Pseudo-monocapped Square Research Articles

Syntheses, structural determination, and binding studies of binuclear nine-coordinate (MnH)4[Ho 2 III (Dtpa)2] · 12H2O and polynuclear nine-coordinate {(MnH)[HoIII(Egta)] · 3H2O} n

Two novel rare earth metal coordination compounds, (MnH)4[Ho 2 III (Dtpa)2] · 12H2O (I) (Mn = methylamine, H5Dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaaceticacid) and {(MnH)[HoIII(Egta)] · 3H2O} n (II) (H4Egta = ethyleneglycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) have been successfully synthesized through direct heating reflux and characterized by FT-IR spectroscopy, thermal analysis, and single-crystal X-ray diffraction techniques (CIF files CCDC nos. 890878 (I) and 1457061 (II)). Complex I shapes a binuclear nine-coordinate structure with distorted tricapped trigonal prismatic conformation and crystallizes in the triclinic crystal system with space group P1. The central Ho3+ ion is coordinated by three nitrogens and six oxygens from two octadentate Dtpa ligands. The cell dimensions are as follows: a = 9.8420(10), b = 12.1319(13), c = 13.2931(15) A, α = 89.223(2)°, β = 68.4280(10)°, γ = 72.1280(10)° and V = 1396.0(3) A3. Complex II adopts a polynuclear nine-coordinate structure with pseudo-monocapped square antiprismatic conformation and crystallizes in the monoclinic crystal system with space group C2/c. The central Ho3+ ion is coordinated by two nitrogens and seven oxygens from two octadentate Egta ligands. The crystal data are as follows: a = 38.4755(13), b =13.5569(5), c = 8.7343(3) A, β = 100.135(3)° and V = 4484.8(3) A3.

Synthesis and structural determination of 2D ladder-like mononuclear nine-coordinate (EnH2)[NdIII(Egta)H2O]2 · 6H2O and ten-coordinate (EnH2)1.5[NdIII(Ttha)] · 5H2O

Two novel lanthanide complexes, (EnH2)[NdIII(Egta)H2O]2 · 6H2O (I) and (EnH2)1.5[NdIII(Ttha)] · 5H2O (II), where En = ethylenediamine, H4Egta = ethyleneglycol-bis-(2-aminoethylether)-N,N,N′,N'-tetraacetic acid and H6Ttha = triethylenetetramine-N,N,N',N'',N''',N'''-hexaacetic acid, have been successfully synthesized through direct heating reflux and their molecular and crystal structures were determined by FT-IR spectroscopy, thermal analysis and single crystal X-ray diffraction (CIF files CCDC nos. 1436598 (I) and 1433221 (II)). X-ray diffraction reveals that I has a nine-coordinate mononuclear structure with pseudo-monocapped square antiprismatic conformation. Complex I crystallizes in a monoclinic system with P21/c space group; a = 13.0919(12), b = 12.6840(11), c = 16.9751(14) A, β = 122.069(3)° and V = 2388.7(4) A3. Complex II takes ten-coordinated structure with a distorted bicapped square antiprismaticprism belong to triclinic crystal system with P1 space group; a = 9.9376(10), b = 12.2178(12), c = 15.2671(16), β = 100.2480(10)° and V = 1609.5(3) A3. Each EnH2 2+ cation in I connects four adjacent [NdIII(Egta)H2O]– anions through hydrogen bonds. In II crystal cell, there are two types of cations, which form hydrogen bonds with the neighboring [NdIII(Ttha)]3– anions, leading to the formation of a 2D ladder-like layer structure. The results showed that the change of ligands can lead to change of the structure of the complexes, coordination numbers and coordination geometries. Thus, it can be concluded that the shape of ligands play a crucial role on the coordinate structure of complexes, coordination numbers and coordination geometries.

Syntheses and structural determination of mononuclear nine-coordinate (MnH)[GdIII(EDTA)(H2O)3] · 4H2O and 2D ladder-like binuclear nine-coordinate (MnH)2[Gd 2 III (H2TTHA)2] · 4H2O

Two title rare earth metal coordination compounds, (MnH)[GdIII(Edta)(H2O)3] · 4H2O (I) and (MnH)2[Gd2III(H2Ttha)2] · 4H2O (II), where Mn = methylamine, H4Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid, H6Ttha = triethylenetetramine-N,N,N′,N″,N′″,N′″-hexaacetic acid), have been successfully synthesized through direct heating reflux and characterized by FT-IR spectroscopy, thermal analysis and single-crystal X-ray diffraction techniques. In complex I, the Gd3+ ion is nine-coordinated by an Edta ligand and three water molecules, yielding a pseudo-monocapped square antiprismatic (MC-SAP) conformation. Complex I crystallizes in the orthorhombic crystal system with space group Fdd2. The cell dimensions are as follows: a = 19.5207(17), b = 35.387(3), c = 12.5118(11) A, and V = 8642.8(13) A3. The central Gd3+ ion of II is also ninecoordinate, forming tricapped trigonal prismatic (TC-TP) conformation with three amine nitrogen atoms and six oxygen atoms. Complex II crystallizes in the monoclinic crystal system with P2/c space group. The crystal data are as follows: a = 14.4301(13), b = 11.2400(11), c = 17.7102(16) A, β = 112.606(2)°, and V = 2651.8(4) A3. There retain outer-protonated and inner-protonated carboxyl oxygen atoms in the [Gd2III(H2Ttha)2]2− complex anion. In II, there are only one type of methylamine cation (MnH+) as the counter ion, which connects [Gd2III(H2Ttha)2]2− complex anions and lattice water molecules through hydrogen bonds, leading to the formation of 2D ladder-like layer structure.

