Molecular structures of chalcone podands: A prognosis of photoinduced transformations in the crystals

A series of chalcone podands with the propenone group in the ortho position of the bridging aryl substituent with respect to the oxyethylene fragment is synthesized. The influence of the preorganization of the chalcone podand molecules in crystals on their ability to participate in topochemical reactions is investigated. From analyzing the X-ray structural data, the highest probability of the solid-state photochemical [2 + 2]cycloaddition is predicted for podands with phenyl substituents and the oxyethylene fragment containing two or three oxygen atoms. The X-ray structural data for the chalcone podand C₃₂H₂₆O₄ (3a) are as follows: a = 7.904(9) Å, b = 14.92(2) Å, c = 21.30(3) Å, β = 91.7(1)°, monoclinic system, space group P2₁/c, Z = 4, V = 2510(5) ų, ρ = 1.26 g/cm³, and R = 0.046; C₃₄H₃₀O₅ (3b): a = 15.738(9) Å, b = 11.889(2) Å, c = 15.0830(15) Å, β = 105.47(14)°, monoclinic system, space group C2/c, Z = 4, V = 2720.0(9) ų, ρ = 1.266 g/cm³, and R = 0.0418; C₃₂H₂₄N₂O₈ (4a): a = 17.9416(18) Å, b = 10.9703(8) Å, c = 41.699(2) Å, β = 105.970(11)°, monoclinic system, space group P2₁/c, Z = 4, V = 2781.4(5) ų, ρ = 1.348 g/cm³, and R = 0.0426; C₃₆H₃₂N₂O₁₀ (4c): a = 7.6286(5)Å, b = 17.9398(10) Å, c = 11.5890(3)Å, β = 95.287(4)°, monoclinic system, space group P2₁/n, Z = 2, V = 1579.27(14) ų, ρ = 1.372 g/cm³, and R = 0.0377; and C₂₈H₂₂O₆ (5a): a = 15.6032(10) Å, b = 8.1131(5) Å, c = 17.7334(11) Å, β = 91.381(5)°, monoclinic system, space group C2/c, Z = 4, V = 2244.2(2) ų, ρ = 1.345 g/cm³, and R = 0.0309.     

Crystal structures of 1,1′-di(methylacetato)- and 1,1′-di(chloroethoxyethyl)-2,2′-biimidazole

1,1′-Di(methylacetato)-2,2′-biimidazole, C₁₂H₁₄N₄O₄, crystallizes from methanol in the space groupP2 ₁/c, wherea=9.535(2),b=13.385(2),c=5.1208(8) Å,V=652.2(2) ų, andZ=4.1,1′-Di(chloroethoxyethyl)-2,2′-biimidazole, C₁₄H₂₀Cl₂N₄O₂, crystallizes from cyclohexane in the space groupPbca, wherea=12.372(2),b=8.959(2),c=14.840(2) Å,V=1644.9(5) ų, andZ=8. The structures were refined toR=0.041 (1380 observed reflections) andR=0.043 (3243 observed reflections), respectively. Both molecules crystallize with coplanar rings and the substituents assume atrans configuration with a center of inversion between the bridging carbon atoms.     

Crystal Structures of 6-methyl-3-phenylsulfonylchroman-4-one andtrans-6-methyl-3-phenylsulfonylchroman-4-ol

The crystal structures of (i) CH₃(C₉H₆O₂)SO₂C₆H₅ and (ii) CH₃(C₈H₈O₂)SO₂?C₆H₅ have been determined by X-ray diffraction. (i) crystallizes in the monoclinic space groupP2₁/c with unit cell parametersa=8.814(1)Å,b=10.310(1)Å,c=15.841(4)Å, β=98.17(1)^o, andZ=4, and (ii) crystallizes in the orthorhombic space groupP2₁2₁2₁ with unit cell parametersa=6.206(1)Å,b=11.752(5)Å,c=19.865(3)Å, andZ=4. The pyran ring in both of them is in the distorted half-chair conformation with differeing degrees of distortion from the ideal.     

