Synthese und Kristallstrukturen von [Cu4(As4Ph4)2(PRR′2)4], [Cu14(AsPh)6(SCN)2(PEt2Ph)8], [Cu14(AsPh)6Cl2(PRR′2)8], [Cu12(AsPh)6(PPh3)6], [Cu10(AsPh)4Cl2(PMe3)8], [Cu12(AsSiMe3)6(PRR′2)6] und [Cu8(AsSiMe3)4(PtBu3)4] (R,R′ = organische Gruppen)

Syntheses and Crystal Structures of [Cu₄(As₄Ph₄)₂(PRR′₂)₄], [Cu₁₄(AsPh)₆(SCN)₂(PEt₂Ph)₈], [Cu₁₄(AsPh)₆Cl₂(PRR′₂)₈], [Cu₁₂(AsPh)₆(PPh₃)₆], [Cu₁₀(AsPh)₄Cl₂(PMe₃)₈], [Cu₁₂(AsSiMe₃)₆(PRR′₂)₆], and [Cu₈(AsSiMe₃)₄(P^tBu₃)₄] (R, R′ = Organic Groups) Through the reaction of CuSCN with AsPh(SiMe₃)₂ in the presence of tertiary phosphines the compounds [Cu₄(As₄Ph₄)₂(PRR′₂)₄] ( 1 – 3 ) ( 1 : R = R′ = ⁿPr, 2 : R = R′ = Et; 3 : R = Me, R′ = ⁿPr) and [Cu₁₄(AsPh)₆(SCN)₂(PEt₂Ph)₈] ( 4 ) can be synthesised. Using CuCl instead of CuSCN results to the cluster complexes [Cu₁₄(AsPh)₆Cl₂(PRR′₂)₈] ( 5–6 ) ( 5 : R = R′ = Et; 6 : R = Me, R′ = ⁿPr), [Cu₁₂(AsPh)₆(PPh₃)₆] ( 7 ) and [Cu₁₀(AsPh)₄Cl₂(PMe₃)₈] ( 8 ). Through reactions of CuOAc with As(SiMe₃)₃ in the presence of tertiary phosphines the compounds [Cu₁₂(AsSiMe₃)₆(PRR′₂)₆] ( 9 – 11 ) ( 9 : R = R′ = Et; 10 : R = Ph, R′ = Et; 11 : R = Et, R′ = Ph) and [Cu₈(AsSiMe₃)₄(P^tBu₃)₄] ( 12 ) can be obtained. In each case the products were characterised by single‐crystal‐X‐ray‐structure‐analyses. As the main structure element 1 – 3 each have two As₄Ph₄^2–‐chains as ligands. In contrast 4 – 12 contain discrete AsR^2–ligands.     

Synthesis and Crystal Structure of a Novel Dinuclear Copper(II) Complex, [Cu2(phen)2(H2O)2(OH)2](HCO3)2 · 6 H2O with phen = 1,10‐phenanthroline

Dark blue plate‐like crystals of [Cu₂(phen)₂ · (H₂O)₂(OH)₂](HCO₃)₂ · 6 H₂O were obtained from a CH₃OH–H₂O solution containing CuCl₂, 1,10‐phenanthroline (phen), sebacic acid and Na₂CO₃. The crystal structure (triclinic, P 1 (no. 2), a = 8.118(1), b = 9.624(1), c = 10.536(1) Å, α = 81.35(1)°, β = 88.51(1)°, γ = 75.77(1)°, Z = 1, R = 0.0332, wR² = 0.0981 for 4163 observed reflections (F ≥ 2σ(F ) out of 4595 unique reflections) consists of divalent [Cu₂(phen)₂(H₂O)₂(OH)₂]²⁺ complex cations, anionic (HCO₃)₂^2– dimers and H₂O molecules. The divalent complex cations (d(Cu…Cu) = 2.905(1) Å) are centered at inversion centers. The Cu atoms are fivefold square‐pyramidally coordinated by two nitrogen and three oxygen atoms from one bidentate chelating phen ligand, two bridging hydroxide groups and one axial water molecule (d(Cu–N)phen = 2.021(2), 2.024(2) Å; d(Cu–O)_OH = 1.941(1), 1.949(1) Å; d(Cu–O)_H2O = 2.254(2) Å). The divalent complex cations are stacked to form 2 D layers parallel (001) with 1 D π‐π stacking interactions along [100] via the terminal phen rings. The dimeric (HCO₃)₂^2– anions and the hydrogen bonded H₂O molecules are sandwiched between the 2 D layers.     

