The gas phase structure of tetrakis(trifluoromethylthio)ethene, CF3S)2C=C(SCF3)2

The geometric structure of (CF₃S)₂C=C(SCF₃)₂ in the vapour phase was determined by electron diffraction. The molecule possesses D₂ symmetry with the S---CF₃ bonds oriented perpendicular to the ethene plane, in alternating directions up-down-up-down. The following skeletal geometric parameters were obtained (r_a distances and angles, experimental uncertainties are 3σ values): C=C = 1.34Å (ass.), C(sp²---S = 1.761(5)Å, S---C(sp³) = 1.832(5)Å, S---C---C = 119.6(4)°, C---S---C = 100.6(13)°, and ø(C=C---S---C) = 90.9(11)°. The gas phase conformation differs considerably from the crystal structure, where the molecule possesses C_i symmetry and the CF₃ groups, which are bonded to cis-standing sulfur atoms, lie on the same side of the ethene plane with dihedral angles ø(C=C---S---C) of 117° and 127°.     

The molecular structure of N-sulfinyl trimethylsilanamine, (CH3)3SiNSO

The geometric structure of (CH₃)₃Si---NSO in the vapour phase has been determined by gas electron diffraction. The molecule possesses a planar Si---N=S=O skeleton with syn conformation. The Si(CH₃)₃ group staggers the N=S double bond. The following skeletal parameters (r_a distances and angles with 3σ errors limits) were obtained: Si---N 1.750(6)Å, N=S 1.508(5)Å, S=O 1.444(4)Å, Si---N=S 133.9(9)°, N=S=O 122.5(10)°. Ab initio calculations (HF/3−21G*) were performed for H₃Si---NSO and confirm the planar syn structure for sulfinyl silanamines.     

Structures and conformations of trifluoromethanesulfonic anhydride, (CF3SO2)2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF3SO2)2CF2

The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF₃SO₂)₂O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF₃SO₂)₂CF₂ have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C₂ symmetry and one with C₁ symmetry. In both compounds structures with C₂ symmetry and dihedral angles SOSC ≈ 100° ((CF₃SO₂)₂O) and SCSC≈ 150° ((CF₃SO₂)₂CF₂ are lowest in energy. According to the GED analyses the dominant conformer of (CF₃SO₂)₂O₂ possesses C₂ symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF₃SO₂)₂CF₂ only one conformer with C₂ symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given.     

Structures and conformations of trifluoromethanesulfonic anhydride, (CF3SO2)2O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF3SO2)2CF2

The geometric structures and conformational properties of trifluoromethanesulfonic anhydride, (CF₃SO₂)₂O, and bis(trifluoromethylsulfonyl)difluoromethane, (CF₃SO₂)₂CF₂ have been studied by gas electron diffraction (GED) and ab initio calculations (HF/3–21G*). The calculations predict for both systems two stable conformers with C₂ symmetry and one with C₁ symmetry. In both compounds structures with C₂ symmetry and dihedral angles SOSC ≈ 100° ((CF₃SO₂)₂O) and SCSC ≈ 150° ((CF₃SO₂)₂CF₂) are lowest in energy. According to the GED analyses the dominant conformer of (CF₃SO₂)₂O possesses C₂ symmetry with SOSC dihedral angles of 99.1(14)°. The presence of up to 30% of the two other conformers cannot be excluded; for (CF₃SO₂)₂CF₂ only one conformer with C₂ symmetry and SCSC dihedral angles of 143(2)° is observed. A complete set of geometric parameters is given.     

Photochemical reaction of W(CO)6 with SnCl4 II. Synthesis and X-ray structure of tetrachlorobis(triphenylphosphine oxide)tungsten(IV), [WCl4(OPPh3)2]

The crystal structure of [WCl₄(OPPh₃)₂](1), formed in the photochemical reaction of W(CO)₆ with SnCl₄ in the presence of triphenylphosphine, has been determined by the single-crystal X-ray diffraction method. The compound crystallizes in the monoclinic space C2/c, with A=14.027(3), B=13.163(3), C=19.621(4) Å, β=96.36(3)°, Z=4. The structure solved by heavy-atom methods has been refined to R=0.0466, for 3489 observed reflections.

The [WCl₄(OPPh₃)₂] molecule possesses a crystallographically imposed C₂ axis passing through the tungsten atom. Despite steric demands, a mutually cis arrangement of triphenylphosphine oxide oxygens is found for [WCl₄(OPPh₃)₂], while there is a slight lengthening of the W---Cl bonds trans to the oxygen atoms.     

