Syntheses aod Crystal Structures of Rare Earth Complexes with Adamantanecarboxylic Acid, [LnL_3(HL)(H_2O)]_2·2EtOH·2H_2O (Ln=Nd (1), La (2))

The title complexes （LnL3 （HL） （H2O） ]2· 2EtOH·2H2O （Ln= Nd （1）, La （2）, HL=adamantanecarboxylic acid） were prepared and determined by single-crystal X-ray diffraction. Both complexes crystallize in triclinic system with space group P 1^-, cell parameters are： complex （1） a = 1.0556（2） nm, b =1.4913（3） nm, c = 1.4920（3） nm, a = 106.26 （3）°, β=93.51（3）°, γ=97.23（3）°, V=2.2253 （5） nm^3, Dcal=1.409 g · cm^-3, Z = I , F （ 000 ） = 990, μ（Mo Kα） = 1. 225 mm^-1, M, = 1884.50; complex （2） a = 1.0453（2） nm, b = 1.4971（3）nm, c = 1.5052（3） nm, α = 106.07（3）°, β =93.58 （3）°, γ=97.56（3）°, V=2.2391（5）nm^3, Dcal= 1.397 g·cm^-3, Z = 1, F（000） =984, μ（Mo Kα） = 1.015 mm^-1, Mr= 1877.88. The final R and wR are 0. 0396 and 0. 1062 for 8589 （1 ≥ 2σ （I）） observed reflections for complex （1）, 0.0505 and 0. 1344 for 8417 （ 1 ≥ 2σ （1） ） observed reflections for complex （2）, respectively. The crystals are consisted of a binuelear molecule. The coordination geometry of the Ln（ Ⅲ ） ion can be described as trieapped trigonal prism.

Synthesis of Eu(Ⅲ) and Tb(Ⅲ) Complexes with New Aryl Amide Type Tetrapodal Ligand and Their Luminescence Properties

A new aryl amide type tetrapodal ligand L (1, 1, 1, 1 tetrakis-{[(2 benzylaminoformyl) phenoxyl]methyl}methane) and its europium and terbium nitrate complexes were synthesized. The luminescence properties of these complexes were also studied.

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 ].

Microwave assisted synthesis, spectroscopic, thermal, and antifungal studies of some lanthanide(Ⅲ) complexes with a heterocyclic bishydrazone

A bishydrazone formed by the condensation of isatinmonohydrazone and salicylaldehyde reacted with lanthanide（Ⅲ） chloride to form complexes of the type [Ln（HISA）2Cl3], where, Ln=La（Ⅲ）, Ce（Ⅲ）, Pr（Ⅲ）, Nd（Ⅲ）, Sm（Ⅲ）, Eu（Ⅲ）, or Gd（Ⅲ） and HISA= [（2-hydroxybenzaldehyde）-3-isatin]bishydrazone. Both reactions were carried out under microwave conditions. The ligand and the metal complexes were characterized on the basis of elemental analysis, molar conductance, magnetic susceptibility measurements, UV visible, infrared, far infrared, and proton NMR spectral data. The ligand acted as neutral tridentate, coordinating through the carbonyl oxygen, azomethine nitrogen, and phenolic oxygen without deprotonation. The ligand and lanthanum（Ⅲ） complex were subjected to X-ray diffraction studies. The X-ray diffraction pattern of ligand exhibited its crystalline nature and that of the lanthanum（Ⅲ） complex indicated its amorphous character. The thermal decomposition behaviour of the complex, [La（HISA）2Cl3], was examined in the temperature range of 40-800 ℃ using TG, DTG, and DTA. The ligand and the metal complexes were screened for their antifungal activities.

Eu(Ⅲ) complexes involving 1,3,5-triazine diphosphine oxides

The 1,3,5-triazine diphosphine oxide ligands with donor-acceptor properties formed strong complexes with europium（Ⅲ） ion in acetonitrile. Spectrophotometric titrations and mass spectra indicated that two ligands coordinated to one europium ion. The stability constants varied from 11.64 to 14.60 （log 13）. Binary complexes exhibited rather weak luminescence in solution. 1,3,5-triazine diphosphine oxides engaged as co-ligands in Eu（Ⅲ） （2-thenoyltrifluoroacetonate）3 complex contributed to the overall photoluminescence and allowed for excitation with longer wavelengths than the parent complex.

