Discrete [Yb(NCS)3(H2O)5] Molecules in Pentaaquatriisothiocyanatoytterbium(III) Monohydrate

Single crystals of [Yb(NCS)₃(H₂O)₅] · H₂O were synthesized from a salt‐metathesis reaction between stoichiometric amounts of aqueous solutions of Yb₂(SO₄)₃ · 8H₂O and Ba(NCS)₂ · 3H₂O driven by the precipitation of Ba(SO₄), followed by isothermic evaporation of the filtered‐off solution at room temperature under atmospheric conditions. These crystals of the title compound came as transparent, colorless and hygroscopic needles. According to the X‐ray diffraction structure analysis [Yb(NCS)₃(H₂O)₅] · H₂O crystallizes in the monoclinic space group P2₁ with the lattice parameters a = 845.38(5), b = 719.26(4), c = 1219.65(7) pm, β = 103.852(3)° for Z = 2. The acentric crystal structure contains crystallographically unique Yb³⁺ cations, each surrounded by three thiocyanate anions, all grafting with their nitrogen atoms, and five water molecules forming a neutral [Yb(NCS)₃(H₂O)₅] complex with square antiprismatic shape, completed by a sixth interstitial water molecule. ATR‐FT infrared and single‐crystal Raman spectra of [Yb(NCS)₃(H₂O)₅] · H₂O confirm these findings.     

Das Chloridnitrat PrCl2(NO3) · 5 H2O mit kationischen und anionischen Komplexen gemäß [PrCl2(H2O)6][PrCl2(NO3)2(H2O)4]

The Chloride Nitrate PrCl₂(NO₃) · 5 H₂O with Cationic and Anionic Complexes according to [PrCl₂(H₂O)₆][PrCl₂(NO₃)₂(H₂O)₄] Green single crystals of PrCl₂(NO₃) · 5 H₂O have been obtained from an aqueous solution of PrCl₃ and Pr(NO₃)₃. The crystal structure [monoclinic, P2/c, Z = 4, a = 1228.8(3), b = 648.4(1), c = 1266.0(4) pm, β = 91.91(3)°] contains cationic and anionic Pr³⁺ complexes according to [PrCl₂(H₂O)₆][PrCl₂(NO₃)₂(H₂O)₄]. Both nitrate groups of the anionic complex act as bidentate chelating ligands. Hydrogen bonds are observed with water molecules as donors and chlorine as well as oxygen atoms as acceptors.     

[Yb3OBr4{N(SiMe3)2}3 (THF)3], ein Amido-Komplex des Ytterbiums mit clusterähnlichem Aufbau

[Yb₃OBr₄{N(SiMe₃)₂}₃(THF)₃], an Amido Complex of Ytterbium with a Clusterlike Structure The title compound has been prepared from YbBr₃ and NaN(SiMe₃)₂ in THF suspension, forming yellow single crystals from hexane solutions which were characterized by a crystal structure determination. Space group P1 , Z = 2, lattice dimensions at ?100°C: a = 1085.4(1), b = 1410.2(1), c = 1912.0(1) pm; α = 78.62(1)°, β = 80.61(1)°, γ = 73.45(1)°, R = 0.025. In the molecular structure of [Yb₃OBr₄{N(SiMe₃)₂}₃(THF)₃] the three ytterbium atoms together with the μ₃-oxygen atom and a μ₃-bromine atom form a distorted trigonal bipyramid. In addition, three μ₂-Br atoms coordinate the Yb atoms in the equatorial plane, whereas the THF molecules and the N(SiMe₃)₂^? ligands are terminally coordinated, thus forming a distorted octahedrally surrounding of the Yb atoms.     

