Diaquabromo(18-crown-6)rubidium and triaqua(18-crown-6)barium dibromide monohydrate: Synthesis and crystal structures

Two complexes are synthesized: diaquabromo(18-crown-6)rubidium [RbBr(18-crown-6)(H₂O)₂] (I) and triaqua(18-crown-6)barium dibromide monohydrate [Ba(18-crown-6)(H₂O)₃]²⁺ 2Br^? · H₂O (II). The orthorhombic structure of compound I (space group Pnma, a = 10.124 Å, b = 15.205 Å, c = 12.544 Å, Z = 4) and the monoclinic structure of compound II (space group C 2/c, a = 17.910 Å, b = 10.315 Å, c = 14.879 Å, β = 123.23°, Z = 4) are determined by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.063 (I) and 0.042 (II) for all 2293 (I) and 3363 (II) independent measured reflections (CAD-4 automated diffractometer, λMoK _α). The complex molecule [RbBr(18-crown-6)(H₂O)₂] in compound I and the randomly disordered cation [Ba(18-crown-6)(H₂O)₃]²⁺ in compound II are of the host-guest type: their Rb⁺ or Ba²⁺ cation (its coordination number is nine) is located in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In structure I, the coordination polyhedron of Rb⁺ is a distorted hexagonal pyramid with a triple apex at the Br^? ligand and two O atoms of the water molecules. In structure II, the Ba²⁺ polyhedron is a distorted hexagonal bipyramid with one apex at the O atom of the water molecule and the other split apex at two O atoms of water molecules.     

ANIONIC COORDINATION COMPLEXES OF Mo AND W WHICH CRYSTALLIZE FROM LIQUID CLATHRATE MEDIA WITH OXONIUM ION-CROWN ETHER CATIONS

Abstract

The complexes [H₃O⁺·18-crown-6][MoOCl₄(H₂O)^?], 1, and [H₂O·aza-18-crown-6·(H⁺)] [MoOCl₄(H₂O)^?], 3, were synthesized from a mixture of Mo(CO)₆, HCl(g), H₂O and either 18-crown-6 for 1 or mono-aza-18-crown-6 for 3, in toluene. For complex 4, [H₂O·aza-18-crown-6·(H⁺)]₂[WOCl₄(H₂O)^?][Cl^?], reaction conditions were as for 3 except W(CO)₆ was used in place of Mo(CO)₆. Similarly, for complex 2, [H₃O⁺·18-crown-6][WOBr₄(H₂O)^?], W(CO)₆ and HBr were used in the reaction mixture. These reactions were promoted by UV radiation and formed liquid clathrates almost immediately upon reaction. X-ray crystal structures were performed on each compound. Complex 1 crystallizes in the triclinic space group P/i with a = 10.206(1), b = 10.486(1), c = 11.701(1) Å, α = 71.11(1), β = 74.60(1), γ = 75.08(1)°, and D _c = 1.649 g cm^?3 for Z = 2. Refinement based on 3925 observed reflections led to a final R value of 0.078. Complex 2 crystallizes in the monoclinic space group P2₁/c with a = 9.710(1), b = 19.824(1), c = 12.399(1) Å, β = 104.58(1)°, and D _c = 2.369 g cm^?3 for Z = 4. Refinement based on 2008 observed reflections led to a final R value of 0.090. Complex 3 crystallizes in the orthorhombic space group Pnmn with a = 16.927(1), b = 12.226(1), c = 11.167(1) Å, and D _c = 1.598 g cm^?3 for Z = 4. Refinement based on 1486 observed reflections led to a final R value of 0.040. Complex 4 crystallizes in the monoclinic space group C2/m with a = 11.761(2), b = 12.096(2), c = 14.966(1) Å, β = 132.91(1)°, and D _c = 1.502 g cm^?3 for Z = 4. Refinement based on 2021 observed reflections led to a final R value of 0.051. In all cases the metal coordination sphere was essentially octahedral with the water ligand trans to the oxo species.     

