Two acetylamino derivatives of 2,4-bis(trichloromethyl)-1,3-benzdioxin showing different types of hydrogen bonding: (a) (C13C)CH⋯O=C and (b) N-H⋯O=C

8-Acetylamino-6-methyl-2,4-bis(trichloromethyl)-1,3-benzdioxin, (I), is monoclinic,P2₁/c,a=15.174(4),b=11.977(7),c=9.911(3)Å,=99.72(2)°. 6-Acetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin, (II), is monoclinic,P2₁/_n,a=5.927(4),b=40.623(1),c =7.120(3)Å,=91.39(4)°. In compound (I) the imino hydrogen atom is locked in an intramolecular hydrogen bond to the proximate oxygen atom of the heterocyclic ring and is not available for intermolecular hydrogen bonding. Instead the weakly acidic hydrogen atom [Cl₃C-C(2)]H takes part in a hydrogen bond to the carbonyl oxygen atom in another molecule. In compound (II) a normal intermolecular hydrogen bond of the type N-HO=C occurs. The 6-acetylam-ino group is twisted about the (C_Ar-N) bond such that the angles NHO=C, C_ArH_ArO=C, NHOH_ArC_Ar, at the carbonyl oxygen group total 360° (where NH is in the related molecule). The packing in both compounds takes the form of infinite chains and in compound (II) partial overlap of the aromatic ring and the acetylamino group, with very little offset, also occurs.     

Crystal structures of five policyclic compounds related to the natural product forskolin

(3(Z),4,6a,9a,9b)-(±)-3a,4,6a,7,8,9,9a,9b-octahydro-4,7,7, 9b-tetramethyl-3a-[3-(methoxymethyloxy)-3-methyl-1-butenyl]-5H-naphto[1,8-de]-1,3-dioxin-6-one (I), C₂₂H₃₆O₅,M _r=378.51, monoclinic,P2₁/n,a=6.330(1),b=14.576(2),c=22.837(2)Å,=93.04(1)°,V=2104.1(2)ų,Z=4,D _c=1.19 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=832,T=298 K,R=0.054 for 1971 observed reflections; (7a,10a,10b,12)-(±)-7a,9, 10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6,-de][1,3,2]-benzodioxin-11-one (II), C₂₀H₂₉O₄,M _r=334.5, triclinic,P-1,a=10.595(2),b=12.152(1),c=8.073(1)Å,=106.53(1),=105.65(1), =66.29(1)°,V=897.9(2)ų,Z=2,D _c=1.24 Mg/m³, (MoK)=0.71069Å,=0.8 cm^–1,F(000)=362,T=298 K,R=0.046 for 2848 observed reflections; (7a,10a,10b,12, 12a)-(±)-7a,9,10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6-de][1,3,2]-benzodioxin-11, 12-diol (III), C₂₀H₃₂O₅ (two molecules in the asymmetric unit),M _r=352.2, triclinic,P-1,a=12.948(3),b=13.615(3),c=12.197(4)Å,=101.16(2),=111.88(2), =69.48(2)°,V=1863.8(9)ų,Z=2,D _C=1.26 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=768,T=298 K,R=0.060 for 4570 observed reflections; 4-acetoxy-4-[[(4a,5,8a)-(±)-hexahydro-4a,6,6-trimethyl-4H-1,3-benzodioxin-4-one]-5-yl]butan-2-one (IV), C₁₇H₂₆O₆,M _r=326.4, monoclinic,P2₁/c,a=10.495(2),b=12.050(2),c=14.216(2)Å,=108.51(1)°,V=1704.8(5)ų,Z=4,D _c=1.27 Mg/m³,(MoK)=0.71069 Å,=0.9 cm^–1,F(000)=704,T=298 K,R=0.049 for2455 observed reflections; (3a,4,5,6,6a,9a,9b)-(±)-4,5-epoxy-decahydro-3, 3a-dihydroxy-2-ethoxy-4,7,7,9b-tetramethyl-naphto-[1,8-bc]-pyran-6-ol-acetate (V), C₂₀H₃₂O₇,M _r=383.5, monoclinic,C2/c,a=10.353(2),b=17.975(3),c=21.188(3)Å,=91.29(1)°,V=3942(1)ų,Z=8,D _c=1.29 Mg/m³,(MoK)=0.71069 Å,=0.8 cm^–1,F(000)=1664,T=298 K,R=0.051 for 2120 observed reflections. We report here the complete structures of four decalin derivatives (compoundsI, II, III, V) and one related compound (compoundIV) synthetized in order to find an efficient synthetic approach for the natural productforskolin.     