Syntheses, structural determination, and binding studies of nine-coordinate mononuclear (mnH)2[DyIII(Httha)]·3H2O and (enH2)3[DyIII(ttha)]2·9H2O

Two dysprosium coordination compounds, (mnH)2[DyIII(Httha)]·3H2O (1) (H6ttha = triethylenetetramine-N,N,N′,N″,N′′′,N′′′-hexaacetic acid and mn = methylamine) and (enH2)3[DyIII(ttha)]2·9H2O (2) (en = ethylenediamine), were synthesized through direct heating and characterized by elemental analysis, FT-IR, thermal analysis, and single-crystal X-ray diffraction. X-ray diffraction analysis displays that 1 is a mononuclear nine-coordinate complex with a pseudo-monocapped square antiprismatic conformation (MCSAP) crystallizing in the monoclinic crystal system with P2(1)/c space group. The crystal data are as follows: a = 16.1363(19) Å, b = 13.9336(11) Å, c = 13.6619(14) Å, β = 102.2490(10)°, and V = 3001.8(5) Å3. There are two kinds of methylamine cation in 1. They connect [DyIII(Httha)]2−and crystal waters through hydrogen bonds, leading to formation of a 2-D ladder-like layer structure. The polymeric 2 also is a nine-coordinate structure with a pseudo-MCSAP crystallizing in the monoclinic crystal system with P2/c space group. The cell dimensions are: a = 17.7801(16) Å, b = 9.7035(10) Å, c = 22.096(2) Å, β = 118.874(2)°, and V = 3338.3(6) Å3. In 2 there are also two types of ethylenediamine cations. One connects three adjacent [DyIII(ttha)]3− complex anions through hydrogen bonds and the other is symmetrical forming hydrogen bonds with two neighboring [DyIII(ttha)]3− complex anions. These hydrogen bonds result in formation of a 2-D ladder-like layer structure as well.

Syntheses, structural determination, and binding studies of mononuclear nine-coordinate (EnH2)1.5[HoIII(Ttha)] · 4.5H2O and two dimensional unlimited network (EnH2)[HoIII(Egta)(H2O)]2 · 6H2O

Two novel complexes, (EnH2)1.5[HoIII(Ttha)] · 4.5H2O (I) (En = ethylenediamine and H6Ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (EnH2)[HoIII(Egta)(H2O)]2 · 6H2O (II) (H4Egta = ethyleneglycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid), were synthesized and their crystal structures were determined by single crystal X-ray diffraction techniques. Complex I has a nine-coordinate mononuclear structure with distorted tricapped trigonal prismatic conformation and crystallizes in the monoclinic crystal system with P2/n space group. The crystal data are as follows: a = 17.7541(18), b = 9.6810(10), c = 22.166(2) A, β = 118.913(2)°, and V = 3335.0(6) A3. Complex II has a mononuclear nine-coordinate structure with pseudo-monocapped square antiprismatic conformation and crystallizes in the monoclinic crystal system with P21/n space group. The crystal data are as follows: a = 12.978(8), b = 12.685(8), c = 14.905(9) A, β = 105.333(7)°, and V = 2366(2) A3. In I, there are two types of EnH22+ anions. They connect to [HoIII(Ttha)]3− by hydrogen bonds leading to the formation of 3D pore structure along z axis. In II, EnH22+ cation connects three adjacent [HoIII(Egta)(H2O)]− complex anions through hydrogen bonds, these hydrogen bonds lead to the formation of 2D network structure in [101] plane. The results showed that ligand structures play a crucial role in crystal and molecular structure of their complexes. In addition, the protonated (EnH22+) cations conjugating to [HoIII(Ttha)]3− and [HoIII(Egta)(H2O)]− complex anions are reviewed, which act as an important beginning for study of Ho(III) complexes conjugating with other various amino and heterocyclic biomolecule.

