Hydrothermal synthesis and crystal structure of two new lanthanide coordination polymers with 1,2-phenylenediacetate

Two new compounds {[Ln₂(1,2-pda)₃(H₂O)₂]·?2H₂O} _n (1,2-H₂pda?=?1,2-phenylenediacetic acid, Ln?=?Tb, 1; Ho, 2) were prepared by hydrothermal reaction and characterized by X-ray crystallography. The Ln³⁺ is nine-coordinate by eight oxygen atoms of six 1,2-pda ligands and one oxygen of water. Ln³⁺ ions are bridged by 1,2-pda ligands via bridging/chelating-bridging pentadentate and chelating-bridging/chelating-bridging hexadentate coordination to form 3-D framework structures. Complex 1 emits strong green fluorescence corresponding to ⁵D₄???⁷F_j (j?=?6–3) transitions of the Tb³⁺.     

Hydrothermal synthesis,crystal structure and magnetic properties of a copper(II) phosphonate

The treatment of 3-ammonium-1-hydroxypropylidene-1,1′-bisphosphonate (H₇ahdp) and 4,4′-bipy with CuCl₂?·?2H₂O resulted in a metal phosphonate [Cu(H₅ahdp)?·?H₂O] _n . Its crystal structure has been characterized by single X-ray crystallography. Although there is no 4,4′-bipy in the lattice structure, it plays a very important role in forming the one-dimensional chain of the polymer. Hydrogen bonds link the chains into a 3D network. The dinuclear secondary building units are observed in the compound. The determination of variable-temperature magnetic susceptibilities (5?～?300?K) shows weak intrachain antiferromagnetic coupling between copper(II) centers. The magnetic data were fitted to the appropriate equations derived from the Hamiltonian H?=??2JS ₁ S ₂, giving the parameter J?=??25.78?cm^?1. Its thermal properties were also investigated.     

Hydrothermal synthesis and structural characterization of three lanthanide coordination polymers with adipic acid and 1,10-phenanthroline

Three new lanthanide coordination polymers, [Ln(Ad)_3/2(Phen)] _n ·2nH₂O (Ln = Eu, 1; Pr, 2; Ad = adipate; Phen = 1,10-phenanthroline) and [Yb(Ad)_3/2(Phen)] _n ·nH₂O 3, were prepared by hydrothermal reactions. The structures of 1, 2 and 3 are reported. In compound 1, Eu(III) ions are bridged by adipate ligands in two modes into 2-D polymeric layers. Adjacent layers are assembled by hydrogen bonding and π–π stacking between 1,10-phenanthrolines into a 3-D supramolecular structure. Compound 2 is isostructural with 1. In compound 3, the Yb(III) ions are connected by adipate ligands in three modes into a 3-D network.     

One new lanthanide complex with mixed sulfate and oxalate ligands: hydrothermal synthesis,crystal structure,and magnetic properties

A new lanthanide complex K[Gd(ox)(SO₄)(H₂O)] (1) with sulfate and oxalate ligands has been synthesized under hydrothermal conditions. The compound crystallizes in the monoclinic space group P₂₁/c with a = 6.5849(1) Å, b = 8.5660(1) Å, c = 14.7660(2) Å, β = 112.470(1)°, C₂H₂GdKO₉S, M = 398.46, Z = 4, V = 769.66(2) ų, F(000) = 740, R ₁ = 0.0199 and ωR = 0.0514. The solid-state DC magnetic susceptibility measurements of 1 revealed antiferromagnetic behavior with an S = 7/2 ground spin state.     

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

Two new lanthanum sulfates DySO₄(OH) 1 and Eu₂(SO₄)₃(H₂O)₈2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) Å, b=10.945(5) Å, c=8.164(4) Å, α=90°, β=93.619(6)°, γ=90°, V=713.0(5) Å³, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) Å, b=6.7676(8) Å, c=18.318(2) Å, α=90°, β=102.265(2)°, γ=90°, V=1642.7 (4) Å³, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner.     

Catalytic efficacy of an oxido-peroxido tungsten(VI) complex: synthesis,X-ray structure and oxidation of sulfides and olefins

An oxido-peroxido tungsten(VI) complex [WO(O₂)L(CH₃OH)] using salicylidene benzoyl hydrazine as a tridentate ONO donor Schiff base (H₂L) has been synthesized and characterized by elemental analysis, IR, ¹H NMR, molar conductance data, and single-crystal X-ray analysis. The complex was used as a catalyst for epoxidation of olefins and oxidation of sulfides. The results show that epoxides and sulfoxides were produced in high yield, turnover number, and selectivity.     