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.     

Synthesis and Characterization of the New Copper Tetraphosphonate Cu2[(HO3PCH2)4C6H2]·2H2O

Following the strategy of using polyfunctional phosphonic acids for the synthesis of three‐dimensional metal phosphonates, the ethyl ester of a tetraphosphonic acid, i. e. 1,2,4,5‐(Et₂O₃PCH₂)₄C₆H₂, was used in the hydrothermal synthesis of the new copper tetraphosphonate, Cu₂[(HO₃PCH₂)₄C₆H₂]·2H₂O ( 1 ). The in situ hydrolysis of the ethyl ester leads to the acid (1,2,4,5‐(H₂O₃PCH₂)₄C₆H₂) which reacts with the Cu²⁺ ions to form the green coarse‐crystalline product. The title compound is the first fully characterized copper tetraphosphonate. Its structure was solved from single crystal data ( 1 : triclinic, , a = 4.9262(10), b = 8.1890(16), c = 11.800(2) Å, α = 71.17(3), β = 89.15(3), γ = 88.56(3)°, V = 450.39(16) ų, Z = 2, R1 = 0.0284, wR₂ = 0.0682). The structure is built up from edge‐sharing CuO₅ polyhedra each containing a single H₂O molecule. Thus, dimeric [Cu₂O₈] units are formed. In the second coordination sphere of each of the Cu²⁺ ions four HO₃PCH₂R units are observed. The [Cu₂O₈] polyhedra are connected to eight other [Cu₂O₈] polyhedra by these organic linkers and a three‐dimensional framework structure is formed. Thermogravimetric, magnetic, and temperature dependent powder XRD measurements and the Raman‐spectrum are also presented.     

Synthesis and Crystal Structure of a Novel A‐Zeolite‐like Copper Complex: [Cu12(SO4)12(3H2O)]·H2O

The reaction of CuBr₂, N(CH₂CH₂COOH)₃, and Nd(NO₃)₃·6H₂O in water adjusted pH = 5‐6 with H₂SO₄ at constant 55 °C afforded a novel three‐dimensional coordination complex [Cu₁₂(SO₄)₁₂(3H₂O)]·H₂O, ( 1 ), which was characterized by IR, elemental analysis, and X‐ray diffraction. The crystal structure data of 1 as follows: Cubic, , a = b = c = 24.018(2) Å, V = 13855 (3) ų, Z = 968, D_c = 1.905 g/cm³, F(000) = 7712, R₁ = 0.0352, wR₂ = 0.0866 (I > 2σ(I)), R₁ = 0.0449, wR₂ = 0.0927 (for all data) and S = 1.075. The analysis of crystal structure indicates that the structure of 1 is similar to that of silicate zeolite (Na₁₂[Al₁₂Si₁₂O₄₈]·27H₂O).     

Synthesis and Characterization of the first Copper(II) Complex of 6‐Azathymine. The Crystal Structure of [[CuCl2(H2O)2(AT)}2] · 2H2O; (AT = 6‐Azathymine)

The reaction of 3, 4‐dihydro‐6‐methyl‐3‐thioxo‐1, 2, 4‐triazin‐5(2H)‐one (6‐aza‐2‐thiothymine, AAT, 1 ) with copper(I) chloride in presence of hydrochloric acid in methanol gives the complex [{CuCl₂(H₂O)₂(AT)}₂] · 2H₂O, 2 , AT = 6‐azathymine) in excellent yield. 2 was characterized by IR spectroscopy and elemental analyses as well as mass spectrometry. Also single‐crystal X‐ray diffraction studies on compound 2 revealed that AT acts as a monodentate ligand in the centrosymmetric binuclear complex via its oxygen atom. Crystal data for 2 at —80 °C: space group P2₁/c with a = 550.1(1), b = 2712.5(1), c = 729.7(1) pm, β = 95.99(1)°, Z = 2, R₁ = 0.0213.     