Direct and outer-sphere coordination of the magnesium ions in the crystal structures of complexes with 2-furancarboxylic acid (I) and 3-furancarboxylic acid (II)

(I) Mg₂C₂₀H₂₄O₁₈ monoclinic,PT,a=10.760(2) Å,b=11.052(2) Å,c=12.822(3) Å, α=105.31(3)^o, β=98.18(3)^o, γ=91.59(3)^o,Z=2. (II) MgC₁₀H₁₄O₁₀, monoclinic,C2/c,a=30.817(6)Å,b=10.499(2)Å,c=9.000(2)Å, β=91.31(3)^o,Z=8. Magnesium in complexes with furoic acids reveals two ways of coordination: direct, when furoic anions are bonded to Mg²⁺ in an ionic fashion and outer-sphere, when cations bind water in the first coordination sphere and furancarboxylic ligands are hydrogen bonded to the water molecules. This results in the formation of three bridging systems: ?Mg?O_carboxyl?C?O_carboxyl?Mg?, ?Mg?O_water ?O_carboxyl?C?O_carboxyl?C?O_carboxyl?Mg?, and ?Mg?O_water?O_carboxyl?C?O_carboxyl?O_water?Mg?. Magnesium 2-furancarboxylate (I) is dimeric, while magnesium 3-furancarboxylate (II) exhibits a polymeric structure.     

Crystal and molecular structures of dimethyl 4-phenylthiosemicarbazidediacetate and its adduct with rhodium(II) acetate

The crystal structures of dimethyl 4-phenylthiosemicarbazidediacetate C₁₃H₁₇N₃O₄S (I) and its adduct [C₈H₁₂O₈Rh₂ (C₁₃H₁₇N₃O₄S)₂] (II) with rhodium(II) acetate are determined by X-ray diffraction analysis. The unit cell parameters of crystals I are as follows: a = 8.066(6) Å, b = 15.812(6) Å, c = 24.977(8) Å, β = 94.88(3)°, space group P2₁/n, and Z = 8. The unit cell parameters of crystals II are a = 8.513(1) Å, b = 16.055(1) Å, c = 16.071(3) Å, β = 104.99(1)°, space group P2₁/c, and Z = 2. In structure I, two crystallographically independent molecules considerably differ from each other in the mutual orientation of the structural fragments containing the ester groups. In the centrosymmetric dimeric complex II, the organic molecule I acts as a monodentate thio ligand and adopts only one conformation.     

X-ray diffraction study of 2,2′,4,4′,6,8,8′,10,10′,12-decamethylbicyclo[5.5.1]hexasiloxane and 2,2′,4,4′,6,8,8′,10,10′,12-decamethylbicyclo[5.5.1]-9-carbahexasiloxane

The crystal structures of two organosilicon compounds are studied by X-ray diffraction at 200 K. Crystals of 2,2′,4,4′,6,8,8′,10,10′,12-decamethylbicyclo[5.5.1]hexasiloxane (C₁₀H₃₀O₇Si₆) are monoclinic, a = 12.260(1) Å, b = 11.716(1) Å, c = 32.169(2) Å, β = 92.802(2)°, space group C2/c, Z = 8, wR2 = 0.132, and R1 = 0.053 for 3989 reflections with F > 4σ(F). Crystals of 2,2′,4,4′,6,8,8′,10,10′, 12-decamethylbicyclo[5.5.1]-9-carbahexasiloxane (C₁₁H₃₂O₆Si₆) are triclinic, a = 10.709(1) Å, b = 11.046(1) Å, c = 12.111(1) Å, α = 117.059(1)°, β = 95.566(1)°, γ = 108.088(1)°, space group $P\bar 1$ , Z = 2, wR2 = 0.115, and R1 = 0.048 for 3948 reflections with F > 4σ(F). It is found that the substitution of the methylene group for the oxygen atom is accompanied by a minor conformational change in the bicyclic fragment and the SiCSi angle changes from the tetrahedral angle to 121.0(1)°. The high variability of the SiOSi bond angles is confirmed.     

Crystal and molecular structures of 2-amino-5-(m-nitrophenyl)-1,3,4-Thiadiazole

2-Amino-5-(m-nitrophenyl)-1,3,4-thiadiazole (C₈H₆N₄O₂S) is studied using IR and ¹H NMR spectroscopy and X-ray diffraction (CAD4 automated diffractometer, λMoK _α, graphite monochromator, 957 unique reflections, Patterson method, R = 0.0326). The crystals are monoclinic, a = 11.832 Å, b = 9.862 Å, c = 8.353 Å, β = 110.40(3)°, V = 913.6(3) ų, d _calcd = 1.212 g cm^?3, μ(MoK _α) = 0.253 mm^?1, Z = 4, and space group P2₁/c. In the crystal, the C₈H₆N₄O₂S molecules form infinite layers parallel to the xz plane. Each layer contains aromatic rings with nitro groups that deviate from the layer plane on either side of the layer. In the packing, the aromatic rings with nitro groups of one layer fill spaces between aromatic rings with nitro groups of the adjacent layers.     

