X-ray diffraction study of the clathrate [MnPy4(NO3)2)]·2Py and complex [MnPy3(NO3)2] formed in the pyridine (Py)-manganese nitrate system

A clathrate compound [MnPy₄(NO₃)₂]·2Py was synthesized and studied by single-crystal X-ray diffraction analysis (KM-4 diffractometer, CuK_α,ω/2? scan mode,? _max=78°). The unit cell is base-centered orthorhombic, space group Ccca, a=12.097(4), b=15.197(4), c=17.213(4) Å, V=3164(2) ų, Z=4, R=0.072, for 632 reflections and 107 parameters in the least-squares analysis. The host molecule has 222 symmetry. Two monodentate nitrato groups and four pyridine ligands are coordinated to Mn(II) along the symmetry axes (the former via O). The pyridine guest molecules lie in the cavities of the crystal framework. For [MnPy₃(NO₃)₂)], only unit cell parameters were determined: a=12.467(5), b=9.514(2), c=16.383(5) Å,β=108.93(4), V=1838(1) ų space group C2/c or Cc (according to extinctions). The pyridine-manganese nitrate system is shown to be analogous to the previously investigated Co, Ni, Cu, Zn, and Cd systems.     

Crystal structure and triboluminescence of the [Tb(BTFA)2(NO3)(TPPO)2] complex

The crystal structure of the [Tb(BTFA)₂(NO₃)(TPPO)₂] complex (TPPO is triphenylphosphine oxide, BTFA is benzoyltrifluoracetone), which exhibits strong triboluminescence, has been established by X-ray crystallography. The crystals are triclinic: a = 11.668(3) Å, b = 11.700(3) Å, c = 12.512(3) Å, α = 65.161(4°), β = 79.120(4)°, γ = 61.860(4)°, space group P1, Z = 1. The central terbium(III) atom coordinates two oxygen atoms from two triphenylphosphine oxide molecules (Tb-O, 2.264(3) and 2.273(3) Å), two oxygen atoms from the nitrate group (Tb-O, 2.460(3) and 2.476(3) Å), and four oxygen atoms from two benzoyltrifluoroacetonate groups (Tb-O, 2.329(3), 2.399(3), 2.351(3), and 2.367(3) Å). The coordination polyhedron of the Tb(III) atom is a distorted dodecahedron. The photoluminescence and triboluminescence spectra of the [Tb(BTFA)₂(NO₃)(TPPO)₂] complex are identical and caused by the f-f luminescence of Tb³⁺.     

Synthesis and molecular structure of catena((μ<Subscript>2</Subscript>-4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione-<Emphasis Type="Italic">O,O'</Emphasis>)- aquadinitratocadmium(II))

A coordination polymer, catena((μ₂-4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane- 2,8-dione-O,O')-aquadinitratocadmium(II) {[Cd(C₁₁H₂₀N₄O₂)(H₂O)(NO₃)₂]} _n } (I), has been prepared for the first time from cadmium(II) nitrate and the bicyclic bisurea 4,4,10,10-tetramethyl-1,3,7,9-tetraazaspiro[5.5]undecane-2,8-dione (TTSU). Its molecular structure has been determined (CIF file CCDC no. 903387). Triclinic crystals: space group P1?, a = 8.9967(4) Å, b = 9.6011(4) Å, c = 12.5131(7) Å, α = 76.307(4)°, β = 73.465(5)°, γ = 63.310(5)°, V = 918.26(8) ų, ρ_calc = 1.789 g/cm³, Z = 2. The Rietveld refinement was carried out at 293 K to confirm the single-phase constitution of the obtained powder sample of I: a = 8.9972(4) Å, b = 9.6104(4) Å, c = 12.5203(4) Å, α = 76.373(3)°, β = 73.485(3)°, γ = 73.485(3)°, V = 919.80(6) ų. A number of lines not corresponding to the main phase and not identified from PDF-2 database are observed on the powder X-ray diffraction pattern. The Rietveld refinement showed that the sample contains 91.4 wt % of the main compound I and 8.6 wt % of the TTSU nitrate admixture. The cadmium atom is coordinated by the O(1) and O(1)ⁱ atoms of two molecules of the organic ligand (L) generated by the symmetry operation (ⁱ1–x,–y,–z), the O(2)ⁱⁱ atom of the third ligand L molecule bound with the supporting one with the symmetry operation (ⁱⁱ–x,–y,–z), a water molecule, and a bidentate and a monodentate nitrate anions. The coordination number of the cadmium atom is 7, the coordination polyhedron is a distorted pentagonal bipyramid. The Cd···Cd distance is 4.0208 (3) Å.     

