Synthesis and characterization of heteronuclear germanium(IV) lanthanide 1,3-diamino-2-propanoltetraacetates: Crystal and molecular structure of the [Ge(OH)(μ-Hpdta)(μ-OH) Ln(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>] · 2H<Subscript>2</Subscript>O complexes (Ln = Tb,Yb)

In the course of systematic studies, heteronuclear germanium lanthanide complexes based on 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) have been synthesized (Ln = Pr (I), Nd (II, the structure was described in [1]), Sm (III), Eu (IV), Gd (V), Tb (VI), Dy (VII), Ho (VIII), Er (IX), Tm (X), Yb (XI), Lu (XII)). Comparative analysis of their structure as a function of the lanthanide ion has been performed. The analysis is based on a combination of physicochemical data on complexes I–XII, including X-ray crystallographic data for two heteronuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] · 2H₂O complexes (Ln = Tb (VI) and Yb (XI). Isostructural crystals of VI and XI are monoclinic, Z = 4, space group P2₁/n, a = 9.340(4) and 9.3133(10) Å, b = 10.4839(14) and 10.4561(10) Å, c = 20.246(2) and 20.1222(10) Å, β = 95.12(3)° and 95.275(10)°, V = 1974.5(10) and 1951.2(3) A³, R1 = 0.0277 and 0.0241 for 4527 and 4751 reflections with I > 2σ(I). Crystals of VI and XI are composed of binuclear [Ge(OH)(μ-Hpdta)(μ-OH)Ln(H₂O)₃] molecules and crystal water molecules. The Ge and Ln atoms in VI and XI are linked by the bridging oxygen atom of the hydroxo group (Ge-O, 1.806(2) and 1.812(2) Å; Ln-O, 2.445(3) and 2.405(2) Å, respectively) and by the deprotonated oxygen atom of the isopropanol group of the Hpdta5-ligand (Ge-O, 1.865(2) and 1.864(2) Å; Ln-O, 2.302(2) and 2.255(2) Å in VI and XI, respectively). The coordination sphere of each of the Ge and Ln atoms involves one nitrogen atom (Ge-N, 2.097(3) and 2.096(3) Å; Ln-N, 2.670(3) and 2.628(3) Å in VI and XI, respectively) and two carboxyl oxygen atoms of four acetate arms of the completely deprotonated heptadentate Hpdta^5? ligand (av. Ge-O, 1.922(3) and 1.920(3) Å; Ln-O, 2.349(2) and 2.298(2) Å in VI and XI, respectively). The coordination polyhedron of the Ge atom is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group (Ge-O, 1.811(2) Å in VI and 1.810(2) Å in XI), and the coordination polyhedron of the Ln atom is completed to an eight-vertex polyhedron by the oxygen atoms of three water molecules (av. Ln-O, 2.378(3) Å in VI and 2.342(3) Å in XI). In the crystals of VI and XI, complex molecules and crystal water molecules are combined by a system of hydrogen bonds into a three-dimensional framework.     

Synthesis,properties, and crystal and molecular structure of potassium nitrilotriacetatodihydroxogermanate(IV) K[Ge(Nta)(OH)<Subscript>2</Subscript>] · H<Subscript>2</Subscript>O

The complex K[Ge(Nta)(OH)₂] · H₂O(H₃Nta is nitrilotriacetic acid) was obtained and studied by IR spectroscopy, thermogravimetry, X-ray powder diffraction, and X-ray crystallography. Crystals of the complex are monoclinic: a = 9.195(3) Å, b = 10.9805(19) Å, c = 10.661(3) Å, β = 95.53(3)°, V = 1071.3(5) ų, Z = 4, space group Cc, R = 0.0560 based on 1335 reflections with I > 2σ(I). The compound is composed of complex anions [Ge(Nta)(OH)₂]^?, K⁺ cations, and water molecules of crystallization. The coordination polyhedron of the germanium atom of the anion is a distorted octahedron composed of the nitrogen atom (Ge-N, 2.080(7) Å) and three carboxylic oxygen atoms (av. Ge-O, 1.931(7) Å) of three acetate branches of the completely deprotonated tetradentate ligand Nta^3? and two hydroxyl oxygen atoms (av. Ge-O, 1.791(8) Å). In the crystals, complex anions, cations, and crystallization water molecules are linked by hydrogen bonds to form a framework.     