Synthesis and crystal structure of 3-ammoniumphenyl sulfone selenate, 3-aminophenyl sulfone [C12H14N2O2S]SeO4 · [C12H12N2O2S]

The crystal structure of [C₁₂H₁₄N₂O₂S]SeO₄ · [C₁₂H₁₂N₂O₂S] was determined by X-ray diffraction on single crystal. Crystals are orthorhombic, space group Pbca, with cell parameters a = 11.545 (1), b = 8.143 (1), c = 55.783(1)Å, V = 5244.2 (8)ų and Z = 8. The structure can be described as organic layers built by [C₁₂H₁₄N₂O₂S]²⁺ cations and [C₁₂H₁₂N₂O₂S] molecules, parallel to ab plane, between which the inorganic groups SeO ₄ ^2? are inserted. In this atomic arrangement, H-bonds between the different species play an important role in the three-dimensional network cohesion.     

The molecular structures of two furanoheliangolides

The heliangolide-class sesquiterpene lactone 8β-angeloyloxy-9α-acetoxycalyculatolide, C₂₂H₂₆O₈,1, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=12.455(3),b=12.601(3),c=14.023(5) Å,V=2200(1)Å,³ Z=4.R=0.059 for 1735 observed data. The 11,13-dihydro-11α, 13-epoxyatripliciolide-8β-angelate, C₂₀H₂₂O₇. 1/2 H₂O,2, crystallizes as the hemihydrate with two molecules in the asymmetric unit in triclinic space groupP1 witha=9.422(1),b=9.559(1),c=12.358(3) Å, α=101.62(2)°, β=91.30(2)°, γ=117.80(1)°,V=955.6(7)ų,Z=2.R=0.046 for 3607 observed data. In both, the 10-membered rings adopt approximate chair-boat conformations. Their conformations are typical for heliangolides. The methyl group C14 is α, while the C-15 has a β-orientation. The α-methylene-γ-lactone istrans-fused at C6 and C7 with H6 β and H7 α. In compound2, the epoxide at C11–C13 has an α orientation.     

Crystal structures of dioxonium hexafluorotantalate and dioxonium hexafluoroniobate complexes with tetrabenzo-30-crown-10

Two isostructural complexes of dioxonium [H₅O₂]⁺ with tetrabenzo-30-crown-10 of the compositions [(tetrabenzo-30-crown-10 · H₅O₂)][TaF₆] (I) and [(tetrabenzo-30-crown-10 · H₅O₂)][NbF₆] (II) are studied using X-ray diffraction. The complexes crystallize in the monoclinic crystal system (space group C2/c, Z = 4). The unit cell parameters of these compounds are as follows: a = 15.6583(12) Å, b = 15.2259(13) Å, c = 16.4473(13) Å, and β = 99.398(6)° for complex I and a = 15.7117(12) Å, b = 15.2785(15) Å, c = 16.5247(15) Å, and β = 99.398(7)° for complex II. These complexes belong to the ionic type. The dioxonium cation [H₅O₂]⁺ in the form of the two-unit cluster [H₃O · H₂O]⁺ is stabilized by the strong hydrogen bond OH?O [O?O, 2.353(4) Å] and encapsulated by the crown ether. Each oxygen atom of the dioxonium cation also forms two oxygen bonds O?O(crown). The crown ether adopts an unusual two-level (pocket-like) conformation, which provides a complete encapsulation of the oxonium associate. The interaction of the cationic complex with the anion in the crystal occurs through contacts of the C-H?F type.     

Crystal and molecular structure of the membrane-active antibiotic enniatin C

The crystal structure of the cyclic hexadepsipeptide antibiotic enniatin C c[-(L-MeLeu-D-Hyi)₃-], C₃₄H₅₉N₃O₉, was established by X-ray structure analysis (sp. gr. P2₁, a = 20.205(5) Å, b = 8.702(2) Å, c = 25.587(6) Å, γ = 97.0(5)°, V = 4465.3(18) ų, Z = 4, R = 0.089 for 3601 reflections with I > 2σ(I)). The unit cell contains two independent molecules of enniatin C, one ethanol molecule disordered over two positions, and approximately two water molecules occupying four positions and forming hydrogen bonds with each other. The independent antibiotic molecules adopt virtually identical conformations similar to those observed in the structures of enniatin B and its Na,Ni-complex. These conformations are characterized by alternating upward and downward orientations of the carbonyl groups and pseudoequatorial orientations of side radicals. The Leu residues have stretched conformations. The N-methylamide groups of the independent antibiotic molecules face each other, whereas the molecules are displaced by approximately 8.4 Å with respect to each other along the mean planes of the rings.     