Coordination compounds of cobalt(II) and cadmium(II) with 2-amino-4-methylpyrimidine: Synthesis, crystal structure, and luminescent properties

The coordination compounds [CoL₂Cl₂] (I) and [CdL₂(H₂O)₂(NO₃)₂] (II) have been synthesized by the reaction of CoCl₂ · 6H₂O and Cd(NO₃)₂ · 4H₂O with L = 2-amino-4-methylpyrimidine (Ampym, C₅H₇N₃), and their structures have been solved. The crystals of complex I are triclinic, space group $P\bar 1$ , a = 5.627(1) Å, b = 11.191(1) Å, c = 12.445(1) Å, α = 81.00(1)°, β = 77.21(1)°, γ = 76.18(1)°, V = 737.7(2) ų, ρ_calcd = 1.567 g/cm³, Z = 2. The crystals of complex II are monoclinic, space group P2₁/c, a = 10.390(1) Å, b = 11.982(1) Å, c = 7.624(1) Å, β = 102.61(1)°, V = 926.1(2) ų, ρ_calcd = 1.760 g/cm³, Z = 2. Discrete [CoL₂Cl₂] moieties are realized in the structure of complex I. The cobalt atom is tetrahedrally coordinated to the two nitrogen atoms of crystallographically nonequivalent ligands L and two chlorine atoms (Co(1)-N_avg, 2.051(4)Å; Co(1)-Cl(1), 2.241(1) Å; Co(1)-Cl(2), 2.263 Å; bond angles at the cobalt atom lie within a range of 102.1°–118.6°). The complexes are linked into supramolecular zigzag chains by N-H...N(Cl) hydrogen bonds. In the structure of complex II, the Cd²⁺ ion (at the inversion center) is coordinated in pairs to the nitrogen atoms of ligand L and the O(NO₃) and O(H₂O) oxygen atoms. The coordination of the Cd²⁺ ion is distorted octahedral (Cd(1)-N(1), 2.341Å; Cd(1)-O(1), 2.340(4) Å; Cd(1)-O(4), 2.327(3) Å; bond angles at the cadmium atom lie within a range of 79.1°–100.9°). N-H...N hydrogen bonds link the complexes into supramolecular chains. These chains are linked into a supramolecular framework by the O-H...O hydrogen bonds between water molecules and NO₃ groups.     

Structure cristalline et polymorphisme du nitrate de cadmium anhydre

Cd(NO₃)₂ undergoes a phase transition at 160°C. The high temperature form is cubic and isomorphic with M(NO₃)₂ (M = Ba, Ca, Sr, Pb). The crystal structure of the low temperature phase has been solved by X-ray diffraction at 20°C, using 774 independent reflections collected with a 4-circle diffractometer. The dimensions of the orthorhombic unit cell are: $\text{a ? c = 7.5073 (14)}$ Å, b = 15.3692 (35) Å, Z = 8, space group Pca2₁. The structure has been refined to the final weighted R = 0.044. The cadmium atoms are nearly in a face-centered arrangement. Each cadmium is octahedrally surrounded by six oxygen, the CdO distances varying from 2.34 to 2.46 Å. Each nitrate group belongs through its three oxygens to three different octahedra. The structural change cubic Cd(NO₃)₂ → orthorhombic Cd(NO₃)₂ is characterized by a small rotation of NO₃ groups in their plane; the face-centered array of cadmium atoms is only slightly modified. The coordination of cadmium atoms changes from 12 to 6, and the approximate doubling of parameter (b) as well as the difference of symmetry can be explained by two different directions of rotation of the NO₃ groups situated in the same plane.     