Structural characterization and photophysical properties of a luminescent trinuclear zinc(II) complex exhibiting multiple coordination geometries

A luminescent trinuclear zinc(II) complex, tris(-2,3-toluenedithiolato)-1:2²S¹;1:2²S¹, 2:3²S²;3S², 1:3²S³;3S³-bis(2,2-bypyridine)-1²N,N,2²N,N-trizinc, containing 3,4-dimercaptotoluene (tdt) and 2,2-bipyridine (bpy) has been synthesized and found to have the trinuclear formulation Zn₃(tdt)₃(bpy)₂ (I). The complex crystallizes in the monoclinic space group P2₁/n with a = 11.7247(12), b = 20.134(2), c = 17.7376(18) Å and = 103.743(2). The complex has two heteroleptic zinc(II) centers exhibiting similar distorted trigonal bipyramidal geometries with the third homoleptic zinc(II) center displaying a flattened tetrahedral geometry. Present in the solid state are both intra- and intermolecular – interactions. The complex is emissive at 77 K in the solid state with an emission maximum at 574± 2 nm with a luminescence lifetime of 7.4± 0.4 ns. The unstructured emission is assigned as a metal-mediated ligand-to-ligand –^* charge transfer transition.     

C−Cl...π(Ar)...Cl−C,Cl...Cl and other interactions in the structures of two 6-substituted-2,4-bis(trichloromethyl)-1,3-benzdioxin's: (I) 6-carboxymethyl; (II) 6-propionyl,an antimethanogenesis food additive

C₁₂H₃Cl₆O₄, (I),M _r=428.91, triclinic, ,a=9.197(1),b=9.336(2),c=9.830(1) Å, =79.29(1), =83.33(1), =85.38(1)°,V=822.16,Z=2,D _x=1.73 Mg m^–3,F(000)=428, (MoK)=0.71069 Å, =10.62 cm^–1, room temperature, finalR=0.033 for 2573 unique counter reflections withF _o>4(F _o). C₁₃H₁₀Cl₆O₃, (II),M _r=426.94, triclinic, ,a=9.374(2),b=9.503(1),c=9.888(4) Å, =79.26(2), =82.10(3), =84.43(1)°,V=854.88,Z=2,D _c=1.66 Mg m^–3,F(000)=428, =0.71069 Å, =10.17 cm^–1, room temperature, finalR=0.030 for 2609 unique counter reflections withF _o>4(F _o). Compounds I and II are isostructural. Centrosymmetric dimers are formed by hydrogen bonds from the two methine hydrogen atoms to the carbonyl oxygen atom. The dimers are linked by Cl...(Ar)...Cl, Cl...O and Cl...Cl interactions to form a three-dimensional pattern. The geometry associated with these interactions is discussed in terms of the electrophile: nucleophile model.     

Distortions in nitramine substituted cubanes: The structures of N,N′-dinitro-1,4-diaminocubane,N,N′-dinitro-N,N′-(2-pyridyl)-1,4-diaminocubane,and 1,2,4,7-tetrakis(N-methoxycarbonylnitramino)cubane

The structures of three nitramine substituted cubane molecules, N,N-dinitro-1,4-diaminocubane (1), N,N-dinitro-N,N-(2-pyridyl)-1,4-diaminocubane (2), and 1,2,4,7-Tetrakis(N-methoxycarbonylnitramino)-cubane (3), have been determined.1 crystallized in the space group P2₁/a with cell dimensionsa=6.545(1),b=9.331(1),c=7.459(1) Å, =105.80(1),2 crystallized in the monoclinic space group P2₁/a with cell dimensionsa=7.545(2),b=8.697(3),c=12.406(4 Å, =96.28(3)°, while3 crystallized in the monoclinic space group P2₁/c with cell dimensionsa=10.866(3),b=6.866(2),c=16.167(6) Å, =108.79(3)°. The metrical parameters of the cubane skeleton showed no significant deviations from those found in other similarly substituted cubane molecules. For2 and3 there were considerable distortions of the nitramine moiety from planarity in contrast to1 where the nitramine moiety was almost exactly planar. The bond distances and angles for the nitramine group in1 indicates a substantial introduction of double bond character into the N–N bond in1, achieved by delocalization of the amine lone pair, compared with2 and3.     