Synthesis of a Triamidoamine Nd2Cl2(μ5-O)Li3 Cluster

[Li(THF)₄][[NN]₂Nd₂Cl₂(μ₅-O)Li₃] ( 2 ) ([NN]^3– = ([Me₃SiNCH₂CH₂)₃N]^3–) was prepared by transmetallation of Li₃[NN] with anhydrous neodymium trichloride in THF. After recrystallization from diethylether/pentane (1 : 2) light blue crystals of 2 were obtained, which were characterized by single crystal X-ray diffraction. Space group: P2₁/n, Z = 4, lattice dimensions at 203 K: a = 1260.8(3), b = 3832.5(8), c = 1569.2(3) pm, β = 106.07(3)°, R₁ = 0.0541. In the anion of 2 a nearly trigonal bipyramidal [Nd₂Li₃(μ₅-O)]⁷⁺ unit is observed.     

Synthesis and X-Ray Structure of New Copper(II) Nitrates: Cu(NO3)2 · H2O and β-modification of Cu(NO3)2

Blue crystals of a Cu(NO₃)₂ · H₂O were synthesized by interaction of CuO with boiling 100% HNO₃. Stable β-Cu(NO₃)₂ modification was obtained by the sublimation of copper(II) nitrate in evacuated ampoule over the 150→100°C temperature gradient for 24 hr. According to X-Ray single crystal analysis Cu(NO₃)₂ · H₂O is monoclinic with a = 6.377(1), b = 8.548(1), c = 9.769(1) Å, β = 100.41(1)°, Z = 4, and space group P2₁/c. β-modification Cu(NO₃)₂ is orthorhombic with a = 14.161(5), b = 7.516(3), c = 12.886(2) Å, Z = 12, and space group Pbcn. In the both structures Cu atoms are square coordinated by 4 O atoms at the distances ranging from 1.92 to 2.02 Å. In each structure there are also additional Cu? O bonds with the distance of 2.33 or 2.35 Å and some weaker ones with the distances in the range of 2.65–2.72 Å. In the Cu(NO₃)₂ · H₂O structure the [CuO₄] squares are connected by the bridging NO₃ groups into zigzag chains, which are linked into layers by the longer Cu? O bonds. In the β-Cu(NO₃)₂ structure the [CuO₄] fragments of two types are joined by the bridging NO₃ groups in a three-dimensional framework. Some correlations were found between N? O distances and coordination functions of O atoms.     

Synthesis and Crystal Structure of [C10N2H10]2[P2Mo5O21(OH)2]·2H2O

The crystal structure of [C₁₀N₂H₁₀]₂[P₂Mo₅O₂₁(OH)₂] · 2H₂O, contains the heteropolyanion, [P₂Mo₅O₂₁(OH)₂]^4—, together with diprotonated 4, 4′‐bipyridine. The heteropolyanion is built up from five MoO₆ octahedra sharing four common edges and one common corner, capped by two PO₃(OH) tetrahedra. The structure is stabilized by hydrogen bonds involving the hydrogen atoms of the 4, 4′‐bipyridine, water molecules and the oxygen atoms of the pentamolybdatobisphosphate. This is the first example that this kind of cluster could be isolated in the presence of a poly‐functional aromatic molecule ion. Crystal data: triclinic, P1¯ (No. 2), a = 9.983(2)Å, b = 11.269(2)Å, c = 17.604(4)Å, α = 73.50(3)°, β = 84.07(3)°, γ = 67.96(3)°; V = 1760.0(6)ų; Z = 2; R₁ = 0.037 and wR₂ = 0.081, for 9138 reflections [I > 2σ(I)].     