1,2-环己二胺缩邻香兰素单核与四核镱稀土配合物的近红外性质

通过配体1,2-环己二胺缩邻香兰素（H₂L）和不同的镱盐反应,合成了4个镱稀土配合物[Yb（H₂L）₂]（ClO₄）₃·2CH₃OH·H₂O（1）,[Yb₄（L）₄（NO₃）₂（H₂O）₂]（PF₆）₂·4CH₃CN（2）,[Yb₄（L）₄（H₂O）₂Cl₂]（PF₆）₂·2CH₂Cl₂·2H₂O（3）和[Yb₄（L）₄（NO₃）₂（H₂O）₂][Yb（NO₃）₃（H₂O）₂（CH₃OH）]（NO₃）₂ ·4CH₂Cl₂·6CH₃OH（4）。X射线单晶衍射分析表明配合物1为零维的单核结构,配合物2~4均为四核结构。研究了4个配合物的近红外发光性能。     

Synthesis and Crystal Structure of [La(phen)2(H2O)2(NO3)2]NO3 · 2(phen)(H2O) with phen = 1,10‐phenanthroline

The title compound [La(phen)₂(H₂O)₂(NO₃)₂](NO₃) · 2(phen)(H₂O) with phen = 1,10‐phenanthroline was prepared by the stoichiometric reaction of La(NO₃)₃ · 6 H₂O and 1,10‐phenanthroline monohydrate in a CH₃OH–H₂O solution. The crystal structure (triclinic, P 1 (no. 2), a = 11.052(2), b = 13.420(2), c = 16.300(2) Å, α = 78.12(1)°, β = 88.77(1)°, γ = 83.03(1)°, Z = 2, R = 0.0488, wR² = 0.1028) consists of [La(phen)₂(H₂O)₂(NO₃)₂]²⁺ complex cations, NO₃^– anions, phen and H₂O molecules. The La atom is 10‐fold coordinated by four N atoms of two bidentate chelating phen ligands and six O atoms of two H₂O molecules and two bidentate chelating NO₃^2– ligands with d(La–O) = 2.522–2.640 Å and d(La–N) = 2.689–2.738 Å. The intermolecular π‐π stacking interactions play an essential role in the formation of two different 2 D layers parallel to (001), which are formed by complex cations and uncoordinating phen molecules, respectively. The uncoordinated NO₃^– anions and H₂O molecules are sandwiched between the cationic and phen layers.     

1，2-环己二胺缩邻香兰素单核与四核镱稀土配合物的近红外性质

通过配体1,2-环己二胺缩邻香兰素（H2L）和不同的镱盐反应,合成了4个镱稀土配合物[Yb（H₂L）₂]（ClO₄）₃·2CH₃OH·H₂O（1）,[Yb₄（L）₄（NO₃）₂（H₂O）₂]（PF₆）₂·4CH₃CN（2）,[Yb₄（L）₄（H₂O）₂Cl2]（PF₆）₂·2CH₂Cl₂·2H₂O（3）和[Yb₄（L）₄（NO₃）₂（H₂O）₂][Yb（NO₃）₃（H₂O）₂（CH₃OH）]（NO₃）₂·4CH₂Cl₂·6CH₃OH（4）。X射线单晶衍射分析表明配合物1为零维的单核结构,配合物2~4均为四核结构。研究了4个配合物的近红外发光性能。     

Synthese,Struktur und Thermolyse der ternären Ammoniumnitrate (NH4)3[M2(NO3)(9] (M  La?Gd)

Synthesis, Structure, and Thermolysis of the (NH₄)₃[M₂(NO₃)₉] (M ? La? Gd) The ternary ammonium nitrates (NH₄)₃[M₂(NO₃)₉] (M ? La-Gd) are obtained as single crystals from a solution of the respective sesquioxides in a melt of NH₄NO₃ and sublimation of the excess NH₄NO₃. In the crystal structure of (NH₄)₃[Pr₂(NO₃)₉] (cubic, P4₃32, Z = 4, a = 1 377.0(1) pm, R = 0.038, R_w = 0.023) Pr³⁺ is surrounded by six bidentate nitrate ligands of which three are bridging to neighbouring Pr³⁺ ions. This results in a branched folded chain, held together by the NH₄⁺ ions which occupy cavities in the structure. (NH₄)₃[Pr₂(NO₃)₉] is the first intermediate product of the thermal decomposition of (NH₄)₂[Pr(NO₃)₅(H₂O)₂] · 2H₂O.     