Erbium(III) and lutecium(III) complexes [Ln(H<Subscript>2</Subscript>O)<Subscript>8</Subscript>][Cr(NCS)<Subscript>6</Subscript>] · 5H<Subscript>2</Subscript>O: Synthesis and crystal structure

[Ln(H₂O)₈][Cr(NCS)₆] · 5H₂O aqua complexes, where Ln = Er (1), Lu (2), have been found in an aqueous solution instead of binary complex salts with an organic ligand in their cation, when crystal products of the reaction between Ln(NO₃)₃ · 6H₂O (Ln = Er, Lu), K₃[Cr(NCS)₆] · 4H₂O, and 8-oxyquinoline (C₉H₇NO) were studied by X-ray diffraction. Crystals of complexes 1 and 2 are isostructural and crystallize in triclinic system, space group P\(\bar 1\), Z = 2. For complex 1: a = 9.0677(4) Å, b = 9.3115(4) Å, c = 16.9595 Å, α = 81.526(2)°, β = 86.153(2)°, γ = 83.879(2)°, V = 1406.33(10) ų, ρ_calc = 1.894 g/cm³; for complex 2: a = 9.0438(3) Å, b = 9.2880(3) Å, c = 16.9181(3) Å, α = 81.7250(10)°, β = 86.1600(10)°, γ = 83.8850(10)°, V = 1396.38(7) ų, ρ_calc = 1.926 g/cm³.     

Synthesis,properties, and molecular and crystal structure of diantipyrylmethanium Bis(μ-tartrato)dihydroxydigermanate(IV) tetrahydrate (HDAm)<Subscript>2</Subscript>[Ge<Subscript>2</Subscript>(μ-L)<Subscript>2</Subscript>(OH)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

The complex (HDam)₂[Ge₂(μ-L)₂(OH)₂] · 4H₂O (I) (H₄L is tartaric acid, Dam is diantipyrylmethane) was synthesized for the first time. The individual character and composition of I was established by elemental analysis and X-ray diffraction. The thermal stability of I was studied. The coordination sites of H₄L in the germanium complex were determined by IR spectroscopy. The structure of I was determined by X-ray crystallography. The crystals of I are triclinic: a = 9.3098(10) Å, b = 9.8088(10) Å, c = 17.6869(10) Å, α = 84.009(10)°, β = 77.926(10)°, γ = 67.088(5)°, V = 1454.3(2) ų, Z = 2, space group P \(\bar 1\), R = 0.0628 for 6343 reflections with I > 2σ(I). The compound is composed of the complex anions [Ge₂(μ-L)₂(OH)₂]^2?, the HDam⁺ cations, and crystal water molecules. In the dimeric anion, the metal atoms are bound to two completely deprotonated ligands L^4?. The latter are coordinated to the metal through the carboxyl (av. Ge-O, 1.911(6) Å) and hydroxyl (av. Ge-O, 1.768(6) Å) oxygen atoms. The coordination of each Ge atom is completed to trigonalbipyramidal by the O atom of the hydroxy ligand in the axial position (av. Ge-O, 1.748(7) Å). Both L^4? ligands are D isomers. In the crystal, the complex anions and crystal water molecules are combined by a system of hydrogen bonds.     