Structure of bis(2-pyridine-N-oxide) diselenide and its formation from tetraphenylantimony(V)selenopyridine-N-oxide

The structure of bis(2-pyridine-N-oxide) diselenide was determined by single crystal X-ray diffraction. The compound crystallized in the triclinic system and the structure was solved in the space group . The lattice constants were determined to bea=7.174(2),b=7.176(2),c=11.070(2) , =87.67(2)°, =73.68(2)°, and =89.57(2)°;Z=2,D _x=1.906 Mg m^–3. The final least squares refinement based on 1942 independent observed reflections yieldedR=0.033,wR=0.044. The Se–Se bond length is 2.326(1) and each Se is coordinated to the O atom of the corresponding N-oxide moiety at a distance of about 2.6 .     

Crystal and molecular structures of 1-(2-carboxypropan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol (1) (C17H21NO4) and 1-(2-carbamoyl propan-2-ylamino)-3-(1-naphthyloxy) propan-2-ol (2) (C17H22N2O3)

The crystal structures of two new-adrenergic antagonists, derivatives of propranolol containing 2-methylalanine fragment are described in this paper. The space groups and unit-cell parameters are: compound1 (C₁₇H₂₁NO₄): monoclinic, space groupP2₁/n,a=5.787(1),b=18.703(4),c=23.526(5)Å,=96.49(2)°; compound2 (C₁₇H₂₂N₂O₃): triclinic, space groupP¯1,a=8.321(1),b=10.121(1),c=10.368(1)Å,=109.49(1)°,=90.49(1)°, =103.48(1)°. The structures were solved by direct methods and refined with full matrix least-squares techniques toR indices of 0.055 and 0.049, respectively. The molecules of compound1 exist in the crystal as dual ions. The molecules of compound2 are compact and their external chain is twisted in a characteristic way (similar to that found in peptides).     

Crystal and molecular structure of [Rh(μ-SBut)(CO)(PPh3)]2

Reaction of [Rh(CO)₂Cl]₂ with Bu ^t SLi followed by refluxing with PPh₃ yields [Rh(-SBu ^t )(CO)(PPh₃)]₂(1). The structure of (1) has been determined by X-ray crystallography. Empirical formula: Rh₂P₂S₂C₄₆H₄₈O₂,M=964.78, triclinic, P¯1,a=11.408(9),b=13.241(8),c=15.830(3) Å,=93.67(3),=93.12(5),=110.8(6)°,Z=2,D _calc=1.44 g cm^–3,R=0.048 (R _w =0.062) for 5939 observed reflections. In the solid state, the compound exhibitscis geometry with respect to the phosphine and CO ligands. The geometry about the two metals is essentially square planar, with a dihedral angle of 103.2°, and a butterfly angle of 102.3°. Compound (1) is stereochemically rigid on the NMR time scale from –80 to +80°C.     

Crystal structure of a second modification of the mercury oxychloride Hg3O2Cl2

The crystal structure of a monoclinic mercury oxychloride of composition Hg₃ O₂ Cl₂ has been described. A crystallographically different mercury oxychloride of the same composition was reported. The crystal structure of this second modification, called the -form, has been established through a single-crystal x-ray diffraction study. The -form is also monoclinic, with space groupP2₁/c andZ = 8. The unit-cell at 25 ° C hasa = 10.826(5),b = 9.310(4),c = 11.5 15(5) Å and = 71.04(8) °. The density is calculated to be 8.53 g cm^–3, that observed by displacement being 8.53(2) g cm^–3. Diffraction data were obtained using the -2 scanning mode on a Picker four-circle automatic diffractometer with CuK radiation. This apparently unsuitable radiation was chosen in order to test rigorously an absorption correction procedure. The structure was refined toR ₁ = 4.0% through conventional least-squares reduction basedF. The structure of -Hg₃ O₂ Cl₂ is found to be markedly different from that of the earlier-determined -Hg₃O₂Cl₂; distorted Hg₄O tetrahedra are linked into a three-dimensional array, terminated at four locations within the cell by covalent Hg-Cl bonds.     