Two lanthanide luminescent coordination compounds based on 3,5-pyrazoledicarboxylate and oxalic acid

Two isostructural 3-D complexes [Ln(pdc)(ox)_0.5(H₂O)₂]?H₂O (Ln = Tb(1), Eu(2); pdc = 3,5-pyrazoledicarboxylate; ox = oxalate) have been synthesized under hydrothermal conditions. Both are characterized by single crystal X-ray diffraction, elemental analysis, and IR. Compounds 1 and 2 possess a 3-D framework with 1-D rectangular channels built from 2-D, brick-like networks, and pdc ligands. The photoluminescence and lifetimes of 1 and 2 in the solid state have been studied.     

Three new lanthanide compounds based on nitronyl nitroxide radical: Crystal structure,magnetic properties,and luminescence properties

Three new lanthanide compounds were obtained using 2-(3-methylthiophene)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) (NIT-3Methien). These compounds, [Gd(hfac)₃(NIT-3Methien)₂]?0.5CH₃(CH₂)₅CH₃ (1: Half n-heptane trihexafluoroacetylacetonate-di-2-(3-methylthiophene)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide gadolinium(III)), [Tb(hfac)₃(NIT-3Methien)₂]?0.5H₂O (2: Half Hydrate trihexafluoroacetylacetonate-di-2-(3-methylthiophene)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide terbium(III)), and [Dy(hfac)₃(NIT-3Methien)₂]?0.5H₂O (3: Half Hydrate trihexafluoroacetylacetonate-di-2-(3-methylthiophene)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide dysprosium(III)), (CH₃(CH₂)₅CH₃ = n-heptane), (hfac = hexafluoroacetylacetonate), were characterized structurally and magnetically. The three compounds crystallize in the triclinic space group P1( - ). Ln(III) ion was eight-coordinate by six oxygens from three hfac ligands and two oxygens from two radicals. In 1, direct current (DC) magnetic studies reveal ferromagnetic interactions between the Gd(III) ion and radicals with J₁ = 0.94 cm^?1. In 2 and 3, there are antiferromagnetic interactions between the Tb(III), or Dy(III) ions and radicals. The luminescence characterizations show that 2 exhibits highly selective luminescent sensing of Cr₂O₇^2? ions.     

Mild hydrothermal synthesis,isomorphous substitution,crystal structure characterization and magnetic properties of BaMP2O7 (M = Mn,Cu)

At mild hydrothermal conditions triclinic modifications of BaMP₂O₇ (M = Mn and/or Cu) have been succeeded. The method offers cheap, one step, impurity free and chemical flexible fabrication of family of metal phosphates that are potential low-dimensional quantum magnets. Partial isomorphous substitution of the Mn²⁺ by Cu²⁺ resulted into mixed-metal solid that has been structurally and magnetically characterized. Rietveld refinement study confirmed the structures and revealed the influence of transition metal substitution. The temperature-dependent magnetic measurements revealed that the system is paramagnetic in almost all temperature range and an apparent antiferromagnetic phase transition occurs around 5 K. Using the Curie–Weiss law, a Curie–Weiss temperature, θ_P = −11.0 K, and a Curie constant C = 3.39 emu K mol⁻¹ was obtained. The small negative θ_P value and the χT behavior as a function of temperature reveal a weak antiferromagnetic interaction between the Cu²⁺/Mn²⁺magnetic centers.     

Synthesis, crystal structure and properties of two 1D nano-chain coordination polymers constructed by lanthanide with pyridine-3,4-dicarboxylic acid and 1,10-phenanthroline

The hydrothermal reactions of LnCl₃·6H₂O (Ln=Eu, Tb), pyridine-3,4-dicarboxylic acid (3,4-pydaH₂), 1,10-phenthroline (phen) and NaOH in aqueous medium yield two metal-organic hybrid materials, [Eu₂(3,4-pyda)₃(phen)(H₂O)·H₂O]_n (1) and [Tb₂(3,4-pyda)₃(phen)(H₂O)·H₂O]_n (2), respectively. Both compounds have similar topology structure containing one-dimensional nano-chain, which is further assembled into a three-dimensional supramolecular network via π-π stacking interactions and hydrogen bonds. To the best of our knowledge, they represent the first example of nano-chain coordination polymers constructed by 3,4-pydaH₂ and chelate heterocylic ligand. Interestingly, the 3,4-pyda anion exhibits three kinds of coordination modes in these complexes. The coordination modes of 3,4-pyda in complexes 1 and 2 have not been observed in other coordination polymers containing 3,4-pyda ligands. Compounds 1 and 2 exhibit strong fluorescent emission bands in the solid state at room temperature. Their magnetic analyses show that they exhibit different magnetic interactions.     