Isolation and Spectroscopic Characterization of Protonated Mixed [Tetrakis (4-pyridyl)porphyrinato] (phthalocyaninato)Rare Earth (Ⅲ)Double-decker Compounds

The treatment of tetrakis (4-pyridyl) porphyrin H2TPyP with a hydrated rare earth (III) acetylacetonate RE(acac)3 · nH2O (RE=Y, Eu, Gd) in 1,2, 4-trichlorobenzene (TCB) pro- duced a monomeric porphyrinato rare earth compound RE (TPyP) acac, which further reacted with dicyanobenzene in amyl alcohol in the presence of 1, 8-diazabicyclo [5. 4. 0] undec-7-ene (DBU), giving HRE(TPyP) (Pc) in a good yield. Upon exposure to air, part of the protonated mixed double-deckers in CHC13 solutions converted slowly to the corresponding neutral complexes RE (TPyP) (Pc). These protonated complexes were characterized by means of UV-V is, IR, NMR, mass spectroscopies. The quaternarization of these protonated mixed double-deckers with methyl iodide produced the salts of tetramethylated cations [HRE(TMPyP) (Pc)]4+.

Syntheses and Structural Studies of Nine-Coordinate Mononuclear K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O and Binuclear K_4[Eu~~Ⅲ__2(Httha)_2]·13.5H_2O Complexes

The crystal and molecular structures of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O (H_4 edta=ethylenediaminetetraacetic acid) and K_4[Eu~~Ⅲ__2(Httha)_2]·13.5H_2O (H_6 ttha=triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses. The crystal of K[Eu~Ⅲ(edta)(H_2O)_3]·3.5H_2O complex belongs to orthorhombic crystal system and Fdd2 space group. The crystal data are as follows: a=1.9849(6)nm, b=3.5598(11)nm, c=1.2222(4)nm, V=8.636(5)nm^3, Z=16, M=596.37, D_c=1.835 g·cm^(-3), μ=3.166 mm^(-1) and F(000)=4752. The final R and wR values are 0.0269 and 0.0692 for 2936 [I>2.0σ(I)] reflections, and 0.0317 and 0.0708 for all 7284 unique reflections, respectively. The [Eu~Ⅲ(edta)(H_2O)_3]-complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O are from one edta ligand and three water molecules. The crystal of the K_4[Eu~Ⅲ_2(Httha)_2]·13.5H_2O complex belongs to monoclinic system and P2(1)/n space group. The crystal data are as follows: a=1.1337(3) nm, b=2.5753(6) nm, c=2.2138(6) nm, β=102.871(5)°, V=6.301(3) nm^3, Z=4, M=1682.33, D_c=1.773 g·cm^(-3), μ=2.339 mm^(-1) and F(000)=3404. The final R and wR are 0.0514 and 0.0906 for 11144 [I>2.0σ(I)] reflections, and 0.0976 and 0.1068 for all 26048 unique reflections, respectively. The complex molecule is composed of two close parts in structure. Every part around the Eu~Ⅲ ion in the [Eu~~Ⅲ__2(Httha)_2]^(4-) complex anion has a nine-coordinate structure with distorted monocapped square antiprismatic prism, in which the ttha ligand coordinates to one central Eu~Ⅲ ion with three N atoms and four O atoms and to the other Eu~Ⅲ ion with two O atoms.