Structural study of complex [Rh(NH3)5(NO2)](NO3)2·H2O, [Rh(NH3)5(NO2)][Pd(NO2)4], and K2[Rh(NH3)(NO2)5]·H2O salts

Compounds [Rh(NH₃)₅(NO₂)](NO₃)₂·H₂O (I) with a = 7.6230(3) Å, b = 7.6230(3) Å, c = 10.3584(4) Å, space group I-42m, Z = 2, d _calc = 2.026 g/cm³, V = 601.93(4) ų, Rh-NH_{3 eq} = 2.074 Å, Rh-NH_{3 ax} (NO₂) = 2.048 Å; [Rh(NH₃)₅(NO₂)][Pd(NO₂)₄] (II) with a = 8.095(3) Å, b = 22.422(8) Å, c = 7.887(3) Å, β = 98.559(17)°, space group Cc, Z = 4, d _calc = 2.461 g/cm³, V = 1415.6(9) ų, Rh-NH_{3 eq} = 2.069 Å, Rh-NH_{3 ax} = 2.090 Å, Rh-NO₂ = 2.002 Å; K₂[Rh(NH₃)(NO₂)₅]·H₂O (III) with a = 7.5177(5) Å, b = 20.9856(15) Å, c = 7.7017(5) Å, space group Cmc2₁, Z = 4, d _calc = 2.439 g/cm³, V = 1215.05(14) ų, Rh-NH_{3 ax} (NO₂) = 2.094 Å, Rh-NO_{2 eq} = 2.030 Å are synthesized and studied using single crystal X-ray diffraction.     

Synthesis and X-ray investigation of Rb<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>] and Cs<Subscript>2</Subscript>[Pd(NO<Subscript>3</Subscript>)<Subscript>4</Subscript>]

Powder and single crystal X-ray diffraction studies have been performed for anhydrous nitrate complexes Rb₂[Pd(NO₃)₄] (I) and Cs₂[Pd(NO₃)₄] (II). Crystal data for I: a = 7.843(1) Å, b = 7.970(1) Å, c = 9.725(1) Å; β = 100.39(1)°, V = 597.9(1) Å ³, space group P2₁/c, Z = 2, d _calc = 2.918 g/cm³; for II: a = 10.309(2) Å, b = 10.426(2) Å, c = 11.839(2) Å; β = 108.17(3)°, V = 1209.0(4) ų, space group P2₁/c, Z = 4, d ^calc = 3.408 g/cm³. The structures are formed by isolated [Pd(NO₃)₄]^2? complex anions and alkali metal cations. The plane-square environment of the Pd atom is formed from the oxygen atoms of the monodentate nitrate groups. The geometrical characteristics of the complex anions are analyzed. Compound II has a short contact Pd...Cs 3.252 Å.     

Synthesis and crystal structure of nickel(II) dinitrate molecular complex with 3,5-lutidine

Complex [Ni(NO₃)₂(3,5-lutidine)₃] (3,5-lutidine, 3,5-Lut-C₇H₉N) was synthesized, and its crystal structure was determined. Complex crystals are monoclinic: space group Cc, a = 14.445(1) Å, b = 10.024(1) Å, c = 17.607(1) Å, β = 108.96(1)°, V = 2411(1) ų, ρ_calcd = 2.389 g/cm³, Z = 4. The structure is built of discrete neutral complexes [Ni(3,5-Lut)₃(NO₃)₂]. The coordination sphere of Ni²⁺ ions is a disordered octahedron, which consists of three crystallographically nonequivalent lutidine ligands (Ni-N, 2.059–2.124 Å) and two oxygen ions of the two nitrate ions (Ni-O, 2.047–2.258 Å).     

Syntheses,crystal structures and properties of two cadmium coordination polymers containing bis (2-methylimidazol-1-yl)methane(2-mBIM) and bis (imidazol-1-yl)methane (BIM) ligands

Coordination polymers, {[Cd(2-mBIM)₃](ClO₄)₂} _n (1) and [Cd(BIM)₂(NO₃)₂] _n (2), have been prepared from the reaction of bis(2-methylimidazol-1-yl)methane(2-mBIM) with Cd(ClO₄)₂ and bis(imidazol-1-yl)methane (BIM) with Cd(NO₃)₂ in ethanol and water, respectively. Their structures were characterized by single crystal X-ray diffraction and IR spectroscopy. Compound 1 crystallizes in the rhombohedral space group R-3c with a = b = 12.3617(5) Å, c = 38.896(3) Å, γ = 120°, V = 5147.5(5) ų, z = 6. The Cd^II occupies a crystallographic inversion center and is coordinated by six N atoms from six distinct 2-mBIM ligands to form a slightly distorted octahedral geometry. Each 2-mBIM is coordinated to two Cd^II cations, linking alternatively four Cd^II cations, resulting in a 32-membered M₄L₄ macrometallacycle. Compound 2 crystallizes in the monoclinic space group C2/m with a = 14.400(3) Å, b = 9.3894(18) Å, c = 8.6926(17) Å, β = 123.499(2)°, V = 980.1(3) ų, z = 2. The Cd coordinates to four nitrogen atoms from four different BIM and two nitrates to form a slightly distorted octahedral geometry. The BIM ligands bridge to form a 1-D infinite double-bridged chain structure with 16-membered M₂L₂ macrometallacyclic structural units.     

