Synthesis, Characterization and Antioxidative Activity of Lanthanide Complexes with Genistein

Six genistein lanthanide complexes, LnL_2 (OAc)·nH_2O [Ln=La(Ⅲ), Sm(Ⅲ), Eu(Ⅲ), Gd(Ⅲ), (Tb(Ⅲ),) Dy(Ⅲ); L=genistein; n=4, 7, 8] were synthesized and characterized on the basis of elemental analyses, IR, (()~1H) NMR spectra and molar conductivity. The scavenging activity of genistein and five lanthanides complexes on the hydroxyl free radicals (OH·) was also investigated by spectrophotometric methods. The results show that the scavenging activity of the complexes is better than that of the ligand and their scavenging ability can be assembled in the following order: Sm>La>Dy>Eu>Tb>L.

Synthesis and Characterization of Some Lanthanide(Ⅲ) Complexes with 4-[N-(2-methoxybenzylimine)formyl]-2, 3-dimethyl-1-phenyl-3-pyazolin-5-one

A series of seven novel lanthanide（Ⅲ ） nitrato complexes with 4-[ N-（2-methoxybenzylimine）formyl] 1-2, 3- dimethyl-1-phenyl-3-pyazolin-5-one （2mbfa）, were synthesized. These complexes were characterized by elemental analysis, molecular mass determination, conductance and magnetic moment measurements, IR, UV-visible, and ^13CNMR spectral studies, In these complexes, the Schiff base, 2mbfa, acts as neutral bidentate ligand by utilizing the carbonyl oxygen and azomethine nitrogen as donor sites. All the three nitrate ions are also coordinated unidentately with 7 coordination for the lanthanide（Ⅲ） ions with a tentative monocapped octahedral geometry for the complexes. All the seven lanthanide（Ⅲ） complexes have a general formula, [ Ln（2mbfa）：（NO3）3 ].

Synthesis and characterization of lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand

The lanthanide complexes containing a bulky tridentate [N,N,O] Schiff base ligand 3,5-But2-2-（OH）C6H2CH=N-8-C9H6N （HL） were synthesized and characterized. The reaction of anhydrous LnCl3 with NaL formed in situ in a 1：1 molar ratio in THF at room temperature afforded the lanthanide Schiff base dichloride complexes LnLCl2（DME） （Ln=Eu （1）; Sm （2））. Complexes 1 and 2 can be used as precursors for the synthesis of the lanthanide cyclopentadienyl Schiff base derivatives. The reactions of complexes 1 and 2 with one equiv of NaCH3C5H4 in THF provided the desired products LnL（CH3C5H4）CI（THF）.THF （Ln=Eu （3）; Sm （4）） in good isolated yields. These complexes were characterized by elemental analysis, IR spectra, and X-ray structural determination, in the case of complexes 3 and 4. The crystal data of complex 3 are monoclinic, P21/C space group, a=1.3370（2） nm, b=1.5190（2） nm, c=1.8910（3） nm, β=109.846（4）°, V=3.6125（8） nm^3, Z=4, Dc=1.416 mg/m^3,μ=1.847 mm^-1, F（000）=1584, R=0.0707, wR=0.1350. The crystal data of complex 4 are monoclinic, P21/c space group, a=1.3383（1） nm, b=1.5210（2） nm, c=1.8960（2） nm, β =109.878（3）°, V=3.6293（7） nm^3, Z=4, Dc=1.407 mg/m^3, μ=1.728 mm^-1, F（000）= 1580, R=0.0670, wR=0.1385.

Hydrothermal Synthesis of Two 3D Lanthanide(Ⅲ) Organometallic Polymers in the 3,5-Pyridinedicarboxylate System with Different Coordination Architecture