Synthesis and characterisation of the methylene-inserted mixed-chalcogenide compounds Fe2(CO)6(μ-SeCH2Te) and Fe2(CO)6(μ-SCH2Te)

The methylene-bridged, mixed-chalogen compounds Fe₂(CO)₆(μ-SeCH₂Te) (1) and Fe₂(CO)₆(μ-SCH₂Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe₂(CO)₆(μ-SeTe) and Fe₂(CO)₆(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2₁/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) ų, Z = 4, D_c = 2.599 g cm⁻³ and R = 0.030 (R_w = 0.047).     

Structural characterisation of [Pt(NH3)4]2[W(CN)8][NO3]·2H2O donor–acceptor complex

The bimetallic [Pt(NH₃)₄]₂[W(CN)₈][NO₃]·2H₂O is characterised by single-crystal X-ray diffraction [S.G.P2₁/m(11), a=8.0418(7), b=19.122(2), c=9.0812(6) Å, Z=2]. All platinum centres have the square-plane D_4h geometry with average dimensions Pt(1)–N 2.042(2) and Pt(2)–N 2.037(10) Å. The octacyanotungstate anion has the square-antiprismatic D_4d configuration with average dimensions W(1)–C 2.164(13), C–N 1.140(12), W(1)–N 3.303(5) Å. The structure exhibits two different mutual orientations of Pt versus W units resulting in Pt(2)–W(1), W(1)^* separations of 4.77(2), 4.55(2)^* and Pt(1)–W(1) of 6.331(8) Å. A centrosymmetric structure reveals groups of two distinct columns: the first is formed by intercalated NO₃⁻ between parallel [Pt(1)(NH₃)₄]²⁺ planes and the second consists of [W(CN)₈]³⁻ interlayered by, parallel to square faces of W-antiprisms, [Pt(2)(NH₃)₄]²⁺. The structure is stabilised through a three-dimensional hydrogen bond network via nitrogen atoms of cyanide ligands, hydrogen atoms of NH₃ ligands, water molecules and oxygen atoms of NO₃⁻ counteranions. The vibrational pattern and the range of ν(CN) frequencies attributable to the electronic environment of W(V) and W(IV) are consistent with the ground state Pt(II)↔W(V) charge transfer.     

Preparation and characterization of M2(SeAr′)6 and mixed ligand M2(OR)2(SeAr′)4 species (M = Mo, W)

Toluene solutions of M₂(NMe₂)₆ (M = Mo, W) react with mesitylene selenol (Ar′SeH) to give M₂(SeAr′) ₆ complexes. MO₂(OR)₆ (R = ^tBu, CH₂^tBu) react with excess> 6 fold) Ar′SeH to give Mo₂ (SeAr′)₆, whilst W₂(OR)₆(py)₂ (R = ⁱPr, CH₂^tBu) react with excess (> 6 fold) Ar′SeH to give W₂(OR)₂(SeAr′)₄. Reaction of MO₂(OPrⁱ)₆ with Ar′SeH produces Mo₂(OPrⁱ)₂ (SeAr′)₄ which crystallizes in two different space groups. These areneselenato complexes are air-stable and insoluble in common organic solvents. X-ray crystallographic studies revealed that the Mo₂(SeAr′)₆ and W₂(SeAr′)₆ compounds are isostructural in the solid state and adopt ethane-like staggered configurations with the following important structural parameters, M---M (W---W/Mo---Mo) 2.3000(11)/2.2175(13) Å, M---Se 2.430 (av.)/2.440 (av.) Å, M---M---SE 97.0° (av.)°. In the solid state W₂(OⁱPr)₂(SeAr′)₄ adopts the anti-configuration with crystallographically imposed C_i symmetry and W---W 2.3077(7) Å, W---Se 2.435 (av.) Å, W---O 1.858(6) Å; W---W---SE 100.27(3)°, 93.8(3)° and W---W---O 108.41(17)°. Mo₂(OPrⁱ)₂(SeAr′) ₄ crystallizes in both P and A2/a space groups in which the molecules are isostructural with each other and the tungsten analogue. Important bond lengths and angles are Mo---Mo 2.180(24) Å, Mo---Se 2.432(av.) Å, Mo---O 1.872(9) Å, Mo---Mo---Se 99.39(9)°, 94.71(8)°, Mo---Mo---O 107.55(28)°.     