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.     

Une famille originale de complexes hétérodinucléaires Co(II)-Ln(III): synthèse et étude magnétostructurale

The cobalt(II) complex of 3-methoxy 2-hydroxybenzaldehyde, L₂Co(H₂O)₂ reacts with lanthanide nitrates to afford dinuclear complexes L₂Co(H₂O)₂Ln(NO₃)₃. An X-ray diffraction study of L₂Co(H₂O)₂Pr(NO₃)₃ has been performed. It crystallizes in the monoclinic space group P2₁/c, in a cell having the dimensions a = 9.4832(11) Å, b = 18.319(2) Å, c = 14.6226(13) Å and β = 106.121(12)° and Z = 4. The magnetic properties of L₂Co(H₂O)₂Gd(NO₃)₃ revealed that a ferromagnetic interaction occurs between the Co²⁺ and Gd³⁺ ions.     

Sc(III), Eu(III), and Gd(III) Complexes with Macrocyclic Cavitand Cucurbit[6]uril: Synthesis and Crystal Structures

Slow evaporation of solutions of Sc and Eu nitrates with macrocyclic cavitand cucurbit[6]uril gives crystals of isostructural complexes [Sc(NO₃)(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ ? 8.5H₂O (space group Pna2₁, a = 32.0065(18) Å, b = 14.7904(8) Å, c = 11.5774(6) Å, V = 5480.6(5) ų, Z = 4) and [Eu(NO₃)(H₂O)₄(C₃₆H₃₆N₂₄O₁₂)](NO₃)₂ ? 6.75H₂O (space group Pna2₁, a = 31.9525(17) Å, b = 14.7203(8) Å, c = 11.8592(6) Å, V = 5578.0(5) ų, Z = 4). The metal to ligand ratio in these complexes is 1 : 1; the complexes are obtained at 0.025–0.1 mol/l concentrations of the metals in solutions. With higher lanthanide concentrations (0.7–1 mol/l), the 2 : 1 complex with cucurbit[6]uril is formed of the composition [{ Gd(NO₃)(H₂O)₅}₂(C₃₆H₃₆N₂₄O₁₂)](NO₃)₄ ? 6.5H₂O (space group \(P\bar 1\), a = 13.3972(6) Å, b = 14.4994(5) Å, c = 18.3290(8) Å, α = 73.5610(10)°, β = 87.2590(10)°, γ = 87.5540(10)°, V = 3409.4(2) ų, Z = 2) and isotypical complex [{Gd(NO₃)(H₂O)₅}₂{(C₅H₅N) ? (C₃₆H₃₆N₂₄O₁₂)}](NO₃)₄ ? 8H₂O with a pyridine molecule inside the cucurbit[6]uril cavity (space group P2₁/n, a = 14.8263(6) Å, b = 13.3688(7) Å, c = 18.5970(9) Å, β = 107.5860(10)°, V = 3513.8(3) ų, Z = 2). According to X-ray diffraction data, the metal atoms of the title complexes coordinate the O atoms in portals of cucurbit[6]uril molecules.     

Synthesis and crystal structure of KBi(C6H4O7) · 3.5H2O

A novel compound, KBi(C₆H₄O₇) · 3.5H₂O (I), has been synthesized in the Bi(NO₃)₂-K₃(HCit) system (HCit^3? is an anion of citric acid C₆H₈O₇) at a component ratio (n) of 8 in a water-glycerol mixture, and its crystal structure has been determined. The crystals are unstable in air. The crystals are triclinic: a = 7.462 Å, b = 10.064 Å, c = 17.582 Å, α = 100.27°, β = 99.31°, γ = 105.48°, V = 1221.2 ų, Z = 2, space group $P\bar 1$ . In the structure of I, asymmetric binuclear fragments [Bi₂(Cit^4?)₂(H₂O)₂]^2? are linked through inversion centers into polymeric chain anions. Ions K⁺ and crystal water molecules are arranged in channels between the chains. The Bi(1)...Bi(2) distances in the binuclear fragment are 4.62 Å, and the Bi(1)...Bi(1) and Bi(2)...Bi(2) distances between bismuth atoms in the chain are 5.83 and 5.95 Å, respectively. The chains are linked through bridging oxygen atoms of the ligands Cit to form layers. In the centrosymmetric four-membered chelate ring Bi₂O₂ formed through Bi-O(Cit) bonds, the distances Bi(1)-Bi(1) are equal to 4.55 Å, and Bi(1)-O are 2.66 and 2.84 Å. The Bi-O bond lengths in I are in the range 2.12–3.16 Å. The Cit ligands act as hexadentate chelating/bridging ligands.     