Synthesis,Crystal Structure and Magnetic Behaviour of the new Tetrameric Gadolinium Carboxylate [Gd4(OH)4(CF3COO)8(H2O)4] · 2.5 H2O

The novel tetrameric gadolinium(III) compound [Gd₄(OH)₄(CF₃COO)₈(H₂O)₄] · 2.5 H₂O was synthesized and structurally characterized by X‐ray crystallography. The Gd³⁺ ions are bridged by hydroxide ions and carboxylate groups to tetramers with Gd³⁺‐Gd³⁺ distances between 384.2(2) and 388.1(2) pm. The compound crystallizes in the monoclinic space group C2/c (Z = 4). The magnetic behaviour of [Gd₄(OH)₄(CF₃COO)₈(H₂O)₄] · 2.5 H₂O was investigated in the temperature range of 2 to 300 K. The magnetic data of this compound indicate antiferromagnetic interactions (J_ex = ?0.0197 cm^?1).     

Preparation,Crystal Structure and Vibrational Spectra of Ca2P2O6·2H2O and [Ca(H2O)3(H2P2O6)]·0.5(C12H24O6)·H2O

The calcium salts Ca₂P₂O₆ · 2H₂O ( 1 ) and [Ca(H₂O)₃(H₂P₂O₆)] · 0.5(C₁₂H₂₄O₆) · H₂O ( 2 ) were prepared and structurally characterized by single‐crystal X‐ray diffraction. Compound 1 crystallizes in the orthorhombic space group Pbca and compound 2 in the monoclinic space group P2₁/n. The crystal structure of compound 1 consists of chains of edge‐sharing [CaO₇] polyhedra linked by hypodiphosphate(IV) anions to form a three‐dimensional network. The crystal structure of compound 2 consists of alternated layers of crown ether and water molecules and respective ionic units. Within the layers of ionic units the Ca²⁺ cations are octahedrally coordinated by three monodentate dihydrogenhypodiphosphate(IV) anions and three water molecules. The IR/Raman spectra of the title compounds were recorded and interpreted, especially with respect to the [P₂O₆]^4– and [H₂P₂O₆]^2– groups. The phase purity of 2 was verified by powder diffraction measurements.     

Ein anionischer Oxohydroxo‐Komplex mit Bismut(III): Na6[Bi2O2(OH)6](OH)2 · 4H2O

An Anionic Oxohydroxo Complex with Bismuth(III): Na₆[Bi₂O₂(OH)₆](OH)₂ · 4H₂O Colourless, plate‐like, air sensitive crystals of Na₆[Bi₂O₂(OH)₆](OH)₂ · 4H₂O are obtained by reaction of Bi₂O₃ or Bi(NO₃)₃ · 5H₂O in conc. NaOH (58 wt %) at 200 °C followed by slow cooling to room temperature. The crystal structure (triclinic, P 1¯, a = 684.0(2), b = 759.8(2), c = 822.7(2) pm, α = 92.45(3)°, ß = 90.40(3)°, γ = 115.60(2)°, Z = 1, R1, wR2 (all data), 0, 042, 0, 076) contains dimeric, anionic complexes [Bi₂O₂(OH)₆]^4— with bismuth in an ψ¹‐octahedral coordination of two oxo‐ and three hydroxo‐ligands. The thermal decomposition was investigated by DSC/TG or DTA/TG and high temperature X‐ray powder diffraction measurements. In the final of three steps the decomposition product is Na₃BiO₃.     

Syntheses and Crystal Structures of the Cyclotriphosphate Hydrates Nd(P3O9)·3H2O,Nd(P3O9)·4.5H2O,RE(P3O9)·5H2O (RE = Pr,Nd), and Na3RE(P3O9)2·6H2O (RE = Pr,Nd)