2∞[Yb2(NH2)2( Pz )4][Yb(NH3)2( Pz )3 Pz H]: Electride Induced Synthesis of a 2D-Ytterbium-Pyrazolate Network

Summary. ² _∞[Yb₂(NH₂)₂(Pz)₄][Yb(NH₃)₂(Pz)₃ PzH], Pz ⁻ = pyrazolate anion, PzH = pyrazole, C₃H₄N₂ is obtained by the reaction of ytterbium metal with pyrazole in liquid ammonia and subsequent increase of the temperature to 200°C resulting in the formation of colorless single crystals of the compound. The X-ray single crystal analysis reveals that the structure consists of ² _∞[Yb₂(NH₂)₂(Pz)₄] planes with neutral [Yb(NH₃)₂(Pz)₃ PzH] monomeric molecules that are located between the planes and ytterbium is trivalent. This is the first example of a two-dimensional network structure of an organic amine of the rare earth elements that derives from an electride induced synthesis. The product decomposes under release of ammonia outside its sealed reaction vessel, viz. if the NH₃ pressure is removed.     

2∞[Yb2(NH2)2(Pz)4][Yb(NH3)2(Pz)3PzH]: Electride Induced Synthesis of a 2D-Ytterbium-Pyrazolate Network

² _∞[Yb₂(NH₂)₂(Pz)₄][Yb(NH₃)₂(Pz)₃ PzH], Pz ⁻ = pyrazolate anion, PzH = pyrazole, C₃H₄N₂ is obtained by the reaction of ytterbium metal with pyrazole in liquid ammonia and subsequent increase of the temperature to 200°C resulting in the formation of colorless single crystals of the compound. The X-ray single crystal analysis reveals that the structure consists of ² _∞[Yb₂(NH₂)₂(Pz)₄] planes with neutral [Yb(NH₃)₂(Pz)₃ PzH] monomeric molecules that are located between the planes and ytterbium is trivalent. This is the first example of a two-dimensional network structure of an organic amine of the rare earth elements that derives from an electride induced synthesis. The product decomposes under release of ammonia outside its sealed reaction vessel, viz. if the NH₃ pressure is removed.     

Single Crystal Growth and Crystal Structure of Anhydrous Mercury(I) Nitrate,Hg2(NO3)2

Polycrystalline anhydrous Hg₂(NO₃)₂ was prepared by drying Hg₂(NO₃)₂·2H₂O over concentrated sulphuric acid. Evaporation of a concentrated and slightly acidified mercury(I) nitrate solution to which the same volumetric amount of pyridine was added, led to the growth of colourless rod‐like single crystals of Hg₂(NO₃)₂. Besides the title compound, crystals of hydrous Hg₂(NO₃)₂·2H₂O and the basic (Hg₂)₂(OH)(NO₃)₃ were formed as by‐products after a crystallization period of about 2 to 4 days at room temperature. The crystal structure was determined from two single crystal diffractometer data sets collected at —100°C and at room temperature: space group P2₁, Z = 4, —100°C [room temperature]: a = 6.2051(10) [6.2038(7)]Å, b = 8.3444(14) [8.3875(10)]Å, c = 11.7028(1) [11.7620(14)]Å, ß = 93.564(3) [93.415(2)]°, 3018 [3202] structure factors, 182 [182] parameters, R[Fμ² > 2σ(Fμ²)] = 0.0266 [0.0313]. The structure is built up of two crystallographically inequivalent Hg₂²⁺ dumbbells and four NO₃^— groups which form molecular [O₂N‐O‐Hg‐Hg‐O‐NO₂] units with short Hg‐O bonds. Via long Hg‐O bonds to adjacent nitrate groups the crystal packing is achieved. The Hg‐Hg distances with an average of d(Hg‐Hg) = 2.5072Å are in the typical range for mercurous oxo compounds. The oxygen coordination around the mercury dumbbells is asymmetric with four and six oxygen atoms as ligands for the two mercury atoms of each dumbbell. The nitrate groups deviate slightly from the geometry of an equilateral triangle with an average distance of d(N‐O) = 1.255Å.     