Equilibrium diagram of KPO3–Y(PO3)3 system, chemical preparation and characterization of KY(PO3)4

Microdifferential thermal analysis (μ-DTA), X-ray diffraction (XRD) and infrared (IR) spectroscopy were used for the first time to investigate the liquidus and solidus relations in the KPO₃–Y(PO₃)₃ system. The only compound observed within the system was KY(PO₃)₄ melting incongruently at 1033 K. An eutectic appears at 13.5 mol% Y(PO₃)₃ at 935 K, the peritectic occurs at 1033 K and the phase transition for potassium polyphosphate KPO₃ was observed at 725 K. Three monoclinic allotropic phases of the single crystals were obtained. KY(PO₃)₄ polyphosphate has the P2₁ space group with lattice parameters: a=7.183(4) Å, b=8.351(6) Å, c=7.983(3) Å, β=91.75(3)° and Z=2 is isostructural with KNd(PO₃)₄. The second allotropic form of KY(PO₃)₄ belongs to the P2₁/n space group with lattice parameters: a=10.835(3) Å, b=9.003(2) Å, c=10.314(1) Å, β=106.09(7)° and Z=4 and is isostructural with TlNd(PO₃)₄. The IR absorption spectra of the two forms show a chain polyphosphates structure. The last modification of KYP₄O₁₂ crystallizes in the C2/c space group with lattice parameters: a=7.825(3) Å, b=12.537(4) Å, c=10.584(2) Å, β=110.22(7)° and Z=4 is isostructural with RbNdP₄O₁₂ and contains cyclic anions. The methods of chemical preparations, the determination of crystallographic data and IR spectra for these compounds are reported.     

The molecular structure and conformation of dichlorotetramethyldisiloxane as determined by gas phase electron diffraction

Dichlorotetramethyldisiloxane is studied by gas-phase electron diffraction at room temperature. The least-squares values of the bond distances (r_g) and bond angles () are: r(C---H)=1.084(5) Å, r(Si---O) = 1.624(2) Å, r(Si---C) = 1.852(2) Å, r(Si---Cl) = 2.067(2) Å, SiOSi = 154.0° (1.5), ClSiO = 110.2° (0.8), ClSiC = 109.6°(0.7), HCSi = 111.7°(1.5), OSiC = 110.0°(0.8), τ₁ (zero corresponds to the Si---Cl bond trans to the Si---O---Si linkage) = 78°(6) and τ₂ = 141°(19). A two-conformer model cannot be ruled out.     

Dimethylchalkogenide als liganden in kationischen cyclopentadienyleisen-bis(phosphin)-komplexen: synthese, reaktivität und kristallstruktur von [C5H5Fe(P(OCH3)3)2(S(CH3)2)]PF6

Thermal displacement of coordinated nitriles RCN (R = CH₃, C₂H₅ or n-C₃H₇) in [C₅H₅Fe(L₂)(NCR)]X complexes (L₂ = P(OCH₃)₃)₂, (P(OC₆H₅)₃)₂ or (C₆H₅)₂PC₂H₄P(C₆H₅)₂ (DPPE)) by E(CH₃)₂ affords high yields of [C₅H₅Fe(L₂)(E(CH₃)₂)]X compounds (E = S, Se and Te; X = BF₄ or PF₆). Spectroscopic data and ligand displacement reactions are presented and discussed together with related observations on [C₅H₅Fe(CO)₂(E(CH₃)₂)]BF₄ compounds. The molecular structure of [C₅H₅Fe(P(OCH₃)₃)₂(S(CH₃)₂)]PF₆ was determined by a single-crystal X-ray diffraction study: monoclinic, space group P2₁/n-C⁵_2h (No. 14) with a = 8.4064(12), b = 11.183(2), c = 50.726(8) Å, β = 90.672(13)° and Z = 8 molecules per unit cell. The coordination sphere of the iron atom is pseudo-tetrahedral with an Fe---S bond distance of 2.238 Å.     

