Zinkiodate – Schwingungsspektren (IR,Raman) und Kristallstruktur von Zn(IO3)2 · 2 H2O

Zinc Iodates – Infrared and Raman Spectra, Crystal Structure of Zn(IO₃)₂ · 2 H₂O The zinc iodates Zn(IO₃)₂ · 2 H₂O and Zn(IO₃)₂ as well as α‐Co(IO₃)₂ · 2 H₂O were studied by X‐ray, IR‐ and Raman spectroscopic methods. The crystal structure of the dihydrate, which is isostructural with the respective cobalt compound, was determined by X‐ray single‐crystal studies (space group P1, Z = 2, a = 490,60(4), b = 667,31(5), c = 1088,85(9) pm, α = 98,855(6), β = 91,119(7), and γ = 92,841(6)°, R1 = 2,55%, 2639 unique reflections I > 2σ(I)). Transconfigurated Zn(IO₃)₄(H₂O)₂ octahedra are threedimensionally connected via common IO₃^– ions parallel to [001] and hydrogen bonds parallel to [100] and [010], respectively. Anhydrous Zn(IO₃)₂ crystallizes in space group P2₁ (Z = 2) with a = 548,9(2), b = 512,4(1), c = 941,8(2) pm, and β = 90,5(3)°. The structure of Zn(IO₃)₂ is a monoclinically distorted variant of the structures of β‐Ni(IO₃)₂ (space group P6₃) and Co(IO₃)₂ (P3). The O–H … O–IO₂ hydrogen bonds of the crystallographically different H₂O molecules of the dihydrates (ν_OD (OD stretching modes of isotopically dilute samples) 2430, 2415, 2333 and 2300 cm^–1, Zn(IO₃)₂ · 2 H₂O, 90 K) are examples to the matter of fact that O … O distances are only a bad measure for the strength of hydrogen bonds. The infrared and Raman spectra as well as a group theoretical treatment are presented and discussed with respect to mutual exclusion principle (possible space groups), the strength of the hydrogen bonds and the distortion of the IO₃^– ions at the C₁ lattice sites.     

Kristallstruktur,Infrarot‐ und Ramanspektren von Kupfertrihydrogenperiodatmonohydrat,CuH3IO6 · H2O

Crystal Structure, Infrared and Raman Spectra of Copper Trihydrogenperiodate Monohydrate, CuH₃IO₆ · H₂O The hitherto unknown compound CuH₃IO₆ · H₂O was studied by X‐ray, IR‐ and Raman spectroscopic methods. The crystal structure was determined by X‐ray single‐crystal studies (space group P2₁2₁2₁, Z = 4, a = 532.60(10), b = 624.00(10), c = 1570.8(3) pm, R1 = 1.85%, 1559 unique reflections (I > 2σ(I))). Isolated, meridionally configurated H₃IO₆^2– ions are coordinated to the copper ions forming double‐ropes in [100]. These ropes are connected in [010] and [001] by hydrogen bonds. The copper ions possess a square pyramidal co‐ordination with the hydrate H₂O on top. The infrared and Raman spectra as well as group theoretical treatment are presented and discussed with respect to the strength of the hydrogen bonds and the co‐ordination of the CuO₅₍₊₁₎ polyhedra and the H₃IO₆^2– ions at the C₁ lattice sites. The hydrogen bonds of the H₂O molecules and H₃IO₆^2– ions (HO–H…O–IO₅H₃ and H₂IO₅O–H…O–IO₅H₃) greatly differ in strength, as shown from both the respective O…O distances: 282.6 and 298.6 pm (H₂O), and 258.8, 259.7, and 270.9 pm (H₃IO₆^2–) and the OD stretching modes of isotopically dilute samples: 2498 and 2564 cm^–1 (90 K) (HDO), and 1786, 2024, and 2188 cm^–1 (H₂DIO₆^2–). The IO stretching modes of the H₃IO₆^2– ions (696–788 cm^–1 and 555–658 cm^–1, 295 K) display the different strength of the respective I–O and I–O(H) bonds (r_I–O: 181.1–188.3 pm and 189.2–194.5 pm).     

