Helical tubulate inclusion compounds of ferrocene and squalene

The inclusion compounds of 2,8-dimethyltricyclo[5.3.1.1^3,9]dodecane-syn-2,syn-8-diol,3, with ferrocene and with squalene have been prepared. The crystal structures of these helical tubulate compounds: (3)₃·(ferrocene)_0.75 [P3₁21,a=b=13.7480(6),c=7.0312(5) Å,Z=1,R=0.038] and (3)₃·(squalene)_0.23 [P3₁21,a=b=13.677(1),c=7.0533(9) Å,Z=1,R=0.042] are described. Supplementary Data relating to this article are deposited with the British Library as supplementary publication No. SUP 82151 (16 pages).     

Inclusion complexes of the natural product gossypol. Clathrate type inclusion complexes of gossypol with carbonyl group containing guests

The crystal structures of 2:1 inclusion complexes of gossypol with methyl propionate (GPMEP) and ethyl acetoacetate (GPEAA) have been determined by X-ray structure analysis. The crystals of GPMEP, C₃₀H₃₀O₈l/2 C₄H₈O₂, are monoclinic, space groupC2/c,a=11.079(3),b = 30.724(7), c = 16.515(5) Å, = 90.46(2)°,V = 5621(3) Å,Z = 8,D _x = 1.33 g cm^–3. The structure has been refined to the finalR value of 0.059 for 1899 observed reflections. The crystals of GPEAA, C₃₀H₃₀O₈l/2 C₆H₁₀O₃, are monoclinic, space groupC2/c,a=11.095(2),b=30.604(9),c = 16.955(5) Å, = 88.27(2)°,V = 5754(3) Å,Z = 8,D _x = 1.35 g cm^–3. The structure has been refined to the finalR value of 0.056 for 2502 observed reflections.In contrast to previously investigated inclusion complexes of gossypol the host molecules do not form centrosymmetric dimersvia hydrogen bonds. In the crystal structures the racemic gossypol is separated into enantiomers forming alternating bimolecular layers. Nearly perpendicular to these chiral bilayers run elongated cavities enclosed on each side by layers of opposite chirality. The surface of these layers is hydrophobic, the polar groups are hidden inside the layer. Guest molecules which are hydrogen bonded to the host are included in cylindrically shaped cavities. Possible hydrogen bonds between host and guest are analysed for this isostructural class of complexes.     

Interaction of dihydroxy host systems with glycols. A comparative study of the crystal structures of 1:1 molecular complexes of 1,4-butanediol with 2,5-bis(4-chlorophenyl)hydroquinone andtrans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene

The title compounds crystallize in space groupC2/c withZ=4; C₁₈H₁₂O₂Cl₂·HO(CH₂)₄OH,a=16.186(3),b=7.626(1),c=16.939(3) Å, =91.32(2)°,R _F =0.048 for 1743 observed MoK reflections; C₂₆H₂₀O₂·HO(CH₂)₄OH,a=11.881(3),b=13.009(4),c=16.689(4) Å, =110.67(2)°,R _F =0.066 for 1783 data points. Both structures feature centrosymmetric hydrogen-bonded (OH)₄ rings formed by molecular components located in special positions. Different packing modes account for the observed conformations (g ⁺ ag ^– andaaa, respectively) of 1,4-butanediol and its possible replacement by 1,2-ethanediol as a guest in the former crystal structure. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82009 (25 pages).Dedicated to Professor H. M. Powell.     

Inclusion complexes of the natural product gossypol. Recognition by gossypol of halogeno methanes. Structure of the dichloromethane complex of gossypol and single crystal conservation after decomposition

The structures of gossypol complexes are extremely sensitive to the halogenomethane present as the guest; e.g. changing the number of Cl atoms in chloromethane derivatives changes the structure of the gossypol complex. The crystals of C₃₀H₃₀O₈·CH₂Cl₂ are monoclinic, space groupC2/c,a=21.320(4),b=19.199(6),c=15.765(2)Å, =113.05(2)^o,V=5916(2)ų,Z=8,D _x=1.35 g/cm³,T=295 K. The structure has been solved by direct methods and refined to the finalR value of 0.084 for 1828 reflections. In the structure H-bonded gossypol molecules form columns, generating channels in the structure which are filled by guest molecules. After decomposition (desolvation) monocrystals of the complexes are conserved without destruction, in which there are rather wide and empty channels though slightly smaller than in the complex. An attempt is made to explain some peculiarities of the behavior of the gossypol polymorph formed on the basis of its structure with empty channels. Supplementary data relevant to this article have been deposited with the British Library Publication No. SUP 82165 (17 pages).     

