Synthesis, characterization, and anticancer properties of rare earth complexes with Schiff base and o-phenanthroline

Five novel ternary complexes of the rare earth ions with o-phenanthroline（Phen） and Schiff base salicylaldehyde L-phenyla- lanine（KHL） were synthesized in ethanol. Their compositions were characterized by elemental analysis, molar conductance, ^1H NMR, FT-IR, and Raman spectra. The formulas of the complexes were verified to be RE（L）（Phen）Cl（H2O） （RE=La^3＋, Ce^3＋, Nd^3＋, Er^3＋, and Gd^3＋; L=Schiff base salicylaldehyde L-phenylalanine; phen=o-phenanthroline）. Methyl thiazolyl tetrazolium （MTT） colorimetry and flow cytometry were used to test the anticancer effect of the complexes with K562 tumor cell. The research showed that the complexes could inhibit K562 tumor cell＇s growth, generation, and induce apoptosis. The inhibition ratio was accelerated by increasing the dosage, and it had significant positive correlation with the medication dosage.

Synthesis, Catalysis of Rare Earth Complexes with Aliphatic Noncyclic Polyether-Amino Acid Schiff Base

Eleven new rare earth complexes with aliphatic Schiff base, condensed from diglycol aldehyde and bis-arginine, were synthesized and characterized. They are confirmed as Ln （H2DAAR） （NO3）3·7H2O （ Ln = La, Pr, Nd, Gd）, Ln3 （H2DAAR）2（NO3）9·5H2O （Ln= Dy, Y）and Ln2（H2DAAR）（NO3）6·3H2O （Ln = La, Nd, Sm, Gd）, Ln3（DAAR） （NO3）7·4H2O （Ln = Dy, Yb, Y） respectively under different molar ratios of metal to ligand （DAAR = diglycol aldehyde bis-arginine）. The present paper deals with a synthetic method and catalytic properties of obtained complexes. The result shows that proper pH value is important for synthesis of the complexes and compositions of the lighter and the heavier rare earth complexes are different under the same reaction condition. Some new complexes obtained have proved their catalytic activity and 80% conversion with the viscosity-average molecular weight 230,000 for the polymerization of methyl methacrylate （MMA） without addition of any cocatalyst.

COMPLEXES OF RARE EARTH NITRATE WITH SCHIFF BASE DERIVED FROM VANILLIN AND P-TOLUIDINE

In this paper,complexes of rare earth nitrate with Schiff base derived from vanillin(3-methoxy-4-hydroxy-benzaldehyde)and p-toluidine[LnL_2(NO_3)_2]NO_3(Ln=La-Eu except Pm,L=Schiff base ligand) have been prepared and characterized.

Magnetocaloric effect and slow magnetic relaxation behavior in binuclear rare earth based RE_(2)(L)_(2)(DMF)4(RE=Gd,Tb,and Dy) complexes

Three binuclear rare earth based complexes combining RE ions with semirigid tricarboxylic ligand(H_(3)L).namely,[RE_(2)(L)_(2)(DMF)_(4)][RE=Gd,Tb,and Dy;H_(3)L=5-((4-Carboxybenzyl)oxy)isophthalic acid;DMF=N,N-dimethylformamide]complexes,were fabricated success fully.The RE_(2)(L)_(2)(DMF)_(4) co mplexe s consist of two central RE ions with the same coordination environment which were connected by two tridentate bridging carboxylic groups and two syn-syn bidentate bridging carboxylic groups originating from the L^(3-)ligands to form the{RE_(2)}dimeric unit,and thus provides the basis for further constructing a dense three-dimensional(3 D)network structure.Moreover,the present RE_(2)(L)_(2)(DMF)_(4) complexes can be described by a topology diagram with the topology point symbol of{4^(2)·6}_(2){4^(4)·6^(2)·8^(7)·10^(2)}.Weak antiferromagnetic(AFM)coupling between the adjacent RE ions for all the present complexes was found according to the magnetic calculations.The observed significant cryogenic magnetocaloric effect(MCE)with the maximum magnetic entropy change-ΔS_(M)^(max) to be 26.3 J/(kg·K)withΔH=7 T in Gd_(2)(L)_(2)(DMF)_(4) complex makes it competitive for the cryogenic magnetic refrigerant.Moreover,the slow magnetic relaxation behavior at 0.2 T dc field with an obvious large U_(eff)/k=45(4)K and τ_(0)=6.5(2)×10^(-10)s was confirmed in Dy_(2)(L)_(2)(DMF)_(4)complex.This work not only provides an effective strategy for obtaining molecular materials with high MCE,but also confirms that tricarboxylate ligands are the ideal choice for constructing stable high dimensional geometric structures.