Osmium(IV) thiocarbamide complexes. Synthesis and crystal and molecular structures of [Os(Thio)<Subscript>2</Subscript>Cl<Subscript>4</Subscript>] · 2H<Subscript>2</Subscript>O

Tetrachlorobis(thiocarbamide)osmium(IV) dehydrate, [Os(Thio)₂Cl₄] · 2H₂O, was synthesized by the reaction of K₂[OsO₂(OH)₄] with thiocarbamide in 6 M HCl. The compound was characterized by chemical analysis and IR, UV, and X-ray photoelectron spectroscopies. The structure was determined by X-ray diffraction analysis. The coordination polyhedron of the osmium atom lying in the axis 2 is a distorted cis-octahedron formed by four chlorine atoms and two sulfur atoms of two monodentate thiocarbamide ligands: Os-S 2.3075(18) Å and Os-Cl 2.3625(18) Å (trans to Cl) and 2.4294(19) Å (trans to S). The conditions for the formation of the osmium(IV) thiocarbamide complexes in HCl solutions were determined using spectrophotometry, and the spectral characteristics of [Os(Thio)Cl₅]^? were obtained.     

Synthesis,properties, and crystal structure of diphenylguanidinium bis(citrato)germanate hydrate (HDphg)<Subscript>2</Subscript>[Ge(HCit)<Subscript>2</Subscript>] · 1.08H<Subscript>2</Subscript>O

Diphenylguanidinium bis(citrato)germanate hydrate (HDphg)₂[Ge(HCit)₂] · 1.08H₂O (I) was prepared for the first time (H₄Cit is citric acid, Dphg is diphenylguanidine). The composition of I was determined using elemental analysis and thermogravimetry; the coordination sites of H₄Cit and the protonation sites of Dphg were identified by IR spectroscopy. Compound I was studied by X-ray diffraction. The crystals are monoclinic, a = 11.179(2) Å, b = 7.6081(15) Å, c = 23.529(5) Å, β = 95.38(3)°, V = 1992.3(7) ų, Z = 2, space group P2₁/c, R = 0.0339 for 2498 reflections with I>2σ(I). In the [Ge(HCit)₂]^2? complex anion, the Ge atom is bond to a distorted octahedral array of six O atoms of the two tridentate chelating HCit^3? ligands (Ge-O, 1.8045–1.9555 Å). In the crystal of I, the anions and cations are combined into layers by a system of hydrogen bonds.     

Synthesis and crystal structures of [K(H<Subscript>2</Subscript>O)(Piv)]<Subscript>∞</Subscript> and [K<Subscript>2</Subscript>(Phen)(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>(Piv)<Subscript>2</Subscript>]<Subscript>∞</Subscript>

A method for the synthesis of potassium pivalates (trimethylacetates) from potassium tert-butoxide and pivalic acid was proposed. The complexes of the formulas [K(H₂O)(Piv)]_∞(I) and [K₂(Phen)(H₂O)₂(Piv)₂]_∞ (II) (Piv denotes the pivalate anion and Phen denotes 1,10-phenanthroline) were obtained and characterized by elemental analysis and IR and ¹H NMR spectroscopy. The crystal structures of complexes I and II were determined using X-ray diffraction. Crystal structure I has a layered motif with two nonequivalent K atoms (C.N.s 5 + 2 and 6). The coordination of phenanthroline in II gives rise to a ribbon motif, the structure containing three nonequivalent K atoms (C.N.s 6, 6 + 1, and 8).     

Heteronuclear alkali metal bis(μ-trihydroxyglutarato)dihydroxodigermanates(IV): The crystal and molecular structure of K<Subscript>4</Subscript>[Ge<Subscript>2</Subscript>(μ-Thgl)<Subscript>2</Subscript>(OH)<Subscript>2</Subscript>] · 4H<Subscript>2</Subscript>O