X-ray structural study of a zinc(II) inclusion complex of a phenolate-pendant cyclam

The molecular structure of phenol-pendant cyclam-zinc(II) complex,4a, has been determined by X-ray structure analysis. Crystals of4a · ClO₄ · CH₃OH (C₁₆H₂₇N₄OZn · ClO₄ · CH₃OH) are monoclinic, space groupP2₁/nn, with four molecules in the unit cell of dimensionsa=31.198(2) Å,b=8.426(1) Å,c=8.214(1) Å, and=93.96(1)°. The structure was solved by the heavy atom method and refined anisotropically toR=0.044,R _w=0.062 for 1551 independent reflections. The complex assumes a five-coordinate, square pyramidal geometry, where zinc(II) is surrounded by the cyclam moiety in a planar fashion with the pendant phenolate anion occupying an axial position. An extremely short Zn-O(phenolate) bond distance of 1.983(5) Å, in conjunction with the 0.288 Å displacement of Zn(II) above the cyclam N₄ plane toward the phenolate, accounts for the extremely low pK _a value of 5.8 for the pendant phenol. These facts about4a, in comparison with the previous findings for the Ni(II) (4b) and Cu(II) complexes (4c) with the same ligand, illustrate well the characteristics of zinc(II) ion coordination properties.This paper is dedicated to the memory of the late Dr C. J. Pedersen.     

Indium-based liquid clathrates. I. The preparation of the first indium liquid inclusion compound and crystal structure of its parent complex, [K · 18-Crown-6]2[InClI2(CH3)][InClI(CH3)2]

The synthesis of the first liquid clathrate derived from an indium precursor is described. The aromatic/anion ratio of the inclusion complex prepared using benzene is 12.4. The use of toluene results in the inclusion of 10.3 guest toluene molecules/anion. The crystal structure of the parent complex, [K·18-Crown-6]₂[InClI₂(CH₃)][InClI(CH₃)₂] was carried out. The compound belongs to the monoclinic space groupP2₁/c, witha=19.508(9),b=8.503(5), andc=29.437(9) Å, =96.55(3)°, andD _calc=1.83 g cm^–3 forZ=4. Least-squares refinement based on 3449 observed reflections led to a finalR=0.099. The structure displays two different environments for the two K⁺ cations in the asymmetric unit. One adopts the near-planar [K·18-crown-6]⁺ configuration while the other K⁺ resides 0.81 Å above the second 18-crown-6 plane. The latter K⁺ is apparently pulled out of the crown by a strong interaction with a Cl^– ion. Supplementary Data related to this article are deposited with the British Library as Supplementary Publication No. SUP 82046 (25 pages).     

The crystal structures ofα,ω-diaminoalkane-cadmium(II) tetracyanonickelate(II) — Aromatic molecule inclusion compounds. VII: Three-dimensional host structures built ofcatena-[cadmium(II) tetra-μ-cyanonickelate(II)] layers and 1,3-diaminopropane, 1,5-diaminopentane or 1,7-diaminoheptane pillar