Structure and Bonding in Some Gd(Ⅲ) Metal Complexes Studied by Three-Dimensional X-Ray Analysis and ^(155)Gd Mssbauer Spectroscopy

Some functional lanthanide metal complexes, such as acetylacetonato complexes, ethylenediaminetetraacetato complexes, were successfully applied for diagnostic technique. The authors are interested in investigating the structure and bonding in lanthanide and actinide metal complexes using 166Er, t55Gd, and 237Np Mtissbauer spectroscopies in connection with single-crystal and/or powder X-ray diffraction, making clear the differences on their structures as well as the differences in the participation of 4f and 5f orbitals in the chemical bonds. In this article, the crystal structures of two novel Gd（Ⅲ） acetylacetonato complexes, Gd（pta）3 · 2H2O （pta = 1,1,1 -trifluoro-5,5-dimethy 1-2,4-hexanedione） and Gd（bfa）3 · 2H2O （bfa = 1, 1, 1 -trifluoro-4-phenyl-2-4-butanedione） were reported. Though both of them were dihydrate and had distorted square antiprismatical structure, Gd（pta）3 · 2H2O crystallizes in the P 2 1/n （#14） monoclinic space group and its lattice parameters are a = 1.4141（6） nm, b = 1.0708（3） nm, c =2.2344（4） nm, β =952.4（2）°, and Gd（bfa）3· 2H2O crystallizes in P 212121 orthorhombic space group and its lattice parameters were a = 1.322 （1） nm, b = 2.295 （1） nm, c = 1. 0786（8） nm. In the meantime, the authors had finished a systematic investigation on the ^155Gd Mossbauer isomer shift （δ） of various Gd（Ⅲ） metal complexes having a different coordination number （C.N.） and different ratios coordinating oxygen to nitrogen. A tendency for the 6 value to decrease with an increase in the C.N, and the number of the nitrogen atom coordinating to Gd was confirmed. This indicated that the Gd-O and/or Gd-N bond in the investigated Gd（Ⅲ） metal complexes had a small covalent contribution, which was possible to be deduced from the O and/or N atoms of the lisands donating electrons to 6s, 5d, and 4f orbitals of Gd.

Studies on some lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine

Seven new lanthanide（Ⅲ） complexes with 4-hydroxyantipyrine were synthesized. These complexes were characterized by elemental analysis, molar conductance, magnetic moment measurements, FT-IR, electronic and 1HNMR spectra, X-ray powder diffraction, and thermogravimetric studies. The ligand, 4-hydroxyantipyrine （hap）, contained carbonyl oxygen and hydroxyl oxygen as potential donor sites. On coordination, deprotonation occurred and as a result, hap acted as a monobasic bidentate ligand. A coordination number 6 was assigned to the lanthanide（Ⅲ） ions in these complexes with orthorhombic structure. All the complexes were thermally stable-150℃ and underwent decomposition in three stages with the formation of Ln2O3 as the final residues.

Syntheses and Crystal Structure of Nine-Coordinate Mononuclear Na[ EuⅢ (edta)(H2O)3] · 4H2O and Binuclear Na4[Eu2Ⅲ(Httha)2]·10H2O Complexes

The crystal and molecular structures of the Na[Eu Ⅲ (edta) ( H2 O) 3] · 4H2O ( edta = ethylenediaminetetraacetic acid) and Na4[Eu2Ⅲ (Httha)2] · 10H2 O ( ttha = triethylenetetraminehexaacetic acid) complexes were determined by single-crystal X-ray structure analyses.The crystal of Na[ EuⅢ (edta) (H2O)3] · 4H2O belongs to orthorhombic crystal system and Fdd2 space group.The crystal data are as follows: a = 1.9415 (15)nm, b = 3.544(3 )nm, c = 1.203(9)nm, V = 8.327(5)nm3, Z = 16, M = 589.27, Dc= 1.880 g· cm-3, μ= 3.108mm-1 and F(000) = 4704.The final R and wR values are 0.0312 and 0.0750 for 2091[I ＞ 2.0σ (I)] reflections, and 0.0344and 0.0766 for all 3932 unique reflections, respectively.The[EuⅢ (edta) (H2O) 3] - anion has a nine-coordinate pseudo-monocapped square antiprismatic structure in which the nine coordinate atoms, two N and seven O, are from one edta ligand and three water molecules.The crystal of Na4[Eu2Ⅲ (Httha)2] · 10H2O belongs to orthorhombic system and Pccn space group.The crystal data are as follows: a = 2.610(3)nm, b = 2.089(3)nm, c = 2.239(3)nm, V =12.208 ( 28 ) nm3, Z = 8, M = 1548.92, Dc= 1.686g·cm-3,μ = 2.115 mm-1andF(000) = 6272.Thefinal R and wR are 0.0625 and 0.1091 for 9834[I ＞ 2.0σ(I)] reflections, and 0.1608 and 0.1471 for all 37818 unique reflections, respectively.The whole complex molecule is composed of two close parts in which each one has a nine-coordinate structure with distorted monocapped square antiprismatic prism.The ttha ligand in the[Eu2Ⅲ (Httha)2] 4- anion coordinates to one Eu Ⅲ ion with three N atoms and four O atoms and to the other Eu Ⅲ ion with two O atoms.