Gitterschwingungsspektren. LXIII. Be(lO3)2 · 4 H2O,ein Hydrat mit ungewöhnlicher Bindungsstruktur und Gitterdynamik

Lattice Vibration Spectra. LXIII. Be(IO₃)₂ · 4 H₂O, a Hydrate with Unusual Bonding and Lattice Dynamics The IR and Raman spectra (4000–50 cm^?1) of Be(IO₃)₂ · 4 H₂O and of deuterated specimens are recorded at 90 and 300 K and discussed in terms of the unusual relations of the masses of the atoms involved and the large polarization power of the beryllium ions. Thus, the translatory modes of the Be²⁺ ions (BeO₄ skeleton vibrations), the librations of the H₂O molecules, and the internal vibrations of the IO₃^? ions in the spectral regions of 300–400 and 600–1000 cm^?1 couple and coincide producing unusual v_H/v_D isotopic ratios of partly < 1. The H-bond donor strengths of the water molecules is so much increased (due to the very large ionic potential of Be²⁺ ions, viz. 49 e nm^?1) (synergetic effect) that the H-bonds formed are similar in strength as those in hydrates of hydroxides with the very strong H-bond acceptor group OH^? (v_OD of matrix isolated HDO molecules 2 074 and 2 244 (H₂O I) and 2 206 and 2 349 cm^?1 (H₂O II))     

Präparation,Kristallstruktur, Schwingungsspektren und thermische Analyse von Kupfer‐tetrahydrogen‐decaoxo‐diperiodat‐hexahydrat CuH4I2O10·6H2O

On Copper‐tetrahydrogen‐decaoxo‐diperiodate‐hexahydrate CuH₄I₂O₁₀·6H₂O: Crystal Structure, Vibrational Spectroscopy and Thermal Analysis By crystallization from a strongly acidic aqueous solution copper‐tetrahydrogen‐decaoxodiperiodate‐hexahydrate CuH₄I₂O₁₀· 6H₂O has been obtained. In the structure of this compound (S.G. P 2₁/c, Nr.14), Z = 2, a = 1060.2(2) pm, b = 551.1(1) pm, c = 1164.7(2) pm, β = 111, 49(3)°) centrosymmetric [H₄I₂O₁₀]^2— anions in the form of two edge sharing octahedra form layers via hydrogen bonds originating from the acidic, trans‐configurated OH groups of the anions. Raman spectra are given and analyzed with respect to the internal vibrations of the periodate anion. The dehydration of the compound takes place via CuH₄I₂O₁₀·3H₂O and Cu(H₂IO₅)₂ which decomposes at 170 °C to Cu(IO₃)₂.     

Zur Kenntnis der Hydrate M(HSeO3)2 · 4H2O (M = Mg,Co, Ni,Zn). Röntgenstrukturanalytische,schwingungsspektroskopische und thermoanalytische Untersuchungen

On the Hydrates M(HSeO₃)₂ · 4H₂O (M = Mg, Co, Ni, Zn) – Crystal Structures, IR, Raman, and Thermoanalytical Investigations From aqueous solutions of M(HSeO₃)₂ single crystals of Mg(HSeO₃)₂ · 4H₂O and of the hitherto unknown compounds Co(HSeO₃)₂ · 4H₂O, Ni(HSeO₃)₂ · 4H₂O and Zn(HSeO₃)₂ · 4H₂O could be obtained. The crystal structures, X-ray powder, IR, Raman and thermoanalytical (DTA, TG, Raman heating) data are presented and discussed. The crystal data of the isotypic compounds are: monoclinic, space group C2/c, Z = 4, Mg: a = 1 464.6(2), b = 755.3(1), c = 1 099.9(1) pm, β = 126.59(1)°, V = 0.9769(1) nm³, Co: a = 1 462.5(2), b = 756.5(2), c = 1 102.2(2) pm, β = 126.53(1)°, V = 0.9798(2) nm³, Ni: a = 1 452.2(2), b = 751.0(1), c = 1 091.5(1) pm, β = 126.28(1)°, V = 0.9595(1) nm³, Zn: a = 1 468.3(2), b = 755.8(1), c = 1 103.1(1) pm, β = 126.79(1)°, V = 0.9804(2) nm³. The crystal structures consist of hexagonal packed [M(HSeO₃)₂ · 2H₂O]_n chains of [MO₄(H₂O)₂] octahedra linked by Se atoms. They contain trigonal pyramidal SeO₂OH^?ions with “free” hydroxyl groups and also “free” molecules of water of crystallization. The hydroxyl groups build strong H-bonds (O? H …? O distances: 265–268 pm). The IR spectra show AB doublett bands in the OH stretching mode region of the hydroxyl groups. The water molecules of crystallization are linked to planar (H₂O)₄ tetramers by H-bonds with unusually short O? H …? O bond distances of 271–273 pm. DTA and TG measurements indicate that thermal decomposition results in the direct formation of the respective diselenite MSe₂O₅. Raman heating measurements show under quasi static conditions the intermediate formation of the anhydrous hydrogen selenites.     