The crystal structures of four novel Hofmann-diam-type clathrates [Cd(tn)Ni(CN)₄]·1.72(o-MeC₆H₄NH₂),3-o, [Cd(tn)Ni(CN)₄]·0.5(m-ClC₆H₄NH₂),3-m, [Cd(daptn)Ni(CN)₄]·1.5(p-MeC₆H₄NH₂),5-p and [Cd(dahpn)Ni(CN)₄]·1.5(2-MeC₉H₆N),7-q have been determined by single crystal X-ray diffraction method [tn:n=3, daptn:n=5, dahpn:n=7 for NH₂(CH₂) _n NH₂.3-o crystallizes in the monoclinic space groupP2/m,a=7.538(2),b=9.314(5),c=7.670(2) Å, =91.03(2)°,Z=1,R=0.047 for 1252 reflections;3-m: orthorhombicPbam,a=12.1714(7),b=15.798(1),c=7.737(1) Å,Z=4,R=0.044 for 1871;5-p: monoclinicP2₁/a,a=13.736(3),b=22.014(4),c=7.762(3) Å, =91.04(3)°,Z=4,R=0.047 for 5281; and7-q: orthorhombicPbam,a=13.599(2),b=27.938(4),c=7.619(2) Å,Z=4,R=0.054 for 3098. Their host structures are topologically the same to those of the previously reported Hofmann-diam-type clathrates: the two-dimensional [CdNi(CN)₄] networks are spanned by NH₂(CH₂) _n NH₂ at every Cd atom to build up the three-dimensional hosts. The number of cavities available for the guest is regulated by the deformation of the 2D networks and the diamine ligand in the host structure. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82192 (37 pages).     

Two clathrates of bis(isothiocyanato)tetrakis(4-methylpyridine)magnesium(II) as a host with 4-methylpyridine as a guest

Two clathrate modifications of the title host with 4-methylpyridine (4-CH₃C₅H₄N) as a guest have been determined at –50°C. [Mg(4-CH₃C₅H₄N)₄(NCS)₂] · 2/3(4-CH₃C₅H₄N) · 1/3H₂O is trigonal, space group , witha=27.630(7),c=11.219(3) ÅV=7417(4) ų,Z=9,D _calc=1.171 g cm^–3,(CuK )=18.506 cm^–1, finalR=0.064. [Mg(4-CH₃C₅H₄N)₄(NCS)₂] · (4-CH₃C₅H₄N) is tetragonal, space group I4_l/a, witha=16.944(7),c=23.552(9)Å,V=6762(5) Å,Z=8,D _calc=1.191 g cm^–3, (CuK )=18.200 cm^–1, finalR=0.071.The structures consist of molecular packings of the same host complex units and the guest species. The Mg(II) cation is octahedrally coordinated to theN-atoms of four 4-methylpyridine and twotrans-coordinated isothiocyanato ligands in the host molecule. The conformations of the molecule are considerably different both in symmetry and in geometry in these two structures. The guest 4-methylpyridine molecules are disordered into channels which have different topology in these two clathrates resulting in different thermal stability.     

Crystal structure of the phenylacetylene-choleic acid

Deoxycholic acid (C₂₄H₄₀O₄, M _r =392.58) and phenylacetylene (C₈H₆, M _r =102.14) form a 2:1 inclusion compound which crystallizes in space groupP2₁2₁2₁ witha=25.542(6),b=13.662(5),c=7.227(2) Å,Z=4. The finalR is 0.07₁ for 2168 observed reflections withI>1.5(I). The crystal packing is characterized by an assembly of antiparallel pleated bilayers of deoxycholic acid molecules which leave empty channels running alongc. Phenylacetylene molecules are accommodated within the cavities in an ordered fashion and are very probably arranged in only one orientation, which was determined by means of Van der Waals energy calculations. Atoms of deoxycholic acid belonging to ring A and to the side-chain are engaged in binding interactions with the guest molecule. The arrangement of the guest molecules supports the experimental results of irradiation, which show a failure of the phenylacetylene molecules to undergo inclusion polymerization. Supplementary Data relevant to this paper have been deposited with the British Library Lending Division under SUP No. 82024 (13 pages).     

Inclusion compounds of thiourea and peralkylated ammonium salts. Part II. Hydrogen-bonded host lattices built of thiourea and cyclic dimeric bicarbonate moieties