New nine-coordinate (NH4)3[YbIII(ttha)]·5H2O and eight-coordinate (NH4)[YbIII(pdta)(H2O)2]·5H2O complexes: Structural determination

The (NH4)3[YbIII(ttha)]·5H2O (I) (H6ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (NH4)[YbIII(pdta)(H2O)2]·5H2O (II) (H4pdta = propylenediamine-N,N,N′,N′-tetraacetic acid) complexes are synthesized by heat-refluxing and acidity-adjusting methods, and their structures are determined by single crystal X-ray diffraction techniques. These two complexes are all mononuclear structures. The complex I crystallizes in ttha monoclinic crystal system with the P21/c space group. The central YbIII ion is nine-coordinated only by one the ligand, and one non-coordinate carboxyl group is left. The crystal data are as follows: a = 10.321(4) A, b = 12.744(5) A, c = 23.203(9) A, β = 91.082(6)°, V = 3051(2) A3, Z = 4, Dc = 1.754 g/cm3, μ = 3.150 mm−1, F(000) = 1636, R = 0.0357, and wR = 0.0672 for 6203 observed reflections with I ≥ 2σ(I). The YbN4O5 part in the [YbIII(ttha)]3− complex anion forms a pseudo-monocapped square antiprismatic polyhedron. The complex II is coordinated with one pdta ligand and two water molecules, which form an eight-coordinate structure, and crystallizes in the triclinic crystal system with the \(P\bar 1\) space group. The YbN2O6 part in the [YbIII(pdta)(H2O)2]− complex anion makes a pseudo-square antiprismatic polyhedron. The crystal data are as follows: a = 9.8923(9)A, b = 10.9627(10) A, c = 12.2618(11) A, α = 67.284(5)°, β = 70.956(6)°, γ = 68.741(5)°, V = 1115.97(18) A3, Z = 2, Dc = 1.843 g/cm3, μ = 4.264 mm−1, F(000) = 618, R = 0.0177, and wR = 0.0409 for 4036 observed reflections with I ≥ 2σ(I).

Syntheses, Characterization and Structural Determination of Nine Coordinated N2H5[Ce(edta)(H2O)3]·4H2O and N2H5[Eu(edta)(H2O)3]·4H2O

Hydrazinium complexes of Ce(III) and Eu(III) ethylenediaminetetra-acetate hydrates have been synthesized in aqueous solution and characterized by hydrazine and metal analyses, elemental analysis, infrared spectra, X-ray power diffraction and single crystal X-ray diffraction techniques. The CeIIIN2O7 parts in the complex anion has a pseudomono-capped square antiprismatic nine-coordinate structure, in which the six coordinated atoms (two N and four O) from the ethylenediaminetetraacetate ion and three water molecules are coordinated to the central rare earth metal ion directly. The EuIIIN2O7 part in the complex anion has the same structure as CeIIIN2O7 part. The crystal of the cerium complex belongs to the orthorhombic crystal system and Fdd2 space group. The crystal data are the follows: a = 19.7281(7) A, b = 35.7790(11) A, c = 12.3244(4) A, α = β =γ = 90°, V = 8699.2(5) A3. The final R and Rw are 0.020 and 0.0589 for with I > 2σ (I) and 3,842 reflections, respectively. The crystal of the europium complex is isostructural with the cerium complex. The crystal data of europium complex are: a = 19.7281(7) A, b = 35.7790(11) A, c = 12.3244(4) A, α = β =γ = 90°, V = 8699.2(5) A3. The final R and Rw are 0.0252 and 0.687 for with I > 2σ (I) and 3,842 reflections, respectively. The X-ray powder diffraction patterns and infrared spectra of the complex are super imposable indicating their structural similarity. Hydrazinium complexes of cerium(III) and europium(III) ethylenediaminetetraacetate hydrates have been synthesized and characterized by analytical, spectral, thermal and X-ray studies. The crystal structures of both the complexes have been described.

Syntheses, structural determination, and binding studies of nine-coordinate mononuclear complexes (EnH2)3[EuIII(Etha)]2 · 11H2O and (EnH2)[EuIII(Egta)(H2O)]2 · 6H2O

Two novel ethylenediaminium salt of europium complexes with aminopolycarboxylic acid ligands, (EnH2)3[EuIII(Ttha)]2 · 11H2O (I) (En is ethylenediamine, H6Ttha is triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (EnH2)[EuIII(Egta)(H2O)]2 · 6H2O (II) (H4Egta is ethyleneglycol-bis(2-aminoethylether)-N,N,N′,N′-tetraacetic acid) complexes were synthesized, and their crystal structures were determined by single-crystal X-ray diffraction techniques. Both of the two complexes adopt nine-coordinate structures with the pseudo-monocapped square antiprism and crystallize in the monoclinic crystal system with the P21/n space group. The crystal data for complex I are as follows: a = 17.8262(8), b = 19.3137(5), c = 20.6233(8) A, β = 111.301(2)°, V = 6615.3(4) A3, Z = 8, ρc = 1.677 mg/m3, μ = 1.981 mm−1, F(000) = 3432, R = 0.0308, and wR = 0.0737 for 43622 observed reflections with I ≥ 2σ(I). The crystal data for complex II are as follows: a = 12.952(3), b = 12.618(2), c = 14.809(3) A, β = 105.695(2)°, V = 2330.0(8) A3, Z = 4, ρc = 1.800 mg/m3, μ = 2.765 mm−1, F(000) = 1276, R = 0.0297, and wR = 0.0638 for 18416 observed reflections with I ≥ 2σ(I). One remarkable feature of the two complexes is that the protonated [EnH22+] cations conjugating to [EuIII(Ttha)]26− and [EuIII(Egta)(H2O)]22− complex anions are reviewed, respectively, which open the path for the EuIII complexes conjugating with other various biomolecules.