IR- und Raman-Spektren der isotypen Iodathydrate M(IO3)2 · 4 H2O (M = Mg,Ni, Co); Kristallstruktur von Co(IO3)2 · 4 H2O

Infrared and Raman Spectroscopy of the Isostructural Iodate Hydrates M(IO₃)₂ · 4 H₂O (M = Mg, Ni, Co)-Crystal Structure of Cobalt Iodate Tetrahydrate The iodate tetrahydrates Mg(IO₃)₂ · 4 H₂O, β-Ni(IO₃)₂ · 4 H₂O, Co(IO₃)₂ · 4 H₂O and their deuterated specimens were studied by X-ray, infrared and Raman spectroscopic methods. The title compounds are isostructural crystallising in the monoclinic space group P2₁/c (Z = 2). The crystal structure of Co(IO₃)₂ · 4 H₂O (a = 836.8(5), b = 656.2(3), c = 850.2(5) pm and β = 100.12(5)°) has been refined by single-crystal X-ray methods (R_obs = 3.08%, 693 unique reflections I₀ > 2σ(I)). Isolated Co(IO₃)₂(H₂O)₄ octahedra form layers parallel (100). Within these layers, the two crystallographically different hydrate water molecules form nearly linear hydrogen bonds to adjacent IO₃^– ions (ν_OD of matrix isolated HDO of Co(IO₃)₂ · 4 H₂O (isotopically diluted samples) 2443 (H3), 2430 (H2), and 2379 cm^–1 (H1 and H4), –180 °C). Intramolecular O–H and intermolecular H…O distances were derived from the novel ν_OD vs. r_OH and the traditional ν_OD vs. r_H…O correlation curves, respectively. The internal modes of the iodate ions of the title compounds are discussed with respect to their coupling with the librations of the hydrate H₂O molecules, the distortion of the IO₃^– ions, and the influence of the lattice potential.     

Synthese und Charakterisierung von Aquapentachloroplatinaten(IV) – Struktur von [K(18-Krone-6)][PtCl5(H2O)]

Synthesis and Characterization of Aquapentachloroplatinates(IV) – Structure of [K(18-crown-6)][PtCl₅(H₂O)] The crown ether complex of the aquapentachloroplatinic acid of the composition [H₁₃O₆][PtCl₅(H₄O₂)] · 2(18-cr-6) ( 2 ) reacts with K₂CO₃ and [NⁿBu₄]OH in aqueous solution to give [K(18-cr-6)][PtCl₅(H₂O)] ( 5 a ) and [NⁿBu₄][PtCl₅(H₂O)] · ¹/₂ (18-cr-6) · H₂O ( 5 b ), respectively. Both compounds were characterized by microanalysis, vibrational (IR, Raman) and NMR (¹H, ¹³C, ¹⁹⁵Pt) spectroscopy. The X-ray structure analysis of 5 a (orthorhombic, pnma; a = 16,550(4), b = 18,044(3), c = 7,415(1) Å; Z = 4; R1 = 0,0183; wR2 = 0,0414) reveals that the crystal is threaded by chains built up of [PtCl₅(H₂O)]^? and [K(18-cr-6)]⁺ units. There are tight K …? Cl contacts (d(K? Cl1)) = 3,0881(9) Å and O_W? H? O_cr hydrogen bridges (d(O1 …? O2) = 2,806(3) Å) between these units. The coordination polyhedron [PtCl₅O] has approximately C_4v symmetry.     