New inclusion complexes R₄N⁺HCO ₃ ^– ·x(NH₂)₂CS·yH₂O (1, R=C₂H₅,x=1,y=1;2, R=n–C₃H₇,x=2,y=0;3, R=n–C₄H₉,x=3,y=0) have been prepared and characterized by X-ray crystallography. Crystal data, MoK radiation:1, space groupPbca,Z=8,a=8.839(2),b=14.930(3),c=24.852(5) Å, andR _F=0.063 for 1419 observed data;2, space groupC222₁,Z=8,a=8.521(3),b=16.941(4),c=32.022(7) Å,R _F=0.054 for 1689 observed data;3, space group ,Z=2,a=9.553(2),b=12.313(3),c=14.228(4) Å, =90.44(2),=103.11(2), =110.12(2)°,R _F=0.044 for 3925 observed data. In the crystal structure of1, the thiourea molecules form hydrogen-bonded zigzag ribbons running parallel to thea axis, and the cyclic dimeric bicarbonate moieties (HCO ₃ ^– )₂ together with water molecules behave likewise. A puckered layer is formed by further lateral hydrogen bonding between these two types of ribbons, and the (C₂H₅)₄N⁺ cations occupy the space between adjacent layers. In the crystal structure of2, the thiourea ribbons are cross-linked orthogonally by (HCO ₃ ^– )₂ unitsvia N–H...O hydrogen bonds to form a composite double layer. Half of the cations are enclosed within and the other half sandwiched between these double layers. In the crystal structure of3, the thiourea molecules form puckered double ribbons running in the [110] direction. The host framework is constructed by cross-linking the double ribbons with bridging bicarbonate dimers, yielding two channel systems aligned parallel to [100] and [111] that accommodate the cationic guests. The structural relationship between the present complexes and the classical thiourea channel adducts is discussed. Supplementary Data relating to this article have been deposited with the British Library as Supplementary Publication No. SUP 82178 (44 pages).     

Novel one-dimensional lanthanide acrylic acid complexes: an alternative chain constructed by hydrogen bonding

Novel one-dimensional (1D) chains of three lanthanide complexes La(L¹)₃(CH₃OH)]·CH₃OH (L¹=(E)-3-(2-hydroxyl-phenyl)-acrylic acid) 1, La(L²)₃(H₂O)₂]·2.75H₂O (L²=(E)-3-(3-hydroxyl-phenyl)-acrylic acid) 2, and La(L³)₃(CH₃OH)₂(H₂O)]·CH₃OH (L³=(E)-3-(4-hydroxyl-phenyl)-acrylic acid) 3 are reported. The crystal structure data are as follows for 1: C₂₉H₂₉LaO₁₁, monoclinic, P2₁/n, a=15.4289(12) Å, b=7.9585(6) Å, c=23.041(2) Å, β=99.657(2)°, Z=4, R₁=0.0637, wR₂=0.0919; for 2: C₂₇H_30.50LaO_13.75, triclinic, P−1, a=8.4719(17) Å, b=13.719(3) Å, c=14.570(3) Å, α=62.19(3)°, β=99.657(2)°, γ=78.22(3)°, Z=2, R₁=0.0384, wR₂=0.0820; and for 3: C₃₀H₃₅LaO₁₃, monoclinic, P2(1)/c, a=9.5667(6) Å, b=24.3911(15) Å, c=14.0448(9) Å, β=109.245(2)°, Z=4, R₁=0.0374, wR₂=0.0630. All the three structure data were collected using graphite monochromated molybdenum Kα radiation and refined using full-matrix least-squares techniques on F². These structures show that four kinds of the carboxylato bridge modes are included in these chains to link the La(III) ions. It is the first time that it has been found that the intra-chain hydrogen bonding can construct an alternative chain even, when the coordination bridge mode is the same along the chain (complex 2). There are 2D and 3D hydrogen bonding in the crystal lattices of complexes 1-3.     

Crystal structure of a non-stoichiometric channel inclusion complex of 1-benzyl-6-phenylpiperidin-2-one-5-carboxylic acid with acetonitrile

C₁₉H₁₉NO₃·x CH₃CN (x=0.3),M _r=643.35, hexagonal, space groupP6₁ (No. 169),a=23.027(5),c=5.775(1) Å,V=2652(1) ų,Z=6. The structure was solved by direct methods and refined toR=0.077 for 1562 observed MoK reflections. The title heterocyclic carboxylic acid was established as thetrans isomer, with the phenyl and carboxyl substituents occupying pseudo-equatorial and equatorial positions, respectively, of the piperidin-2-one ring in a half-chair conformation. Acid host molecules related by the 6₁ screw operation are linked by intermolecular O–H...O (cyclic amide) hydrogen bonds to generate an open channel bounded by coaxial intertwined helices each having a pitch of 5c. Within each channel of free diameterca. 6.0 Å the acetonitrile molecules partially occupy highly disordered sites which do not lie on thec axis. Supplementary Data relating to this article are deposited with the British Library as Supplementary Publication No. SUP 82067 (13 pages).     

