Crystal structure of dimethylgold(III) 8-hydroxyquinolinate and 8-mercaptoquinolinate

A crystal-chemical study of dimethylgold(III) complexes with 8-hydroxyquinoline (CH₃)₂Au(OR) and 8-mercaptoquinoline (CH₃)₂Au(SR) (R = C₉H₆N) was performed. Crystal data for (CH₃)₂Au(OR): a = 8.7133(17) Å, b = 27.875(6) Å, c = 8.6688(17) Å, β = 102.76(3)°, Z = 8, ρ(calc) = 2.401 g/cm³, space group P2₁/c, R = 0.0909; for (CH₃)₂Au(SR): a = 3.5401(7) Å, b = 15.689(3) Å, c = 19.910(4) Å, β = 99.81(3)°, Z = 4, ρ(calc) = 2.361 g/cm³, space group P2₁/c, R = 0.0712. Both structures are molecular and involve neutral (CH₃)₂Au(L) molecules, L = C₉H₆NO or C₉H₆NS. In the structures, the molecules are arranged in stacks joined by van der Waals interactions. The average Au…Au intrastack distances are 3.57 Å and 4.34 Å for (CH₃)₂Au(OR) and 3.5 Å for (CH₃)₂Au(SR).     

Aquanitrilotris(methylenephosphonato)bis(dimercury(I)) hydrate, [(Hg2)2(H2O)N(CH2PO3)3H2] · H2O: Synthesis,structure, and properties

A reaction of dimercury(I) dinitrate with nitrilotris(methylenephosphonic acid), N(CH₂PO₃)₃H₆, gave the complex [(Hg₂)₂(H₂O){N(CH₂PO₃)₃H₂}] · H₂O. The crystals of the complex are triclinic, space group \(P\bar 1\), Z = 2, a = 8.3436(3), b = 9.0744(3), c = 11.1124(4) Å, α = 91.875(3)°, β = 104.452(3)°, γ = 92.195(3)° (CIF file CCDC no. 1051860). The atoms of either dimercury cation are coordinated differently, making up a distorted tetrahedron and a distorted trigonal bipyramid. The ligand is coordinated to the Hg atoms through seven donor atoms: six (out of nine) O atoms and a N atom. The coordination involves the formation of chelate rings: two four-membered, three five-membered, a six-membered, and an eight-membered ring (CIF file CCDC no. 1051860).     

Synthesis and structure investigation of Co(III) complex salts with the perrhenate anion

Complex salts of the composition [Co(NH₃)₆](ReO₄)₃·2H₂O (I), [Co(en)₃](ReO₄)₃ (II), [Co(NH₃)₅H₂O](ReO₄)₃·2H₂O (III), and [Co(NH₃)₅Cl](ReO₄)₂·0.5H₂O (IV) are obtained. Their crystal structures are determined by single crystal XRD. Crystallographic characteristics: (I) a = 9.9797(3) Å, b = 12.6994(3) Å, c = 14.7415(4) Å, β = 102.870(1)°, C2/c space group; (II) a = 8.0615(3) Å, b = 8.4483(4) Å c = 8.8267(4) Å, α = 61.923(2)°, β = 89.552(2)°, γ = 72.295(2)°, P1 space group; (III) a = 8.0086(4) Å, b = 12.9839(6) Å, c = 17.5122(7) Å, β=91.858(1)°, P2₁/n space group; (IV) a = 14.9446(3) Å, b = 14.6562(4) Å, c = 12.2434(4) Å, Cmc2₁ space group.     