Two coordination polymers of lanthanide complexes [（Dy）2（3,5-PDA）3（H2O）2]n 1 and [（Pr）2（3,5-PDA）3（H2O）3]n 2 （3,5-PDA = pyridine-3,5-dicarboxylate） have been synthesized under hydrothermal conditions. The prepared compounds were characterized by elemental analysis, IR and TG analyses and single-crystal X-ray structure determination. Complex 1 crystallizes in monoclinic, space group C2/c with a = 14.104（2）, b = 11.1129（16）, c = 15.086（2） , β = 92.138（2）o, V = 2362.8（6） 3, Z = 4, C21H13Dy2N3O14, Mr = 856.34, Dc = 2.407 g·cm-3, F（000） = 1616, μ（MoKα） = 6.359 mm-1, the final R = 0.0422 and wR = 0.1016 for 2000 observed reflections with I 2σ（I）. Complex 2 crystallizes in triclinic, space group P with a = 8.9441（13）, b = 9.3959（14）, c = 14.625（2） , α = 98.065（2）, β = 95.481（2）, γ = 104.9130（10）o, V = 1164.7（3） 3, Z = 2, C21H15Pr2N3O15, Mr = 831.18, Dc = 2.370 g·cm-3, F（000） = 800, μ（MoKα） = 4.224 mm-1, the final R = 0.0355 and wR = 0.0731 for 4092 observed reflections with I 2σ（I）. These polymers are constructed from the 3,5-PDA ligand but they exhibit different kinds of metal-organic framework structures. Complexes 1 and 2 are constructed from M-C-O zigzag corner-linked chains （M = Dy and Pr）. In 1, the chains are composed of 8-coordinated DyⅢ centers, while the chains are made up of 8- and 9-coordinated PrIII centers in complex 2. These chains are cross-linked to each other by the pyridine rings of 3,5-PDA ligands, generating three-dimensional architectures. The magnetic behavior of compound 1 has been investigated, showing it exhibits antiferromagnetic interactions among the DyⅢ ions.

Synthesis and Characterization of Heteropolytungstosilicate Complexes with the Lanthanide Elements

Lanthanide heteropoly compounds K15[Ln(HSiW9O34)2]·28H2O(Ln = La, Ce, Nd), denoted as Ln(SiW9)2, were synthesized and characterized by element analysis, TG-DTA, IR, UV, XPS and XRD. The results show that partial oxygen in Ln(SiW9)2 was coordinated with Ln3- , where Ln-3 was in the inner side of the heteropoly anions, while the fundamental structure of SiW9 had little change. The result was supported by ion exchange experiment.

Synthesis, Characterization and Properties of Lanthanide Nitrate Complexes with Isonicotinoyl Hydrazone

Some light-lanthanide nitrate complexes were obtained by the reaction of lanthanide nitrate with isonicotinoyl hydrazone (HL = N,N'-diisonicotinoyl-2-hydroxy-5-methyl-isophthalaldehyde dihydrazone) in methanol. The general formula of the complexes is Ln(L) (NO3)(2) . nH(2)O(Ln = La, Ce, Pr, Nd and Sm; n = 0, 1). The complexes were characterized by elemental analyses, conductance, thermal analyses, UV and IR spectra. The results show that the lanthanide ion in each complex is coordinated by oxygen and nitrogen atoms of the ligand (L) and the oxygen atoms of the nitrate. The amide-oxygen atoms of L coordinate to the Ln ions in its keto-form. The magnetic susceptibility of the neodymium complex shows that the magnetic data obey Curie-Weiss law in the range of 75K < T < 300K.

Synthesis of Lanthanide Cryptates by Transmetalation Reaction

New lanthanide cryptates [LnL](ClO_4)_3 (Ln=Eu 3+, Ce 3+, Pr 3+, Sm 3+, Gd 3+, Tb 3+; L=1, 4, 12, 15, 18, 26, 31, 39, 42, 43, 44-undecaazapentacyclo-[13.13.13.1 6, 10.1 20, 24.1 33, 37]-tetratetraconta-4, 6, 8, 10(44), 11, 18, 20, 22, 24(43), 25, 31, 33, 35, 37(42), 38-penta decaene) were synthesized by transmetalation reaction of lanthanide perchlorates with its barium cryptate which was obtained by [2+3] template condensation of tren with 2,6-diformylpyridine in the presence of barium perchlorate, and characterized by elemental analysis, IR and electrospray mass spectrum.

Studies on Rare Earth Complexes with Crown Ether (ⅩⅩⅣ)——Synthesis and Characterization of Complexes of Lanthanide Isothiocyanates with Dibenzo-30-crown-10

Introduction The study of metal complexes with the crown ether is a quite interesting research field, but the research has mainly focused on the metal complexes with some crown ethers with a relatively small cavity such as 12-crown-4, 15-crown-5 and 18- crown-6 as well as their derivatives. Crown ethers with a larger cavity contain more oxygen atoms, so they have the ability to form the complexes of a higher co-

Synthesis and Characterization of Lanthanide Complexes Involving Cyclopentadienyl and Benzohydroximic Acid Ligand

By the reaction of Cp 3Ln with HL(Cp=η 5 C 5H 5, cyclopentadienyl; Ln=Yb, Tm, Er, Ho, Dy, Gd, Pr; HL=benzohydroximic acid), seven new complexes of the general formula Cp 2LnL were synthesized. All the complexes were characterized by elemental analysis, infrared spectra, and mass spectra. Based on these data, the probable structure was proposed.