Complexation of Ethanol by a Helical Tubuland Diol Host

The cage compound 4,7-dimethylpentacyclo[6.3.0.0^2,6.0^3,10.0^5,9]undecane-anti-4,anti-7-diol 3 and its 4,7-bis(d ₃-methyl) derivative 4 form 1:1 cocrystalline complexes with ethanol instead of the expected helical tubulate inclusion compounds. The X-ray crystal structure of (4)·(ethanol) [(C₁₃H₁₂D₆O₂)·(C₂H₆O), Cmca, a 19.049(2), b 14.932(2), c 10.117(1) Å, Z 8, R 0.061] shows that the key supramolecular synthon is a hydrogen-bonded (O — H)₆ cycle of hydroxy groups constructed from two ethanols (in ring positions 1 and 4) and four diols. This uncommon centrosymmetric motif permits efficient lattice packing of ethanol and both diol enantiomers into layers without requiring the self-resolution that would be mandatory in forming the helical tubulate structure.     

Hydrothermal syntheses and structures of two novel vanadium selenites, {[VO(OH)(H2O)](SeO3)}4·2H2O and (H3NCH2CH2NH3)[(VO)(SeO3)2]

Two novel vanadium selenites {[VO(OH)(H₂O)](SeO₃)}₄·2H₂O 1 and (H₃NCH₂CH₂NH₃)[(VO)(SeO₃)₂] 2 were synthesized by hydrothermal method and their crystal structures were determined by single-crystal X-ray diffraction. It is characterized by inductively coupled plasma (ICP), thermogravimetric (TG) and elemental analyses. Compound 1 crystallizes in the monoclinic system, space group C2/c, a=21.2250(11) Å, b=12.6309(6) Å, c=17.0249(10) Å, β=96.830(3)°, V=4531.8(4) Å³ and Z=8, R₁ [I>2σ(I)]=0.0344, wR₂ [I>2σ(I)]=0.119; Compound 2 crystallizes in the monoclinic system, space group P2₁/c, a=9.6389(4) Å, b=6.9922(3) Å, c=15.0324(5) Å, β=102.297(2)°, V=989.90(7) Å³ and Z=4, R₁ [I>2σ(I)]=0.0452, wR₂ [I>2σ(I)]=0.117. {[VO(OH)(H₂O)](SeO₃)}₄·2H₂O has a 1D structure constructed from the {[VO(OH)(H₂O)](SeO₃)}_∞ chains. (H₃NCH₂CH₂NH₃)[(VO)(SeO₃)₂] has a layered structure composed of alternating VO₅ and SeO₃ units with protonated ethylenediamine as interlayer guest.     

Crystal structure of the 2:1 inclusion compound between deoxycholic acid and quadricyclane

The 2:1 inclusion compound formed between deoxycholic acid (C₂₄H₄₀O₄,M _r=392.58) and quadricyclane (C₇H₈,M _r=92.14) crystallizes in space groupP2₁2₁2₁ witha=27.150(7),b=13.359(3),c=14.161(4) Å,Z=4. The structure was refined toR=0.08₆ andR _w=0.08₈ for 2079 observed reflections withI>2.5(I). The crystal packing is very similar to that found in the norbornadiene-deoxycholic acid inclusion compound and is characterized by an assembly of antiparallel pleated bilayers, formed by molecules of deoxycholic acid held together through hydrogen bonds. Quadricyclane occupies approximately the same position of norbornadiene and its atoms give rise to good van der Waals interactions with some methyl groups of deoxycholic acid. Supplementary Data relating to the article are deposited with the British Library as Supplementary Publication No. SUP 82006 (14) pages. To obtain copies, see page ii of this issue.     