Triaqua(18-crown-6)strontium tetrachlorocuprate(II) hemihydrate: Synthesis and crystal structure

The new complex [Sr(18-crown-6)(H₂O)₃]²⁺[CuCl₄]^2? · 0.42H₂O was obtained; its crystal structure was determined by X-ray diffraction analysis: space group P2₁, a = 10.305 Å, b = 13.570 Å, c = 17.566 Å, β = 98.23 °, Z = 4 (direct method, anisotropic full-matrix least-squares method, R = 0.053 from independent reflections; CAD-4 automated diffractometer, λMoK _α). The asymmetric part of the unit cell comprises two independent “guest-host” complex cations [Sr(18-crown-6)(H₂O)₃]²⁺, two independent complex anions [CuCl₄]^2?, and a hydrate water molecule with a position population of 0.84(1).     

Second crystal modification of 1,10-diazonia-18-crown-6 dichloride

The second crystal modification (II) of 1,10-diazonia-18-crown-6 dichloride [H₂DA18C6]²⁺·2Cl^?, where [H₂DA18C6]²⁺ is the 1,10-diaza-18-crown-6 dication (DA18C6) with two protonated nitrogen atoms, was investigated by XRD. The monoclinic modification (II) (space group P2₁/n, a = 9.600 Å, b = 5.689 Å, c = 15.749 Å, β = 91.03°, Z = 2) was solved by direct methods and refined by full-matrix least squares analysis in an anisotropic approximation to R = 0.032 for all 2494 independent reflections collected (CAD-4 automatic diffractometer, λMoK _α). In modification II, the conformation of the DA18C6 dication and the ion packing differ from those in triclinic modification I investigated previously.     

Synthesis and crystal structure of octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6

A new crystalline complex octaaqua(di-μ-bromo)dimanganese(II) dibromide 18-crown-6, [Mn₂Br₂(H₂O)₈]Br₂ · 18C6, is synthesized and studied by X-ray diffraction analysis. The crystals of compound I are triclinic, space group $P\bar 1$ , a = 9.093 Å, b = 9.683, Å, c = 10.032 Å, α = 111.35°, β = 116.23°, γ = 92.64°, Z = 1. The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.028 for 3276 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). The [Mn₂Br₂(H₂O)₈]²⁺ complex cation lying at the inversion center is binuclear with two bridging Br atoms and eight water molecules. The coordination polyhedron of one Mn²⁺ cation is a distorted cis-octahedron with two Br atoms and four O atoms of the water molecules at its corners. The centrosymmetric 18C6 molecule has an usual conformation. A crystal of compound I contains a developed three-dimensional network of intermolecular (interionic) hydrogen bonds.     

<Emphasis Type="Italic">trans</Emphasis>-Diaquatetra(nitrato-O,O′)dysprosium(III) (18-crown-6)potassium acetonitrile solvate: Synthesis and crystal structure

A new complex K(18-crown-6)][Dy(NO₃)₄(H₂O)₂] · CH₃CN (I) is synthesized, and its structure is studied by X-ray diffraction analysis (space group P ₂1/c, a = 17.200 Å, b = 13.377 Å, c = 13.087 Å, β = 94.21°, Z = 4, full-matrix anisotropic least squares to R = 0.033 for 5283 independent reflections, CAD-4 automated diffractometer, λMoKα radiation). The crystal structure of the compound exists as infinite polymer chains formed by coordination bonds and composed of alternating complex anions [Dy(NO₃)₄(H₂O)₂]^? and cations [K(18-crown-6)]⁺.     

Crystal structure of a Mn(II) complex with isatin-hydrazone-S-benzyldithiocarbazate

The reaction of Mn(OAc)₂·4H₂O with isatin-hydrazone-S-benzyldithiocarbazate (HIsa-SBn) results in the formation of a bis-ligand complex [Mn(Isa-SBn)₂]·2DMF. Its single crystal is obtained and the structure is determined by X-ray diffraction. It belongs to a monoclinic space group C2/c with the cell parameters: a = 23.290(4) Å, b = 11.4980(18) Å, c = 18.483(5) Å, V = 4087.6(14) ų. The Mn(II) atom is six-coordinated with two amide O atoms, two azomethine N atoms, and two thiolate S atoms, resulting in a distorted octahedral geometry.     