Three novel lanthanide complexes with imidazole-4,5-dicarboxylate ligand: Hydrothermal syntheses, structural characterization, and properties

Three novel lanthanide complexes, namely, [Ce(Himdc)(H₂imdc)(H₂O)₃]·H₂O (1), {[Dy(Himdc)(Ox)_0.5(H₂O)₂]·H₂O}_n (2), and {[Nd(Himdc)(Ox)_0.5(H₂O)₂]·H₂O}_n (3) (H₃imdc = imidazole-4,5-dicarboxylic acid, Ox = oxalate), have been successfully prepared by the assembly of lanthanide ions and H₃imdc ligand under different synthetic conditions. All of the complexes have been characterized by means of elemental analysis, IR, TG analysis, luminescence spectroscopy as well as single-crystal X-ray diffraction analysis. The 3D supramolecular structure of 1 is constructed from 1D zig-zag chains through the hydrogen bonding interactions. Complex 2 possesses the chair-shaped secondary building units (SBUs) with Dy₆(Himdc)₄(Ox)₂ and meso-helical chains (P + M), resulting in a novel 2D structure based on the linkages of oxalate ligand. Complex 3 also presents 2D layer structure with uninodal 6-connected net topology, but crystallizes in the different space group and owns higher coordination number of the central metal atom than complex 2. The luminescence property of 2 is investigated in the solid state at room temperature.     

Tetrathiafulvalene-based lanthanide coordination complexes: Synthesis,crystal structure,optical and electrochemical characterization

The explorative lanthanide coordination chemistry of 4′,5′-bis-(propylthio)tetrathiafulvenyl[i]dipyrido[3,2-a:2′,3′-c]phenazine (TTF-dppz) is described. Thereby, four new Ln(III) complexes, [Ln(NO₃)₃(TTF-dppz)₂] with Ln(III) = Nd (1), Eu (2), Gd (3), Tb (4), have been prepared and characterized. An X-ray crystallographic study of [Gd(NO₃)₃(TTF-dppz)₂] (3) shows that the Gd(III) ion is coordinated to six oxygen atoms from three bidentate nitrate ligands and four nitrogen atoms from two bidentate TTF-dppz molecules forming a distorted bicapped square antiprism coordination geometry. The UV-vis spectra of the four Ln(III) complexes show very strong absorption bands in the UV region consistent with ligand centred electronic π-π* transitions and an intense broad absorption band in the visible region corresponding to a spin-allowed electronic π-π* ¹ILCT transition from the TTF-dppz ligand. Upon coordination, the ¹ILCT band of the free TTF-dppz ligand is bathochromically shifted. The electrochemical studies reveal that all complexes undergo two reversible oxidation and one (quasi)reversible reduction processes, ascribed to the successive oxidations of the TTF moiety and the reduction of the dppz unit, respectively. Moreover, the magnetic properties of complexes 3 and 4 are discussed.     

Hydrothermal synthesis, structure and thermal stability of diamine templated layered uranyl-vanadates

Six new layered uranyl vanadates (NH₄)₂[(UO₂)₂V₂O₈] (1), (H₂EN)[(UO₂)₂V₂O₈] (2), (H₂DAP)[(UO₂)₂V₂O₈] (3), (H₂PIP)[(UO₂)₂(VO₄)₂].0,8H₂O (4), (H₂DMPIP)[(UO₂)₂V₂O₈] (5), (H₂DABCO)[(UO₂)₂(VO₄)₂] (6) were prepared from mild-hydrothermal reactions using 1,2-ethylenediamine (EN); 1,3-diaminopropane (DAP); piperazine (PIP); 1-methylpiperazine (MPIP); 1,4-diazabicyclo[2,2,2]octane (DABCO). The structures of 1, 4, 5 and 6 were solved using single-crystal X-ray diffraction data while the structural models of 2 and 3 were established from powder X-ray diffraction data. In compounds 1, 2, 3 and 5, the uranyl-vanadate layers are built from dimers of edge-shared UO₇ pentagonal bipyramids and dimers of edge-shared VO₅ square pyramids further connected through edge-sharing. In 1 and 3, the layers are identical to that occurring in the carnotite group of uranyl-vanadates. In 2 and 5, the V₂O₈ dimers differ in orientation leading to a new type of layer. The layers of compound 4 and 6 are built from chains of edge-shared UO₇ pentagonal bipyramids connected by VO₄ tetrahedra and are of uranophane-type anion topology. For the six compounds, the ammonium or organoammonium cation resides in the space between the inorganic layers. Crystallographic data: 1 monoclinic, space group P2₁/c with a=6.894(2), b=8.384(3), c=10.473(4) Å and β=106.066(5)°, 2 monoclinic, space group P2₁/a with a=13.9816(6), b=8.6165(3), c=10.4237(3) Å and γ=93.125(3)°, 3 orthorhombic, space group Pmcn with a=14.7363(8), b=8.6379(4) and c=10.4385(4) Å, 4 monoclinic, space group C2/m with a=15.619(2), b=7.1802(8), c=6.9157(8) Å and β=101.500(2)°, 5 monoclinic, space group P2₁/b with a=9.315(2), b=8.617(2), c=10.5246(2) Å and γ=114.776(2)°, 6 monoclinic, space group C2/m with a=17.440(2), b=7.1904(9), c=6.8990(8) Å and β=98.196(2)°.     