Crystal structure and triboluminescence of the [Eu(TTA)2(NO3)(TPPO)2] complex

The crystal structure of [Eu(TTA)₂(NO₃)(TPPO)₂] (I) (TTA = thenoyltrifluoroacetone, TPPO = triphenylphosphine oxide) possessing intense triboluminescence was established by X-ray crystallography. The crystals are triclinic, noncentrocymmetrical: a = 11.047(3) Å, b = 11.794(3) Å, c = 12.537(3) Å; α = 102.635 (4)°, β = 102.088(4)°,γ = 117.765(3)°; space group P1, Z = 1. The central Eu(III) atom coordinates two oxygen atoms of two TPPO molecules at distances of 2.271 Å and 2.282 Å, two oxygen atoms of the nitrate group at distances of 2.478 Å and 2.481 Å, four oxygen atoms of two TTA ions at distances of 2.365 Å, 2.381 Å, and 2.363 Å, 2.371 Å (coordination number is 8). The coordination polyhedron of the Eu(III) atom is a distorted dodecahedron. Possible reasons for spectral differences in the Stark structure of photo-and triboluminescence of I are discussed.     

Synthesis and structure of complex compound Rh(III) of (NH4)2[Rh(NO2)3(NH3)(µ-OH)]2 composition

The crystalline structure of a new compound Rh(III) of (NH₄)₂[Rh(NO₂)₃(NH₃)(μ-OH)]₂ composition has been determined. The crystallographic characteristics are H₁₆N₁₀O₁₄Rh₂: a = 6.3963(2) Å, b = 9.3701(4) Å, c = 13.6646(5) Å, β = 102.266(1)°, V = 800.28(5) ų, Z = 2, d _calc = 2.432 g/cm³. The distance Rh...Rh in the dimer is 3.200 Å. Original Russian Text Copyright ? 2006 by S. P. Khranenko, I. A. Baidina, and S. A. Gromilov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 47, No. 2, pp. 380–384, March–April, 2006.     

Synthesis and crystal structure of the coordination polymer of silver with 4,4′-bipyridylethylene [Ag(Bpe)](NO3)·3H2O

The compound [Ag(Bpe)](NO₃)·3H₂O (Bpe = 4,4′-bipyridylethylene, C₁₂H₁₀N₂) is prepared and its crystal structure is determined. The crystals are triclinic: a = 9.073(2) Å, b = 10.074(2) Å, c = 10.391(2) Å, α = 61.18(3)°, β = 72.11(3)°, γ = 68.62(3)°, space group P $\bar 1$ , V = 764.7(3) ų, ρ(calcd) = 1.764 g/cm³, Z = 2. The structure is composed of polymeric cationic chains, [Ag(Bpe)] _∞ ⁺ , NO ₃ ^? counterions, and water molecules. The Ag⁺ ions are bound to the two N atoms of two crystallographically nonequivalent Bpe ligands and form a nearly linear coordination (Ag(1)-N(1), 2.129 Å; Ag(1)-N(2), 2.120(4) Å; N(1)Ag(1)N(2), 169.9(2)°).     

Synthesis and structure of the oxalatotetranitratouranylate complex (NH4)2[{UO2(NO3)2}2(μ4-C2O4)] · 2H2O

The reaction of diaquadinitratouranyl with ammonium nitrate in ethanol gave the single crystals of ((NH₄)₂[}UO₂(NO₃)₂}₂(μ₄-C₂O₄)] · 2H₂O (I).The structure of the complex was studied by X-ray diffraction. The crystals are monoclinic, a = 8.6497(10) Å, b = 11.7001(10) Å, c = 20.2135(10) Å, β = 93.924(10)°, space group P2₁/c, Z = 4, V = 2040.9(3) ų. The structural units of the crystal are island binuclear groups [{UO₂(NO₃)₂}₂(μ₄-C₂O₄)]^2?, ammonium cations, and crystal water molecules. The structure has a complex three-dimensional packing provided by electrostatic attraction forces of the counterions and the hydrogen bond system involving water molecules, oxalate, nitrate, and uranyl ions. The IR spectra of I confirm the X-ray diffraction data.     