Synthesis and crystal structure (1,10-diaza-18-crown-6-N,N′,O,O′)dichloromanganese(II)

A new crystalline complex (1,10-diaza-18-crown-6-N,N′,O,O′)dichloromanganese(II) [MnCl₂(DA18C6)] (I) is synthesized and studied by single-crystal X-ray diffraction. The structure of compound I (space group P2₁/c, a = 11.827 Å, b = 7.580 Å, c = 19.715 Å, β = 98.76°, Z = 4) is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.026 for all 3055 independent measured reflections (CAD4 automated diffractometer, λMoK _α radiation). The [MnCl₂(DA18C6)] complex molecule in I is of the host-guest type: its Mn²⁺ cation is asymmetrically arranged in the cavity of the DA18C6 ligand and coordinated by its four heteroatoms, namely, the two N atoms and two O atoms, and by the two Cl^? anions. The coordination polyhedron of the Mn²⁺ cation (six-coordination) may be described as a distorted pentagonal bipyramid with one unfilled vertex or as a distorted square pyramid with one split vertex at the two O atoms of the DA18C6 ligand. The DA18C6 ligand in I has an unusual asymmetric conformation. The complex molecules in a crystal of I are linked by a pair of N-H···Cl intermolecular hydrogen bonds into centrosymmetric dimers.     

Synthesis and crystal structure of triaqua(18-crown-6)calcium bis(perchlorate) 18-crown-6 monohydrate

A complex [Ca(18C6)(H₂O)₃]²⁺(ClO ₄ ^? · 18C6 · H₂O is synthesized and studied by X-ray diffraction analysis. The structure (space group P2₁/n, a = 11.570 Å, b = 16.024 Å, c = 22.225 Å, β = 98.89°, Z = 4) is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.075 for 5305 independent reflections (CAD4 automated diffractometer, λMoK _α radiation). In the complex cation of the host-guest type, the Ca²⁺ cation lies in the cavity of the 18-crown-6 ligand and is coordinated by all the six O atoms and three O atoms of three water molecules. In a crystal, the alternating complex anions, 18C6 molecules, and water molecules are joined by hydrogen bonds into broad infinite chains along the y axis. The disordered ClO ₄ ^? anions are bonded to these chains on the side through hydrogen bonds.     

Synthesis and crystal structure of aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(perchlorato-O)potassium perchlorate

A new compound, aqua(dibenzo-18-crown-6)potassium (dibenzo-18-crown-6)(perchlorato-O)potassium perchlorate ([K(DB18C6)(H₂O)]⁺ · [K(ClO₄)(DB18C6)] · ClO ₄ ^? ; compound I) is synthesized and studied by X-ray crystallography. The crystals are triclinic: a = 9.050 Å, b = 9.848 Å, c = 26.484 Å, α = 82.87°, β = 84.16°, γ = 77.93°, Z = 2, space group P $\bar 1$ . The structure is solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.058 for 5960 independent reflections (CAD4 diffractometer, λMoK _α radiation). A complex cation [K(DB18C6)(H₂O)]⁺ and a complex molecule [K(ClO₄)(DB18C6)] are of the host-guest type; they are linked into a dimer through two K⁺ → π(C) bonds formed by one of the two K⁺ cations with two C atoms of the benzene ring of the DB18C6 ligand from the adjacent complex. Both DB18C6 ligands in I have a butterfly conformation with approximate symmetry C _2v .     