Heterometallic potassium and sodium trihydroxyglutaratogermanates of the formulas K₄[Ge₂(μ-Thgl)₂(OH)₂] · 4H₂O (I) and Na₄[Ge₂(μ-Thgl)₂(OH)₂] · 5H₂O (II) (H₅Thgl is trihydroxyglutaric acid) were obtained for the first time and characterized by elemental analysis, X-ray powder diffraction, thermogravimetry, and IR spectroscopy. Complex I was examined by single-crystal X-ray diffraction. The crystals are triclinic; a = 7.5933(15) Å, b = 7.628(4) Å, c = 10.516(4) Å, α = 104.01(3)°, β = 101.041(17)°, γ = 97.50(3)°, V = 570.0(3) ų, Z = 1, space group \(P\bar 1,R\bar 1 = 0.0479\) for 2848 reflections with I > 2σ (I). Complex I is made up of the centrosymmetric dimeric complex anions [Ge₂(μ-Thgl)₂(OH)₂]^4?, the potassium cations, and water molecules of crystallization. In the anion, the two Ge atoms are bridged by two fully deprotonated ligands Thgl^5?. The coordination polyhedron of the Ge(IV) atom is a distorted trigonal bipyramid. Its equatorial plane is made up of the O atom of the terminal OH group (Ge-O…OH, 1.760(2) Å) and the O atoms of two alcohol groups of two ligands Thgl^5? (av. Ge-O_alc, 1.797(2) Å; the angles O_eqGe(1)O_eq, 110.12°–137.11°). The axial positions are occupied by the O atom of the alcohol group (Ge-O_alc, 1.853(2) Å) and the carboxyl O atom of one carboxylate group (Ge-O_carb, 1.944(2) Å) of two symmetry-related ligands Thgl^5?. The angle O_axGeO_ax is 163.68(10)°. The second carboxylate group of the ligand Thgl^5? is not coordinated to the Ge atom. The coordination numbers of the cations K(1)⁺ and K(2)⁺ are seven and nine, respectively (K(1)-O, 2.685–2.889 Å; K(2)-O, 2.675–3.262 Å). In the crystal, the structural units are united into a three-dimensional framework.     

Synthesis and crystal structure of complex [Mn(Imdc)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 2H<Subscript>2</Subscript>O and its interaction with DNA

Under hydrothermal conditions, the complex [Mn(lmdc)₂(H₂O)₂] · 2H₂O (I) was synthesized and characterized by elemental analysis and IR spectrum (HImdc = 4,5-imidazofedicarboxylic acid). The crystal structure of I was determined by single-crystal X-ray diffraction (crystallizing in the monoclinic crystal system, P ₂/c space group, a = 11.000(2), b = 7.1281(14), c = 12.696(3) Å, β = 122.45(3), Z = 2. In I, the Mn²⁺ ion was chelated by two Imdc with one of their nitrogen atoms and a carboxylic oxygen atom, while two water molecules occupy the axial position of the Mn atom forming a distorted octahedral geometry. Three-dimensional structure of I was formed by intermolecular hydrogen bonds. UV-Vis and fluorescence spectra of I interacting with DNA show that insertion is the main binding mode between I and fish sperm DNA. Gel electrophoresis shows that I cleaves both supercoiled and circular pBR322 DNA to form a small molecular fragment.     

Germanium(IV) bischelates with 2-hydroxynaphthaldehyde pyridinoylhydrazones: The crystal and molecular structure of the complex with isonicotinoylhydrazone (H<Subscript>2</Subscript>Inf), [Ge(Inf · HCl)<Subscript>2</Subscript>] · 5H<Subscript>2</Subscript>O

The reactions of GeCl₄ with 2-hydroxynaphthaldehyde pyridinoylhydrazones (H₂L) in methanol give complexes [Ge(L · HCl)₂] · nH₂O. The data of mass spectrometry, thermogravimetry, and IR and ¹H NMR spectroscopy indicate that the ligand molecules are protonated at the pyridine nitrogen atom with hydrogen chloride and coordinated to germanium in the tridentate mode through the azomethine nitrogen atom and the oxyazine and oxy group oxygen atoms. The structure of the complex with isonicotinoylhydrazone (H₂Inf), [Ge(Inf · HCl)₂] · 5H₂O has been determined by X-ray diffraction     

Synthesis and characterization of heteronuclear germanium(IV) and lanthanum(III) (chromium(III)) complexes with 1,3-diamino-2-propanoltetraacetic acid: Crystal and molecular structure of [Ge(OH)(μ-Hpdta)(μ-OH)La(H2O)4] · H2O