Structures of 8α-(2′-methylbutyryloxy)-9α-hydroxymontahibisciolide,a new skeletal type of sesquiterpene lactone,and of its precursor 8α-isobutyryloxy-9-oxo-germacra-4E, 1(10)Z-dien-6β,12-olide

The structures of a new skeletal type of sesquiterpene lactone, containing a seven, five, fivering system, and of its putative precursor, a 9-oxo-melampolide, have been confirmed by single crystal X-ray structure determination. The central 5-membered ring of the new skeleton istrans-fused to the cycloheptene ring andcis-fused to the lactone ring. Transannular interactions and the geometry of thetrans carbon-carbon double bond of the oxo-melampolide and the keto-group at C9, suggest that the new seven, five, five tricyclic skeleton-type of montahibisciolide can easily be reached by a transannular cyclization process. The isobutyrloxy group of the oxo-melampolide is disordered into two partially populated conformations. 8-(2-Methylbutyryloxy)-9-hydroxymontahibisciolide,3, C₂₀H₂₈O₅, crystallizes in orthorhombic space groupP2₁2₁2₁ witha=8.294(2),b=9.740(2),c=22.675(1) Å,V=1832(1)ų,Z=4. The structure was refined toR=0.043 andR _w=0.048 for 2898 observed reflections with CuK radiation. 8-isobutyryloxy-9-oxo-germacra-4E, 1(10)Z-dien-6, 12-olide,4, C₁₉H₂₄O₅, crystallizes in monoclinic space groupC2 witha=32.879(7),b=5.793(2),c=9.884(4)Å, =99.01(3)°,V=1859.5(9)å³,Z=4. The structure was refined toR=0.054 andR _w=0.064 for 1010 observed reflections with MoK radiation.     

Pentacoordinated tin(II); crystal structure of dichloro-[2,2′∶6′,2″-terpyridyl]-tin(II)

The crystal structure of a well-defined 5-coordinate complex, dichloro-(2,26, 2-terpyridyl)-tin(II), is described. The stereochemistry of this complex is strongly influenced by the stereochemically active pair of electrons, illustrating clearly the potential donor capabilities of this molecule. The complex (C₁₅H₁₁Cl₂N₃Sn) crystallizes in the monoclinic space groupC2/c (No. 15) witha=15.770(5),b=9.450(2),c=10.482(2) Å,=97.53(2)°,Z=4. The finalR value is 0.029 for 1085 observed reflections.     

Synthesis,structure and fluorescent property of a novel inorganic–organic zinc compound

Single crystals of a symmetrically substituted molecule, [Zn(C₃N₆H₆)(H₂O)_0.5Cl₂] (C₃N₆H₆)(H₂O)(1), have been obtained. The crystal structure of 1 shows the existence of novel layered type supramolecular structure constructed by dumbbell-shape coordinated Zn moleculeand one 2,4,6-triamine-s-triazine ligand. Crystallographic data for 1: monoclinic system, space group: C2/c, a = 12.2532(9), b = 13.8606(10), c = 18.3603(13) Å, = 99.7860(10), V = 3072.9(4) ų and Z = 8, D_c = 1.758 Mg/m³, R₁ = 0.0518. The fluorescent property of 1 has also been studied. The luminescent property of 1 attributable to both ligand ^* transitions and electronic transfer of Zn^II O transitions.     