Rare earth complexes with noncyclic polyether-methionine Schiff base

A novel Schiff base (TAMET) was synthesized by the condensation of tetraglycol aldehyde with methionine and a mild oxidant CrO3. (C5H5N)2 was selected for the reaction. Seven new rare earth complexes with this Schiff base have been synthesized and characterized by elemental analysis, TG-DTA, molar Conductivity, magnetic susceptibility and IR, especially 1H NMR spectra. Information was obtained from reflectance spectra and the coordination of sulfur atom to rare earths was discussed. The experimental results show that these compounds have some biological activity and could dispose of O2?-.

Room temperature polymerization of alkyl isocyanates catalyzed by rare earth Schiff base complexes

The polymerization of alkyl isocyanates catalyzed by rare earth chloride salen complexes/triisobutyl aluminum (Ln(H2salen)2Cl3·2C2H7OH/Al(i-Bu)3) at room temperature was investigated. The influences of ligand structure, catalyst composition, polymerization temperature, polymerization time, the concentration of catalyst and monomer, and the polymerization solvent on the polymerization of isocyanates were studied. It was found that under the polymerization conditions, examined La(H2salenA)2Cl3·2C2-H7OH/Al(i-Bu)3 (H2salenA= N,N′-disalicylideneethylene diamine) is a fairly high efficient catalyst for the polymerization of n-hexyl isocyanate (n-HexNCO) to prepare high molecular weight poly(n-hexyl isocyanate) (PHNCO) with narrower molecular weight distribution at room temperature. PHNCO could be prepared with yield of 74.0%, number-average molecular weight (M n) of 40.20×104 and MWD of 1.79 under the following optimum conditions: [Al]/[La] = 30 (molar ratio), [n-HexNCO]/[La] = 100 (molar ratio), [n-HexNCO] = 3.43 mol/L polymerization at 20°C for 12 h in toluene. In the same polymerization conditions, poly (n-octyl isocyanate) (PONCO) with yield of 67.3%, and poly(n-butyl isocyanate) (PBNCO) with yield of 45.5%, could be prepared respectively. The kinetics of the polymerization of n-HexNCO was also investigated and found to be first-order with respect to both monomer and catalyst concentrations.

The Antitumor Pharmaceutical Study on Some Rare Earth-Schiff's Base Complexes

It has been reported that the complexes of Schiff’s base with the transition elements possess some anticarcinogenic activities, but no such study of complexes of rare earth elements with Schiff’s base has ever appeared. Scientists have paid much attention to the rare earth elements with pharmaceutical activity. Taking advantage of the coordination

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.

Studies on Heterobinuclear Complexes of Ln^(3+) and Zn^(2+) with Acyclic Polyether Schiff Base

Eight novel heterobinuclear complexes of Ln3+ and Zn2+ with salicylidene diethylene glycol diamine(SALDA) Schiff base (NO3)22H2O(Ln=Pr, Nd, Sm, Gd, Tb, Er, Yb, Y) were synthesized and characterized on the basis of IR and UV, particularly by1H and13C NMR spectra. It is confirmed that the azomethine nitrogen, ethereal oxygen and a part of phenolic oxygen atoms coordinate to the central ions.

Synthesis and Spectral Properties of Mixed-Ligand Complexes of Lanthanide Perchlorate with Bis-(phenylsulfinyl)ethane and Organic Lewis Bases

Six lanthanide complexes with bis(phenylsulfinyl)ethane(bphse) and organic bases(phen: 1,10 phenanthroline and bipy: 2,2'-bipyridine) were synthesized and characterized by elemental analysis, conductance and spectral (IR, UV Visible) data. The complexes were Ln(bphse) 2(bipy)(ClO 4) 3· n H 2O and Ln 2(bphse) 3(phen) 2(ClO 4) 6·H 2O(where Ln=Nd, Eu and Gd; n =0～2). IR spectral data confirmed that the lanthanide ions were coordinated by oxygen atoms from bphse and nitrogen atoms from phen or bipy. Exitation and emission spectra of Eu complexes were measured and discussed.

Synthesis and Thermal Decomposition Kinetics of La(Ⅲ) Complex with Unsymmetrical Schiff Base Zwitterion Ligand

A new unsymmetrical solid Schiff base (LLi) was synthesized using L-lysine, o-vanillin and 2-hydroxy-l-naphthaldehyde. Solid La(Ⅲ) complex of this ligand [LaL(NO3)](NO3)·2H2O was prepared and characterized by elemental analyses, IR, UV and molar conductance. The thermal decomposition kinetics of the complex for the second stage were studied under non-isothermal condition by TG and DTG methods. The kinetic equation may be expressed as: dα/dt=A·e-E/RT·(1-α)2. The kinetic parameters(E, A), activation entropy S≠ and activation free-energy G≠ were also gained.