Synthesis and crystal structures of heterobimetallic Fe-Cd,Fe-Zn,and Fe-In complexes containing hemilabile phosphorus/oxygen and silicon/oxygen bridging ligands

The reactions of K[Fe{Si(OMe)₃}(CO)₃(PY)][PY=Ph₂PCH₂C(O)Ph, Ph₂PCH₂C(O)[(-C₅H₄)FeCp] (Cp=⁵-C₅H₅), Ph₂P(CH₂)₂CN] with CdCl₂·2.5H₂O, ZnX ₂ (X=Cl, I) or InCl₃ afforded Fe-Cd-Fe or Fe-M(-X)₂ M-Fe (M=Cd, Zn, In;X=Cl, I) and Fe-InCl₂ complexes. Some of them contain an unusual and labile -²-SiO alkoxysilyl bridge which may be associated with a bridging mode for the ketophosphine ligand (first such example structurally established), thus providing original results in bimetallic chemistry on the intramolecular coordination of oxygendonor functions ofchemically different hemilabile ligands firmly attached to a neighboring metal center. The structures of the trinuclear complex (3), of the chlorobenzene solvate of the tetranuclear complex (4a·C₆H₅Cl) and of [mer-(OC)₃{(EtO)₃Si} (4e) have been determined by X-ray diffraction. Crystals of 3 are orthorhombic, space groupPbcn, witha=19.010(4),b=11.766(5),c=26.998(7)Å, andZ=4. Crystals of4a·C₆H₅Cl are monoclinic, space groupC2/c witha=22.455(3),b=17.680(2),c=16.627(4)Å, =90.80(4)°, andZ=4. Crystals of4e are monoclinic, space groupC2/c witha=25.392(5),b=18.554(6),c=16.28(1)Å, =120.73(3)°, andZ=4. The structures were solved using direct methods and Fourier difference techniques and refined by blocked full-matrix least squares toR=0.035 (R _w =0.049) for 2719 observed reflections, toR=0.042 (R _w =0.056) for 3082 observed reflections, and toR=0.057 (R _w =0.075) for 1850 observed reflections for3, 4a·C₆H₅Cl and4e, respectively. The Fe-Zn complexes (9a), (9b) and (9c) were prepared and characterized by spectroscopic methods.Part 21 in the Series: Complexes with Functional Phosphines. Part 20: P. Braunstein, S. Coco Cea, A. DeCian, and J. Fischer (1992).Inorg. Chem. 31, 4203.     

Synthesis ofN,N′-ditosyl-8, 19-dimethoxy-2,5-diaza-[6.1]-naphthyl-cyclophane: crystal and molecular structure of its 1∶1 chloroform solvate

The title compound, C₄₁H₄₀N₂O₆S₂, has been synthesised in good yield and was found to form a 11 inclusion compound with CHCl₃ and other organic solvents. The crystal and molecular structure of the CHCl₃ solvate has been determined by single crystal X-ray analysis and refined to anR-value of 0.034 for 3229 reflections. The compound is monoclinic, space groupP2₁/c, witha=15.316(1),b=14.515(1),c=18.720(3) Å, =101.98(1)^o, andZ=4. One molecule of chloroform is included in the crystal lattice. Supplementary data relevant to this article have been deposited with the British Library as Supplementary Publication No. SUP 82146 (9 pp.).     

Hydrothermal chemistry of Th(IV) with aromatic dicarboxylates: New framework compounds and in situ ligand syntheses

A novel thorium (IV) coordination polymer, Th(C₅H₂N₂O₄)₂(H₂O)₂ (1), has been prepared under the hydrothermal reaction of thorium nitrate tetrahydrate and 3,5-pyrazoledicarboxylic acid (H₃pdc). Compound 1 (orthorhombic, P2₁2₁2₁, a=6.9362(5) Å, b=10.7806(8) Å, c=17.9915(14) Å, Z=2, R₁=0.0210, wR₂=0.0470) consists of thorium metal centers connected via H₃pdc linkages to form an overall three-dimensional structure containing π-π interactions between the pyrazole rings. 2,3-Pyrazinedicarboxylic acid (H₂pzdc) was explored as well to (1) study the effect of the location of the carboxylic groups around the aromatic ring and (2) produce heterometallic compounds. Thorium (IV) and copper (II) were combined with H₂pzdc, resulting in an interesting decomposition reaction characterized though the isolation of Th(C₂O₄)₂(H₂O)₂·2H₂O (2) (monoclinic, C2/c, a=13.8507(12) Å, b=7.8719(7) Å, c=10.7961(16) Å, β=118.0310(10)°, Z=2, R₁=0.0160, wR₂=0.0349), Cu(C₆H₂N₂O₄) (3) (monoclinic, C2/c, a=11.499(3) Å, b=7.502(2) Å, c=7.402(2) Å, β=93.892(5)°, Z=4, R₁=0.0472, wR₂=0.0745) and Cu(C₅H₃N₂O₂)(NO₃)(H₂O) (4). The capture of these species provides mechanistic evidence for the formation of the oxalate anions observed in 2 via the decarboxylation of H₂pzdc to yield the linker in 4: 2-pyrazinecarboxylate anions.     