Synthesis and structure of Pt(II) acetamidate complexes containing <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethyl-substituted ethylenediamine and trimethylenediamine

Reactions of acetamide with platinum(II) diamines [Pt(N,N-DimeEn)Cl₂], [Pt(Tm)Cl₂], and [Pt(N,N-DimeTm)Cl₂] (N,N-DimeEn = (CH₃)₂N(CH₂)₂NH₂, Tm = NH₂(CH₂)₃NH₂, N,N-DimeTm = (CH₃)₂N(CH₂)₃NH₂) with preliminary precipitation of chlorine ions by silver salts gave binuclear Pt(II) acetamidates [Pt₂(CH₃)₂N(CH₂)₂NH₂)₂(μ-NHCOCH₃)₂](NO₃)₂ · H₂O (I), [Pt₂(NH₂(CH₂)₃NH₂)₂)(μ-NHCOCH₃)₂](NO₃)₂ · H₂O (II), and [Pt₂(CH₃)₂N(CH₂)₃NH₂)₂(μ-NHCOCH₃)₂](HSO₄)₂ (III), whose crystal structures were determined. Crystals of I are monoclinic: a = 14.459(2) Å, b = 17.197(3) Å, c = 9.822(2) Å, β = 105.923(10)°, V = 3348.6(8) ų, space group P2(1)/c, Z = 4, R _hkl = 0.0419 for 6663 reflections. Complex I is a binuclear acetamidate with bridging (NHCOCH₃)^? ligands, one of which is bound to two Pt atoms through the N and O atoms, and the other ligand is bound only through the N atom. The Pt-Pt distance is 2.987(1) Å. Crystals of II are monoclinic: a = 10.213(7) Å, b = 13.373(9) Å, c = 16.533(11) Å, β = 97.971(9)°, V = 2236(3) ų, space group P2(1)/n, Z = 4, R _hkl = 0.557 for 6462 reflections. The Pt-Pt distance is 3.057(1) Å. Crystals of III are monoclinic: a = 10.557(12) Å, b = 18.531(2) Å, c = 14.4744(17) Å, β = 108.705(2)°, V = 2682(5) ų, space group P2(1)/n, Z = 4, R _hkl = 0.569 for 8506 reflections. The Pt-Pt distance is 3.202(1) Å. Complexes II and III are binuclear acetamidates, in which two chelating Pt(Tm) or Pt(N,N-DimeTm) moieties are coordinated through the N and O atoms of (NHCOCH₃)^? cis-bridges.     

Crystal structures of rhodium(III) aqua ion with tetrahedral anions

The crystal structures of compounds of the composition [Rh(H₂O)₆]₂(SO₄)₃·5H₂O (I) and [Rh(H₂O)₆]PO₄ (II) are determined. Crystallographic data for I: a = 7.272(9) Å, b = 27.047(1) Å, c = 12.464(9) Å, β = 97.038(10)°, P2₁ space group, Z = 4, d _x = 2.184 g/cm³; for II: a = 9.746(6)Å, b = 6.877(7) Å, c = 23.623(6) Å, β = 100.601(10)°, C2/c space group, Z = 8, d _x = 2.611 g/cm³. Compounds are analyzed by IR spectroscopy and powder XRD. Crystalline phase I is well soluble in water, whereas II is almost insoluble.     

Synthesis and crystal structures of tetraacetylethylenediamine and <Emphasis Type="Italic">N</Emphasis>-(2-ammoniumethyl)carbamate

Two ethylenediamine derivatives—N-(2-ammoniumethyl)carbamate HN(COO^?)CH₂CH₂N⁺H₃ (I) and tetraacetylethylenediamine (H₃CC(O))₂NCH₂CH₂N(C(O)CH₃)₂ (II) (synthesized for the first time)—have been synthesized and characterized by X-ray crystallography. Compounds I and II are isolated as minor admixtures upon an attempt to synthesize ethylenediamine complexes of lanthanum and neodymium nitrates, respectively. The crystals of I and II are monoclinic: a = 7.778 Å, b = 8.060 Å, c = 7.568 Å, β = 95.73°, Z = 4, space group P2₁/c (I); a = 5.946, b = 10.255, c = 9.343 Å, β = 95.72°, Z = 2, space group P2₁/c (II). The bond lengths and bond angles lie within the corresponding standard values. Compounds I and II have different conformations of the N-C-C-N ethylenediamine moiety: gauche in I and trans in II, and the corresponding torsion angles are equal to 66.6° and 180°, respectively.     