Syntheses, structural determination, and binding studies of binuclear eight-coordinate (enH2)[GdIII 2(pdta)2(H2O)2] · 8H2O and mononuclear nine-coordinate (enH2)[GdIII(egta)(H2O)]2 · 6H2O

The (enH2)[GdIII 2(pdta)2(H2O)2] · 8H2O (1) (en = ethylenediamine and H4pdta = propylenediamine-N, N, N′, N′-tetraacetic acid) and (enH2)[GdIII(egta)(H2O)]2 · 6H2O (2) (H4egta = ethyleneglycol-bis-(2-aminoethylether)-N, N, N′, N′-tetraacetic acid) complexes were synthesized and characterized by infrared spectrum, thermal analysis, and single-crystal X-ray diffraction. The complex (enH2)[GdIII 2(pdta)2(H2O)2] · 8H2O has a binuclear eight-coordinate structure with pseudo square antiprism and crystallizes in the monoclinic crystal system with C2/c space group. Through a carboxylate bridge, an infinite 1-D zigzag polymeric binuclear [GdIII 2(pdta)2(H2O)2]2− complex anion is formed. All infinite zigzag polymeric complex anions link through hydrogen bonds, yielding a layer structure. (enH2)[GdIII(egta)(H2O)]2 · 6H2O has a mononuclear nine-coordinate structure with pseudo monocapped square antiprism and crystallizes in the monoclinic crystal system with P21/n space group. Each enH2 2+ cation, through hydrogen bonds, connects two adjacent [GdIII(egta)(H2O)]− complex anions.

Syntheses, structural determination, and binding studies of nine-coordinate (enH2)3[TbIII(ttha)]2·11H2O and eight- coordinate (enH2)[TbIII(pdta)(H2O)]2·8H2O

Two complexes, (enH2)3[TbIII(ttha)]2 · 11H2O (1) (en = ethylenediamine and H6ttha = triethylenetetramine-N, N, N ′, N ″, N ′′′, N ′′′-hexaacetic acid) and (enH2)[TbIII(pdta)(H2O)]2 · 8H2O (2) (H4pdta = propylenediamine-N, N, N ′, N ′-tetraacetic acid), were synthesized and characterized by elemental analysis, infrared spectrum, UV-Vis spectrum, fluorescence spectrum, and single-crystal X-ray diffraction. The central TbIII of 1 is nine-coordinate, pseudo-monocapped square antiprism with four nitrogens and five oxygens from one ttha, and crystallizing in the monoclinic crystal system with P21/n space group. There is a free (non-coordinate) carboxylate (–CH2COO−) in the . The central TbIII of 2 is eight-coordinate in a standard square antiprism with two nitrogens and four oxygens of one pdta, one oxygen from a carboxylate of an adjacent pdta, and one oxygen from water, crystallizing in the monoclinic crystal system with C2/c space group. Binding between the with or [TbIII(pdta)(H2O)]− is reviewed, providing the basis for interaction of TbIII complexes with biomolecules.

Mononuclear nine-coordinate Na[SmIII(edta)(H2O)3] · 5H2O and one dimensional unlimited ladderlike eight-coordinate {[SmIII(Hpdta)(H2O)] · 2H2}O n Complexes: Synthesis and Structural Determination

The Na[SmIII(edta)(H2O)3] · 5H2O (H4edta = ethylenediamine-N,N,N′,N′-tetraacetic acid) and {[SmIII(Hpdta)(H2O)] · 2H2O}n (H4pdta = propylenediamine-N,N,N′,N′-tetraacetic acid) complexes were prepared with heat-refluxing and acidity-adjusting methods, respectively. And their composition and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. The Na[SmIII(edta)(H2O)3] · 5H2O complex shapes a mononuclear structure, and crystallizes in the orthorhombic crystal system with space group Fdd2. The central SmIII ion is nine-coordinated by one hexadentate edta ligand and three water molecules. The crystal data are as follows: a = 19.139(10) A, b = 35.00(2) A, c = 11.928(10) A, V = 7989(9) A3, Z = 16, Dc = 2.014 g/cm3, μ = 3.046 mm−1, F(000) = 4848, R = 0.0439, and wR = 0.0941 for 3434 observed reflections with I ≥ 2σ(I). The SmN2O7 part in [SmIII(edta)(H2O)3]− complex anion forms a pseudo-monocapped square antiprismatic polyhedron. The {[SmIII(Hpdta)(H2O)] · 2H2O}n complex is prepared with protonated pdta ligand firstly, which forms one dimensional unlimited ladderlike eight-coordinated structure, and crystallizes in the monoclinic crystal system with space group P21/n. The central SmIII ion, in one construction unit, is coordinated by two nitrogen atoms from one hexadentate pdta ligand and six oxygens from the same pdta ligand, one water molecule and one carboxylic group of neighbour pdta ligand, respectively. The crystal data are as follows: a = 12.720(3) A, b = 9.3800(19) A, c = 14.420(3) A, β = 96.11(3)°, V = 1710.7(6) A3, Z = 2, Dc = 1.971 g/cm3, μ = 3.492 mm−1, F(000) = 1004, R = 0.0225 and wR = 0.0607 for 3182 observed reflections with I ≥ 2σ(I). Otherwise, each part of SmN2O6 in {[SmIII(Hpdta)(H2O)] · 2H2O} complex segment adopts a pseudo-square antiprismatic polyhedron.