Synthesis of the Early Lanthanide Complexes[Li(DME)3][MeCpLn(NPh2)3](Ln=La,Pr,Nd)and X-Ray Crystal Structure of La Complex

The reaction of MeCpLnCl·2LiCl·nTHF with 2 equivalent of LiNPh_2 in THF,hexane and toluene mixture solution gives the new complex[Li(DME)_2][(η~5-MeCp)Ln(NPh_2)_3](Ln=La,Pr,Nd)by extraction with DME.They have been characterized by elemental analysis,IR and NMR.The La complex crystallizes in the monoclinic space group P2_1/c with α=1.8335(6)nm,b=1.6576(5)nm,c=1.7461(6)nm, β=96.04°,V=5.277 nm^2,Z=4,D_c=1.26g·cm^(-3),R=0.057 and R_w=0.048(1≥2.5σ(I_o))for 3378 reflec- tions.The complex consists of a pair of a cation and an anion.La^(3+) is coordinated by one methylcyclopentadienyl and three diphenylamidos to form six-coordinate pseudotetrahedron with the mean Ln-N and La-C(ring)distances of 0.2459(8)and 0.2843(11)nm,respectively.

Solvothermal Synthesis,Crystal Structure and Optical Property of Lanthanide Selenidostannate [{Tb(en)_3}_2(μ-OH)_2]Sn_2Se_6 with a 3-D H-bonded Network

An inorganic-organic hybrid lanthanide selenidostannate [{Tb（en）3}2（μ-OH）2]Sn2Se6（1） was synthesized by the solvothermal method.1 crystallizes in the monoclinic system,space group P21/n with a=10.120（2）,b=11.781（3）,c=15.403（3）,β=99.534（5）°,V=1811.1（7）3,Mr=1423.62,Z=2,Dc=2.611 g/cm3,μ=11.281 mm-1,F（000）=1312,S=1.101,the final R= 0.0400 and wR=0.0853 for 3242 observed reflections with Ⅰ 〉2σ（Ⅰ）.1 consists of a [Sn2Se6]4-and a [{Tb（en）3}2（μ-OH）2]4＋ ions.The [Sn2Se6]4-anion is constructed by two SnSe4 tetrahedra sharing a common edge.The binuclear [{Tb（en）3}2（μ-OH）2]4＋ complex is composed of two [Tb（en）3]3＋ ions joined by two μ-OH bridging ligands.The Tb3＋ ion lies in an eight-coordinated bicapped trigonal prism.In 1,the [Sn2Se6]4-and [{Tb（en）3}2（μ-OH）2]4＋ moieties are connected into a 3-D network via N-H···Se and O-H···Se H-bonds.

Reaction in situ found in the synthesis of a series of lanthanide sulfate complexes and investigation on their structure, spectra and catalytic activity

A series of lanthanide sulfates coordination complexes, Ln2(SO4)3(H2O)8 (Ln = Pr (1), Nd (2), Tb (3), Sm (4), Dy (5), Gd (7), Ho (8)), and EuK(SO4)2 (6), were constructed by the reaction in situ of lanthanide ions (Ln3+) with flexible dodecanedioic acid and rigid aromatic 5-sulfosalicylic acid under hydrothermal conditions. All of them were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The crystal structures and coordination modes of metal centers and sulfate ions, as well as the novel reaction mechanism and different conditions of lanthanide ions and 5-sulfosalicylic acid to form the series of lanthanide sulfate complexes, were discussed in detail. Solid-state properties for these crystalline materials, such as thermal stability and powder X-ray diffraction have been investigated. Additionally, the photoluminescent characterizations of the complexes 3, 4, 5 and 6, and the catalytic properties of all the complexes about cyclohexane being oxidized into cyclohexanone/cyclohexanol were investigated and compared.

SYNTHESIS AND CHARACTERIZATION OF COMPLEXES OF LANTHANIDE NITRATES WITH 2,2'-BIPYRIDYL

The interactions of 2,2'-bipyridyl with the lanthanide nitrates were studied and complexes of the formula Ln(NO_8)_8(bipy)_8 were isolated from water -ethanol mixed solvent.The complexes were characterized by elemental analysis, conductivity measurments,IR spectra and DAT-TG analysis.