Phosphaniminato-Komplexe von Seltenerdelementen. Die Kristallstrukturen von [Yb2Cp3(NPPh3)3], [YCp(NPPh3)(μ-OSiMe2NPPh3)]2 und [M(NPPh3)2(μ-OSiMe2NPPh3)]2 mit M = Y und Sm

Phosphoraneiminato Complexes of Rare-Earth Elements. Crystal Structures of [Yb₂Cp₃(NPPh₃)₃], [YCp(NPPh₃)(μ-OSiMe₂NPPh₃)]₂, and [M(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ with M = Y and Sm The ytterbium complex [Yb₂Cp₃(NPPh₃)₃] with sesqui distribution of cyclopentadienide and phosphoraneiminato ligands is made from YbCp₂Cl and LiNPPh₃ in boiling toluene and isolated as yellow, moisture sensitive crystals, which enclose three molecules of toluene per unit cell. [Yb₂Cp₃(NPPh₃)₃] · 3 C₇H₈ ( 1 ): Space group Pbca, Z = 8, lattice dimensions at –80 °C: a = 2727.6(2), b = 1977.5(1), c = 2848.9(2) pm; R = 0.0541. Two of the (NPPh₃)^–-groups link the ytterbium atoms to a nonplanar Yb₂N₂ four-membered ring with a folding angle of 17.1° along the Yb…Yb connecting line. The third (NPPh₃)^– group is terminally bonded with a short Yb–N distance of 214.2 pm. [YCp(NPPh₃)(μ-OSiMe₂NPPh₃)]₂ · 4 C₇H₈ ( 2 ) originates from YCpCl₂ and LiNPPh₃ in boiling toluene with Baysilon-paste participating forming colourless, moisture sensitive crystals. Space group P2₁/c, Z = 2, lattice dimensions at –80 °C: a = 1469.0(1), b = 1234.1(1), c = 2761.5(2) pm, β = 93.196(10)°; R = 0.0518. In 2 the yttrium atoms are linked via the oxygen atoms of the (OSiMe₂NPPh₃)^– groups to form a centrosymmetric Y₂O₂ four-membered ring with Y–O bonds of different lengths. Together with the terminally bonded (NPPh₃)^–-ligand, the η⁵-C₅H₅^– group, and the N atom of the siloxyphosphaneimine group, which functions as a donor atom, the Y atoms achieve coordination number five. [Y(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ · 2 C₇H₈ ( 3 ) and [Sm(NPPh₃)₂(μ-OSiMe₂NPPh₃)]₂ ( 4 ) originate from the metal trichlorides with KNPPh₃ in THF with Baysilon paste participating and subsequent crystallization from toluene as colourless, moisture sensitive crystal needles. 3 : Space group P2₁/n, Z = 2, lattice dimensions at –80 °C: a = 1804.1(2), b = 1401.8(1), c = 2221.6(2) pm, β = 98.716(9)°; R = 0.0537. 4 : Space group P 1, Z = 1, lattice dimensions at –80 °C: a = 1363.4(1), b = 1364.9(1), c = 1650.6(1) pm; α = 112.457(8)°, β = 91.948(9)°, γ = 114.974(8)°; R = 0.0308. 3 and 4 form centrosymmetric dimeric molecules in which the metal atoms are linked via the oxygen atoms of the (OSiMe₂NPPh₃)^– groups to form M₂O₂ four-membered rings with M–O bonds of varying length. Together with the terminally bonded (NPPh₃)^– ligands and the N atom of the siloxyphosphaneimine ligand, which functions as a donor atom, the metal atoms achieve coordination number five.     

Synthesis and Structural Characterization of Several Ytterbium Bis(trimethylsilyl)amides Including Base‐free [Yb{N(SiMe3)2}2(μ‐Cl)]2 — A Coordinatively Unsaturated Complex with Additional Agostic Yb···(H3C—Si) Interactions

The reaction of YbCl₃ with two equivalents of NaN‐(SiMe₃)₂ has afforded a mixture of several ytterbium bis(trimethylsilyl) amides with the known complexes [Yb{N(SiMe₃)₂}2(μ‐Cl)(thf)]₂ ( 1 ) and [Yb{N(SiMe₃)₂}₃]( 4 ) as the main products and the cluster compound [Yb₃Cl₄O{N(SiMe₃)₂}₃(thf)₃]( 2 ) as a minor product. Treatment of 1 and 2 with hot n‐heptane gave the basefree complex [Yb{N(SiMe₃)₂}₂(μ‐Cl)]₂ ( 3 ) in small yield. The structures of compounds 1—4 and the related peroxo complex [Yb₂{N(SiMe₃)₂}₄(μ‐O₂)(thf)₂]( 5 ) have been investigated by single crystal X‐ray diffraction. In the solid‐state, 3 shows chlorobridged dimers with terminal amido ligands (av. Yb—Cl = 262.3 pm, av. Yb—N = 214.4 pm). Additional agostic interactions are observed from the ytterbium atoms to four methyl carbon atoms of the bis(trimethylsilyl)amido groups (Yb···C = 284—320 pm). DFT calculations have been performed on suitable model systems ([Yb₂(NH₂)₄(μ‐Cl)₂(OMe₂)₂]( 1m ), [Yb₂(NH₂)₄(μ‐Cl)₂]( 3m ), [Yb‐(NH₂)₃]( 4m ), [Yb₂(NH2₄(μ‐O₂)(OMe₂)₂]( 5m ), [Yb{N‐(SiMe₃)₂}₂Cl] ( 3m/2 ) and Ln(NH₂)₂NHSiMe₃ (Ln = Yb ( 6m ), Y ( 7m )) in order to rationalize the different experimentally observed Yb—N distances, to support the assignment of the O—O stretching vibration (775 cm ^‐1) in the Raman spectrum of complex 5 and to examine the nature of the agostic‐type interactions in σ‐donorfree 3 .     