Nine-coordinate dinuclear Na6[Gd 2 III (Ttha)2] · 8H2O and mononuclear (H2En)3[GdIII(Ttha)]2 · 11H2O complexes: Synthesis and structural determination

The Na6[Gd2III(Ttha)2] · 8H2O (I) (H6Ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid) and (H2En)3[GdIII(Ttha)]2 · 11H2O (II) (En = ethylenediamine) complexes were prepared with heat-refluxing and acidity-adjusting methods, respectively. Their composition and structures were determined by elemental analysis and single-crystal X-ray diffraction techniques. Complex I shapes a binuclear and nine-coordinated structure and crystallizes in the orthorhombic crystal system with space group Pccn. The central Gd3+ ion is coordinated with one Ttha ligand by three N atoms and four O atoms and with one adjacent Ttha ligand by two O atoms. The crystal data are as follows: a = 26.036(13) A, b = 21.007(10) A, c = 22.694(12) A, V = 12412(11) A3, Z = 8, c = 1.699 g/cm3, μ = 2.254 mm−1, F(000) = 6368, R = 0.0602, and wR = 0.1146 for 3434 observed reflections with I ≥ 2σ(I). The GdN3O6 part in the [Gd2III(Ttha)2]6− complex anion forms a pseudo-tricapped trigonal prismatic geometry. Complex II is also nine-coordinate, but mononuclear and crystallizes in the monoclinic crystal system with space group P21/n. While the central Gd3+ ion is coordinated by four nitrogen atoms and five oxygen atoms from the same Ttha ligand. The crystal data are as follows: a = 17.7726(17) A, b = 19.2942(17) A, c = 20.6045(19) A, β = 111.4600(10)°, V = 6575.6(10) A3, Z = 8, c = 1.693 g/cm3, μ = 2.102 mm−1, F(000) = 3428, R = 0.0333 and wR = 0.0827 for 14792 observed reflections with I ≥ 2σ(I). Otherwise, the GdN4O5 part in each [GdIII(Ttha)]3− complex anion adopts a pseudo-monocapped square antiprismatic polyhedron.

10.1007/s11173-008-2009-5

The three title complexes, NH4[HoIII(Edta)(H2O)3] · 1.5H2O (I) (H4Edta = ethylenedianine-N,N,N′,N′-tetraacetic acid), (NH4)4[Ho III2 (Dtpa)2] · 9H2O (II) (H5Dtpa = diethylenetriamine-N,N,N′,N″,N″-entaacetic acid), and (NH4)3[HoIII(Ttha)] · 5H2O (III) (H6 Ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid), have been prepared and characterized by FT-IR, elemental analyses, and single-crystal X-ray diffraction technique. Complex I has a nine-coordinate mononuclear structure with distorted monocapped square antiprismatic conformation and its crystal structure belongs to orthorhombic system and Fdd2 space group. The crystal data are as follows: a = 19.343(9), b = 35.125(17), c = 12.364(6) Å, V = 8400(7) Å3, Z = 16, M = 552.26, ρcalcd = 1.747 g cm−3 μ = 3.828 mm−1, and F(000) = 4368. Complex II has a binuclear nine-coordinate pseudomonocapped square antiprismatic conformation and its crystal structure belongs to triclinic system and space P1 group. The crystal data are as follows: a = 9.7637(16), b = 9.9722(16), c = 12.945(2) Å, α= 85.853(2)°, β = 77. 140(2)°, γ = 77.140(2)°, V = 1198.4(3) Å3, Z = 1, M = 1340.80, ρcalcd = 1.858 g cm−3, μ = 3.380 mm−1, and F(000) = 674. As for complex III, it also has nine-coordinate mononuclear structure with distorted tricapped trigonal prism and its crystal structure belongs to monoclinic system andP21/c space group. The crystal data are as follows: a = 10.349(3), b = 12.760(4), c = 23.142(7) Å, β = 91.020(6)°, V = 3055.6(16) Å3, Z = 2, M = 797.55, ρcalcd = 1.734 g cm−3, μ = 2.674 mm−1, and F(000) = 1624. The results showed that although the ligands are different from one another in the shape and the numbers of coordination atoms, they all have nine-coordinate structures. However, one of them has binuclear structure and the other two have mononuclear structures because of the difference of the ligands.

