Disordered crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane dibromide dihydrate

The disordered crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane dibromide dihydrate, [H₂(2.2.2-Crypt)]²⁺·2Br^?2H₂O (I) was studied by X-ray diffraction (XRD) analysis. The orthorhombic structure of I (space group Aba2, a = 21.036(3) Å, b = 14.453(2) Å, c = 8.525(1) Å, Z = 4) was solved by direct methods and refined by full-matrix least squares in anisotropic approximation to R = 0.045 over all 2695 independent (taking into account anomalous scattering) reflections collected (CAD-4 automatic diffractometer, λCuK_α).     

Synthesis of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Dinitrate Hydrate and Its Disordered Crystal Structure

4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane dinitrate hydrate [H₂(Crypt-222)]²⁺?2NO ₃ ^? ?H₂O is prepared as a crystalline salt and studied by single crystal X-ray diffraction. In its crystal structure the 2,2,2-cryptand dication is disordered and has two different conformations with 55.3 and 44.7% probabilities. Hydrogen atoms of this dication at the two protonated bridgehead nitrogen atoms are directed inside the cavity. One of two NO ₃ ^? anions is also disordered and has two different orientations with 77 and 23% probabilities. Geometric parameters of the molecular ions and water molecule (bond lengths, bond angles, etc.) are determined with a reasonable accuracy, and their packing in the crystal structure is established.     

Synthesis and crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Bis(citrate) hydrate

A crystalline salt of 2.2.2-cryptand and citric acid, 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(citrate) hydrate [H₂(Crypt-222)]²⁺·2(C₆H₇O₇)^? · 1.65H₂O, was synthesized and studied by single crystal X-ray diffraction. In the crystal structure of this salt, the 2.2.2-cryptand dication is somewhat disordered, and its H atoms at two protonated N atoms are oriented inside the cryptand cavity. Two independent citrate anions are essentially different, as different COOH groups in them are deprotonated. The geometric parameters (bond lengths, bond angles, etc.) of the molecular ions and water molecules are determined with a relatively high accuracy. The structural units form a three-dimensional system of intermolecular (interionic) hydrogen bonds.     

Synthesis and crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(hydrogen oxalate)

A crystalline salt of 2.2.2-cryptand and oxalic acid, 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(hydrogen oxalate), [H₂(Crypt-222)]²⁺·2(C₂HO₄)^?, was synthesized and studied by single crystal X-ray diffraction. In the crystal structure of this salt, the 2.2.2-cryptand cation has a rare conformation of the exo-exo type in which the H atoms at the two protonated N atoms are oriented outside the cryptand cavity. The geometric parameters (bond lengths, bond angles, torsion angles) of the [H₂(Crypt-222)]²⁺ cation and two independent C₂HO ₄ ^? anions were found with a fairly high accuracy, and the crystal packing was determined. These ions are linked by interionic hydrogen bonds to form thick infinite layers parallel to the (xz) plane.     

Crystal Structure of 4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Triaquachlorolithium Dichloride

The crystal adduct (1 :1) 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane triaquachlorolithium dichloride, [H₂(Crypt-222)]²⁺ · 2Cl^– · [LiCl(H₂O)₃] (I), was synthesized and studied using X-ray diffraction analysis. Structure I (space group R3, a = 7.922 Å, c = 37.207 Å, Z = 3) was solved by direct methods and anisotropically refined by the full-matrix least-squares method to R = 0.034 for 1363 independent reflections (CAD4 autodiffractometer, MoK ). Crystal I consists of disordered 2.2.2-cryptand dications, chloride anions, and tetrahedral [LiCl(H₂O)₃] complexes. All of them lie on threefold axes. There are tridentate ⁺N–H (···O)₃ hydrogen bonds in the [H₂(Crypt-222)]²⁺ dication. The crystal structure of adduct I contains a complex interionic hydrogen bonding system.     

Crystal Structure of 4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Semihydrate Oxonium Tribromide

The crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo-[8.8.8]hexacosane semihydrate oxonium tribromide, [H₂(2.2.2-Crypt)·0.55H₂O]²⁺·H₃O⁺·3Br⁻ (I) was determined by XRD analysis. The triclinic structure of I (space group P , a = 10.026 Å, b = 11.292 Å, c = 13.115 Å, α = 78.37°, β = 72.11°, γ = 77.50°, Z = 2) was solved by direct methods; full-matrix least-squares refinement in an anisotropic approximation converged to R = 0.055 for all 4057 independent reflections collected (CAD-4 automatic diffractometer, λCuK _α).Original Russian Text Copyright © 2004 by A. N. Chekhlov__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 1136–1141, November–December, 2004.     