Zur Struktur der basischen Diquecksilber(I)-nitrate. II. Kristallstruktur des Hg10(OH)4(NO3)6

Crystal Structure of the Basic Dimercury(I) Nitrates. II. Crystal Structure of Hg₁₀(OH)₄(NO₃)₆ . The crystal structure of Hg₁₀(OH)₄(NO₃)₆ has been determined from single crystal x-ray diffraction data. The unit cell is triclinic, space group P1 , a = 999.4(5), b = 909.9(5), c = 765.9(2) pm, α = 85.98(4), β = 78.70(3), γ = 109.83(5)°; Z = 1, R = 6.2%, R_w = 8.2%. Finite cationic chains [(Hg₂)₅(OH)₄(NO₃)₂]⁴⁺ are joined together by weak van der Waals-type interactions between neighbouring Hg and O atoms, thus forming ribbons running along [100]. The coordination sphere of the Hg atoms is completed by further nitrate ions, which lead to the formation of a loose framework. Thereby the metal atoms are not surrounded by simple coordination polyhedra.     

Synthesis and structure of copper(II) trans-diaqua-bis(3-hydroxybenzoylhydrazine) nitrate dihydrate [Cu(C7H8O2N2)2(OH2)2](NO3)22H2O

Synthesis of [Cu(m-HBH)₂(OH₂)₂](NO₃)₂·2H₂O, where m-HBH = C₇H₈O₂N₂ (3-hydroxybenzoylhydrazine), is described. The structure of the compound was studied by X-ray phase analysis and IR spectroscopy; crystal data are a = 57.415(6) Å, b = 19.760(2) Å, c = 7.586(2) Å; Fdd 2, Z = 16, R(F) = 0.053. The compound consists of [Cu(m-HBH)₂(OH₂)₂]²⁺ complex cations, NO ₃ ^? anions, and two water molecules. The similarity between the IR spectra of Cu(m-HBH)₂(NO₃)₂·nH₂O and Co(m-HBH)₂(NO₃)₂·5H₂O, element analysis data, and crystal data obtained at the first stage of X-ray analysis show that the structures and compositions of these compounds are identical relative to the type of surroundings of the central atom. In contrast to the cobalt compound [Co(m-HBH)₂(OH₂)₂](NO₃)₂·3H₂O, in which the cobalt atom has a nearly regular octahedron as a coordination polyhedron, the copper(II) compound has a square bipyramid around the copper atom; c.n. is 6 = 4 + 2 (planar distances: 2.013(2) Å, 2.021(2) Å, 2.033(3) Å, 2.087(3) Å; axial distances: 2.367(3) Å, 2.374(3) Å) and lacks one crystallization water molecule.     