Intercalation Assembly, Characterization and Luminescent Properties of Novel Supramolecular Composite Materials, Tb(Ⅲ) Complex with Tetrapodal Ligand-Montmorillonite

Two kinds of Tb（ Ⅲ ） complexes with tetrapodal ligand, [TbL（NO3）]^3＋ and [TbL]^3＋ （L： 1,1, 1＇, 1＇-tera （ 2-pyridinecarboxylester ）-di （ trimethylpropane）） were intercalated into the interlayer space of montmorillonite （MT） by ion exchange and coordination reaction of L with the Tb^3＋ ion existing in the interlayer space of Tb-MT respectively. The obtained luminescent supramolecular composite materials, [ TbL （NO3） ]^2＋-MT and [TbL]^3＋-MT were characterized by elemental analysis, XRD, FT-IR, UV-vis and thermal analysis. At the same time, the luminescent properties of the materials were also studied. The results show that the intercalated materials with regular layered structure, good thermal stability and the interlayer spacing （d001） approximates to the size of the complex ions which are located in the interlayer space of MT in the form of a monolayer.

Photoluminescence and electrochemiluminescence studies of chosen rare earths systems

Eu（Ⅲ） complexes with chosen Keggin polyoxomatalates, POM, containing organic counter cations （tetrabutylarnmonium, tetrabutylphosphonium, triphenylethylphosphonium）, were synthesized, and their photophysical properties were studied. The synthesized complexes had the general formula of XnH5-n[EuSiW11O39], formulated based on the results of elemental and thermogravimetric analysis and FTIR spectroscopy. The photophysical properties of the obtained compounds were investigated using photoluminescence and electrochemiluminescence, ECL, methods in solutions and solids. The most intense luminescence of Eu（Ⅲ） was observed for the complexes with tetrabutylarnmonium cations. After the addition of phenanthroline to the XnH5-n[EuSiW11O39] solutions, a large increase in the Eu（Ⅲ） luminescence intensity and a lengthening of its luminescence lifetime were observed as a result of the formation of ternary complexes. Attempts to apply ECL as a method of light emission by generating species capable of forming excited states in Ln/POMs, i.e., Tb（Ⅲ） and Eu（Ⅲ） in the Na9EuW10O36 and Na9TbW10O36 complexes, were made. The influence of the POM complexes on the ECL was also tested using the Tb/EDDHA （EDDA=ethylenediamine di（o-hydroxyphenylacetic acid）） complex, which is effective in generating ECL.

Crystal Structure and Fluorescent Study of a Binuclear Europium(Ⅲ) Complex

A novel binuclear Eu（Ⅲ） complex [Eu2（dpa dioxide）2（NO3）4（bpdioxide）-（EtOH）] （dpa dioxide = di-2-pyridylamine N,N＇-dioxide, bpdioxide = 2,2＇-bipyridine N,N＇-dioxide） has been synthesized and it exhibits strong and sharp fluorescent emission at 614 nm under UV radiation of 245 nm at room temperature. X-ray structural determination indicates two independent Eu（Ⅲ） ions in the structure with different EuO8N and EuOgN environments. The compound crystallizes in the triclinic system, space group P1, with a = 10.8089（7）, b = 11.4670（8）, c = 17.1440（12） A, α = 92.834（2）, β = 93.854（3）, γ = 95.433（2）°, Z = 2, Dc = 1.876 g/cm3, V= 2107.3（2） A3, F（000） = 1168.0, the final R = 0.032 and wR = 0.086 for 6331 observed reflections with I 〉 2σ（I）.