Synthesis and structure of N1-e-benzo-4,7,13,16,21,26-hexaoxa-1,10-diazabicyclo[8.8.8]hexacos-23-yl-N2-phenylthiourea. Derivative of a bifunctional complexing agent

A cryptand with an aminobenzo group 4,7,13,16,21,24-hexaoxa-5,6-(4′-aminobenzo)-1,10-diazabicyclo-[8.8.8]hexacosane, has been synthesized as a bifunctional complexing intermediate for investigation of the labeling of proteins with metal radionuclides. This amine, although unstable, can be prepared as the stable stannic salt. The free base was converted to the corresponding phenylthiourea by 1) reaction with phenyliso-thiocyanate and 2) conversion to its isothiocyanate followed by reaction with aniline. The thiourea structure was confirmed by X-ray crystallographic analysis.     

Crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo [8.8.8]hexacosane (2S,3S)-tartrate

Crystal structure of (2S,3S)-tartrate of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo-[8.8.8]hexacosane, [H₂(Crypt-222)]²⁺·(C₄H₄O₆)^2? (I) has been studied by single crystal X-ray diffraction. Triclinic structure of I (space group P1, a = 8.424 Å, b = 13.011 Å, c = 13.806 Å; α = 116.37°, β = 106.45°, γ = 91.81°; Z = 2) was solved by the direct method and refined in the full-matrix anisotropic approximation to R = 0.140 for 5850 measured independent reflections (automated diffractometer CAD-4, λMoK _α). In the structure of I, two independent dications of 2.2.2-cryptand (nitrogen atoms are protonated) are linked to the approximate inversion symmetry and have a rare conformation of exo-exo type, when two atoms sitting on N atoms are protruded out of their cavity. The centroids of two crystallographically unique (2S,3S)-tartrate dianions are bound with the same approximate inversion center. An extended system of hydrogen bonds is developed in the crystal of I.     

4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Bis[dibromodichloroiron(III)]: Synthesis and Crystal Structure

A novel complex salt, namely, 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis[dibromodichloroiron(III)] [H₂(Crypt-222)]²⁺[FeBr₂Cl₂] ₂ ^? (I), was synthesized and structurally characterized by X-ray diffraction analysis (monoclinic crystal system, a = 13.550 Å, b = 11.018 Å, c = 12.813 Å, β = 117.52°, space group C2, Z = 2). The structure was solved by the direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.089 from 2593 independent reflections (CAD4 automated diffractometer, λMoKα radiation). In the crystal structure I, four bifurcate positions of Br and Cl in the tetrahedral anion [FeBr₂Cl₂]^? are a randomly disordered mixture of these atoms. The dication of 2.2.2-cryptand (with two protonated N atoms) in the crystallographic axis 2 contains trifurcate N⁺-H (?O)₃ hydrogen bonds.     

Crystal Structure of 4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Diiodide

The disordered crystal structure of 4'7'13'16'21'24-hexaoxa-1'10-diazoniabicyclo[8.8.8]hexa-cosane diiodide, [H₂(2.2.2-Crypt)]^{2 +}·2I^-, was studied by single crystal X-ray diffraction. The 2.2.2-cryptanddication is disordered, exists in the form of two different conformers A, B randomly occupying thesame place in the unit cell with 71.5 and 28.5% probability, respectively. In both conformers A and B, thehydrogen atoms at the bridgehead nitrogen atoms are directed inside the cavity (crypta) of the conformer. The geometric parameters (bond lengths, bond angles, torsion angles) of these conformers were found, and the packing of these cations and iodide anions in the crystal were determined. The iodide anions have contacts only with the methylene hydrogen atoms of conformers A and B.     

Synthesis and crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis[dichloro(thiocyanato)copper(II)]

A new complex salt [4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis[dichloro(thiocyanato)copper(II)], [H₂(Crypt-222)][CuCl₂(SCN)]₂, is synthesized and studied by X-ray diffraction analysis. The crystals are monoclinic (space group C2/c, a = 14.603 Å, b = 8.330 Å, c = 25.091 Å, β = 100.76°, Z = 4). The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.047 for 2943 independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). The Cu²⁺ cations and Cl^? and SCN^? anions form infinite polymeric chains of spiro-conjugated alternating centrosymmetric four-membered CuCl₂Cu cycles and eight-membered Cu(SCN)₂Cu cycles through coordination bonds. The coordination polyhedron of the Cu²⁺ cation is a distorted trigonal bipyramid. The [H₂(Crypt-222)]²⁺ dication contains trifurcate N⁺-(…O)₃ bonds on axis 2.     