Synthesis and study of ammonium decamolybdodimetallates

Ammonium decamolybdodimetallates (NH₄)_n[M₂Mo₁₀O₃₄(OH)₄] · 7H₂O, where M = Cr³⁺ (n = 6), Cu²⁺ (n = 8), or Ni²⁺ (n = 8), were synthesized for the first time and studied by X-ray diffraction, thermogravimetry, and IR spectroscopy. The compounds crystallize in the triclinic system with the following unit cell parameters: a = 10.68(2) Å, b = 9.46(2) Å, c = 7.97(2) Å, α = 75.12(3)°, β = 96.82(3)°, γ = 102.21(3)°, V = 754.4(3) ų, ρ_calcd = 4.05 g/cm³, Z = 1 for the chromium compound; and a = 10.57(2) Å, b = 9.29(2) Å, c = 8.47(2) Å, α = 73.91(3)°, β = 96.05(3)°, γ = 104.71(3)°, V = 854.3(3) ų, ρ_calcd = 3.68 g/cm³, Z = 1 (for the copper compound); and a = 10.96(2) Å, b = 8.95(2) Å, c = 7.40(2) Å, α = 71.76(3)°, β = 97.04(3)°, γ = 102.91(3)°, V = 875.3(3)ų, ρ_calcd = 3.65 g/cm₃, Z = 1 for the nickel compound.     

Synthesis and X-ray structural characterization of dioxomolybdenum(VI) complexes with N′-(5-chloro-2-hydroxybenzylidene)-4-methylbenzohydrazide and N′-(2-hydroxybenzylidene)-4-methylbenzohydrazide

Two new dioxomolybdenum(VI) complexes, [MoO₂(ClHm)(CH₃OH)] (I) and [MoO₂(Hm)(CH₃OH)] (II) with the hydrazone ligands H₂ClHm and H₂Hm derived from 4-methylbenzohy-drazide with 5-chlorosalicylaldehyde and salicylaldehyde, respectively, have been synthesized and structurally characterized by physicochemical methods and single-crystal X-ray determination. The crystal of I crystallizes in the triclinic space group \(P\bar 1\), with a = 7.839(2), b = 9.656(3), c = 11.548(4) Å α = 88.885(3)°, β = 87.454(3)°, γ = 88.996(3)°, V = 873.0(5) ų, Z = 2, R ₁ = 0.0292, wR ₂ = 0.0685, S = 1.092. The crystal of II crystallizes in the triclinic space group \(P\bar 1\), with a = 7.780(2), b = 10.584(3), c = 10.628(3) Å, α = 91.462(3)°, β = 104.818(3)°, γ = 103.288(3)°, V = 820.1(4) ų, Z = 2, R ₁ = 0.0403, wR ₂ = 0.0784, S = 1.065. An X-ray analysis indicates that the structures of both complexes are similar to each other. The molybdenum atom in each complex is in an octahedral coordination environment constructed by two oxo groups, an NO₂ donor set of the hydrazone ligand, and one methanol O atom.     

Hexa(isothiocyanato)chromates(III) of Some Yttrium Group Lanthanide(III) and Europium Complexes with Nicotinic Acid: Synthesis and Crystal Structures

Double ionic complexes [M(C₅H₅NCOO)₃(H₂O)₂][Cr(NCS)₆] · nH₂O, where M = Eu (I), n = 1.15; Dy (II), Er (III), n = 1.5; M = Yb (IV), n = 2, have been synthesized by the reaction between M(NO₃)₃, M = Eu, Dy, Er, Yb, K₃[Cr(NCS)₆], and nicotinic acid (C₅H₅NCOO) in an aqueous solution and studied by chemical analysis, IR spectroscopy, and X-ray diffraction. Crystals of complexes I–IV are monoclinic, space group P2₁/n, Z = 4; a = 9.5358(2) Å, b = 25.4871(5) Å, c = 15.4303(4) Å, β = 105.513(1)°, V = 3613.6(1) ų, ρ_calcd = 1.799 g/cm³ for I, a = 9.5901(5) Å, b = 25.8599(15) Å, c = 15.6316(9) Å, β = 106.829(2)°, V = 3710.6(4) ų, ρ_calcd = 1.782 g/cm³ for II, a = 9.5640(3) Å, b = 25.8936(11) Å, c = 15.6498(7) Å, β = 106.895(2)°, V = 3708.3(3) ų, ρ_calcd = 1.791 g/cm³ for III, and a = 9.5049(2) Å, b = 25.6378(4) Å, c = 15.5120(3) Å, β = 106.934(1)°, V = 3616.1(1) ų, ρ_calcd = 1.864 g/cm³ for IV.     