Synthesis, Structure and Properties of a Two-dimensional Samarium(Ⅲ) Complex of 1,3-Benzenedicarboxylic Acid and 1,10-Phenanthrolin

The title complex [Sm2（bdc）3（phen）2]n （1, H2bdc = 1,3-benzenedicarboxylic acid, phen = 1,10-phenanthrolin）, a new samarium（III） complex based on ligand H2bdc and 1,10-phen- anthrolin, has been hydrothermally synthesized and characterized by elemental analysis, FT-IR, and single-crystal X-ray diffraction. The crystal structure reveals that the Sm（1） centre adopts an eight-coordinated distorted square anti-prism coordination geometry, while the Sm（2） centre adopts a nine-coordinated distorted monocapped square prism coordination geometry. The ligand bdc2- takes two different connecting modes and links the Sm（llI） centers to give rise to a 2D network structure. Further, 2D layers of 1 are connected together to form a 3D structure through C-H-O hydrogen bonding interactions. The luminescent property and thermal stability of complex 1 are studied. 1 belongs to the triclinic system, space group P1 with a = 10.7367（5）, b = 14.3750（7）, c = 13.7505（3）A, a = 92.8840（10）, β = 104.4010（10）, ）, = 98.1400（10）°, Z= 2, V= 2143.44（18） A3, Mr = 1153.44, Dc = 1.787 g/cm3, F（000） = 1128,μ= 2.784 mm-1, the final R = 0.0279 and wR = 0.0720 for 8226 observed reflections with 1 〉 2σ（I）.

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.

Structure of Complexes of Lanthanides with N,N′-Dimethyl-3-Oxa-Glutaramic Acid

A new stripping agent N,N-dimethyl-3-oxa-glutaramic Acid (DOGA) was used in TRPO process to simplify the TRPO process. The structures of the complexes of the DOGA with Eu(Ⅲ), Nd(Ⅲ), La(Ⅲ) were characterized with extended X-ray absorption fine structure spectroscopy (EXAFS), infrared spectra (IR) and mass spectra (MS). The molecular formula of the complexes of Eu(Ⅲ) and Nd(Ⅲ) is deduced to be M(DOGA)_3, and only La(Ⅲ) can form the complex HM(DOGA)_4 under condition of high consistency of the DOGA. The coordination number of Ln(Ⅲ) in the complexes is 8, and all of coordinated donor atoms are O atoms. For Eu(Ⅲ), Nd(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of Ln-O are 0 240 nm, 0 244 nm respectively, while the numbers of the second O shell are 2.4, and the average coordination bond lengths of Ln-O are 0 260 nm, 0 262 nm. For La(Ⅲ), the coordination numbers of O atom in the first coordination shell is 6 and the average coordination bond lengths of La-O are 0 258 nm, while the number of O atom in the second coordination shell is 4.4, and the average coordination bond length of La-O is 0 28 nm. The results of IR and MS show that there is no water coordinating with Ln(Ⅲ) in the complexes.

Synthesis, Characterization and Crystal Structure of Quaternary Complex of Gadolinium (Ⅲ)

A new quaternary mixed anion complex of gadolinium(Ⅲ), [Gd(CH 3CH 2COO) 2(N O 3)(phen)] 2, was synthesized and structurally characterized. The ESR spectr um of the complex with effective g values of 5.314, 2 473 and 1.880 in poly crys talline powder at room temperature is quite different from the U spectrum. The c oordination number of Gd 3+ is nine with a monocapped square antiprism geom etry. And the stacking effect was observed in the complex. The crystal of the co mplex belongs to triclinic with space group P 1, a=0.9626(4) n m, b=0.9732(4) nm, c=1.1758(5) nm, α=102.45(1)°, β=108.16(1) °, γ=96.68(2)°, V=1.0018(7) nm3, Z=2, D c=1.80 g·cm -3 , μ(MoKα)=33.63 mm -1, F(000)=530, GOF=1.80, R=0.023 and R w=0.027.

