃)₃ (Ln=Pr, Nd) andLnL ₃(NO₃)₃· ·3 H₂O (Ln=Sc, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) were isolated. They were investigated by means of thermoanalysis, IR spectroscopy, X-ray diffraction and molar conductivity.

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L=2,2-Bipyridin-N,N-dioxid=bpyO₂=C₁₀H₈N₂O₂.     

The syntheses and magnetic properties of a series of heterospin [LnIIICuII 4] pentanuclear complexes

Twelve oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes Ln[Cu(PMoxd)]₄(ClO₄)₃ · 5H₂O (Ln = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Yb, and PMoxd = the N,N′-Bi(α-pyridylmethyl)-oxamide dianion) and 12 oxamide-bridged Ln(III)–Cu(II) heteropentanuclear complexes with the formula of Ln[Cu(PEoxd)]₄(ClO₄)₃ · 5H₂O (PEoxd = the N,N′-Bi(α-pyridylethyl)-oxamide dianion) were synthesized and characterized. The magnetic properties of Gd[Cu(PMoxd)]₄(ClO₄)₃ · 5H₂O (7) and Gd[Cu(PEoxd)]₄(ClO₄)₃ · 2H₂O (19) show that there are ferromagnetic interactions between Gd(III) and Cu(II) in the complexes with J _Cu–Gd = 1.38 cm^?1 and J _Cu–Gd = 1.00 cm^?1, respectively. Fluorescent quenching phenomena for Eu[Cu(PMoxd)]₄(ClO₄)₃ · 5H₂O (6) and Tb[Cu(PMoxd)]₄(ClO₄)₃ · 5H₂O (8) were also observed.     

Studies on solid state synthesis and the oxygenation property of cobalt (II) Schiff base (vanilline polyamine) complexes

Three new cobalt complexes were synthesized by solid-state reaction at room temperature and the resultant Co complexes reacted with two equivalent oxygen molecules at room temperature to produce the oxygenated complexes [Co·(L₁)₂·(O₂)₂](NO₃)₂·2H₂O (L₁ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl)-diethylenetriamine), [Co·(L₂)₂·(O₂)₂](NO₃)₂·2H₂O (L₂ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl)-triethylenetetramine), and [Co·(L₃)₂·(O₂)₂](NO₃)₂·2H₂O (L₃ = N, N’-bis(4-hydroxyl-3-methoxy-benzyl-tetraethylenepentamine). The oxygenated complexes were characterized by elemental analysis, IR (Infrared), ¹H-NMR (Nuclear Magnetic Resonance), and UV-Vis (Ultraviolet Visual) spectrometry, and TG/DTA (Thermogravimetry/Differential Thermal Analysis) analysis, and molar conductance. The coordinated oxygen contents in the oxygenated complexes were also determined by weight method. It was supposed that only one O₂ molecule coordinated to the Co ion forming a superoxo type oxygenated complex. Translated from Acta Chimica Sinica, 2006, 64(15): 1517–1522 (in Chinese)     

Thermal stability of amino acid-(tyrosine and tryptophan) coated magnetites

The thermal stability of two amino acid-(tyrosine and tryptophan) coated magnetite and their corresponding precursors, [Fe₂^IIIFe^II(Tyr)₈]·9H₂O and [Fe₂^IIIFe^II(Trp)₂(OH)₄](NO₃)₂·8H2O (where tyrosine=Tyr and tryptophan=Trp), was analyzed in comparison with free amino acids. The complexes present a lower thermal stability relative to the free ligand, due to the catalytic effect introduced by the iron cation and the presence of NO₃⁻ groups. The presence of NO₃⁻ group determines also a different degradation’s stoichiometry of the amino acid anion comparative with the one expressed by the free ligand molecule. The amino acid bonded to magnetite decomposes in two steps, its presence inducing an increasing of γ-Fe₂O₃→Fe₂O₃ conversion temperature.     