Alkalimolybdotellurate: Darstellung und Kristallstruktur von Rb6[TeMo6O24] · 10H2O und Rb6[TeMo6O24] · Te(OH)6 · 6H2O

Alkaline Molybdotellurates: Preparation and Crystal Structures of Rb₆[TeMo₆O₂₄] · 10H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6H₂O Single crystals of Rb₆[TeMo₆O₂₄] · 10 H₂O and Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O, respectively, were grown from aqueous solution. Rb₆[TeMo₆O₂₄] · 10 H₂O possesses the space group P1 . The lattice dimensions are a = 963.40(13), b = 972.56(12), c = 1 056.18(13) pm, α = 97.556(10), β = 113.445(9), γ = 102.075(10)°; Z = 1, 2 860 reflections, 215 parameters refined, R_g = 0.0257. The centrosymmetrical [TeMo₆O₂₄]^6? anions are stacked parallel to [010]. Rb(2) is coordinated with one exception by water molecules only. Folded chains consisting of [TeMo₆O₂₄]^6? anions and Rb(2) coordination polyhedra which are linked to pairs represent the prominent structural feature. Rb₆[TeMo₆O₂₄] · Te(OH)₆ · 6 H₂O crystallizes monoclinically in the space group C2/c with a = 1 886.4(3), b = 1 000.9(1), c = 2 126.5(3) pm, and β = 115.90(1)°; Z = 4, 3 206 reflections, 240 parameters refined, R_g = 0.0333. It is isostructural in high extent with (NH₄)₆[TeMo₆O₂₄] · Te(OH)₆ · 7 H₂O. Hydrogen bonds between Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions establish infinite strands. The [TeMo₆O₂₄]^6? anions gather around Te(OH)₆ providing channel-like voids extending parallel to [001].     

Zur Kenntnis des Calciumbromats und - iodats,Kristallstruktur, röntgenographische,IR- und Raman-spektroskopische und thermoanalytische Untersuchungen

On Calcium Bromated and Iodates – Crystal Structure, X-Ray, IR and Raman Spectroscopical and Thermoanalytical Investigations The phase relationships (and both decomposition and disproportionation)of bromates and iodates of alkaline earth metals are studied by means of thermal analyses (DTA, DSC, TG) and (high-temperature) X-Ray, IR-, and (high-temperature) Raman spectroscopic measurements. The following compounds have been established: Ca(IO₃)₂ · 6 H₂O oF 216, the isotypic Ca(BrO₃)₂ · H₂O and Ca(IO₃)₂ · H₂O mP 48, Ca(IO₃)₂ I (Lautarit) mP 36, Ca(IO₃)₂ II and Ca(BrO₃)₂. The Crystal structure of Ca(IO₃)₂ · H₂O (brüggenite) (space group P2₁/c, Z = 4) has been determined by single crystal X-ray diffraction (MoKα). The final R value for 3888 reflections with I_o > 3σ₁ is 0.0487. The structures of bromates and iodates of alkaline earth metals known so far are discussed with respect to the energetic (mode frequencies) and geometric (bond lengths) distortion of the XO₃–ions as well as the strengths of H-bonds present in the respective hydrates.     

Nonanatrium-bis(hexahydroxoaluminat)-trihydroxid-hexahydrat (Na9[Al(OH)6]2(OH)3 · 6H2O) – Kristallstruktur,NMR-Spektroskopie und thermisches Verhalten

Nonasodium Bis(hexahydroxoaluminate) Trihydroxide Hexahydrate (Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O) – Crystal Structure, NMR Spectroscopy and Thermal Behaviour The crystal structure of the nonasodium bis(hexahydroxoaluminate) trihydroxide hexahydrate Na₉[Al(OH)₆]₂(OH)₃ · 6H₂O (4.5 Na₂O Al₂O₃ · 13.5 H₂O) (up to now described as 3 Na₂O · Al₂O₃ · 6H₂O, 4Na₂O · Al₂O₃ · 13 H₂O and [3 Na₂O · Al₂O₃ · 6H₂O] [xNaOH · yH₂O], respectively) was solved. The X-ray single crystal diffraction analysis (triclinic, space group P1 , a = 8.694(1) Å, b = 11.344(2) Å, c = 11.636(3) Å, α = 74.29(2)°, β = 87.43(2)°, γ = 70.66(2)°, Z = 2) results in a structure, consisting of monomeric [Al(OH)₆]^3? aluminate anions, which are connected by NaO₆ octahedra groups. Furthermore the structure contains both, two hydroxide anions only surrounded by water of crystallization and OH groups of [Al(OH)₆]^3? aluminate anions and a hydroxide anion involved in three NaO₆ coordination octahedra directly and moreover connected with a water molecule by hydrogen bonding. The results of ²⁷Al and ²³Na-MAS-NMR investigations, the thermal behaviour of the compound and possible relations between the crystal structure and the conditions of coordination in the corresponding sodium aluminate solution are discussed as well.     