Synthesis, Characterization, Thermal Decomposition Mechanism and Non-Isothermal Kinetics of Salicylaldehyde Salicylhydrazone and Its Complex of Erbium(Ⅲ)

The salicylaldehyde salicylhydrazone and its complex of Er(Ⅲ) were synthesized. The formulae K·4H_2O(HL=[C_(14)H_(10)N_2O_3]^(2-), the bivalent form of the salicylaldehyde salicylhydrazone) were determined by elemental analysis and EDTA volumetric analysis. Molar conductance, IR, UV and X-ray power diffraction were carried out for the characterizations of the complex and the ligand. There are two stable five-numbered and six-numbered circles in the complex. The thermal decompositions of the ligand and the complex with the kinetic study are carried out by non-isothermal thermogravimetry. The stages of the decompositions were identified by TG-DTG curve. The non-isothermal kinetic data were analyzed by means of integral and differential methods. The possible reaction mechanism and the kinetic equation were investigated by the corresponding kinetic parameters.The activation energy value of the main step decomposition are also calculated by Kissinger′s method and Ozawa′s method.

Syndiotactic Polymerization of Styrene and Copolymerization with Ethylene Catalyzed by Chiral Half-sandwich Rare-earth Metal Dialkyl Complexes

The syndiotactic polymerization of styrene（St） and the copolymerization of St with ethylene（E） were carried out by using a series of chiral half-sandwich rare-earth metal dialkyl complexes（Cp^x＊） as the catalysts. The complexes are Ln（CH2SiMe3）2（THF）（1-4： Ln = Sc（1）, Ln = Lu（2）, Ln = Y（3）, Ln = Dy（4）） bearing chiral cyclopentadienyl ligand containing bulky cylcohexane derivatives in the presence of activator and AliBu3. For the St polymerization, a high activity up to 3.1 × 10^6 g of polymer mol Ln^-1·h^-1 and a high syndiotactic selectivity more than 99% were achieved. The resulting syndiotactic polystyrenes（sPSs） have the molecular weights（Mn） ranging from 3700 g·mol^-1 to 6400 g·mol^-1 and the molecular weight distributions（Mw/Mn） from 1.40 to 5.03. As for the copolymerization of St and E, the activity was up to 2.4 × 10^6 g of copolymer mol Sc^-1·h^-1·MPa^-1, giving random St-E copolymers containing syndiotactic polystyrene sequences with different St content in the range of 15 mol%-58 mol%. These results demonstrate that the bulky cyclopentadienyl ligands of the chiral half-sandwich rare-earth metal complexes effectively inhibit the continued insertion of St monomers into the（co）polymer chain to some extent in comparison with the known half-sandwich rare-earth metal complexes.

Density functional theory study of the magnetic properties of rare earth complexes:the magnetic coupling mechanism in Y~Ⅲ and Gd~Ⅲ complexes with nitronyl nitroxide

The magnetic coupling interactions of the nitronyl nitroxide radicals bound to diamagnetic(YⅢ) and paramagnetic(GdⅢ) rare earth ions in two model magnetic systems based on novel rare earth organic radical complexes Ln(hfac)3(NITPhOCH3)2(Ln=YⅢ 1,GdⅢ 2;hafc = hexafluoroacetylacetonate;NIT-PhOCH3 = 4'-methoxyo-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been investigated by density functional theory(DFT).The magnetic coupling mechanisms were also explored from the viewpoint of molecular orbital and spin density populations.DFT calculations show that the empty 4d-orbitals of YⅢ and 5d-orbitals of GdⅢ play an important role in the antiferromagnetic coupling between the two nitronyl nitroxide radical ligands,and that the ferromagnetic coupling between the GdⅢ ion and the radical magnetic centers can be attributed to the nearly complete localization of the isotropic 4f-shell and singly occupied magnetic orbital(π) of the nitronyl nitroxide.