The molecular structure of dibutylbis(2-pyridinethiolato-5-ethyl ester)tin(IV), [SnBu2(TNEE)2]

The crystal structure of [SnBu₂(TNEE)₂], (HTNEE=5-ethyl ester of 2-mercaptopyridine-5-carboxylic acid) has been determined by X-ray single crystal diffraction study. The crystal is triclinic, space groupP,a=10.042(1),b=18.421(2),c=7.979(1) Å, =98.7(1), =107.3(1), =87.7(1)^o,V=1393(1) ų, and Z=2 The tin center is coordinated to two butyl groups and to the nitrogen and the sulfur atoms of two ligand molecules in a very distorted trapezoidal bipyramid.     

Synthesis and structural characterization of 2,6-bis-(N-methylenemorpholino)-4-ter-butylphenol

The crystal and molecular structure of the title compound, C₂₀H₃₂N₂O₃, has been determined from X-ray diffraction data using CuK radiation (=1.5418 Å). The compound crystallizes in triclinic space groupP1^¯ with a=8.828(1),b=18.680(1),c=6.272(2)Å, =93.42(1), =0.24(2), =77.93(1)°,V=1009.4(2)ų, andZ=2. The structure was solved by direct methods and the full-matrix least-squares refinement leads the finalR-factor to 0.065 for 3481 observed reflections withI3(I). The phenyl ring is planar and the morpholino rings assume perfect chair conformation. The molecules are held together by van der Waals forces.DCB Contribution No. 810.     

Trimethylamine-N-oxide induced disproportionation of Re2(CO)10: Synthesis and X-ray crystal structure of [fac-Re(CO)3(ONMe3)3] [ReO4]

An attempted synthesis of [Re(CO₃) (-OH)]₄,1, by reacting Re₂(CO)₁₀ with an excess of NMe₃O in THF resulted instead in isolation of a disproportionation product, [fac-Re(CO)₃(ONMe₃)₃][ReO₄],2. The structure of2 was determined via X-ray crystallography: tri-clinic,P1^¯,a=9.499(5),b=9.841(2),c=13.448(2)Å,=109.92(2),=106.89(3), =93.15(4)°,D _calc=2.22 g^–3 andZ=2. Least-squares refinement based on 1606 observed (I>3(I)) reflections gave final values ofR=0.040 andR _w=0.047. The cation is a distorted octahedron that exhibits several structural manifestations of steric crowding among the bulky NMe₃O ligands.     

Crystal structure oftrans-tetrachlorobis[2-(2-1H-imidazolyl)-1H-imidazolium]cadmium(II), [Cd(H3biim)2Cl4]

The reaction between cadmium(II) chloride and 2,2'-bi-1H-imidazole (H₂biim) in an acidic solution affords [Cd(H₃biim)₂Cl₄] (H₃biim=2-(2-1H-imidazolyl)-1H-imidazolium) in 63% yield. The compound crystallizes in the triclinic space groupP1, wherea=8.072(2),b=8.100(2),c=8.593(2) Å, =75.89(2), =62.94(2), =63.29(1)°,V=446.4(2) ų, andZ=1. The central Cd atom exhibits an octahedral geometry composed of a Cl₄N₂ core. The Cd-N bond distance is 2.392(2) Å. Cd–Cl distances are 2.5919(9) and 2.671(1) Å.     

Structure oftrans-dichlorooxobis(triphenylphosphine)rhenium(V), ReCl2O(OEt)(Ph3P)2

C₃₈H₃₅Cl₂O₂P₂Re,M _r=842, triclinic,P¯1,a=17.71(2),b=11.33(1),c=9.82(1) Å,=114.60(3),=90.84(3), =78.05(3),V=1747(2) ų,D _m(flotation)=1.60,D _x=1.60 Mg m^–3 forZ=2, MoK, =0.7107 Å,=41.6 cm^–1,F(000)=836, room temperature. The structure was solved by standard methods from diffractometer data and refined to a conventionalR of 3.4% for 5412 observed reflections. The Re atom is six coordinate octahedral withtrans-Cl atoms andtrans-Ph₃P groups. Relevant bond distances are: Re-P 2.533(1) and 2.535(1) Å, Re-O(ethoxo) 1.888(4) Å, and Re-O(oxide) 1.699(4) Å. The ethyl chain is partially disordered.     