Competition between H<Subscript>2</Subscript>O and CH<Subscript>3</Subscript>OH molecules in the formation of the simplest stable proton disolvates and their solvation in aqueous methanol solutions of KOH and CH<Subscript>3</Subscript>OK

IR spectroscopic and quantum chemical methods are used to study the competition between water and methanol molecules in the formation of the simplest stable proton disolvates and their subsequent solvation in the case of solutions of KOH in CH₃OH and CH₃OK in H₂O with similar stoichiometries (~1:3-3.5). The complexes found in these solutions are analysed to determine their composition and structure: they are found to be heteroions (CH₃O?H?OH)^– solvated by two similar solvent molecules. In both cases, there are virtually no complexes of the second possible type (CH₃OH·(CH₃O?H?OCH₃)^–··H₂O or CH₃OH·(HO?H?OH)^–·H₂O), which appears to be due to the stoichiometric compositions of the solutions. It is shown that a DFT calculation (B3LYP/6-31++G(d,p)) of linear complexes with strong (~15-30 kcal/mol) H bonds reproduces, with good accuracy, the IR spectra of the solutions, which consist mainly of these complexes.     

Magnesiumiodatdecahydrat Mg(IO3)2 · 10 H2O – Kristallstruktur,Ramanspektren, thermischer Abbau,lone-pair-Radius von Iod(V)

Magnesium Iodate Decahydrate Mg(IO₃)₂ · 10 H₂O – Crystal Structure, Raman Spectra, Thermal Decomposition, Lone-Pair Radius of Iodine(V) Mg(IO₃)₂ · 10 H₂O crystallizes in the triclinic space group P1 (a = 654.25(9), b = 1109.8(2), c = 1176.7(2) pm; α = 105.470(8), β = 104.086(8), γ = 101.744(8)°; Z = 2). The structure has been determined by single-crystal X-ray diffraction at 273 K, and refined to a final R value of 0.0272 for 4372 observed reflections (I > 2σ(I)). The magnesium ions are coordinated to six different H₂O molecules forming a slightly distorted octahedron with Mg? O distances varying between 202.2(2) and 211.6(3) pm. The hexaaquamagnesium ions are arranged parallel to (010). The two kinds of iodate ions and the four different “free” water molecules are filled between the layers thus formed. There are twenty independent hydrogen bonds with O … O distances from 268.7(3) to 287.6(4) pm. On the basis of all intermolecular I … I distances of iodates reported in the literature, 180 pm are recommended as van-der-Waals radius resp. lonepair radius of iodine(V). DSC and Raman spectroscopic experiments as well as high-temperature Raman and X-ray measurements were performed and are discussed with respect to the energetic and geometric distortion of the IO₃^? ions and the dehydration of the decahydrate via the tetrahydrate (308 K) to Mg(IO₃)₂ (428 K).     

Synthesis,characterization and thermal behaviour of adducts

The photoproduct of octacyanomolybdate(IV) and -tungstate(IV) with ethylenediamine and triethylenetetramine give complexes of the type K₃[Mo(O₂)(O)(OH)(C₉H₇ON)]·3C₉H₇ON I, K₂[W(O₂)(O) (C₉H₇ON)₃] II and K₃[Mo(CN)₃(OH)₄(C₉H₇ON)]·2C₉H₇ON·3H₂O III with 8-quinolinol (oxine). The IR spectra of the complex III shows the presence ofv(CN) peaks in the range 2047–2108 cm^?1 and oxine groupv(C-O) in the complex I, II and III in the range of 1100–1150 cm^?1. The lower region of IR spectra shows the M=O stretching while the higher thev(N-H) andv(OH). Thermal studies show the removal of uncoordinated water at 131?C from complex III. The decomposition of complexes I and II start from 150 and 212?C respectively. Oxine and cyano molecules were removed in stages at higher temperatures. The final product of the thermal decomposition was oxide which was of polymeric nature. The kinetic parameters viz. order of reaction ‘n’ and activation energy ‘E’ were determined by different methods.     