Syntheses and crystal structures of nine-coordinate K2[EuIII(dtpa)(H2O)]·5H2O and Na2[TbIII(Httha)]·6H2O complexes

The title complexes, K2[EuIII(dtpa)(H2O)]·5H2O (H5dtpa = diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid), Na2[TbIII(Httha)]·6H2O (H6ttha = triethylenetetramine-N,N,N′,N′,N″,N″-hexaacetic acid), were prepared, and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques. The crystal of K2[EuIII(dtpa)(H2O)]·5H2O belongs to triclinic crystal system and \( P\bar 1 \) space group. The crystal data are as follows: a = 8.3540(17), b = 10.147(2), c = 15.059(3) α = 84.63(3)A, β = 82.02(3)°, γ = 83.96(3)°, V = 1253.1(4)A3, Z = 2, R = 0.0325 and wR = 0.1013 for 4407 observed reflections with I ≥ 2σ(I). The [EuIII(dtpa)(H2O)]2− has a nine-coordinate pseudo-monocapped square antiprismatic structure, in which the nine coordinate atoms, three N and six O are from one dtpa ligand and one water molecule. The crystal of the Na2[TbIII(Httha)]·6H2O belongs to monoclinic system and P21/c space group. The crystal data are as follows: a = 10.3976(10), b = 12.7908(13), c = 23.199(2) A = 90.914(2)°, V = 3084.9(5)A3, Z = 4, R = 0.0309 and wR = 0.0704 for 5429 observed reflections with I ≥ 2σ(I). In the [TbIII(Httha)]2−, the Tb3+ ion is nine-coordinated yielding a pseudo-monocapped square antiprismatic conformation, in which the ttha ligand coordinates to the central Tb3+ ion with four N atoms and five O atoms. There is a free non-coordinate carboxyl group (−CH2COOH) that can be modified by some biological molecules having target function.

Synthesis and structures of nine-coordinate K[SmIII (Edta)(H2O)3] · 2H2O and Ten-Coordinate K2[SmIII(Pdta)(H2O)2]2 · 4.5H2O complexes

The title complexes, K[SmIII(Edta)(H2O)3] · 2H2O(I)(H4Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid) and K2[SmIII(Pdta)(H2O)2]2 · 4.5H2O (II) (H4Pdta = propylenediamine-N,N,N′,N′-tetraacetic acid), were prepared and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques, respectively. Complex I has a mononuclear structure, and the Sm3+ ion is nine-coordinated by an Edta ligand and three water molecules, yielding a pseudo-monocapped square antiprismatic conformation, and the complex crystallizes in the orthorhombic crystal system with space group Fdd2. The crystal data are as follows: a = 19.84(5), b = 35.58(9), c = 12.15(3) A, V = 8580(38) A3, Z = 16, ρc = 1.925 g/cm3, μ = 3.010 mm−1, F(000) = 4976, R = 0.0252, and wR = 0.0560 for 3510 observed reflections with I ≥ 2σ(I). Complex II has a binuclear structure and the Sm3+ ion is ten-coordinated by a Pdta ligand, two oxygen atoms from a carboxylic group of adjacent Pdta ligand and two water molecules, yielding a distorted bicapped square antiprismatic prism. The complex crystallizes in the triclinic crystal system with space group P\( \bar 1 \). The crystal data are as follows: a = 8.9523(15), b = 10.7106(15), c = 11.6900(19) A, α = 80.613(5)°, β = 80.397(5)°, γ = 76.530(4)°, V = 1065.7(3) A3, Z = 1, ρc = 1.970 g/cm3, μ = 2.532 mm−1, F(000) = 1620, R = 0.0332 and wR = 0.0924 for 5390 observed reflections with I ≥ 2σ(I).

Synthesis and structures of nine-coordinate K[Dy(Edta)(H2O)3] · 3.5H2O, (NH4)3 [Dy(Ttha)] · 5H2O, and eight-coordinate NH4[Dy(Cydta)(H2O)2] · 4.5H2O complexes