Structure and properties of the volatile isomers of bis(1,1,1-trifluoro-5,5-dimethylhexane-2,4-dionato) of platinum(II)

In the work, isomeric complexes of platinum(II) with the (ptac)^–1 pivaloyltrifluoroacetonate ion (Pt((CH₃)₃–CO–CH–CO–CF₃)₂) are studied. The synthesis and chromatographic separation of Pt(ptac)₂ isomers are described, TGA data for the separated isomers are given, and the crystal structures of the solid phases are studied. The cis-Pt(ptac)₂ complex crystallizes in the space group P-1, a = 10.7091(4) Å, b = 12.7787(6) Å, c = 16.0154(8) Å, α = 92.389(2)°, β = 90.868(2)°, γ = 112.1260(10)°, V = 2027.39(16) ų, Z = 4, d _calc = 1.918 g/cm³. The trans-Pt(ptac)₂ complex crystallizes in the space group C2/m, a = 13.3235(5) Å, b = 8.5515(3) Å, c = 9.6694(3) Å, β = 118.5880(10)°, V = 967.38(6) Å3, Z = 2, d _calc = 2.010 g/cm3. The structures of the complexes are molecular, the Pt atom has a square coordination of four oxygen atoms of two ligands; for cis-Pt(ptac)2, the Pt–Oav distance is 1.968 Å, for trans-Pt(ptac)2 it is 1.980 Å.     

Crystal structures of 1,1,1-trifluoro-4-hydroxy-4-phenyl-but-3-en-2-one, 2,2,6,6-tetramethyl-3-hydroxy-hept-3-en-5-one, 2,2,6,6-tetramethyl-3-methylamino-hept-3-en-5-one and a study of the ability of these ligands to complex formation with metals

Crystal structures are determined (Bruker Nonius X8 Apex, 4K CCD-detector, λMoK _α, graphite monochromator, T 150 K and 293 K) for two β-diketones F₃CC(O)CH₂C(O)Ph (1) (space group P2₁/c, a = 7.0713(3)Å, b = 11.5190(6)Å, c = 11.3602(6) Å, β = 99.405(2)°, V = 912.90(8) ų, Z = 4), (CH₃)₃CC(O)CH₂C(O)C(CH₃)₃ (2) (space group Pbca, a = 11.5536(8) Å, b = 11.5796(10) Å, c = 17.2523(13) Å, V = 2308.1(3) ų, Z = 8) and a ketoimine (CH₃)₃CC(NCH₃)CH₂C(O)C(CH₃)₃ (3) (space group I4₁/a, a = 18.7687(6) Å, b = 18.7687(6) Å, c = 14.5182(6) Å, V = 5114.2(3) ų, Z = 16). All structures are molecular and comprise isolated molecules joined by van der Walls interactions. The substitution energy of a Na atom for a hydrogen atom in free ligands is calculated by the hybrid B3LYP quantum chemical method. A successful preparation of Na(I) chelates with ligands 1, 2 and failed attempts to prepare a complex with ligand 3 are in accordance with the calculations. Geometrical simulation of a copper(II) complex with ligand 3 reveals the overlap of CH₃ groups which hinders the complexation.     

Hexafluorosilicates of cobalt(II) complexes with dimethylsulfoxide and dimethylformamide

New double complexes [Co(DMSO)₆][SiF₆] ? 2H₂O (I) and [Co(DMF)₃(H₂O)₃][SiF₆] ? DMF (II) have been synthesized and studied by IR spectroscopy and X-ray diffraction. Crystals of complex I belong to the tetragonal symmetry system, space group R3?, Z = 3, a = 11.8232(3) Å, c = 18.4699(5) Å, V = 2235.97(10) ų, ρ_calc = 1.573 g/cm³. Crystals of complex II are triclinic, space group P1?, Z = 2, a = 8.6264(4) Å, b = 10.1419(4) Å, c = 13.9657(6) Å, α = 100.847(2)°, β = 98.549(2)°, γ = 93.479(2)°, V = 1181.71(9) ų, ρ_calc = 1.539 g/cm³.     