Phase formation in the ZrO(NO3)2-H3PO4-RbF-H2O system: the PO 43? /Zr = 0.5 section

We studied phase formation in the ZrO(NO₃)₂-H₃PO₄-RbF-H₂O system along PO₄³⁻/Zr = 0.5 (mol/mol) and RbF/Zr = 1–5 (mol/mol) sections with 2–10 wt % ZrO₂ in the starting solution. We recovered amorphous rubidium oxofluorophosphatozirconate Rb₂Zr₃OF₆(PO₄)₂ · 2H₂O and the following fluorophosphatonitratozirconates: Rb₂ZrF₄(PO₄)_0.33NO₃, which forms large cubic system crystals; weakly crystallized RbZr₃OF₃(PO₄)₂(NO₃)₂ · 5H₂O; and amorphous Zr₃OF₃(PO₄)₂NO₃ · (7–8) H₂O. A shown by its IR spectrum, Rb₂ZrF₄(PO₄)_0.33NO₃ contains NO₃- and PO₄ groups that are not coordinated to zirconium, meaning that this is a triple salt ZrF₄ · Rb(PO₄)_0.33 · RbNO₃. The formula units of the RbZr₃OF₃(PO₄)₂(NO₃)₂ · 5H₂O and Zr₃OF₃(PO₄)₂NO₃ · (7–8)H₂O phases are only conventional. All compounds have been recovered for the first time.     

Crystal Structure of the Mixed‐Valent Basic Mercury Nitrate HgI2(NO3)2·HgII(OH)(NO3)·HgII(NO3)2·4HgIIO [= Hg8O4(OH)(NO3)5]

Light‐yellow single crystals of the mixed‐valent mercury‐rich basic nitrate Hg₈O₄(OH)(NO₃)₅ were obtained as a by‐product at 85 °C from a melt consisting of stoichiometric amounts of (Hg^I₂)(NO₃)₂·2H₂O and Hg^II(OH)(NO₃). The title compound, represented by the more detailed formula Hg^I₂(NO₃)₂·Hg^II(OH)(NO₃)·Hg^II(NO₃)₂·4Hg^IIO, exhibits a new structure type (monoclinic, C2/c, Z = 4, a = 6.7708(7), b = 11.6692(11), c = 24.492(2) Å, β = 96.851(2)°, 2920 structure factors, 178 parameters, R1[F² > 2σ(F²)] = 0.0316) and is made up of almost linear [O‐Hg^II‐O] and [O‐Hg^I‐Hg^I‐O] building blocks with typical Hg^II‐O distances around 2.06Å and a Hg^I‐O distance of 2.13Å. The Hg₂²⁺ dumbbell exhibits a characteristic Hg‐Hg distance of 2.5079(7) Å. The different types of mercury‐oxygen units form a complex three‐dimensional network exhibiting large cavities which are occupied by the nitrate groups. The NO₃^? anions show only weak interactions between the nitrate oxygen atoms and the mercury atoms which are at distances > 2.6Å from one another. One of the three crystallographically independent nitrate groups is disordered.     

Preparation,crystal structure and luminescence of lanthanide coordination polymers with 2,2′-dimethyl-4,4′-bipyridine-N,N′-dioxide

Four coordination polymers of the bidentate ligand 2,2′-dimethyl-4,4′-bipyridine-N,N′-dioxide (L), [La(L)(NO₃)₃(H₂O)] _n (1), {[Gd₂(L)₃(NO₃)₆]·6H₂O} _n (2), {[Sm(L)₂(H₂O)₄]·3ClO₄·2L·4H₂O} _n (3) and {[Nd(L)₂(H₂O)₄]·3ClO₄·2L·4H₂O} _n (4) have been synthesized by the diffusing solvent mixture method. Results of X-ray diffraction analysis reveal that 1, with a Ln/L stoichiometry of 1:1, displays a rare 3-D three-fold interpenetrating diamondoid framework, while 2 has a Ln/L stoichiometry of 1:1.5 and exhibits a polycatenane network with a {8²,10} topology and large channels accommodated by water. Complexes 3 and 4, with Ln/L stoichiometry of 1:2, have 3-D two-fold interpenetrating diamondoid structures and large voids. Nonlinear optical property of 2 and luminescence of 3 were also investigated.     

Synthesis,characterization and DNA-binding studies of 1-(pyridin-2-yl)-3-tosylurea and its Nd<Superscript>III</Superscript>, Eu<Superscript>III</Superscript> complexes

1-(Pyridin-2-yl)-3-tosylurea(HL) and its two lanthanide complexes, LnL₃ · H₂O [Ln = Nd(1), Eu(2)], have been synthesized and characterized on the base of elemental analyses, molar conductivities, IR spectra and thermal analyses. In addition, the DNA-binding properties of the two complexes have been investigated by absorption, fluorescence and viscosity measurements. The experimental results indicated that the complex (1) and (2) can bind to DNA; the binding affinity of the complex (1) is higher than that of complex (2) and the intrinsic binding constants of complex (1) and complex (2) with DNA were 1.24 × 10⁴ m ⁻¹ and 8.7 × 10³ m ⁻¹, respectively. In addition, some factors that influence the fluorescent intensity were also discussed.     