Hydrothermal synthesis and structure of one-dimensional Co(dien)2(VO3)3·(H2O) (dien=diethylenetriamine)

One-dimensional Co(dien)₂(VO₃)₃·(H₂O) was prepared from the hydrothermal reaction of NH₄VO₃, Co₂O₃, diethylenetriamine (dien) and H₂O at 130 °C. The compound crystallizes in the monoclinic system, space group P2₁/c with a=16.1581(6) Å, b=8.7006(3) Å, c=13.9893(4) Å, β=103.1483(11)°, V=1915.13(11) Å³, Z=4, and R₁=0.0268 for 3060 observed reflections. Single crystal X-ray diffraction revealed that the structure is composed of infinite one-dimensional chains formed by corner-sharing VO₄ tetrahedra with Co(dien)³⁺ complex cations and crystallization water molecules occupying the interchain positions, which are held together to a three-dimensional network via extensive hydrogen-bonding interactions. The compound, with a new zig-zag conformation of metavanadate chains, is the first example of vanadium oxides incorporating trivalent transition metal coordination groups. Other characterizations by elemental analysis, IR and thermal analysis are also described.     

Magnetic investigation of Cu(NH3)4(NO3)2

The magnetic properties of Cu(NH₃)₄(NO₃)₂ have been measured at low temperatures. Broad maxima in both the susceptibility and specific heat are observed and are consistent with linear chain behavior of a Heisenberg antiferromagnet, with J/k = 3.9 ± 0.1 K. Long-range order sets in at T_c = 0.15 ± 0.01 K, and the ratio kT_c/|J| = 0.038 is the lowest observed as yet for a one-dimensional, S = 1/2 antiferromagnet.     

[(Me3Sn)2(Me3Sb)M(CN)6]∞ (M = Fe, Ru): Neuartige Organo-Sn/Sb-Polymere von besonderer chemischer und thermischer stabilität

The thermally (decomp. temp. 300°C) and completely air stable, novel coordination polymers [(Me₃Sn^IV)₂(Me₃Sb^V)M^II(CN)₆]_∞ with M = Fe and Ru can be prepared by co-precipitation from aqueous solutions of Me₃SnCl, Me₃SbBr₂ and K₄[(M(CN)₆], or, alternatively, by the ion-exchange-like reaction of the polymers [A(Me₃Sn)₃M(CN)₆]_∞ (A⁺ = Et₄N⁺, Cp₂Co⁺, Me₃Sn⁺ etc.) with Me₃SbBr₂. IR-spectroscopic findings suggest a statistical distribution of quasi-octahedral M(CN-Sn··)_6-x(CNSb ··)_x building blocks (with x = 0–6) within a three-dimensional network.     

Mononuclear Pt(II) and Pd(II) 1,4-dithiolato complexes. Crystal structures of [Pt((−) DIOS) (PPh3)2] and [Pd(S(CH2) 4S)(Ph2P(CH2) 3PPh2)]. Application in styrene hydroformylation

Addition of 1,4-dithiols to dichloromethane solutions of [PtCl₂(P-P)] (P-P = (PPh₃)₂, Ph₂P(CH₂)₃PPh₂, Phd₂P(CH₂)₄PPh₂; 1,4-dithiols = HS(CH₂)₄SH, (−)DIOSH₂ (2,3-O-isopropylidene-1,4-dithiol-l-threitol), BINASH₂ (1,1′-dinaphthalene-2,2′-dithiol)) in the presence of NEt₃ yielded the mononuclear complexes [Pt(1,4-dithiolato)(P-P)]. Related palladium(II) complexes [Pd(dithiolato)(P-P)] (P-P=Ph₂P(CH₂)₃PPh₂, Ph₂P(CH₂)₄PPh₂; dithiolato = ⁻S(CH₂)₄S⁻, (−)-DIOS) were prepared by the same method. The structure of [Pt((−)DIOS)(PPh₃)₂] and [Pd(S(CH₂)₄S)(Ph₂P(CH₂)₃PPh₂)] complexes was determined by X-ray diffraction methods. Pt—dithiolato—SnC1₂ systems are active in the hydroformylation of styrene. At 100 atm and 125°C [Pt(dithiolate)(P-P)]/SnCl₂ (Pt:Sn = 20) systems provided aldehyde conversion up to 80%.     