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.     

Supramolecular architecture of catechol and its 2:1 complex with dimethylsulfoxide

The crystal structures of catechol (o-dihydroxybenzene) and its 2:1 complex with dimethylsulfoxide are determined at T = 150 K. Crystal data: C₁₄H₁₈O₅S, M = 298.37, triclinic, space group P \(\bar 1\), unit cell parameters: a = 7.7285(13) Å, b = 9.9924(17) Å, c = 10.3188(18) Å, α = 89.963(4)°, β = 89.968(4)°, γ = 69.076(5)°, V = 744.3(2)ų, Z = 2, D _x = 1.331 g/cm³, R1 = 0.048; C₆H₆O₂, M = 110.11, monoclinic, space group P2₁/n, a = 9.8206(6)Å, b = 5.5903(3)Å, c = 10.4439(6)Å, β = 114.952(2)°; V = 519.85(5) ų, Z = 4, D _x = 1.407 g/cm³, R1 = 0.0289. In the 2:1 complex the molecules are joined in a supramolecular ensemble by D-H...A hydrogen bonds (D = O, C; A = O, π); in catechol they are bonded only by O-H...O. The state diagram of the catechol-dimethylsulfoxide system is examined by DTA.     

Synthesis and crystal structures of cobalt(III) and zinc(II) complexes derived from 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol with urease inhibitory activity

A new mononuclear cobalt(III) complex, [CoL₂(N₃)]₂ · CH₃OH (I), and a new mononuclear zinc(II) complex, [ZnLCl(CH₃OH)] (II) (HL = 4-chloro-2-[(2-morpholin-4-ylethylimino)methyl]phenol), were prepared and structurally characterized by elemental analyses, infrared spectroscopy, and single- crystal X-ray diffraction. The crystal of I is monoclinic: space group P2₁/c, a = 18.742(2) Å, b = 15.197(2) Å, c = 25.646(2) Å, β = 125.996(3)°, V = 5909.8(11) ų, Z = 4. The crystal of II is monoclinic: space group P2₁/c, a = 7.257(1) Å, b = 24.707(2) Å, c = 9.637(1) Å, β = 101.557(2)°, V = 1692.9(3) ų, Z = 4. The Co atom in I is in an octahedral coordination, and the Zn atom in II is in a trigonal-bipyramidal coordination. The urease inhibitory test shows that complex I has strong urease inhibitory activity, while complex II has no activity.     

Crystal structures of copper(II) and zinc(II) complexes derived from 3-(2-pyridyl)pyrazole

Two dinuclear complexes [Zn(μ-L)(NO₃)(H₂O)]₂ (1) and [Cu₂(μ-L)₂(HL)₂](NO₃)₂(C₁₂H₈Br₂)_0.5·H₂O (2), (HL = 3-(2-pyridyl)pyrazole, C₁₂H₈Br₂ = 4,4′-dibromobiphenyl) are synthesized under hydrothermal conditions and characterized by elemental analysis and X-ray single crystal diffraction. Crystal data for 1: triclinic, \(P\bar 1\), a = 8.8478(7) Å, b = 15.0550(11) Å, c = 16.4310(12) Å, α = 107.588(4)°, β = 112.498(3)°, γ = 115.595(3)°, V = 2099.8(9) ų, Z = 2; for 2: triclinic, \(P\bar 1\), a = 7.2870(15) Å, b = 8.6840(17) Å, c = 9.3290(19) Å, α = 107.588(4)°, β = 112.498(3)°, γ = 115.595(3)°, V = 528.77(18) ų, Z = 1. Complex 1 and 2 are both dinuclear structures which are further packed into a 1D supramolecular chain and a 3D supramolecular framework via weak C–H…O hydrogen bond interactions respectively.     

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.     