Crystal and Molecular Structure of Non-hydrated and Hydrated Piperidinium-acet-o-Cl-anilide-chloride

Crystallizations from water and alcoholic solution respectively yield different crystal and molecular structures of Piperidinium-acet-o-Cl-anilide-chloride. The non-hydrated compound crystallizes from alcoholic solution in the space group P 2₁/c with 4 formula units C₁₃H₁₈N₂OCl₂ in the unit cell of dimensions a = 12.352 Å, b = 6.864 Å, c = 19.018 Å and β = 113.98°. The hydrated modification has the space group C 2/c with 8 formula units C₁₃H₁₈N₂OCl₂ and 8 H₂O molecules in the unit cell. The lattice constants are a = = 24.159 Å, b = 8.966 Å, c = 14.179 Å and β = 90.50°. The X-ray structure analyses were carried out to investigate the hydrogen bonds and the change of the molecular conformation caused by linking of water molecules to the drug molecules.     

Crystal and molecular structure of 11,12-dihydroxydrim-8(9)-en-7-one

The crystal structure of 11,12-dihydroxydrim-8(9)-en-7-one was determined by X-ray diffraction. The unit cell parameters are a = 7.534(3), b = 12.192(5), c = 8.067(4) Å, β = 98.01(3) Å, space group P2₁, and Z = 2 for C₁₅H₂₄O_3. The structure was solved by direct methods and refined in the anisotropic approximation to R = 0.051 and R _w = 0.113. The intramolecular O-H?O hydrogen bond [2.892(6) Å] between the hydroxy groups closes an additional seven-membered H-ring in the molecule. In the crystal, the intermolecular O-H?O hydrogen bond [2.857(4) Å] between the hydroxyl group and the carbonyl oxygen atom links the molecules related by the translation along the c-axis to form infinite chains.     

Molecular and crystal structure of the echinochrome complex with dioxane

The molecular and crystal structures of a complex of echinochrome (2,3,5,6,8-pentahydroxy-7-ethyl-1,4-naphthoquinone) with dioxane are determined. The molecular complex 2(C₁₂H₁₀O₇) · C₄H₈O₂ crystallizes in the form of dark red transparent thin plates. The crystal data of the compound are as follows: a = 4.563(1) Å, b = 6.382(1) Å, c = 22.812(4) Å, α = 91.955(5)°, β = 90.408(5)°, γ = 104.801(4)°, space group $P\overline 1 $ , and Z = 2. The crystal structure is solved by direct methods and refined to R ₁ = 0.0656 and wR ₂ = 0.1196.     

Crystal and molecular structure of phenanthrolinium peroxodisulfate dihydrate (C<Subscript>12</Subscript>H<Subscript>9</Subscript>N<Subscript>2</Subscript>)<Subscript>2</Subscript>S<Subscript>2</Subscript>O<Subscript>8</Subscript> · 2H<Subscript>2</Subscript>O

The crystal structure of (HPhen)₂S₂O₈ · 2H₂O is studied using X-ray diffraction. The crystals are monoclinic, a = 23.716(5) Å, b = 10.220(2) Å, c = 13.103(3) Å, β = 128.03(2)°, V = 2501.6(9) ų, Z = 4, space group C2/c, and R = 0.0745 for 1579 reflections with I > 2σ(I). The crystal is built of S₂O ₈ ^2? centrosymmetric anions, HPhen ⁺ cations, and molecules of crystallization water. Hydrogen bonds link the structural units into chains. Within a chain, stacking interactions are observed between the phenanthroline rings (the interplanar spacing between the rings is 3.8 Å, and the dihedral angle between their planes is 8°). The data of IR spectroscopy confirm the formation of the N(Phen)-H bond.     

Crystal structure of <Emphasis Type="Italic">p</Emphasis>-carboxyphenylhydrazone benzoylacetone

The crystal structure of p-carboxyphenylhydrazone benzoylacetone is determined. The crystals are monoclinic, a = 13.614(4) Å, b = 11.388(2) Å, c = 20.029(6) Å, β = 104.82(2)°, V = 2339(9) ų, Z = 8, space group C2/c, and R = 0.038 for 1622 reflections with I > 2σ(I). The crystal is built of C₁₇H₁₄N₂O₄ neutral molecules that are linked by O-H?O hydrogen bonds between the carboxyl groups into centrosymmetric pseudodimers. The effect of carboxylation of the phenylhydrazone fragment and the position of the carboxyl group on the molecular packing in the crystal is determined. The N(1)-H(1N)?O(1) intramolecular hydrogen bond (N-H, 0.94 Å; H?O, 1.87 Å; N?O, 2.59 Å; and the N-H?O angle, 133°) is formed in the molecule.     