Synthesis and crystal structure of triaqua[0.25(bromo)1.75(nitrato-O)]copper(II) 18-crown-6 hydrate (solvate)

A complex triaqua[0.25(bromo)1.75(nitrato-O)]copper(II) 18-crown-6 hydrate (solvate), [CuBr_0.25(NO₃)_1.75(H₂O)₃] · 18-crown-6 · 5H₂O, is synthesized, and its crystal structure is studied by X-ray diffraction analysis (space group Cmc2₁, a = 13.705, b = 14.583, c = 13.174 Å, Z = 4; direct method, full-matrix least-squares refinement in the anisotropic approximation to R = 0.069 for 2547 independent reflections; CAD-4 automated diffractometer, λMoK _α radiation). The mixed complex molecule is a randomly disordered mixture of [Cu(NO₃)₂(H₂O)₃] and [CuBr(NO₃)(H₂O)₃] molecules with site occupancies of 0.875 and 0.125, respectively. The mixed complex molecule and 18-crown-6 molecule lie on the m plane. In the main complex molecule [Cu(NO₃)₂(H₂O)₃], the coordination polyhedron of the Cu²⁺ cation is a slightly distorted square pyramid. The 18-crown-6 molecule has the conformation of a crown with the approximate symmetry D _3d .     

Synthesis and crystal structure of diaqua(trinitrato)iron(III) 18-crown-6

A novel complex adduct, diaqua(trinitrato)iron(III) 18-crown-6, [Fe(NO₃)₃(H₂O)₂] · 18-crown-6, was synthesized and its crystal structure was studied by X-ray diffraction: space group C2/c, a = 10.073, b = 18.069, c = 25.326 Å, β = 91.51°, Z = 8. The structure was solved by the direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.076 for 4090 independent reflections (CAD-4 automated diffractometer, λMoK_α). The structure contains isolated complex molecule [Fe(NO₃)₃(H₂O)₂] and two halves of independent molecules 18-crown-6, one of which is statistically disordered about axis 2, while another one is located around the inversion center and is somewhat disordered with respect to the latter. In the complex molecule, the coordination polyhedron of the Fe³⁺ cation is a distorted pentagonal bipyramid with five O atoms of three NO ₃ ^? ligands in a base and two O atoms of two water molecules in the axial vertices. The alternating complex molecules and the disordered 18-crown-6 molecules are joined by hydrogen bonds into “thick” infinite chains along the z axis.     

Synthesis and crystal structure of bis(μ-periodato-<Emphasis Type="Italic">O,O′,O″</Emphasis>)bis(18-crown-6)dirubidium

A new binuclear complex, bis(μ-periodato-O,O′,O″)bis(18-crown-6)dirubidium [Rb₂(IO₄)₂(18-crown-6)₂] (I), is synthesized. Its crystal structure is studied by single-crystal X-ray diffraction analysis (space group P2₁/n, a = 11.942 Å, b = 8.394 Å, c = 19.664 Å, β = 101.08°, Z = 4, direct method, anisotropic full-matrix least-squares approximation, R = 0.030 for 2823 independent reflections, CAD-4 automated diffractometer, λMoK _α radiation). Complex I is binuclear and centrosymmetric, consisting of two cationic monomers [Rb(18-crown-6)]⁺ of the host-guest type linked through two tridentate IO ₄ ^? bridging ligands. The coordination polyhedron of the Rb⁺ cation (coordination number 9) can be described as a distorted hexagonal pyramid with a base of six O atoms of one 18-crown-6 ligand and one threefold vertex at three O atoms of the two IO ₄ ^? bridging ligands. The 18-crown-6 ligand has a usual crown conformation.     

Stability and structure in solution of potassium and barium complexes with N,N’-diaryldiaza-18-crown-6: Crystal structure of N,N’-Bis(4-dimethylaminophenyl)diaza-18-crown-6 and its complex with barium perchlorate