Cs6[TeMo6O24] · 2 Te(OH)6 · 4 H2O ? eine Tellursäure-reiche Einschlußverbindung

Cs₆[TeMo₆O₂₄] · 2 Te(OH)₆ · 4 H₂O – A Telluric Acid-rich Inclusion Compound Single crystals of Cs₆[TeMo₆O₂₄] · 2 Te(OH)₆ · 4 H₂O have been grown from aqueous solution. It crystallizes triclinically in space group P1 with Z = 1, a = 1 086.6(1), b = 1 095.6(1), c = 1 105.5(1) pm, α = 118.83(1), β = 106.22(1) and γ = 100.00(1)°. X-ray structure determination (5 755 reflections, 251 parameters, R_g = 0.0355) revealed an infinite chain consisting of hydrogen bonded (OH …? O 259.4(5) – 267.4(6) pm) Te(OH)₆ molecules and [TeMo₆O₂₄]^6? anions to be the Prominent structural feature. Further hydrogen bonds between neighbouring Te(OH)₆ molecules connect these chains to yield a two-dimensionally infinite arrangement.     

Darstellung,Kristallstruktur, Schwingungsspektren und Normalkoordinatenanalyse von K2[OsCl5(CO)] · H2O

Synthesis, Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of K₂[OsCl₅(CO)] · H₂O The X-ray structure determination of K₂[OsCl₅(CO)] · H₂O (monoclinic, space group P2₁/c a = 13.600(2), b = 7.122(1), c = 22.186(11) Å, β = 98.66(3)°, Z = 8) revealed two crystallographic independent bat very similar complex anions [OsCl₅(CO)]^2? with rough C_4v point symmetry. Due to the stronger trans influence of the carbonyl group the bond lengths in the Cl? Os? CO axis Os? Cl = 2.449(2), 2.430(2) Å are langer as compared with the octahedron basis Os? Cl = 2.340-2.370 Å. The water of crystallization is coordinated to potassium (K? OH₂ = 2.625-2.815 Å). Using the molecular parameters the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constants are f_d(CO) = 15.30, f_d(OsC) = 3.88, f_d(OsCl) = 1.81, f_d(OsCl) = 1.36, f_d(OH) = 7.65, 7.82, 7.79 mdyn/Å. The strengthening of the Os? C bond by stronger back donation of the Os^III(d⁵) complex in comparison with the isostructural Os^IV (d⁴) compound is discussed.     

An inorganic complex of silver (III): K5Ag(IO5OH)2 · 8H2O

The chemical preparation and crystal structure of the trivalent silver salt K₅Ag(IO₅OH)₂ · 8H₂O are described (monoclinic, space group Cc; a = 21.79(4), b = 6.320(3), c = 15.16(3) Å, β = 96.14(4); four formula units per unit cell). The structure is refined until R = 0.033 for 2718 reflections. Isolated Ag(IO₅OH)^5?₂ units occur, which contain trivalent silver ions surrounded by four oxygen atoms from two IO₆ octahedra in rectangular configuration. The differences in the IO bond lengths, as well as the small deviations of the crystal structure from centrosymmetry, are in agreement with an antiperiplanar position of the OH groups in both octahedra.     

Na2Mg(SO3) · 2H2O. Ein neues ternäres Magnesiumsulfit Kristallstruktur,schwingungsspektroskopische und thermoanalytische Untersuchungen

Na₂Mg(SO₃)₂ · 2H₂O. A New Ternary Magnesium Sulfite. Crystal Structure, Thermoanalytical, I.R., and Raman Data Single crystals of the hitherto unknown Na₂Mg(SO₃)₂ · 2 H₂O have been obtained by crystallization from Mg(HSO₃)₂ solutions saturated with NaCl and with the technique of gel crystallization. The crystal structure of the triclinic Na₂Mg(SO₃)₂ · 2 H₂O (P1 , Z = 1, a = 752.4(1), b = 590.3(1), c = 517.8(1) pm, α = 106.25(1), β = 109.80(1), and γ = 101.49(1)°) has been determined using single crystal X-ray diffraction data. The Mg? O distances of the nearly regular MgO₆ octahedra are between 206.6 and 210.5 pm. The MgO₆ octahedra are connected by sulfite bridges forming chains in [001], which are held together by strong hydrogen bridges. The SO₃^2? ions have nearly C_3v symmetry. The results of thermoanalytical and I.R. and Raman spectroscopic measurements are reported and discussed. The O? D stretching modes of HDO molecules in partially deuterated samples show that the water molecules differ strongly from C_2v symmetry.     