The title complexes, K[Dy(Edta)(H2O)3] · 3.5 H2O (I) (H4Edta = ethylenediamine-N,N,N′,N′-tetraacetic acid), (NH4)3[Dy(Ttha)] · 5H2O (II) (H6Ttha = triethylenetetramine-N, N,N′,N″,N‴,N‴-hexaacetic acid), and NH4[Dy(Cydta)(H2O)2] · 4.5H2O (III) (H4Cydta = trans-1,2-cyclohexanediamine-N,N,N′,N′-tetraacetic acid), were prepared, and their compositions and structures were determined by elemental analyses and single-crystal X-ray diffraction techniques, respectively. In complex I, the Dy3+ ion is nine-coordinated by an Edta ligand and three water molecules, yielding a pseudo-monocapped square antiprismatic conformation, and the complex crystallizes in the orthorhombic crystal system with space group Fdd2. The crystal data are as follows: a = 19.751(7), b = 35.573(12), c = 12.227(4) A, V = 8591(5) A3, Z = 16, space group Fdd2 ρc = 1.877 g/cm3, μ = 3.742 mm−1, F(000) = 4800, R = 0.0259, and wR = 0.0616 for 3218 observed reflections with I ≥ 2σ(I). For complex II, the Dy3+ ion is nine-coordinated by a Ttha ligand, yielding a pseudo-monocapped square antiprismatic conformation, and the complex crystallizes in the monoclinic crystal system with space group P21/c. In addition, there is a free non-coordinate carboxyl group (-CH2COO−) in the [Dy(Ttha)]3− complex anion. The crystal data are as follows: a = 10.353(3), b = 12.746(4), c = 23.141(7) A, β = 91.005(5)°, V = 3053.2(15) A3, Z = 4, space group P21/c ρc = 1.730 g/cm3, μ = 2.532 mm−1, F(000) = 1620, R = 0.0332 and wR = 0.0924 for 5390 observed reflections with I ≥ 2σ(I). For complex III, the Dy3+ ion is eight-coordinated by a ligand Cydta and two water molecules, yielding a distorted square antiprismatic conformation, and the complex crystallizes in the triclinic system with space group P $$ \bar 1 $$ . The crystal data are as follows: a = 8.604(3), b = 10.012(4), c = 14.369(6) A, α = 88.330(6)°, β = 75.363(6)°, γ = 88.285(6)°, space group P $$ \bar 1 $$ V = 1196.9(8) A3, Z = 2, ρc = 1.776 g/cm3, μ = 3.194 mm−1, F(000) = 644, R = 0.0445 and wR = 0.1041 for 3931 observed reflections with I ≥ 2σ(I).

Syntheses and structures of nine-coordinate NH4[HoIII(Edta)(H2O)3] · 1.5H2O, (NH4)4[Ho 2 III (Dtpa)2] · 9H2O, and (NH4)3[HoIII(Ttha)] · 5H2O complexes

The three title complexes, NH4[HoIII(Edta)(H2O)3] · 1.5H2O (I) (H4Edta = ethylenedianine-N,N,N′,N′-tetraacetic acid), (NH4)4[Ho 2 III (Dtpa)2] · 9H2O (II) (H5Dtpa = diethylenetriamine-N,N,N′,N″,N″-entaacetic acid), and (NH4)3[HoIII(Ttha)] · 5H2O (III) (H6 Ttha = triethylenetetramine-N,N,N′,N″,N‴,N‴-hexaacetic acid), have been prepared and characterized by FT-IR, elemental analyses, and single-crystal X-ray diffraction technique. Complex I has a nine-coordinate mononuclear structure with distorted monocapped square antiprismatic conformation and its crystal structure belongs to orthorhombic system and Fdd2 space group. The crystal data are as follows: a = 19.343(9), b = 35.125(17), c = 12.364(6) A, V = 8400(7) A3, Z = 16, M = 552.26, ρcalcd = 1.747 g cm−3 μ = 3.828 mm−1, and F(000) = 4368. Complex II has a binuclear nine-coordinate pseudomonocapped square antiprismatic conformation and its crystal structure belongs to triclinic system and space P1 group. The crystal data are as follows: a = 9.7637(16), b = 9.9722(16), c = 12.945(2) A, α= 85.853(2)°, β = 77. 140(2)°, γ = 77.140(2)°, V = 1198.4(3) A3, Z = 1, M = 1340.80, ρcalcd = 1.858 g cm−3, μ = 3.380 mm−1, and F(000) = 674. As for complex III, it also has nine-coordinate mononuclear structure with distorted tricapped trigonal prism and its crystal structure belongs to monoclinic system andP21/c space group. The crystal data are as follows: a = 10.349(3), b = 12.760(4), c = 23.142(7) A, β = 91.020(6)°, V = 3055.6(16) A3, Z = 2, M = 797.55, ρcalcd = 1.734 g cm−3, μ = 2.674 mm−1, and F(000) = 1624. The results showed that although the ligands are different from one another in the shape and the numbers of coordination atoms, they all have nine-coordinate structures. However, one of them has binuclear structure and the other two have mononuclear structures because of the difference of the ligands.