It has been shown that N,N’-diaryldiaza-18-crown-6 ethers with p-dimethylamino-and p-methoxy groups in the benzene ring (aryl is 4-Mc₂NC₆H₄) (I) and 4-MeOC₆H₄ (II) form complexes with potassium and barium salts. The influence of these salts on the UV and ¹H NMR spectra of crown ethers I and II has been studied. The stability constants (logβ) of the complexes increase in the series II · Ba(ClO₄)₂ (2.0), I · Ba(ClO₄)₂ (2.3), II · KBr (2.8), I · KBr (3.0). N,N’-bis(4-dimethylphenylamine)diaza-18-crown-6 (L, I) and its complex with barium perchlorate Ba(ClO₄)₂ · L (III) are characterized by X-ray crystallography. The crystals of I are monoclinic: a = 13.778(2) Å, b = 5.9731(9) Å, c = 17.542(3) Å, β = 106.65(1)°, V = 1383.1(4) ų, Z = 2, space group P2₁/n, R = 0.0374 for 990 reflections with I > 2σ(I). The crystals of III are monoclinic: a = 17.275(4) Å, b = 8.017(2) Å, c = 26.935(4) Å, β = 100.47(2)°, V = 3669(1) ų, Z = 4, space group C2/c, R = 0.0320 for 1897 reflections with I > 2σ(I). The molecules of I and III are centrosymmetric. In III, the Ba atom is in the center of substituted diaza-18-crown-6 (DA18C6). The Ba atom is coordinated by all six donor atoms of diaza-18-crown-6 (av. Ba-O, 2.779(3) Å; Ba-N, 3.004(4) Å) and four oxygen atoms of two asymmetrically bound perchlorate groups (Ba-O, 2.832(4) and 3.031(4) Å) arranged below and above the plane of substituted diaza-18-crown-6. The conformations of the macrocycle in free and coordinated L are different.     

Solid-state Structures for 2-Methoxy-1,3-xylyl-18-crown-5 and 2-Methoxy-1, 3-xylyl-21-crown-6: A Search for C–H···O Interactions

Solid-state structures have been determined for 2-methoxy-1,3-xylyl-18-crown-5 (4) (monoclinic, P2₁/n, a = 11.361(3) Å, b = 8.352(3) Å, c = 18.627(4) Å, β = 91.05(2)°, Z = 4) and 2-methoxy-1,3-xylyl-21-crown-6 (5) (monoclinic, Pc, a = 9.996(2) Å, b = 11.321(2) Å, c = 8.642(2) Å, β = 100.095(4)^o, Z = 2). In both molecules, the aromatic units are tilted with respect to the polyether ring and the methoxyl methyl hydrogens are oriented toward ether oxygen atoms of the rings. The interatomic distances, particularly the H···O distance and angles provide important information regarding the strength of the C–H···O interactions.     

Synthesis and study of hydrogen hexamolybdonickelate and hydrogen hexamolybdozincate with the cobaltammine cation

[Co(NH₃)₆] · H₂[NiMo₆O₁₈(OH)₆] · 6H₂O (I) and [Co(NH₃)₆] · H₂[ZnMo₆O₁₈(OH)₆] · 6H₂O (II) have been synthesized and studied by mass spectroscopy, thermogravimetry, and X-ray powder diffraction. The crystals of compounds I and II are monoclinic, Z = 1; for compound I: a = 16.10 Å, b = 5.58 Å, c = 12.22 Å, β = 117.86°, V = 1045.14 ų, and ρ_calcd = 2.26 g/cm³; for compound II: a = 16.12 Å, b = 5.52 Å, c = 12.12 Å, β = 117.90°, V = 1043.21 ų, and ρ_calcd = 2.21 g/cm³.     

Preparation and study of hydrogen hexamolybdometallates(III) with the hexamminecadmium cation

Hydrogen hexamolybdogallate and hexamolybdoaluminate with the hexamminecadmium cation [Cd(NH₃)₆] · H[GaMo₆O₁₈(OH)₆] · 6H₂O (I) and [Cd(NH₃)₆] · H[AlMo₆O₁₈(OH)₆] · 6H₂O (II) were synthesized and studied by mass spectrometry, thermogravimetric analysis, powder X-ray diffraction, and IR spectroscopy. The crystals are monoclinic; I: a = 10.82 Å, b = 3.69 Å, c = 11.99 Å, β = 91.06°, V= 469.72 ų, ρ_calcd = 2.34 g/cm³, Z = 2; II: a = 10.81 Å, b = 3.67 Å, c =11.98 Å, β = 91.08°, V = 469.78 ų, ρ_calcd = 2.38 g/cm³, Z = 2.     