Hydrothermal synthesis,crystal structure,and properties of a novel magnesium phosphonate with a 1D chain structure

A novel 1D chain magnesium phosphonate with a 1D channel system along the c-axis, [Mg(H₄L)(H₂O)₃]_n (1) (H₄L^2-=HN(CH₂PO₃H)₃)^2-, has been synthesized under hydrothermal condition using triphosphonate ligand. The MgO₆ polyhedra and NC₃ planes are connected by phosphonate groups to form a 1D chain. The chains are interlinked by hydrogen bonds into 2D layers. Adjacent layers are further linked via hydrogen bonds to build a 3D network structure. The luminescent property of complex 1 has been also studied. For the complex 1, a blue fluorescent emission band with a maximum peak at 460 nm was observed.     

Yttrium-succinates coordination polymers: Hydrothermal synthesis, crystal structure and thermal decomposition

New polymeric yttrium-succinates, Y₂(C₄H₄O₄)₃(H₂O)₄·6H₂O and Y₂(C₄H₄O₄)₃(H₂O)₂, have been synthesized, and their structures (solved by single crystal XRD) are compared with that of Y₂(C₄H₄O₄)₃(H₂O)₂·H₂O. Three compounds were obtained as single phases, and their thermal behaviour is described.     

Hydrothermal synthesis and crystal structure of a new two-dimensional zinc citrate complex

A new two-dimensional compound C₁₂H₁₄O₁₆Zn₃ (1), containing seven-coordinate zinc atoms was prepared by the hydrothermal technique. The compound obtained was characterized by TG-DTA, single crystal X-ray diffraction, elemental analysis and FT-IR analysis. Single-crystal X-ray diffraction analysis shows that compound 1 crystallizes with monoclinic symmetry in the space group P2₁/c, a?=?6.1552(13)?Å, b?=?14.546(3)?Å, c?=?9.581?Å, β?=?102.66(2)°, V?=?836.9(4)?ų, Z?=?2, R1?=?0.0311, wR2?=?0.0830.     

Mo(CO)3(NCMe)(PPh3)2: Synthesis, X-ray structure and evaluation of its catalytic activity for the homogeneous hydrogenation of olefins and their mixtures

The complex Mo(CO)₃(NCMe)(PPh₃)₂, was synthesized by the reaction of Mo(NCMe)₃(CO)₃ with two equivalents of PPh₃ and characterized by UV–Vis, IR, NMR and X-ray diffraction. This complex was used as a catalyst precursor for the hydrogenation of 1-hexene, styrene, cyclohexene and 2,3-dimethyl-1-butene and their mixtures under moderate conditions in homogeneous media. Under mild reaction conditions (T = 373 K, P = 60 atm), the substrates showed the following reactivity order: styrene > 1-hexene > cyclohexene > 2,3-dimethyl-1-butene. A quaternary equimolar mixture showed a different hydrogenation order: 1-hexene > cyclohexene > styrene > 2,3-dimethyl-1-butene; the presence of dibenzothiophene or mercury does not interfere with the activity of the catalyst.     

Chiral ansa-bridged η-cyclopentadienyl molybdenum complexes: Synthesis, structure and application in asymmetric olefin epoxidation

Ansa-bridged η⁵-cyclopentadienyl carbonyl molybdenum complexes were synthesized with stereogenic centers located in the side chain. An exemplary X-ray crystal structure and the catalytic activity for asymmetric olefin epoxidation are reported. In non-chiral epoxidation the compounds show a good catalytic activity, comparable to activities observed for the related non-chiral complexes of composition CpMo(CO)₃X (X = Cl, CH₃). For the asymmetric epoxidation of trans-β-methylstyrene the chiral induction is up to ca. 20%. The high ring strain of the ansa-bridged system hampers, unfortunately, its stability under oxidative condition.