Several rare‐earth cyclotriphosphate hydrates were obtained from mixtures of sodium cyclotriphosphates and the respective rare‐earth chlorides. Nd(P₃O₉) · 3H₂O [P$\bar{6}$ , Z = 3, a = 677.90(9), c = 608.67(9) pm, R₁ = 0.016, wR₂ = 0.038, 312 data, 36 parameters] was obtained by a solid state reaction and is isotypic with respective rare‐earth phosphate hydrates, while all the others adopt new structure types. Nd(P₃O₉) · 4.5H₂O [C2/c, Z = 8, a = 1644.6(3), b = 756.11(15), c = 1856.1(4) pm, β = 97.25(3)°, R₁ = 0.032, wR₂ = 0.081, 1763 data, 194 parameters], Nd(P₃O₉) · 5H₂O [P2₁/c, Z = 4, a = 773.75(15), b = 1149.1(2), c = 1394.9(3) pm, β = 106.07(3)°, R₁ = 0.042, wR₂ = 0.082, 1338 data, 194 parameters], Pr(P₃O₉) · 5H₂O [P$\bar{1}$ , Z = 2, a = 745.64(15), b = 889.07(18), c = 934.55(19) pm, α = 79.00(3), β = 80.25(3), γ = 66.48(3), R₁ = 0.059, wR2 = 0.089, 1468 data, 193 parameters], Na₃Nd(P₃O₉)₂ · 6H₂O [P2₁/n, Z = 4, a = 1059.78(18), b = 1207.25(15), c = 1645.7(4) pm, β = 99.742(17), R₁ = 0.047, wR₂ = 0.119, 1109 data, 351 parameters] and Na₃Pr(P₃O₉)₂ · 6H₂O [P2₁/n, Z = 4, a = 1061.42(16), b = 1209.0(2), c = 1635.5(3) pm, β = 99.841(13), R₁ = 0.035, wR₂ = 0.062, 1323 data, 350 parameters] were obtained by careful crystallization at room temperature. A thorough structure discussion is given. The infrared spectrum of Nd(P₃O₉) · 4.5H₂O is also reported.     

A Novel Dinuclear Copper(II) Complex Molecule: Synthesis and Crystal Structure of Cu2(phen)2(H2O)2(C5H6O4)2 with phen = 1,10‐phenanthroline

Blue crystals of Cu₂(phen)₂(H₂O)₂(C₅H₆O₄)₂ were obtained from a CH₃OH–H₂O solution containing CuCl₂, 1,10‐phenanthroline (phen), glutaric acid and Na₂CO₃. The crystal structure (monoclinic, P2₁/c (no. 14), a = 10.271(1), b = 10.595(1), c = 15.585(1) Å, β = 107.105(3)°, Z = 2, R = 0.0328, wR² = 0.1027 for 3376 observed reflections (F ≥ 2σ(F ) out of 3728 unique reflections) is built up of dinuclear Cu₂(phen)₂(H₂O)₂(C₅H₆O₄)₂ complex molecules centered at inversion centers. The Cu atoms are square‐pyramidally coordinated by two nitrogen atoms of one bidentate chelating phen ligand and three oxygen atoms from two bridging glutarate anions and one axial water molecule (d(Cu–N) = 2.018(2), 2.024(2) Å; basal d(Cu–O) = 1.949(2), 1.956(2) Å; axial d(Cu–O) = 2.382(2) Å). Through the π‐π stacking interactions extending in a direction, the complex molecules are interlinked into 2 D layers parallel to the ac plane. The resultant 2 D layers are held together by hydrogen bonds between water molecules and uncoordinated carboxyl oxygen atoms.     

Complexation of the 2, 4, 6‐Triallyloxy‐1, 3, 5‐triazine with Copper(I,II) Chlorides. Syntheses and Crystal Structures of [CuCl2·2C3N3(OC3H5)3], [Cu7Cl8·2C3N3(OC3H5)3], and [Cu8Cl8·2C3N3(OC3H5)3]·2C2H5OH