Strong Equatorial Crystal Field Enhances the Axial Anisotropy and Energy Barrier for Spin Reversal Process in Yb2 Single Molecule Magnets

The importance of equatorial crystal fields on magnetic anisotropy of ytterbium single molecule magnets (SMMs) is observed for the first time. Herein, we report three similar dinuclear ytterbium complexes with the formula [Yb₂(3-OMe-L)₂(DMF)₂(NO₃)₂]⋅DMF ( 1 ), [Yb₂(3-H-L)₂(DMF)₂(NO₃)₂]⋅DMF⋅H₂O ( 2 ), and [Yb₂(3-NO₃-L)₂(DMF)₂(NO₃)₂] ( 3 ), [where 3-X-H₂L=N′-(2-hydroxy-3-X-benzylidene)picolinohydrazide, X=OMe ( 1 ), H ( 2 ) NO₂ ( 3 )]. Detailed magnetic measurements reveal the presence of weak antiferromagnetic interactions between the Yb centers and a field-induced slow relaxation of magnetization in all complexes. A higher energy barrier for spin reversal was observed for complex 1 (U_eff=50 K) and it decreases in the order of 2 (47 K) to 3 (40 K). Notably, complex 1 shows a remarkable energy barrier within the frequency range of 1–850 Hz reported for Yb-based SMMs. Further, ab initio calculations show a higher axial anisotropy and lower quantum tunneling of magnetization (QTM) in the ground state for 1 compared to 2 and 3 . It was also observed that the presence of a strong crystal field in the equatorial plane (when the ∡ O1−Yb−O3 bond angle is close to 90°) enhances the axial anisotropy and improves the SMM behavior in the studied complexes. Both the experimental and theoretical analysis of relaxation dynamics discloses that Raman and QTM play major role on slow relaxation process for all complexes. To provide more insight into the exchange interactions, broken-symmetry DFT calculations were performed.     

Synthesis and structural characterization of binuclear ytterbium(III) complexes with 2-amino and 3-amino benzoic acid

Two novel homobinuclear ytterbium(III) complexes, [Yb₂(2AMB)₆(H₂O)₄] · 2C₂H₆O (I) and Yb₂(3AMB)₆(H₂O)₄] · 3H₂O (II) (2AMB = 2-aminobenzoic acid, 3AMB = 3-aminobenzoic acid) have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis and X-ray crystallography (CIF files CCDC nos. 950103 (I), 921652 (II)). Complex I crystallizes in triclinic space group \(P\bar 1\) and complex II crystallizes in monoclinic space group P2₁/n. X-ray analysis shows that both complexes (I, II) have the dinuclear structure. The central Yb³⁺ ions in both complexes are eight-coordinated adopting distorted YbO₈ dodecahedral geometry. Each Yb³⁺ ion is coordinated to two O atoms from bridging carboxylate, four O atoms from the chelating carboxylate ligands and two O atoms of water molecules. The crystal structure of I and II are stabilized by N-H…O, O-H…O, O-H…N, and C-H…O hydrogen bonds, C-H…π interactions and weak π-π stacking interactions.     

Crystal structure of the dinitratotetrakis(pyridine)nickel(II) clathrate with pyridine as guest, [NiPy4(NO3)2]·2Py

The structure of the [NiPy₄(NO₃)₂]·2Py clathrate was determined by single crystal X-ray diffraction analysis (KM-4 diffractometer, λMoK_a radiation, graphite monochromator, ω/2θ scan mode, θ_max=30°, 640 reflections, R=0.065). Orthorthombic base-centered unit cell, space group Ccca, a=12.148(5), b=15.019(4), c=16.96(1) Å, Z=4C₃₀H₃₀N₈NiO₆, d_calc=1.411 g/cm³. The structure is of island type and consists of distorted octahedral trans-[NiPy₄(NO₃)₂] (host) and pyridine (guest) molecules. The Ni(II) cation coordinated by four nitrogens of the pyridine ligands and two oxygens of the nitrato groups lies in the special position 222; the twofold axes coincide with the directions of the metal-ligand bonds. The guest pyridine molecules lie on the twofold axes that are parallel to the c axes and are oriented in such a way that the total dipole moment of the guest subsystem is zero.     

Hydroxo Bridged Dinuclear Rare Earth Complexes: Syntheses and Crystal Structures of [Ln2(phen)4(H2O)4(OH)2](NO3)4(phen)2 with Ln = Er,Lu