4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane Penta(nitrato)lanthanate(III): Synthesis and Crystal Structure

A new complex salt, 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane penta(nitrato)lanthanate(III) (H₂(Crypt-222)]²⁺ · [La(NO₃)₅]^2?), is synthesized. Its crystal structure is studied using X-ray diffraction analysis (space group Pbcm, a = 9.517 Å, b = 13.358 Å, c = 24.585 Å, Z = 4; direct method, full-matrix least-squares in the anisotropic approximation, R = 0.039 for 4650 measured independent reflections). The [La(NO₃)₅]^2? complex anion lies on the m plane, and the 2 axis passes through the 2.2.2-cryptand dication with two protonated nitrogen atoms. The coordination polyhedron of the La³⁺ cation (coordination number 11) is a distorted octahedron with five bifurcated vertices, each containing two O atoms from the same NO ₃ ^? . ligand. The [La(NO₃)₅]^2? anions are joined into infinite polymer chains along the y axis through the NO ₃ ^? bridging ligand.     

Tetrakis(Isothiocyanato)zinc(II) 4,7,13,16,21,24-Hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane: Synthesis and Crystal Structure

The salt tetrakis(isothiocyanato)zinc(II) 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane, [H₂(Crypt-222)]²⁺ · [Zn(NCS)₄]^2– (I), was synthesized and its structure was determined using X-ray diffraction analysis: space group P2₁/n, a = 13.734 Å, b = 11.627 Å, c = 20.816 Å, = 91.51°, Z = 4. The structure was solved by direct methods and anisotropically refined by the full-matrix least-squares method to R =0.093 for 4920 independent reflections (CAD4 autodiffractometer, CuK radiation). The structural units of crystal I are 2.2.2-cryptand dications (with two protonated nitrogen atoms) and complex anions [Zn(NCS)₄]^2–. The coordination polyhedron of the Zn²⁺ cation is a distorted tetrahedron. The 2.2.2-cryptand dication contains trifurcate N–H(...O)₃ hydrogen bonds.     

Disordered crystal structure of 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane <Emphasis Type="Italic">bis</Emphasis>(picrate) hydrate

For 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane bis(picrate) hydrate [H₂(Crypt-222)]²⁺·2Pic^?·1.19 H₂O (I), its disordered crystal structure has been determined by X-ray diffraction (XRD) analysis. The structure of I (space group \(P\bar 1\), a = 10.662 Å, b = 12.586 Å, c = 15.342 Å, α = 107.73°, β = 102.33°, γ = 90.49°, Z = 2) was solved by direct methods and refined by full-matrix least-squares in an anisotropic approximation to R = 0.111 for all 5000 independent reflections collected (CAD-4 automatic diffractometer, CAD-4, λMoK_α). The 2.2.2-cryptand dication is disordered and has two different conformations with probabilities of 66.7% and 33.7%. In addition to one independent water molecule, the cavity of the dication has a low-probability site of another water molecule, whose occupancy is 0.19. In the two independent picrate anions, some of their NO₂ groups are disordered over two orientations. The crystal structure of I has various interionic (intermolecular) and intracation hydrogen bonds.     

4,7,13,16,21,24-hexaoxa-1,10-diazaniabicyclo[8.8.8]hexacosane tetra(nitrato-O)copper(II): Synthesis and crystal structure

A new crystalline complex salt, 4,7,13,16,21,24-hexaoxa-1,10-diazaniabicyclo[8.8.8]hexacosane tetra(nitrato-O)copper(II) [H₂(Crypt-222)]²⁺ · [Cu(NO₃)₄]^2?(I), is synthesized and studied using X-ray diffraction analysis (space group P2₁/c, a = 10.264 Å, b = 14.798 Å, c = 19.516 Å, β = 100.20°, Z = 4). The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.032 for 4050 independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). Salt I exist in crystals as individual ions: the [Cu(NO₃)₄]^2? complex anion and the slightly disordered dication of 2.2.2-cryptand with two protonated nitrogen atoms. The Cu²⁺ cation has a square coordination somewhat distorted toward a flattened tetrahedron with four coordination bonds with the O atoms of the four NO ₃ ^? ligands. Trifurcate hydrogen bonds of the [H₂(Crypt-222)]²⁺ type are observed in the N-H(? O)₃ dication.     

Crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane monohydrate picrate

The crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane monohydrate picrate, [H(Crypt-222) H₂O]⁺·Pic^? (I), has been studied by X-ray crystallography. The structure of I (space group P2₁/c, a = 9.336 Å, b = 19.497 Å, c = 16.420 Å; β = 94,84°, Z = 4) was solved by direct methods and refined by full-matrix least squares in an anisotropic approximation to R = 0.056 for all 3877 independent reflections collected (CAD-4 automatic diffractometer, λMoK _α). This compound is one of the few representatives of the class of crystal salts containing a 2.2.2-cryptand cation with a protonated nitrogen atom that have been synthesized and studied by X-ray crystallography. The void of the cation contains a water molecule held by three H bonds. Crystal I also has unusual H bonds of C-H…O type that link the neighboring 2.2.2-cryptand cation and the picrate anion.     

Disordered crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane isocyanurate

X-ray spectral analysis has been applied to study the crystal structure of 4,7,13,16,21,24-hexaoxa-1-aza-10-azoniabicyclo[8.8.8]hexacosane isocyanurate of an unusual composition: [H_1.2(Crypt-222)]^1,2+ · [H_0.8(Crypt-222)]^0.8+·2(C₃H₂N₃O₃)^? (I). The structure of I (space group C2/c, a = 37.840 Å, b = 13.760 Å, c = 19.456 Å, β = 91.21°, Z = 8) was solved by a direct method and refined by the full-matrix least-squares technique in the anysotropic approximation up to R = 0.119 over 6500 independent reflections measured (autodiffractometer CAD-4, λ-MoK _α). The structure of I has two independent cations of 2.2.2-cryptand linked by the proximate pseudo-center of inversion and they have a rare conformation of exo-exo type, in which H atom or lone pair at both their node atoms N are directed outward their cavity. In the structure of I, all H atoms at N atoms of cations and half of H atoms of isocyanurate anions are disordered and have the populations of positions 0.7, 0.5, and 0.3. There is a developed system of interionic hydrogen bonds in the crystal structure of I.     

Isothermal Titration Calorimetry Study of a Bistable Supramolecular System: Reversible Complexation of Cryptand[2.2.2] with Potassium Ions

Isothermal titration calorimetry (ITC) is used to investigate the thermodynamics of the complexation of potassium ions by 1,10‐diaza‐4,7,13,16,21,24‐hexaoxabicyclo[8.8.8]hexacosane (cryptand[2.2.2]) in aqueous solution. By changing the pH of the solution it was possible to trigger the reversible complexation/decomplexation of the cryptand in consecutive in situ experiments and to assess for the first time the use of ITC to monitor the thermodynamics of a bistable system.     

The Zintl ion [As7]2-: an example of an electron-deficient As(x) radical anion

[K(2,2,2-crypt)](2)[As(7)]·THF, 1 (2,2,2-crypt = 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane) is the first well characterized seven-atom radical anion of group 15. UV-Vis spectroscopy confirms the presence and electronic structure of [As(7)](2-). Cyclic voltammetry in DMF solution shows the As(7)(3-)/As(7)(2-) redox couple as a one-electron reversible process. Theoretical investigations explore the bonding and properties of compound 1.     

<Emphasis Type="Italic">trans</Emphasis>-Tetraaqua(dibromo)nickel(II) 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane dibromide: Synthesis and crystal structure

A new complex, trans-tetraaqua(dibromo)nickel(II) 4,7,13,16,21,24-hexaoxa-1,10-diazoniabicyclo[8.8.8]hexacosane dibromide, [NiBr₂(H₂O)₄][H₂(Crypt-222)]Br₂ (I), was synthesized and its crystal sructure was studied by X-ray diffraction analysis: space group P2₁/c, a = 13.573, b = 8.328, c = 14.523 Å, β = 111.08°, Z = 2. Structure I was solved by a direct method and refined by full-matrix least-squares method in anisotropic approximation to R = 0.067 on 2684 independent reflections (CAD-4 autodiffractometer, λMoKα). The octahedral complex molecule [NiBr₂(H₂O)₄] and the [H₂(Crypt-222)]²⁺ dication (with two protonated N atoms) are located around the inversion center; the latter is statistically disordered. The dication contains trifurcate hydrogen bonds N-H(…O)₃. Crystal I also contains intermolecular hydrogen bonds O(w)-H…Br^?, which join the complex molecules [NiBr₂(H₂O)₄] and the Br^? anions into infinite “thick” layers parallel to the plane yz.