HETEROCYCLIC SCHIFF BASE NEODYMIUM COMPLEX AS CATALYST FOR RING-OPENING POLYMERIZATION OF ε-CAPROLACTONE

An aromatic heterocyclic Schiff base neodymium complex bearing thiazole was synthesized and its activity in the ring-opening polymerization ofε-caprolactone(CL)was examined.The conditions of the CL/Nd molar ratio,monomer concentration,polymerization time and temperature were investigated.Activities of ca.171 kg/Nd·h were obtained under the optimum condition(CL/Nd=1600(molar ratio),[CL]=2.26 mol L^(-1),1 h at 50℃),giving a poly(ε-caprolactone)(PCL)of number-average molecular weight M_n=5.4×10~4 and molecular...

Synthesis and Characterization of Lanthanum Complexes with Amino Acid Schiff Base

Six new complexes of lanthanum with amino acid Schiff base ligands, A-F, were prepared in methanol-aqueous solution. The composition and properties of the title complexes were characterized by elemental analysis, molar conductance, infrared, electronic spectra, H-1 NMR, thermogravimetric and differential thermal analysis.

Syntheses and Characterizations of Cu Ln Heterobinuclear Complexes with Schiff Base from 3-Formylsalicylic Acid and Ethylene Diamine

Seven heterobinuclear complexes of Cu-Ln with N, N'-bis(3-carboxylsali cylidene) ethylenediamine(ES) were synthesized and characterized by elemental analysis, molar conductivity, thermogravimetry, IR and electronic spectra. The room temperature magnetic moments show that there are basically no spin exchange interactions between the ions of Cu2+ and Ln(3+) in the CuLnESCl . nH(2)O compounds.

Synthesis and Application of Lanthanide Complexes with Schiff Base of Pridoxylidence-Glycine

A series of novel rare earths complexes with Schiff base of pridoxylidence-glycine acid (HL) were synthesized in absolute methanol under argon atmosphere. The complexes were characterized by elemental analysis, molar conductivity, IR, UV spectra, and H-NMR spectra et al. Data indicate that the complexes have a general formula Ln LCl2.3H(2)O (Ln = La, Y, Sm, Gd, Dy, Yb; L = C10H11N2O4). Effects of the complexes (Ln = La) on physiological and biochemical indexes of plants under Pb stress were studied. The experiments shown that the complexes obviously mitigated Pb pollution results in decreasing of chlorophyll content, rising of cell membrane permeability, changing catalase(CAT) and distribution of Pb.

Lanthanum heterocyclic Schiff-base complex initiated ring-opening polymerization of ε-caprolactone

Lanthanum complex supported by the heterocyclic Schiff-base ligand of N-(2-pyridyl)-3,5-di-tert-butyl-salicylaldimine was prepared and employed for the ring-opening polymerization(ROP)ofε-caprolactone(ε-CL).The polymers obtained with this initiator showed a unimodal molecular weight distribution implied that only one active species was present.Mechanism study revealed that the polymerization proceeds via acyl-oxygen bond cleavage.

Density Functional Theory Study on La Complex with Schiff-base as Building Block

Quantum density functional theory （DFT） results are reported for the building block [LaL^1（NO3）] of La complex [LaL^1（NO3）]NO3·5H2O （L^1 = （CH3）2CHCH2CH（NCHC4H3O）COO^-）. The structure was optimized and the calculation results show that the lanthanum ion is coordinated by one nitrogen atom and three oxygen atoms of L^1 and two oxygen atoms of nitrate ion. The bond length of La-N is 0.2637 nm and the average length of La-O is 0.2526 nm, which are consistent with the literatures. In addition, the stabilities, electronic structural characteristics and IR spectra of the complex have been analyzed, which describe the coordination of lanthanum ion with other atoms in detail.

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 ].

我国Schiff碱稀土配合物的研究进展

本文对近二十年来Schiff碱稀土配合物的类型、合成方法、谱学性质、结构及在催化。

酰基吡唑啉酮缩β-丙氨酸稀土配合物的合成与光谱表征

在非水溶剂中,β丙氨酸与苯甲酰基吡唑啉酮反应制备出新氨基酸席夫碱试剂:1苯基3甲基4苯甲酰基吡唑啉酮5缩β丙氨酸(HL)。通过回流席夫碱与稀土硝酸盐合成了10种稀土配合物。元素分析与摩尔电导值表明新配合物的组成为[REL2NO3](nH2O(RE=La,Sm,Eu,Tb,Y,n=2;RE=Pr,Ndn=1;RE=Dy,Er,Yb,n=3)。运用红外光谱、紫外光谱、核磁共振谱和荧光光谱对配合物进行了表征。结果表明席夫碱配体以3齿形式配位,RE3+的配位数为8。在可见光区522nm;573,584nm处分别发现Er和Nd配合物的超灵敏跃迁吸收峰。配合物的荧光光谱主要体现稀土离子的ff跃迁发光,配体的发光影响较小。配合物的荧光强度:ITb>ISm>IEu>IDy。