Reactions of phenanthroline (phen) and Er(NO₃)₃ · 5 H₂O or Lu(NO₃)₃ · H₂O in CH₃OH/H₂O yield [Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄(phen)₂ with Ln = Er ( 1 ), Lu ( 2 ). Both isostructural complex compounds crystallize in the triclinic space group P 1 (no. 2) with the cell dimensions: a = 11.257(2) Å, b = 11.467(2) Å, c = 14.069(2) Å, α = 93.93(2)°, β = 98.18(1)°, γ = 108.14(1)°, V = 1696.0(6) ų, Z = 1 for ( 1 ) and a = 11.251(1) Å, b = 11.476(1) Å, c = 14.019(1) Å, α = 93.83(1)°, β = 98.27(1)°, γ = 108.27(1)°, V = 1689.0(3) ų, Z = 1 for ( 2 ). The crystal structures consist of the hydroxo bridged dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cations, hydrogen bonded NO₃^– anions and π‐π stacking (phen)₂ dimers. The rare earth metal atoms are coordinated by four N atoms of two phen ligands and four O atoms of two H₂O molecules and two μ‐OH groups to complete tetragonal antiprisms. Via two common μ‐OH groups, two neighboring tetragonal antiprisms are condensed to a centrosymmetric dinuclear [Ln₂(phen)₄(H₂O)₄(OH)₂]⁴⁺ complex cation. Based on π‐π stacking interactions and hydrogen bonding, the complex cations and (phen)₂ dimers form 2 D layers parallel to (1 0 1), between which the hydrogen bonded NO₃^– anions are sandwiched. The structures can be simplified into a distorted CsCl structure when {[Ln₂(phen)₄(H₂O)₄(OH)₂](NO₃)₄} and (phen)₂ are viewed as building units.     

Synthesis and crystal structure of the monoclinic modification of Yb(ReO4)3(H2O)4

Ytterbium(III) tetraaquatris(tetraoxorhenate(VII)), Yb(ReO₄)₃(H₂O)₄, was prepared by the reaction of Yb₂O₃ with concentrated HReO₄ at room temperature. The colorless compound crystallizes in the monoclinic space group P2₁/n (No. 14) with four formula units per unit cell (a=730.5(1) pm, b=1484.1(5) pm, c=1311.7(2) pm, β=93.69(1)). The main feature of the crystal structure is the formation of chains _∞¹[Yb(H₂O)₄(ReO₄)₂(ReO₄)_2/2] running along [100]. This arrangement shows distorted cubic antiprisms of [Yb(H₂O)₄(ReO₄)₂(ReO₄)_2/2] interconnected via the ReO₄⁻ ligands. The chains are held together in the solid by hydrogen bonding. The compound is paramagnetic and follows the Curie-Weiss law with a magnetic moment of 4.0 μ_B at room temperature and θ=−42 K. It loses hydration water in two steps at temperatures below 400 K; decomposition begins at 850 K, forming Yb₂O₃(Re₂O₇)₂ and is complete at 1350 K leading to Yb₂O₃ as final product.     

2,2′‐Bipyrimidine as Efficient Sensitizer of the Solid‐State Luminescence of Lanthanide and Uranyl Ions from Visible to Near‐Infrared

Treatment of Ln(NO₃)₃?nH₂O with 1 or 2 equiv 2,2′‐bipyrimidine (BPM) in dry THF readily afforded the monometallic complexes [Ln(NO₃)₃(bpm)₂] (Ln=Eu, Gd, Dy, Tm) or [Ln(NO₃)₃(bpm)₂]?THF (Ln=Eu, Tb, Er, Yb) after recrystallization from MeOH or THF, respectively. Reactions with nitrate salts of the larger lanthanide ions (Ln=Ce, Nd, Sm) yielded one of two distinct monometallic complexes, depending on the recrystallization solvent: [Ln(NO₃)₃(bpm)₂]?THF (Ln=Nd, Sm) from THF, or [Ln(NO₃)₃(bpm)(MeOH)₂]?MeOH (Ln=Ce, Nd, Sm) from MeOH. Treatment of UO₂(NO₃)₂?6H₂O with 1 equiv BPM in THF afforded the monoadduct [UO₂(NO₃)₂(bpm)] after recrystallization from MeOH. The complexes were characterized by their crystal structure. Solid‐state luminescence measurements on these monometallic complexes showed that BPM is an efficient sensitizer of the luminescence of both the lanthanide and the uranyl ions emitting visible light, as well as of the Yb^III ion emitting in the near‐IR. For Tb, Dy, Eu, and Yb complexes, energy transfer was quite efficient, resulting in quantum yields of 80.0, 5.1, 70.0, and 0.8 %, respectively. All these complexes in the solid state were stable in air.