Synthesis and Crystal Structure of Lanthanide Schiff Base Complex [2-OC_6H_4CHN(2,6-i-Pr_2C_6H_3)]_2ErCl(THF)

The lanthanide Schiff base complex [2-OC6H4CHN(2,6-i-Pr2C6H3)]2ErCl(THF) (C42H52ClErN2O3) has been prepared by the reaction of anhydrous LnCl3 with 2 equiv. of the sodium salt of the bidentate Schiff base N-(2,6-diisopropylphenyl)salicylaldimine in THF. The crystal structure was determined by X-ray diffraction analysis. The crystal belongs to triclinic, space group P1 with a = 9.200(1), b = 13.637(2), c = 16.705(2) ? a = 74.493(7), b = 77.979(8), g = 81.306(8), V = 1965.2(4) ?, Z = 2, Mr = 835.60, Dc = 1.412 g/cm3, F(000) = 854, T = 193 K, l(MoKa) = 0.7107 ?and m = 22.38 cm-1. The final R = 0.052 and wR = 0.076 for 8386 observed reflections with I ≥ 2s(I).

Two Novel 2D Lanthanide-organic Frameworks Based on Different Carboxylate-containing Mixed Ligands

Two novel lanthanide-organic polymers [Er2（pdc）2（o-bdc）（H2O）2]·H2O（1,H2pdc = 2,6-pyridinedicarboxylic acid,o-H2bdc = 1,2-benzenedicarboxylic acid） and Er（Himdc）（mbdc）0.5（H2O）（2,H3imdc = 4,5-imidazoledicarboxylic acid,m-H2bdc = 1,3-benzenedicarboxylic acid） have been synthesized and characterized by elemental analysis,IR,thermogravimetric analysis and X-ray single-crystal diffraction studies.1 crystallizes in monoclinic,space group P21/c,while 2 in the orthorhombic space group Pbcn.Both compounds 1 and 2 display two-dimensional network structures. For 1, the tetranuclear parallelogram {Era} cluster as a building block is further assembled into a wonderful 2D grid, and the layers are interconnected via hydrogen bonds and π-π stacking interactions to yield a 3D supramolecular architecture; for 2, its configuration is a rare double-decker structure. These two complexes represent good examples for using mixcarboxylate-containing ligands to construct diverse 2D lanthanide coordination polymers.

Syntheses, Structures and Photoluminescence of Two New Layered Lanthanide Coordination Polymers with Thiophenedicarboxylic Acid and 1,10-Phenanthroline

Two isostructural layered coordination polymers constructed from mixed ligands, [Ln2（tdc）3（phen）2（H2O）2] （Ln = Sm 1, Eu 2, H2tdc = thiophene-2,5-dicarboxylic acid, phen = 1,10-phenanthroline）, have been hydrothermally synthesized and characterized by elemental analysis, IR and single-crystal X-ray diffraction. Crystal data for 1： triclinic, space group P1 with a = 10.546（2）, b = 11.201（2）, c = 18.644（4）A, α = 106.69（3）, β = 91.27（3）, γ = 94.43（3）°, Dc = 1.909 g·cm-3, F（000） = 1180, μ = 2.992 mm^-1, Z = 2, the final R = 0.0300 and wR = 0.0656 for 6968 observed reflections with I 〉 2σ（I）. And those for 2： triclinic, space group P1^- with a = 10.557（2）, b = 11.159（2）, c = 18.588（2） A, α = 106.945（6）, β = 91.255（6）, γ = 94.359（6）°, Dc = 1.927 g·cm^-3, F（000） = 1184, μ = 3.204 mm^-1, Z = 2, the final R = 0.0221 and wR = 0.0459 for 6328 observed reflections with I 〉 2σ（I）. The title complexes show a two-dimensional （2D） square grid structure constructed from paddle-wheel-like [Ln2（CO2）4] dimers and tdc ligands. The 2D layers were further assembled into a 3D supramolecular assembly via O-H…O hydrogen bond. The photoluminescence properties of complexes 1 and 2 were investigated.

Syntheses of Alkaline Earth and Lanthanide Cryptates with Pyridine-Based Group

New alkaline earth metal cryptates [ML]（NO3）2 ·2H2O （M=Ca^2＋, Sr^2＋, Ba^2＋; L = 1, 4,12,15,18, 26, 31, 39, 42, 43, 44-undecaazapentacyclo- [ 13.13.13.1^6,10 .1^20,24 .1^33,37 ]-tetratetraconta -4, 6, 8, 10（44）, 11, 18, 20, 22, 24（43）, 25, 31, 33, 35, 37（42）, 38-pentadecaene） were synthesized by [2 ＋ 3 ] template condensation of tris（2-aminoethyl） amine with 2, 6-diformylpyridine, and then by transmetallation reactions of the calcium cryptate [CaL] （NO3）2·2H2O with corresponding lanthanide ions; three lanthanide cryptates [ LnL] （NO）3·3H2O （Ln = Eu, Gd, Tb） were synthesized and characterized by physical methods. The crystal structure of the terbium cryptate [TbL] （NO）3·3H2O was studied by X-ray analysis. The central atom was coordinated by three pyridyl and six imino nitrogen atoms and exhibited a distorted tricapped trigonal prismatic coordination geometry.