Crystal structure of calcium dihydroethylenediaminetetraacetate(2-) dihydrate Ca(H2Edta)·2H2O

The crystals of Ca(H₂Edta)·2H₂O (orthorhombic system, a = 8.5919(7) Å, b = 17.807(2) Å, c = 18.941(2) Å; Z = 8, space group Pbca) precipitate from solutions of Na₂H₂Edta·2H₂O and CaCl₂. The Ca atom is surrounded by the oxygen atoms of the water molecule and the carboxyl groups of the five neighboring H₂Edta^2? anions with protonated nitrogen atoms (distorted octahedron). As a result, a three-dimensional framework of [Ca(H₂O)H₂Edta)] with built-in crystal water molecules is formed.     

(18-Crown-6)sodium tribromide and (18-crown-6)potassium triiodide (with an admixture of bromodiiodide): Synthesis and crystal structure

Two crystalline host-guest complexes are synthesized and studied using X-ray diffraction analysis: (18-crown-6)sodium tribromide [Na(18-crown-6)]⁺ · Br ₃ ^? (I) and (18-crown-6)potassium tribromide (with an admixture of bromodiiodide) [K(18-crown-6)]⁺ · (Br_0.25I_2.75)^? (II). The structures of compound I (space group P2₁/_{n, a} = 8.957 Å, b = 8.288 Å, c = 14.054 Å, β = 104.80°, Z = 2) and compound II (space group Cc, a = 8.417 Å, b = 15.147 Å, c = 17.445 Å, β = 99.01°, Z = 4) are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.098 (I) and 0.036 (II) for all 2311 (I) and 2678 (II) independent measured reflections on a CAD-4 automated diffractometer (λMoK _α). Similar crystalline complexes I and II exist as infinite chains of alternating complex cations and trihalide anions linked to each other through weak Na-Br or K-I coordination bonds. In [Na(18-crown-6)]⁺ and [K(18-crown-6)]⁺ complex cations, the Na⁺ or K⁺ cation (coordination number is eight) is located in the center of the cavity of the 18-crown-6 ligand and coordinated by the six O atoms and two terminal Br or I atoms of two trihalide anions lying on opposite sides of the rms plane of the crown ligand.     

Syntheses and crystal structures of hydrated complexes of strontium and barium bromides with 18-crown-6

Two complexes, namely, triaqua(18-crown-6)strontium dibromide monohydrate (I) and diaquabromo(18-crown-6)barium bromide (II), are synthesized. Their crystal structures are determined by X-ray diffraction analyses. For complex I, space group C2/c, a = 17.547 Å, b = 10.246 Å, c = 14.786 Å, β = 123.08°, Z = 4. For complex II, space group Pnma, a = 17.753 Å, b = 17.465 Å, c = 6.629 Å, Z = 4. The structures are solved by a direct method and refined by the full-matrix least-squares method in the anisotropic approximation to R = 0.056 (I) and 0.042 (II) for 2696 (I) and 2440 (II) independent reflections (CAD-4 automated diffractometer, λMoK _α radiation). Both complex cations—randomly disordered [Sr(18C6)(H₂O)₃]²⁺ in complex I and [BaBr(18C6)(H₂O)₂]⁺ in complex II—are of the host-guest type. The Sr²⁺ (Ba²⁺) cation resides in the cavity of the 18-crown-6 ligand and coordinated by all six O atoms. In the structures complexes I and II, the coordination polyhedra of the Sr²⁺ and Ba²⁺ cations (coordination number 9) can be described as distorted hexagonal bipyramids with one apex at the O atom of the water molecule in complex I or at the Br^? ligand in complex II and the other split apex at the O atoms of two water molecules.