Syntheses, structures, characterizations and charge-density matching of novel amino-templated uranyl selenates

Five hybrid organic-inorganic uranyl selenates have been synthesized, characterized and their structures have been determined. The structure of (C₂H₈N)₂[(UO₂)₂(SeO₄)₃(H₂O)] (EthylAUSe) is monoclinic, P2₁, a=8.290(1), b=12.349(2), c=11.038(2) Å, β=104.439(4)°, V=1094.3(3) Å³, Z=2, R₁=0.0425. The structure of (C₇H₁₀N)₂[(UO₂)(SeO₄)₂(H₂O)]H₂O (BenzylAUSe) is orthorhombic, Pna2₁, a=24.221(2), b=11.917(1), c=7.4528(7) Å, V=2151.1(3) Å³, Z=4, R₁=0.0307. The structure of (C₂H₁₀N₂)[(UO₂)(SeO₄)₂(H₂O)](H₂O)₂ (EDAUSe) is monoclinic, P2₁/c, a=11.677(2), b=7.908(1), c=15.698(2) Å, β=98.813(3)°, V=1432.4(3) Å³, Z=4, R₁=0.0371. The structure of (C₆H₂₂N₄)[(UO₂)(SeO₄)₂(H₂O)](H₂O) (TETAUSe) is monoclinic, P2₁/n, a=13.002(2), b=7.962(1), c=14.754(2) Å, β=114.077(2)°, V=1394.5(3) Å³, Z=4, R₁=0.0323. The structure of (C₆H₂₁N₄)[(UO₂)(SeO₄)₂(HSeO₄)] (TAEAUSe) is monoclinic, P2₁/m, a=9.2218(6), b=12.2768(9), c=9.4464(7) Å, β=116.1650(10)°, V=959.88(12) Å³, Z=2, R₁=0.0322. The inorganic structural units in these compounds are composed of uranyl pentagonal bipyramids and selenate tetrahedra. In each case, tetrahedra link bipyramids through vertex-sharing, resulting in chain or sheet topologies. The charge-density matching principle is discussed relative to the orientations of the organic molecules between the inorganic structural units.     

Reactions of 2H-3,4-dihydro-1,4-benzoxazin-6(8aH)-ones with 2,4,6-trimethylbenzonitrile oxide,III

Summary Regio-, stereo- and siteselectivity of the cycloadditions of trimethylbenzonitrile oxide with 2H-3,4-Dihydro-1,4-benzoxazin-6(8aH)-ones have been investigated. The structures of the obtained products were elucidated by means of homonuclear NOE difference spectroscopy and HMQC and HMBC spectra. The structure of 6-Benzyl-9a-methoxy-3-mesityl-9b-methyl-7,8,9a,9b-tetrahydro-3aH-1,2-oxazolo-[4,5-h]1,4-benzoxazin-4(6H)-on5 was elucidated from a single crystal X-ray structure analysis at ambient temperature: C₂₇H₃₀N₂O₄, M=446.55g/mol, monoclinic, P2₁/c,a=10.372 (34) Å,b=11.908 (21) Å,c=20.040 (34) Å, =97.16 (17)°,V=2455.8 (1.9)ų,Z=4,d _c=1.208g/cm³, =0.08mm^–1,R=0.0546.Dedicated to Prof. Ott with best wishes for his 70^th birthday