Interaction of copper(II) chloride with 2, 4, 6‐triallyloxy‐1, 3, 5‐triazine leads to formation of copper(II) complex [CuCl₂·2C₃N₃(OC₃H₅)₃] ( I ). Electrochemical reduction of I produces the mixed‐valence Cu^{I, II} π, σ‐complex of [Cu₇Cl₈·2C₃N₃(OC₃H₅)₃] ( II ). Final reduction produces [Cu₈Cl₈·2C₃N₃(OC₃H₅)₃]·2C₂H₅OH copper(I) π‐complex ( III ). Low‐temperature X‐ray structure investigation of all three compounds has been performed: I : space group P1¯, a = 8.9565(6), b = 9.0114(6), c = 9.7291(7) Å, α = 64.873(7), β = 80.661(6), γ = 89.131(6)°, V = 700.2(2) ų, Z = 1, R = 0.0302 for 2893 reflections. II : space group P1¯, a = 11.698(2), b = 11.162(1), c = 8.106(1) Å, α = 93.635(9), β = 84.24(1), γ = 89.395(8)°, V = 962.0(5) ų, Z = 1, R = 0.0465 for 6111 reflections. III : space group P1¯, a = 8.7853(9), b = 10.3602(9), c = 12.851(1) Å, α = 99.351(8), β = 105.516(9), γ = 89.395(8), V = 1111.4(4) ų, Z = 1, R = 0.0454 for 4470 reflections. Structure of I contains isolated [CuCl₂·2C₃N₃(OC₃H₅)₃] units. The isolated fragment of I fulfils in the structure of II bridging function connecting two hexagonal prismatic‐like cores Cu₆Cl₆, whereas isolated Cu₆Cl₆(CuCl)₂ prismatic derivative appears in III . Coordination behaviour of the 2, 4, 6‐triallyloxy‐1, 3, 5‐triazine moiety is different in all the compounds. In I ligand moiety binds to the only copper(II) atom through the nitrogen atom of the triazine ring. In II ligand is coordinated to the Cu^II‐atom through the N atom and to two Cu^I ones through the two allylic groups. In III all allylic groups and nitrogen atom are coordinated by four metal centers. The presence of three allyl arms promotes an acting in II and III structures the bridging function of the ligand moiety. On the other hand, space separation of allyl groups enables a formation of large complicated inorganic clusters.     

配合物Cu(C14H9NO3)(C3H4N2)的合成、晶体结构及性质研究

合成了配合物Cu(C₁₄H₉NO₃)(C₃H₄N₂)[C₁₄H₉NO₃^2- 为N-(2-羧基苯基)-水杨醛亚胺,C₃H₄N₂为咪唑].晶体属正交晶系,空间群Pca2₁,晶胞参数a=0.94453(12)nm,b=1.12278(9)nm,c=2.9123(4)nm,V=3.0885(6)nm³,Mr=370.84,Z=8,最终的偏离因子R=0.036,wR=0.087,GOF=0.975.三齿Schiff碱配体中的二个氧原子、一个氮原子和咪唑的一个氮原子与铜原子配位,形成扭曲的平面正方形结构.通过元素分析,IR,UV,CV和TG表征了配合物的结构.     

Münzmetallcluster mit verbrückenden Imido‐ und Amidoliganden: [{Li(dme)3}4][Cu18(NPh)11] und [Ag6(NHPh)4(PnPr3)6Cl2]

Copper and Silver Clusters with Bridging Imido and Amido Ligands From the reactions of copper and silver chloride with tertiary phosphines and lithiated aniline the compounds [{Li(dme)₃}₄][Cu₁₈(NPh)₁₁] ( 1 ) and [Ag₆(NHPh)₄(PⁿPr₃)₆Cl₂] ( 2 ) were obtained. The structure of the anion in 1 is closely related to the structures of the reported clusters [Cu₁₂(NPh)₈]^4– [1] and [Cu₂₄(NPh)₁₄]^4– [2]: 1 represents the third phenyl imido bridged copper cluster which contains parallel Cu₃‐ and Cu₆‐planes. The dimeric compound 2 consists of two Ag₃ units with bridging phenyl amido ligands. Two chloride and six phosphine ligands complete the ligand sphere and shield the metal core effectively.     