Thermochemistry of rare earth complexes [Ln(Ala)2(Im)(H2O)](ClO4)3 (Ln=Pr, Gd)

The two complexes, [Ln(Ala)₂(Im)(H₂O)](ClO₄)₃ (Ln=Pr, Gd), were synthesized and characterized. Using a solution-reaction isoperibol calorimeter, standard enthalpies of reaction of two reactions: LnCl₃⋅6H₂O(s)+2Ala(s)+Im(s)+3NaClO₄(s)=[Ln(Ala)₂(Im)(H₂O)](ClO₄)₃(s)+3NaCl(s)+5H₂O(l) (Ln=Pr, Gd), at T=298.15 K, were determined to be (39.26±0.10) and (5.33±0.12) kJ mol^–1 , respectively. Standard enthalpies of formation of the two complexes at T=298.15 K, Δ_fH^Θ_m {[Ln(Ala)₂(Im)(H₂O)](ClO₄)₃(s)} (Ln=Pr, Gd), were calculated as –(2424.2±3.3) and –(2443.4±3.3) kJ mol^–1 , respectively.     

基于柔性四羧酸的三个一维/二维/三维Zn(Ⅱ)/Co(Ⅱ)配合物的晶体结构及荧光性质

通过水热/溶剂热合成的方法制备了3个 Zn(Ⅱ)/Co(Ⅱ)配合物{[Zn(H2L)(H2O)3]·H2O·0.5H4L}n(1)、{[Co(L0.5(4,4'-bpy)]·0.5H2O}n(2)和{[Co(L)0.5(pbmb)(H2O)]·H2O}n(3)(H4L=5,5'-(hexane-1,6-diyl)-bi...     

基于一个四羧酸配体构筑的具有(4,8)-连接的镧系金属-有机框架材料及对小分子的检测试验

以3,3'',5,5''-四-（羧基苯基）联苯为配体（H₄L）,与镧系金属Ln（Ⅲ）盐反应,自组装形成了5个具有三维孔洞结构的镧系金属-有机框架材料：{[Ln₃L₂(H₂O)₇]·(OH)·10DMA}_n(Ln=Gd (1a); Ln=Ho(2a), {[Ln₃L₂(H₂O)₃]·(OH)·mDMA}_n (Ln=Er,m=10(1b); Ln=Yb, m=9(2b); Ln=Lu, m=10(3b))。单晶X射线衍射分析表明,这些MOFs属于2种系列的类质同晶化合物,分别属于正交晶系Ccca空间群和单斜晶系C2/c空间群。有机小分子溶剂交换荧光研究发现,2b对小分子二氯甲烷和甲苯荧光有增强效应,表现出良好的荧光探测功能。     

Synthesis, crystal structure and characterization of a 2-D network organic-inorganic hybrid polymer with [α-BW12O40]5? as building blocks

A two-dimensional network compound [Ce(DMF)₄(H₂O)][α-BW₁₂O₄₀]·H₂O·(HDMA)₂ (HDMA = protoned dimethylamine, DMF = N,N-dimethylformamide) was synthesized from α-H₅BW₁₂O₄₀·nH₂O, Ce(NO₃)₃·6H₂O and DMF and characterized by IR, UV spectra and TG-DTA. The result of the X-ray single crystal diffraction indicates that the crystal is monoclinic, space group P2₁/n, with unit cell dimensional: a = 1.1983(3), b = 2.4216(5), c = 1.9517(4) nm, β = 92.91(3)°, Z = 4, R ₁ = 0.07710, wR ₂ = 0.1416. Structural analysis indicates that every [Ce(DMF)₄(H₂O)]³⁺ building block is surrounded by three adjacent [α-BW₁₂O₄₀]⁵⁻ polyanions, meanwhile, every [α-BW₁₂O₄₀]⁵⁻ polyanion interconnects with three neighboring [Ce(DMF)₄(H₂O)]³⁺ subunits, by making use of which two-dimensional network structure can be constructed. The result of thermogravimetric analysis manifests that the title compound has two-stage weight loss and the decomposition temperature of the title polyanionic framework is 560°C. The electrochemical analysis shows the title polyanion has three-step redox processes in the pH = 4–7 media.