The molecular structure of di-t-butylamine, NH[C(CH3)3]2, as determined by gas-phase electron diffraction: an exceptionally sterically hindered amine

Gaseous di-t-butylamine, NHBu^t₂, has been studied by electron diffraction at a nozzle temperature of ca. 293 K. The diffraction data reveal that this amine is exceedingly hindered. Repulsive steric interactions between the Bu^t groups are mainly relieved by an opening of the CNC valence angle to 135(3)°. Evidence of steric strain may also be found in the non-zero tilts (2–3°) of the Bu^t groups, defining the angle of rotation of these groups about axes through the N-bonded carbon atoms orthogonal to the NC₂ plane. The N---C and C---C bonds, 1.467(13) and 1.561(6) Å, respectively, are on the other hand relatively unstrained. Other principal geometrical parameters are unexceptional: C---H = 1.103(10) Å, NCC = 111.3(1.5)° (mean value) and CCH = 106(2)°. The position of the N-bonded hydrogen atom relative to the NC₂ plane could not be determined. The torsional positions of the Bu^t groups, with respect to the N---C bonds, could not be derived from least-squares refinements. A large number of models with Bu^t groups in various fixed positions were considered; the best fit between the observed and theoretical intensity data was obtained with one Bu^t group being twisted 19° away from the position typified by one C---C bond of this group being anti to the remote N---C bond, and the other Bu^t group similarly twisted by 30°. When viewed along the N---C bonds, the Bu^t groups are twisted in the same direction. Viewed along the C(N)C axis, these groups come close to being staggered with respect to each other. The values of the above bond distances are those of r_a parameters. Parenthesized values denote error limits, being least-squares standard deviations multiplied by a factor of three.     

Hydrothermal syntheses and crystal structures of bimetallic cluster complexes [{Cd(phen)2}2V4O12]·5H2O and [Ni(phen)3]2[V4O12]·17.5H2O

The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen₂)₂V₄O₁₂]·5H₂O (1) and [Ni(phen)₃]₂[V₄O₁₂]·17.5H₂O (2). Crystal data: C₄₈H₅₂Cd₂N₈O₂₂V₄ (1), triclinic. a=10.3366(10), b=11.320(3), c=13.268(3) Å, =103.888(17)°, β=92.256(15)°, γ=107.444(14)°, Z=1; C₇₂H₁₃₁N₁₂Ni₂O_29.5V₄ (2), triclinic. a=12.305(3), b=13.172(6), c=15.133(4), =79.05(3)°, β=76.09(2)°, γ=74.66(3)°, Z=1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59° <θ<26.02° and 2.01°<θ<25.01° using the ω-scan technique, respectively. The structure of 1 consists of a [V₄O₁₂]⁴⁻ cluster covalently attached to two {Cd(phen)₂}²⁺ fragments, in which the [V₄O₁₂]⁴⁻ cluster adopts a chair-like configuration. In the structure of 2, the [V₄O₁₂]⁴⁻ cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the [V₄O₁₂]⁴⁻ unit and crystallization water molecules.     

Crystal Structure, Nano-particle Morphology and Interaction with ATP of [ NH3 CH2 CH（ NH2 ） CH3 ]2 [ M（ Ⅵ ） O2 （ OC6 H4 O）2 ] （M = Mo0. 6 W0. 4 ） and Its Activity to Promote DNA Cleavage

The title complex [NH_3CH_2CH(NH_2)CH_3]_2 [M(Ⅵ)O_2(OC_6H_4O)_2](M= Mo_(0.6)W_(0.4))was synthesized via a simple solution-phase chemical route.The determination of single crystal X-ray diffraction revealed that the title compound is crystallized in a monoclinic system with P2(1)/n space group,a=1.0913(10)nm,b=1.0442(10)nm,c=1.8842(19)nm,α=90°,β=96.530(17)°,γ=90°,Z=4,and V=2.133(4)nm3.The mononuclear anionic unit [M(Ⅵ)O2(OC6H4O)2]2-displays chiral pseudo-octahedral [MO_6] coordination geometry and is linked by chiral cations via hydrogen bond and π…π stacking interaction.The transmission electron microscopy images show that the title complex is comprised of nano-particles with diameters ranging from 20 to 50 nm.The NMR study shows the 1H downfield chemical shifts of [NH_3CHaHbCH(NH_2)CH_3] cations in the title complex when it is mixed with adenosine-triphosphate(ATP),and the chemical shift difference between Ha and Hb is increased greatly,and most of the catecholate ligands dissociate from the central metal atoms.The DNA cleavage activity experiment reveals that DNA cleavage promoted by the title complex is lower than that by Na_2MoO_4 which possesses antitumor pro-perty,but higher than that by Na_2WO_4.     