Two heteronuclear germanium(IV) and lanthanum(III) (chromium(III)) complexes with 1,3-diamino-2-propanoltetraacetic acid (H₅Hpdta) have been synthesized. The compounds have been characterized by elemental analysis and X-ray powder diffraction data. The structure of [Ge(OH)(??-Hpdta)(??-OH)La(H₂O)₄] · H₂O (I) has been determined by X-ray crystallography. The crystals are monoclinic, a = 9.3805(3) ?, b = 10.3023(4) ?, c = 21.6527(6) ?, ?? = 94.829(2)°, V = 2085.10(12) ?³, Z = 4, space group P2₁/n, R1 = 0.0294 based on 5480 reflections with I > 2??(I). Compound I is composed of binuclear [Ge(OH)(??-Hpdta)(??-OH)La(H₂O)₄] molecules and crystal water molecules. In the dimeric molecule, the germanium and lanthanum atoms are linked by the bridging oxygen atom of the hydroxo ligand and the oxygen atom of the deprotonated isopropanol group of Hpdta^5?. The coordination spheres of germanium and lanthanum each contains one nitrogen atom and two carboxyl oxygen atoms of the four acetate arms of the heptadentate Hpdta^5? ligand. The Ge coordination polyhedron is completed to a distorted octahedron by the oxygen atom of the terminal hydroxo group, and the lanthanum coordination polyhedron is completed to a nine-vertex polyhedron by the oxygen atoms of four water molecules. In crystal, the complex molecules and crystal water molecules are combined by a system of hydrogen bonds.     

Synthesis,Structure and Property of Oxo-Bridged Binuclear Iron(III) Complex [Fe(phen)(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>]<Subscript>2</Subscript>O⋅2SO<Subscript>4</Subscript>

An oxo-bridged binuclear iron(III) complex, [Fe(phen)(H₂O)₃]₂O2SO₄, has been synthesized and structurally characterized by elemental analysis (EA), IR, TG-DSC and X-ray. Its crystal structure has been determined by X-ray crystallography. It crystallizes in the orthorhombic system, space group P2₁2₁2, with lattice parameters a = 17.650(4), b = 8.5133(17), c = 9.971(2) Å; V = 1498.2(5) ų, _calcd = 1.763 g/cm³ and Z = 4 for R₁ = 0.0601. The crystal structure indicated that two octahedrally coordinated iron(III) ions bridged with oxygen atoms formed a non-linear complex. The bond angle of Fe–O–Fe is 163.9(4). The data of EA and IR are in good agreement with the crystal structure. The thermal gravity (TG) data indicate that there are four decomposition steps with three endothermic peaks. The final product of the thermal decomposition may be Fe(C₂H₈N₂)SO₄.     

Diphenylguanidinium (ethylenediaminetetraacetato)hydroxogermanate hydrate (HDphg)[Ge(OH)(Edta)] · H<Subscript>2</Subscript>O: Synthesis,physicochemical characterization,and crystal structure

The onium compound based on the germanium(IV) complex with ethylenediamine-N,N,N ¹,N ¹-tetraacetic acid (H₄Edta) and diphenylguanidine (Dphg), (HDphg)[Ge(OH)(Edta)] · H₂O, has been isolated in the solid state and studied by physicochemical methods. Its crystal structure has been determined by the X-ray diffraction method. The crystals are monoclinic, a = 7.0179(9) Å, b = 28.797(8) Å, c = 13.477(2) Å, β = 104.301(12)°, V = 2639.3(9) Å₃, Z = 4, space group P2₁/c, R = 0.045 for 2524 reflections with I > 2σ(I). The onium compound is built of diphenylguanidinium cations HDphg⁺, [Ge(OH)(Edta)]^? anions, and water molecules of crystallization. In the complex anion, the Ge atom is coordinated by two nitrogen atoms and three oxygen atoms of three acetate arms of the pentadentate chelating ligand Edta^4? (av. Ge-N, 2.095(4) Å; Ge-O, 1.891(3) Å). The fourth acetate arm is deprotonated and is not involved in coordination with the metal. The coordination of the metal atom is completed to an octahedral one by the O atom of the hydroxo ligand (Ge-OH 1.759(3) Å). The structural units in crystal are linked by a system of hydrogen bonds.     