Stable crystalline adducts of 1,6-bis(o-hydroxyanilino)-1,5-hexadiene-3,4-dione withN,N-dimethyl carboxamides and urea derivatives

The red colored and poorly soluble 1,6-bis(o-hydroxyanilino)-1,5-hexadiene-3,4-dione (3f) forms stable adducts5 and7 of exact stoichiometric ratios withN,N-dimethyl carboxamides4 and ureas6. The adducts are yellow colored and easily soluble in organic solvents. The crystal structure of3f (monoclinic space groupP2 ₁/c witha=7.903(2),b=10.941(2),c=8.976(3) Å, =90.13(2)°) indicates planarity with extensive delocalization of the -electrons. The poor solubility is referred to the formation of strong intermolecular hydrogen bonds (H(O)...O3 andH(O)...O3=1.79 Å). The crystal structure of the 12 DMF adduct5a (monoclinic space groupP2 ₁/c witha=6.068(1),b=19.668(2),c=10.645(1) Å, =107.791(8)°) shows a less pronounced delocalization of the -electrons which might be the explanation for the color change from red to yellow. In5a the intermolecular hydrogen bonds of3f are interrupted by forming new hydrogen bonds from the hydroxyl group to the carbonyl group of DMF (H(O)...O(L) andH(O)...O(L)=1.86 Å), whereby the solubility is markedly changed. The thermal stability of the addition products5 and7 was determined by thermogravimetry.     

The synthesis and structure of 1,2,3,4-tetrahydro-2,4,4-trimethyl-8-nitroimidazo[1,5-d] [1,2,4]triazin-1-one,C8H11N5O3: A heterocycle with a rare ring system

The title compound (IV) was isolated as a by-product during the course of purification of 4-nitroimidazol-5-(N-methyl)hydrazide (II) by silica gel flash chromatography, employing chloroform-acetone (4:1) as the eluting solvent. The crystals are monoclinic, space groupP2₁/c,a=7.425(1),b=13.615(2),c=10.359(2) Å,=97.66(1)°,d _caled=1.44 g cm^–3, (MoK)=1.06 mm^–1,T=298 K. The number of unique reflections=2401, reflections withI3 (I)=1773;R=0.051,R _w =0.061. The bond distances inIV are: N-N, 1.419(3); N-C(=0), 1.359(3); N(H)-C(CH₃), 1.457(3); N(C)-C(CH₃), 1.501(3); N=C, 1.316(3); C=C, 1.368(3), N-C(=N), 1.353(3); N-C(=C), 1.367(2) Å.     

Novel manganese(III) oxidation chemistry: X-ray crystal structures of (1α,2α,4β)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-1,2,3,4-tetrahydronaphthalene (compound A) and (1α,2α,4β)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-1,2,3,4-tetrahydronaphthalene (compound B)

CompoundA is (1,2,4)-1,2-diacetoxy-4-(4-methoxyphenyl)-6-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, monoclinic, P2₁/n, witha=11.074(3),b=10.353(4),c=17.616(4)Å,=94.96(2)°,V=2012.1ų,D _calc=1.27 g cm^–3 and=0.55 cm^–1 forZ=4. Least-squares refinement of 1371 observed [F ₀5 (F ⁰)] reflections led to the final agreement index ofR=0.052. A twofold disorder was observed for the 1-acetoxy group whereas the 2-acetoxy group was ordered. CompoundB, (1,2,4)-1,2-diacetoxy-4-(2-methoxyphenyl)-8-methoxy-l,2,3,4-tetrahydronaphthalene, C₂₂H₂₄O₆,M _r=384.43, crystallizes in the monoclinic space group, P2₁/c, witha=16.209(2),b=10.076(1),c=13.357(4)Å,=111.41(2)°,V=2030.9ų,D _calc=1.26 g cm^–3 and=0.54 cm^–1 forZ=4. A final agreement index ofR=0.045 was realized by least-squares refinement of 1486 observed [F _o5 (F _o)] reflections. Intermolecular interactions in the cell lattices of compoundsA andB are noted. The title compoundsA andB were prepared by manganese(III) acetate oxidative dimerization of two molecules of 4-methoxystyrene and 2-methoxystyrene, respectively.