Syntheses and Structures of Lanthanide Complexes with Isonicotinate

The crystal structures of two coordination polymers [Ln(IN)3(H2O)2]n (Ln = Nd 1, Gd 2; IN = isonicotinate) were determined by single-crystal X-ray diffraction and further chara- cterized by IR, elemental analysis and thermogravimetric analysis. Crystal data for 1: monoclinic, space group P21/c, a = 9.6636(5), b = 19.7532(10), c = 11.6183(6) ?, β = 112.032(1)°, V = 2055.83(18) ?3, Z = 4, Dc = 1.766 g/cm3, F(000) = 1076, μ = 2.575 mm–1 and R = 0.0493; Crystal data for 2: monoclinic, space group C2/c, a = 20.251(2), b = 11.6199(11), c = 9.8240(9) ?, β = 115.505(3)°, V = 2086.4(3) ?3, Z = 4, Dc = 1.781 g/cm3, F(000) = 1092, μ = 3.228 mm–1 and R = 0.0695. In the title compounds, the center atoms Ln(III) are in a distorted square antiprismatic geometry and linked by bridging isonicotinate to form an infinite chain. The intermolecular hydro- gen bonds lead to the formation of three-dimensional supramolecular structures.

A 3-D Supramolecular Framework with Open Channels Constructed from Lanthanide Ions and Mixed Ligands

A 3-D supramolecular framework, [Er（pybz）2（Hnds）（H2O）2]·H2O （1, Hpybz = 4- pyridin-4-yl-benzoic acid, H2nds = naphthalene-1,5-disulfonic acid）, based on lanthanide ions and mixed ligands has been hydrothermally synthesized. The structure was determined by single-crystal X-ray diffraction and further characterized by IR, elemental analysis and thermogravimetric analysis. Compound 1 crystallizes in the monoclinic system, space group P21/n with a = 9.849（2）, b = 22.526（5）, c = 17.167（4） A, β =105.461（4）° and V = 3670.9（2） A^3. In 1, two seven-coordinated Er^3＋ ions are bridged by two pybz^- ligands to form a dimeric [Er2（COO）2] unit, which is further orderly linked by carboxyl of pybz^-ligand to obtain a 1-D chain running along the a axis. Interestingly, significant H-bonding and π-π stacking interactions link the neighboring parallel chains leading to a 3-D supramolecular network structure which displays 1-D rhombus open channels （17.2A× 22.5A）.

Syntheses and Structures of Three Novel 1-D Lanthanide-isonicotinate Coordination Polymers

Three novel lanthanide-IN coordination polymers [Ln（IN）3（H2O）2], （Ln = Sm 1, Dy 2, Eu 3; IN = isonicotinate） have been hydrothermally synthesized and characterized by FT-IR spectra, elemental analysis and TG analysis. Single-crystal X-ray diffraction shows that 1, 2 and 3 are isostructural. Crystal data for 1： monoclinic, space group C 2/c, a = 15.8384（14）, b = 14.2662 （12）, c = 9.5073（7） A, β = 97.705（4）°, V = 2128.8（3） A^3, Z = 4, Dc = 1.724 g/cm^3, F（000） = 1084 , μ = 2.806 mm^-1 and R = 0.0226; Crystal data for 2： monoclinic, space group C 2/c, a = 15.7890（3）, b = 14.1356（6）, c = 9.5152（3） A, β= 97.899（2）°, V = 2103.52（12） A^3, Z = 4, Dc = 1.784 g/cm^3, F（000） = 1100, μ = 3.601 mm^-1 and R = 0.0406; Crystal data for 3： monoclinic, space group C 2/c, a = 15.802（5）, b = 14.242（4）, c = 9.513（3） A, β = 97.695（5）°, V = 2121.8（10） A^3, Z = 4, Dc = 1.735 g/cm^3, F（000） = 1088 ,μ = 3.004 mm^-1 and R = 0.0273. In the three compounds, the Ln（Ⅲ） centers are eight-coordinated with antiprismatic geometry. The Ln（IN）3（H2O）2 unit connects mutually to form a one-dimensional double zigzag chain via isonicotinate oxygen bridging. The infinite chains are further linked by inter-chain hydrogen-bonding to form a three-dimensional supramolecular network.