Synthesis and crystal structure of the complex [Nd(2-EOBA)<Subscript>3</Subscript>(phen)(H<Subscript>2</Subscript>O)]<Subscript>2</Subscript> · H<Subscript>2</Subscript>O

A novel lanthanide complex of [Nd(2-EOBA)₃(phen)(H₂O)]₂ · H₂O (2-EOBA = 2-ethoxylbenzoate, phen = 1,10-phenanthroline), has been synthesized and structurally characterized by single crystal X-ray diffraction. The complex crystallizes in monoclinic, space group P2(1)/n with a = 14.7453(18) Å, b = 12.3628(15) Å, c = 19.473(2) Å, α = 90°, β = 93.349(2)°, γ = 90°. Two Nd³⁺ ions are connected together by two bridging 2-EOBA ligands and each Nd³⁺ ion is further coordinated by two chelating 2-EOBA ligands, one chelating phen molecule and one water molecule. The coordination number of Nd³⁺ ion is nine. The coordination geometry of Nd³⁺ ion is a distorted monocapped square-antiprism.     

Crystal structure of Mg pivalate hydrate Mg(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>(Piv)<Subscript>2</Subscript> · 3H<Subscript>2</Subscript>O

Single crystals of Mg pivalate hydrate, Mg(H₂O)₆(Piv)₂ · 3H₂O (HPiv = (CH₃)₃CCOOH) are synthesized and their structure is determined by X-ray diffraction method. The crystals are rhombic: a = 10.917(2) Å, b = 12.625(2) Å, c = 31.394(8) Å, Z = 8, space group Pbca, R ₁ = 0.0525. The Mg atom has octahedral surrounding of the O atoms of water molecules (Mg-O 2.044–2.137 Å). The cationic chains of [Mg(H₂O)₆] _∞ ²⁺ lie in the voids of doubled network anionic layers of [(H₂O)₃(Piv)₂] _∞∞ ^2? . Inside the layer, the pivalate anions alternate with water molecules in the xy plane, being bonded to them by hydrogen bonds. The cationic chains and the anionic layers are united into layered packs by hydrogen bonds between coordinated water molecules and pivalate anions and between coordinated and crystal hydrate water molecules.     

Clathrate [Zn(C<Subscript>6</Subscript>H<Subscript>5</Subscript>COO)<Subscript>2</Subscript>(H<Subscript>2</Subscript>O)<Subscript>2</Subscript>] · 2CH<Subscript>3</Subscript>COOH: Synthesis and crystal structure

The clathrate [Zn(C₆H₅COO)₂(H₂O)₂] · 2CH₃COOH (I) was obtained for the first time from zinc(II) benzoate. The individuality, the unit cell parameters, and the number of “guest” molecules in complex I were determined from X-ray diffraction and derivatographic data. Its crystal structure was solved.     

Manganese(II) 9-Molybdomanganate(IV), [Mn(H<Subscript>2</Subscript>O)<Subscript>4</Subscript>]<Subscript>3</Subscript> · [MnMo<Subscript>9</Subscript>O<Subscript>32</Subscript>] · 2H<Subscript>2</Subscript>O: Synthesis,thermal analysis,IR spectra,and crystal structure

The [Mn(H₂O)₄]₃ · [MnMo₉O₃₂] · 2H₂O complex was synthesized and studied by X-ray diffraction, thermogravimetry, powder X-ray diffraction, and IR spectroscopy. The crystals are trigonal: space group R32, a = 14.811(2) Å, c = 14.232(2) Å, V = 2703.7(8) ų, M = 1848.5, Z = 3, ρ(calcd.) = 3.419 g/cm³.     