Photochemical synthesis and structural characterization of (η-C5Me5)3Mo3(CO)4(μ2-H)(μ3-O): an unprecedented 46-electron trimolybdenum cluster containing a localized monoprotonated Mo---Mo double bond

Irradiation of the 30-electron Mo₂(η⁵-C₅Me₅)₂(CO)₄ and Re₂(CO)₁₀ in toluene solution (containing H₂O) afforded (in 1–2% yields) a novel triangular metal cluster, (η⁵-C₅Me₅)₃Mo₃(CO)₄(η₂-H)(η₃-O) (1), which was characterized by a single-crystal X-ray diffraction study. Compound 1, of pseudo C_s-m symmetry, has a triangulo-Mo₃(η₃-O) core with composite Mo---H---Mo and Mo---Mo electron-pair bonds along one unusually short edge (2.660(1) Å) and Mo--- electron-pair bonds along the other two edges (2.916(1) and 2.917(1) Å). The edge-bridged hydride ligand, which displays a characteristic high-field proton NMR resonance at δ −17.79 ppm, was not found from the crystallographic determination but was located via a quantitative potential-energy-minimization method. This procedure unambiguously established that the optimized hydrogen position, which corresponds to a distinct coordination site with identical Mo---H distances of 1.85 Å, is the only one that can be sterically occupied by a metal-bound hydride ligand. This 46-electron species is the first electron-deficient trimolybdenum cluster containing a monoprotonated Mo---Mo double bond; its existence is attributed to ligand overcrowding due to the bulky pentamethylcyclopentadienyl rings. Black (η⁵- C₅Me₅)₃Mo₃(CO)₄(η₂-H)(η₃-O) · 1/2THF crystallizes with two formula species in a triclinic unit cell of P1 symmetry with a 8.603(4), b 11.115(4), c 19.412(11) Å, 80.69(4)°, β 101.10(4)°, and γ 98.88(3)° at −40° C. Least-squares refinement (RAELS with 221 variables) of one independent Mo₃ molecule and a centrosymmetrically-disordered THF molecule converged at R₁(F) 5.62%, R₂(F 6.88% for 8460 independent diffractometry data (I₀ ρ 3σ(I₀ collected at −40° C with Mo-K radiation     

Syntheses and structural determination of nine-coordinate K3[Nd(nta)2(H2O)]·6H2O and K3[Er(nta)2(H2O)]·5H2O

The syntheses and structural determination of Nd^III and Er^III complexes with nitrilotriacetic acid (nta) were reported in this paper. Their crystal and molecular structures and compositions were determined by single-crystal X-ray structure analyses and elemental analyses, respectively. The crystal of K₃[Nd^III(nta)₂(H₂O)]·6H₂O complex belongs to monoclinic crystal system and C2/c space group. The crystal data are as follows: a=1.5490(11) nm, b=1.3028(9) nm, c=2.6237(18) nm, β=96.803(10)°, V=5.257(6) nm³, Z=8, M=763.89, D_c=1.930 g cm⁻³, μ=2.535 mm⁻¹ and F(000)=3048. The final R₁ and wR₁ are 0.0390 and 0.0703 for 4501 (I>2σ(I)) unique reflections, R₂ and wR₂ are 0.0758 and 0.0783 for all 10474 reflections, respectively. The Nd^IIIN₂O₇ part in the [Nd^III(nta)₂(H₂O)]³⁻ complex anion has a pseudo-monocapped square antiprismatic nine-coordinate structure in which the eight coordinate atoms (two N and six O) are from the two nta ligands and a water molecule coordinate to the central Nd^III ion directly. The crystal of the K₃[Er^III(nta)₂(H₂O)]·5H₂O complex also belongs to monoclinic crystal system and C2/c space group. The crystal data are as follows: a=1.5343(5) nm, b=1.2880(4) nm, c=2.6154(8) nm, b=96.033(5)°, V=5.140(3) nm³, Z=8, M=768.89, D_c=1.987 g cm⁻³, μ=3.833 mm⁻¹ and F(000)=3032. The final R₁ and wR₁ are 0.0321 and 0.0671 for 4445 (I>2σ(I)) unique reflections, R₂ and wR₂ are 0.0432 and 0.0699 for all 10207 reflections, respectively. The Er^IIIN₂O₇ part in the [Er^III(nta)₂(H₂O)]³⁻ complex anion has the same structure as Nd^IIIN₂O₇ part in which the eight coordinate atoms (two N and six O) are from the two nta ligands and a water molecule coordinate to the central Nd^III ion directly.