[H<Subscript>2</Subscript>OT][PdCl<Subscript>4</Subscript>], a salt of the protonated oxythiamine cation with the tetrachloropalladate(II) tetrachloride anion synthesis and crystal structure

The interaction of oxythiamine chloride hydrochloride with a solution of palladium chloride in hydrochloric acid affords a salt of protonated oxythiamine [H₂OT][PdCl₄] (I) (HOT is 4-methyl-3-[(2′-methyl-4′-oxo-3′,4′-dihydropyrimidinyl-5′)methyl]-5-(2-hydroxyethyl)thiazolium, C₁₂H₁₆N₃O₂S⁺). The crystal structure of salt I is determined by X-ray diffraction analysis. The crystals are monoclinic: a = 9.474(3) Å, b = 13.822(2) Å, c = 13.626(4) Å, β = 93.42(2)°, V = 1781.2(3) ų, Z = 4, space group P2₁/n. The structural units of salt I are doubly-charged cations [H₂OT]²⁺ and anions [PdCl₄]^2? joined by hydrogen bonds and electrostatic interaction into dimeric supermolecules. The thiazolium and pyrimidine rings in the cation are planar (the dihedral angle between the planes is 89.6°) and oriented relative to the linking methylene center to form torsion angles Φ _t = 64.9° and Φ _p = 49.9° characteristic of the V′ conformation.     

Structure and thermal properties of volatile copper(II) complexes with β-diimine derivatives of acetylacetone and the structure of 2-(methylamino)-4-(methylimino)-pentene-2 crystals

Copper(II) chelates with β-diimine derivatives of acetylacetone that have a general formula of Cu(R¹C(NR²)CHC(NR²)R¹)₂, where R¹, R² are alkyl substituents, are synthesized. The complexes were identified using elemental analysis, melting point measurements, and high-temperature mass spectrometry data. Knudsen technique is employed to determine the vapor pressure temperature dependence, and standard thermodynamic parameters of sublimation ΔH _T ⁰ and ΔS _T ⁰ are derived. A single crystal X-ray diffraction study is carried out for copper(II) complexes of Cu(CH₃-C(NCH₃)-CH-C(NCH³)-CH₃)₂ (a = 10.363(1) Å, b = 11.978(1) Å, c = 12.653(1) Å, V = 1570.6(3) ų, space group Pnc2, Z = 4, d _calc = 1.328 g/cm³, R = 0.027), Cu(CH₃-C(NC₂H₅)-CH-C(NC₂H₅)-CH₃)₂ (a = 11.782(4) Å, b = 13.951(8) Å, c = 25.591(8) Å, V = 4206(3) ų, space group C222¹, Z = 8, d _calc = 1.169 g/cm³, R = 0.10), and also 2-(methylamino)-4-(methylimino)-pentene-2 CH₃-(C=(NCH₃))-CH=(C-(NHCH₃))-CH₃ (a = 12.129(2) Å, b = 12.034(2) Å, c = 5.692(1) Å, β = 107.05(3)°, V = 794.3(3) ų, space group Cc, Z = 4, d _calc = 1.055 g/cm³, R = 0.06). Van der Waals lattice energy E _cryst is calculated for the cooper(II) complexes by the atom-atom potential technique. The calculated values are compared to experimental sublimation enthalpies Δ H _T ⁰ .     

Synthesis and crystal structure of methylammonium dicitratoborate

Methylammonium dicitratoborate CH₃NH₃[(C₆H₆O₇)₂B] (I) was synthesized for the first time. The crystal structure of the compound was studied by X-ray crystallography. Crystals of I are triclinic, space group P \(\bar 1\), a = 8.9726(3) Å, b = 10.1039(3) Å, c = 10.7231(4) Å, α = 66.894(1)°, β = 85.347(1)°, γ = 84.991(2)°, V = 889.57(5) ų, Z = 2, ρ_calcd = 1.580 g/cm³. Crystals of I are built up from large dicitratoborate anions with a spiran structure and methylammonium cations. The crystals have a layered structure. A hydrogen-bond system is formed by seven independent contacts O(N)-H?O.