Synthesis and crystal structure of [Na(H<Subscript>2</Subscript>O)<Subscript>4</Subscript>][EuL<Subscript>4</Subscript>] · 0.775CH<Subscript>2</Subscript>Cl<Subscript>2</Subscript> (HL = 1,3-bis(1,3-dimethyl-1H-pyrazol-4-yl)-1,3-propanedione)

[Na(H₂O)₄][EuL₄] · 0.775CH₂Cl₂ (I) has been synthesized by the reaction of Eu(NO₃)₃ · 6H₂O with 1,3-bis(1,3-dimethyl-1H-pyrasol-4-yl)-1,3-propanedione (HL) in the presence of NaOH. Its crystal structure has been solved by X-ray diffraction analysis. Crystals are tetragonal; a = 16.2401(5) Å, c = 11.9113(4) Å, V= 3141.50(17) ų, ρ_calcd = 1.427 g/cm³, μ(MoK _α) = 1.140 mm^?1, space group P4/n, Z = 2. The structural units forming a crystal of compound I are [EuL₄]^? complex anions, [Na(H₂O)₄]⁺ cations, and CH₂Cl₂ molecules. The coordination polyhedron of the Eu atom is an Archimedean antiprism formed by the O atoms of four bidentate chelate ligands L^?.     

[H<Subscript>4</Subscript>(4,4′-Bipy)<Subscript>3</Subscript>][Sc(OH)(H<Subscript>2</Subscript>O)<Subscript>5</Subscript>]<Subscript>2</Subscript>Cl<Subscript>8</Subscript>: Synthesis,structure, and solid-phase thermal transformation

The reaction of [Sc(OH)(H₂O)₅]₂Cl₄ · 2H₂O in isopropanol with 4,4′-Bipy in CHCl₃ produced a crystalline compound, which was identified as [H₄(4,4′-Bipy)₃][Sc(OH)(H₂O)₅]₂Cl₈ (I) by elemental analysis, IR spectra, and single-crystal X-ray diffraction. In the structure of compound I, the three protonated diimine molecules form a centrosymmetric trimer via N...N hydrogen bonds. The polyhedron around the Sc atom is an octahedron with one split vertex. The excursion of the Sc atom from the plane formed by the oxygen atoms (water molecules) toward the hydroxo bridges is 0.5 Å. The thermolysis of compound I generates ScCl₃, whereas the final decomposition product of the precursor dimer is ScOCl.     

Crystal structure and quantum chemical investigation of [Cd(NTO)<Subscript>4</Subscript>Cd(H<Subscript>2</Subscript>O)<Subscript>6</Subscript>] · 4H<Subscript>2</Subscript>O

[Cd(NTO)₄Cd(H₂O)₆] •4H₂O was synthesized by mixing the aqueous solution of 3-nitro-1, 2,4-triazol-5-one (NTO) and cadmium carbonate. The single crystal structure was determined by a four-circle X-ray diffractometer. The crystal is monoclinic, space group C2/c with crystal parameters of a = 2.1229(3) nm, b = 0.6261(8) nm, = 2.1165(3) nm, β= 90.602 (3)°, V= 2.977(6) nm₃, Z = 4, D_c = 2.055 g • cm_-3, μ = 15.45 cm_-1 and F(000) = 1824. 2523 observable independent reflections with F₀4σ(F₀) were used for the determination and refinement of the crystal structure. Lorentz-polarization and absorption correction were applied. The final R is 0.0282 and wR = 0.0792. The analytical results show that the Cd⁺² has two kinds of coordinate bonds in one crystal. One Cd⁺² coordinates with 4 NTO anions and another coordinates with 6 water molecules to form a binucleate complex with a structure of tetrahedron and tetragonal bipyramid, respectively. By using SCF-PM3-MO method, the electron structure of cadmium complex of NTO has been calculated. The analysis of the calculated results shows that when [Cd(NTO)₄Cd(H₂O)₆] • 4H₂O is heated, the crystallization waters will be dissociated first and the ligand waters second and NO₂ group has priority of leaving when NTO⁻ is decomposed. Analysis of the energy level and composition of localized molecular orbitals indicates that both the two Cd²⁺ bond to the coordinating atom with 5s