The syntheses and structures of ten-coordinate K6[PrIII(ttha)]2 · 10H2O and nine-coordinate K4[(Httha)2] · 14H2O complexes

The title complexes, K6[PrIII(ttha)]2 · 10H2O and K4[(Httha)2] · 14H2O (H6ttha = triethylenetetraaminehexaacetic acid), have been prepared and characterized using IR, elemental analyses and single-crystal X-ray diffraction techniques. The crystal of K6[PrIII(ttha)]2 · 10H2O has a ten-coordinate mononuclear structure with a distorted bicapped square antiprismatic prism, belonging to the triclinic crystal system and P space group. The crystal data are as follows: a = 9.697(4) Å, b = 16.183(6) Å, c = 20.957(8) Å, V = 2963.0(19) Å3, Z = 2. The crystal of K4[(Httha)2] · 14H2O belongs to the monoclinic crystal system and P21/n space group, with a = 11.2787(10) Å, b = 25.706(2) Å, c = 22.058(2) Å, V = 6231.5(10) Å3, Z = 4, and is a binuclear nine-coordinate pseudo-monocapped square antiprism. The results provide the dividing point of nine-coordinate and ten-coordinate rare earth complexes with ttha ligand.

Syntheses, characterization, and structure determination of nine-coordinate Na[YIII(edta)(H2O)3]· 5H2O and eight-coordinate Na[YIII(cydta)(H2O)2]·5H2O complexes

Syntheses and structure determination of the YIII complexes with ethylenediaminetetraacetic acid (H4edta) and trans-1,2-cyclohexanediaminetetraacetic acid (H4cydta) are reported. The crystal and molecular structures of the complexes, as well as their molecular formulas and compositions, were determined by single-crystal X-ray structure analyses, NMR, IR, thermogravimetric measurements, and elementary analyses. The crystal of the Na[YIII(edta)(H2O)3]·5H2O complex belongs to the orthorhombic crystal system and space group Fdd2. The crystal data are as follows: a = 19.355(5) A, b = 35.431(11) A, c = 12.122(3) A, V = 8313(4) A3, Z = 16, M = 544.23, Dc = 1.739 g·cm−3, µ = 2.908 mm−1 and F(000) = 4480. The final R and Rw are 0.0483 and 0.1172 for 3284 (I > 2σ(I)) unique reflections, R and Rw are 0.0678 and 0.1440 for all 8499 reflections, respectively. The YIIIN2O7 part in the [YIII(edta)(H2O)3]− complex anion has a pseudo-monocapped square antiprismatic nine-coordinate structure, in which the six coordinated atoms (two N and four O) from the edta ligand and three water molecules are coordinated to the central YIII ion directly. The crystal of the Na[YIII(cydta)(H2O)2]·5H2O complex belongs to the triclinic crystal system and $$P\bar 1$$ space group. The crystal data are as follows: a = 8.405(2) A, b = 9.970(2) A, c = 14.763(4) A, α = 88.538(4)°, β = 76.193(4)°, γ = 88.100(4)°, V = 1200.6(5) A 3, Z = 2, M = 580.31, Dc = 1.605 g·cm−3, µ = 2.519 mm−1 and F(000) = 600. The final R and Rw are 0.0381 and 0.0911 for 4198 (I > 2σ(I)) unique reflections, R and Rw are 0.0530 and 0.1041 for all 6186 reflections, respectively. The YIIIN2O6 part in the [YIII(cydta)(H2O)2]− complex anion has a pseudo square antiprismatic eight-coordinate structure in which the six coordinated atoms (two N and four O) from the cydta ligand and two water molecules are coordinated to the central YIII ion directly.

Syntheses of rare earth metal complexes with aminopolycarboxylic acids and study on structural changes: Nine-coordinated mononuclear K2[DyIII(dtpa)(H2O)]·6H2O and binuclear K4[HoIII 2(dtpa)2]·4H2O

The crystal and molecular structures of mononuclear K2[DyIII(dtpa)(H2O)]·6H2O (H5dtpa = diethylenetriaminepentaacetic acid) and binuclear K4[HoIII 2(dtpa)2]·4H2O complexes have been determined by single-crystal X-ray structure analyses. The crystal of K2[DyIII(dtpa) (H2O)]·6H2O complex belongs to the triclinic crystal system, space group. The [DyIII (dtpa)(H2O)]2− complex anion has a nine-coordinate pseudo-monocapped square antiprismatic structure, in which the nine coordinated atoms (three N and six O) are from one dtpa ligand and one water molecule. The crystal of K4[HoIII 2(dtpa)2]·4H2O complex belongs to triclinic crystal system, space group. The [HoIII 2(dtpa)2]4− complex anion is composed of two identical parts and every HoIIIO6N3 has a nine-coordinate, distorted monocapped square antiprismatic structure, in which the dtpa ligand coordinates to one central HoIII ion with three N atoms and five O atoms and to the other HoIII ion with one O atom in the same coordinated carboxylic group. Although the DyIII and HoIII ions have close ionic radii (1.052 and 1.041 Å) and electronic configuration (f 9 and f10) they form mononuclear and binuclear nine-coordinate complexes, respectively. Perhaps there is a critical ionic radius for mononuclear and binuclear structures, namely the dtpa complexes of rare earth metals with larger ionic radii than 1.052 Å of DyIII ion adopt a mononuclear nine-coordinate structure, while those with smaller ionic radii than 1.041 Å of HoIII ion adopt a binuclear nine-coordinate structure.