4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]-hexacosane Bis(nitrate-hydrogennitrate): Synthesis and crystal structure

A crystalline adduct of 2.2.2-cryptand and nitric acid, [H₂(Crypt-222)]²⁺·2(NO ₃ ^? ·HNO₃) (I), is synthesized and studied using X-ray diffraction analysis. The monoclinic structure of compound I (space group C2/c, a = 13.326 Å, b = 15.262 Å, c = 15.020 Å, β = 98.96°, Z = 4) is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.067 for 2647 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). In the structure of compound I, the 2.2.2-cryptand dication lies on an axis 2 and has an endo-endo conformation, for which two H atoms at two protonated N atoms are directed inside the cavity. One of the NO ₃ ^? ·HNO₃ dimers is situated in the inversion center, and the other dimer lies on another axis 2 and is disordered over three orientations. All H atoms in the NO ₃ ^? ·HNO₃ dimers are equiprobably disordered over two close sites. Each of the two NO ₃ ^? ·HNO₃ dimers is formed by the very strong disordered N-O-H···O=N hydrogen bond between the nitric acid molecule and nitrate anion.     

Synthesis and crystal structure of (2.2.2-cryptand)(nitrato-O,O’)lead(II) nitrate monohydrate

A new complex, (2.2.2-cryptand)(nitrato-O,O’)lead(II) nitrate monohydrate [Pb(NO₃)(Crypt-222)]⁺ · NO ₃ ^? · H₂O, is synthesized and characterized by X-ray crystallography. The structure of the complex (space group Pbca, a = 14.196 Å, b = 14.001 Å, c = 26.745 Å, Z = 8) is solved by direct methods and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.073 for 3474 unique reflections (CAD4 automated diffractometer, λMOK _α). The structure contains the host-guest complex cation [Pb(NO₃)(Crypt-222)]⁺. The Pb²⁺ cation is located in the cavity of the 2.2.2-cryptand ligand and is coordinated by all eight heteroatoms (6O + 2N) of the cryptand ligand and two O atoms of the NO ₃ ^? ligand. The coordination polyhedron of the Pb²⁺ cation (ten-coordinate) is a strongly distorted hexagonal bipyramid with a base of four O atoms and two N atoms of the cryptand ligand and with two bifurcated axial vertices at two O atoms of the nitrate ligand and two O atoms of the cryptand ligand. The disordered NO ₃ ^? anion and the water molecule are linked by hydrogen bonds.     

Crystal Structure of the Mixed‐Valent Basic Mercury Nitrate HgI2(NO3)2·HgII(OH)(NO3)·HgII(NO3)2·4HgIIO [= Hg8O4(OH)(NO3)5]

Light‐yellow single crystals of the mixed‐valent mercury‐rich basic nitrate Hg₈O₄(OH)(NO₃)₅ were obtained as a by‐product at 85 °C from a melt consisting of stoichiometric amounts of (Hg^I₂)(NO₃)₂·2H₂O and Hg^II(OH)(NO₃). The title compound, represented by the more detailed formula Hg^I₂(NO₃)₂·Hg^II(OH)(NO₃)·Hg^II(NO₃)₂·4Hg^IIO, exhibits a new structure type (monoclinic, C2/c, Z = 4, a = 6.7708(7), b = 11.6692(11), c = 24.492(2) Å, β = 96.851(2)°, 2920 structure factors, 178 parameters, R1[F² > 2σ(F²)] = 0.0316) and is made up of almost linear [O‐Hg^II‐O] and [O‐Hg^I‐Hg^I‐O] building blocks with typical Hg^II‐O distances around 2.06Å and a Hg^I‐O distance of 2.13Å. The Hg₂²⁺ dumbbell exhibits a characteristic Hg‐Hg distance of 2.5079(7) Å. The different types of mercury‐oxygen units form a complex three‐dimensional network exhibiting large cavities which are occupied by the nitrate groups. The NO₃^? anions show only weak interactions between the nitrate oxygen atoms and the mercury atoms which are at distances > 2.6Å from one another. One of the three crystallographically independent nitrate groups is disordered.