Synthesis and Crystal Structure of the Azide K4[Re6Sei8(N3)a6]·4H2O; Luminescence,Redox, and DFT Investigations of the [Re6Sei8(N3)a6]4– Cluster Unit

The reaction of K₄[Re₆Seⁱ₈(OH)^a₆] · 8H₂O with NaN₃ in water results in the formation of [Re₆Seⁱ₈(N₃)^a]^4– units that crystallize with K⁺ and H₂O to form K₄[Re₆Seⁱ₈(N₃)^a₆] · 4H₂O [P2₁/c (N°14), a = 9.0595(3) Å, b = 13.2457(4) Å, c = 13.2040(5) Å, β = 94.472(1)°]. In the solid state, the unit is characterized by N₃ linear groups forming bond angles of roughly 120° with the Re₆ cluster. The positions of the ν_as and ν_sy bands as well as N–N–N deformation modes of the N₃ groups are discussed. Luminescence properties of the [Re₆Seⁱ₈(N₃)^a]^4– unit were measured in the solid state and in an acetonitrile solution. The redox potential of the [Re₆Seⁱ₈(N₃)^a]^4–/[Re₆Seⁱ₈(N₃)^a]^3– system was measured in acetonitrile. Experimental results were analyzed in the light of density functional theory calculations.     

Syntheses and Crystal Structures of Hydrated Ternary Cerium Sulfates: Mixed‐valence K5Ce2(SO4)6·H2O and K2Ce(SO4)3·H2O

A new chemical and structural interpretation of K₅Ce₂(SO₄)₆·H₂O ( I ) and a redetermination of the structure of K₂Ce(SO₄)₃·H₂O ( II ) is presented. The mixed‐valent compound I crystallizes in the space group C2/c with a = 17.7321(3), b = 7.0599(1), c = 19.4628(4) Å, β = 112.373(1)° and Z = 4. Compound I has been discussed earlier with space group Cc. In the structure of I , there are pairs of edge sharing cerium polyhedra connected by sulfate oxygen atoms in the μ₃ bonding mode. These cerium dimers are linked through edge and corner sharing sulfate bridges, forming layers. The layers are joined by potassium ions which together with the water molecules are placed between the layers. No irregularity in the distribution of the Ce^III and Ce^IV to cause the lost of a crystallographic center of symmetry was detected. We suggest that the charge exerted by the extra f¹ electron for every cerium dimer is delocalized over the Ce1–O₂–Ce2 moiety in a non‐bonding mode. As a result, the oxidations state of each cerium ion is a mean value between III and IV at each atomic position. Compound II crystallizes in the space group C2 with a = 20.6149(2), b = 7.0742(1), c = 17.8570(1) Å, β = 122.720(1)° and Z = 8. The hydrogen atoms have been located and the absolute structure has been established. Neither hydrogen atom positions nor anisotropic displacement parameters were given in the previous reports. In compound II , the cerium polyhedra are connected by edge and corner sharing sulfate groups forming a three‐dimensional network. This network contains Z‐shaped channels hosting the charge compensating potassium ions.     

Mixed‐ligand Copper(II) Complexes with N‐isopropyl‐iminodiacetato(2‐) and C‐phenyl‐imidazole Ligands. Crystal Structures of H2iPIDA, [Cu(iPIDA)(H2ϕim)(H2O)]·3H2O and [Cu(iPIDA)(H5ϕim)]n

The crystal of the N‐isopropyl‐iminodiacetic acid ( 1 ) consists of a 3D H‐bonded framework where the zwitterion (H₂iPIDA^±) is intra‐stabilized by one N⁺‐H···O interaction and both carboxyl are half‐protonated and involved in linear O‐H···O inter‐molecular bridges of 2.46 Å. The mixed‐ligand complexes [Cu(iPIDA)(H2?im)(H₂O)]·3H₂O ( 2 ) and [Cu(iPIDA)(H5?im)]_n ( 3 ) have also been synthesized and studied by thermal, spectral, magnetic and X‐ray diffraction methods. Both complexes exhibit a square base pyramidal coordination, type 4+1. Compound 3 is the less steric hindered 'remote' isomer, with H5?im instead of H4?im.