The molecular structures of three germacrolides related to parthenolide

The germacrolide-class sesquiterpene lactone, 1,10-epoxyparthenolide, C₁₅H₂₀O₄,1, crystallizes with two independent molecules in monoclinic space groupP2₁ witha=10.6845(5),b=9.0763(4),c=15.4326(7) Å, β=105.887(4)°,V=1439.4(3) ų,Z=4.R=0.037 for 2425 observed data. Its 11βH, 13-dihydro-derivative 1,10-epoxydihydroparthenolide, C₁₅H₂₂O₄,2, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=7.6414(10),b=12.559(2),c=14.6821(14) Å,V=1409.0(3) ų Z=4.R=0.031 for 1555 observed data. The corresponding unexposidized compound, 11βH,13-dihydrocostunolide, C₁₅H₂₂O₂,3, crystallizes with three independent molecules in orthorhombic space groupP2₁2₁2₁ witha=7.3576(5),b=23.505(3),c=24.185(2) Å,V=4182(1) ų,Z=12.R=0.070 for 2767 observed data. In all, the 10-membered rings adopt approximate chair-chair conformations. In all, the double bonds or epoxidized double bonds are E, both methyl groups on the 10-ring are β, and the α-methylene-γ-lactone (or α-methyl-γ-lactone) istrans-fused at C6 and C7 with H6 β and H7 α. In the dihydro compounds, the H at C11 is β.     

Crystal structure of cholest-4-ene-3,6-dione: A steroid

The crystal structure of cholest-4-ene-3,6-dione (C₂₇H₄₄O₂) has been determined by X-ray diffraction methods. The compound crystallizes in the monoclinic crystal system (space group P2₁) with the unit cell parameters a = 10.503(4) Å, b = 8.059(1) Å, c = 14.649(1) Å, β = 105.4(2)°, and Z = 2. The structure has been refined to an R value of 0.035 for 2252 observed reflections. Ring A of the steroid nucleus exists in a sofa conformation, while rings B and C adopt a chair conformation. The five-membered ring D exhibits a half-chair conformation. The molecules in the unit cell are linked together by the C-H?O hydrogen bonds.     

Crystal structure of 4-phenyl-3,5-dioxacyclohexyl-1, 1′-cyclopentane-2′,3″-(1,5,8,11-tetraoxacyclotridecane)

The structure of the title compound is determined by X-ray diffraction (DAR-UMB diffractometer, θ-θ/2θ scan mode, MoK _α radiation, direct method). The crystal is monoclinic, a = 24.582(6) Å, b = 22.812(8) Å, c = 8.647(3) Å, γ = 60.64(2)°, ρ _calcd = 1.232 g/cm³ space group A2/a, and Z = 8 for C₂₂H₃₂O₆. The molecule consists of four fragments: 13-crown-4 (A), 1,3-dioxane (B), a five-membered ring (C) acting as a bridge between fragments A and B, and a phenyl ring (D). Introduction of the bulky ring C as a bridge into the molecule results in significant deviations (up to ±0.014 Å) of the ether O atoms from planarity. The conformation of the macrocyclic fragment is [3433] according to the Dale notation. The C—H?O 1,4-interactions, which are energetically favorable occur in the propylene part of 13-crown-4: the C(2)?O(5) and C(4)?O(1) distances are 2.82 Å. The molecules in the structure form planar networks parallel to the xy plane. The intermolecular contacts correspond to the van der Waals interactions.     

Synthesis and crystal structure of 2-propyl-5-phenyl-1, 4-dioxo-1,2,3,4,5,6,7,8-octahydro-[1,4,2]diazaphosphorino [1,2-a][1,3,2]benzodiazaphosphorine 3-oxide

The synthesis and structure characterization of 2-propyl-5-phenyl-1,4-dioxo-1,2,3,4,5, 6,7,8-octahydro-[1,4,2]diazaphosphorino[1,2-a][1,3,2]benzodiazaphosphorine 3-oxide are described. The title compound has been designed to incorporate proximate carbonyl and phosphoryl groups in a heterocycle fused to benzophosphadiamide heterocycle. Crystal data: C₁₉H₂₀N₃O₃P, Monoclinic, space group P2(1)/c, with a = 9.7585(9) Å, b = 21.4319(19) Å, c = 17.7900(16) Å, β = 100.823(2)°, Z = 8, V = 3654.5(6) ų. The crystal structure shows that the proximate carbonyl and phosphoryl groups are not coplanar, and the [1,4,2]diazaphosphorino moiety prefers the boat conformation.