Kristallstrukturen des Sr(BrO3)2 · H2O,Ba(BrO3)2 · H2O,Ba(IO3)2 · H2O,Pb(CIO3)2 · H2O und Pb(BrO3)2 · H2O

Crystal Structure of Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O The crystall structures of the isostructural halates Sr(BrO₃)₂ · H₂O, Ba(BrO₃)₂ · H₂O, Ba(IO₃)₂ · H₂O, Pb(ClO₃)₂ · H₂O, and Pb(BrO₃)₂ · H₂O were determined using X-ray single crystal data (monoclinic space group C2/c? C, Z = 4), The mean bond lengths and bond angles of the halate ions in the Ba(ClO₃)₂ · 1 H₂O-type compounds, which correspond to those of other halates, are Cl? O, 149.0, Br? O, 165.9, I? O, 180.2 pm, ClO₃^?, 106.4, BrO₃^?, 104.0, and IO₃^?, 99.6°. The structure data obtained are discussed in terms of possible orientational disorder of the water molecules, strengths of the hydrogen bonds, influence of the lead ions on the structure, and site group distortion of the halate ions.     

Self‐Assembly of Polyoxometalate‐Supported Ln‐H nydroxo/Oxo Clusters with 1D Extended Structure: [LnIII(H2O)7Cr(OH)6Mo6O18]n·4nH2O (Ln = Ce,Sm, Eu)

Three novel polyoxometalate compounds consisting of Anderson‐type anions and trivalent lanthanide cations, [Ln(H₂O)₇Cr(OH)₆Mo₆O₁₈]_n·4nH₂O (Ln = Ce 1 ; Sm 2 ; Eu 3 ), have been synthesized in aqueous solution and characterized by single crystal X‐ray diffraction, elemental analyses, IR spectra, and TG analyses. Single crystal X‐ray diffractions reveal that the structures of the 1:1 composite compound formed by the heteropolyanion [Cr(OH)₆Mo₆O₁₈]^3? as the building unit and the [Ln(H₂O)₇]³⁺ complex fragment as the linker, which exhibit a type of zig‐zag chain with alternating cations and anions through the Mo‐Ot′‐Ln‐Ot′‐Mo linkage in the crystal. The magnetic properties of 1 ? 3 have been studied by measuring their magnetic susceptibility over the temperature range of 2‐300 K. The UV‐vis spectra of 1 give the Mo‐O and Cr^III‐O charge transfer transitions at 203 and 543 nm, respectively. In addition, the fluorescent characteristic transition of the Eu³⁺ ions in compound 3 is reported.     

Ungewöhnliche H-Brückenbindungen in Natriumhydroxidmonohydrat: Röntgen- und Neutronenbeugung an NaOH · H2O bzw. NaOD · D2O

Unusual H-Bonds in Sodium Hydroxide Monohydrate: X-Ray and Neutron Diffraction on NaOH · H₂O and NaOD · D₂O, respectively X-ray data revealed the structure of NaOH · H₂O including the H positions. Neutron diffraction on microcrystalline NaOD · D₂O was used for comparison of H with D positions: The compound crystallizes in a layer-type structure with the sequence …? /O Na O O Na O/ …? closely related to that of hydrargillite Al(OH)₃ with …? /O 2/3 Al O O 2/3 Al O/ …?. Between OH^? ions as acceptors and H₂O molecules mäandric, one-dimensional infinite strong H-bonds occur with d(O…?O) = 2.66 Å and 2.69 Å. These lie within O-layers that coordinate Na⁺ ions. Bridge-bonds between OH^? ions as donors and H₂O molecules as acceptors connect the /O Na O/-layers with d(O…?O) = 3.18 Å.