Crystal structures of two modifications oftrans-1,3-bis(3,4-dimethoxyphenyl)-2,3-epoxy-1-propanone

trans-1,3-Bis(3,4-dimethoxyphenyl)-2,3-epoxy-1-propanone exhibits dimorphism and crystallizes in a monoclinic form from ethanol and in a trigonal form from chloroform/hexane. The crystal structures of the two modifications were determined by single-crystal X-ray diffraction methods. The monoclinic form crystallizes in space groupP2_t/c with ,b=7.986(1),c=25.223(4) , =94.83(2)°,V=1747.9(6) andZ=4.R=0.052 for 1236 reflections [I>3(I)]. The trigonal form crystallizes in space group witha=36.048(6),c=8.313(5) ,V=9355(6) andZ=18 (hexagonal axes).R=0.101 for 1216 reflections [I>3(I)]. In the trigonal crystals there are channels in thec-direction with a diameter of approximately 10 . Possible explanations for the comparatively highR-value are discussed.     

Crystal structure of 14, α-hydroxy,sandarocopimar-7, 15-diene-19-oic acid

C₂₀H₃₀O₃, M _r =318.46, Monoclinic,P2₁,a=12.232(2) ,b=11.491(2) ,c=14.160(3) , =115.2°(3),V=1800.3(7) ³,Z=4,D _x =1.18 Mg m^–3, (CuK)=1.5418 , =5.3 cm^–1,F(000)=696,T=298 K. FinalR=0.044 for 2645 reflections withI>2. The two crystallographically independent molecules in the unit cell adopt essentially similar conformations. The structure reveals atrans relationship between the hydrogen at C(9) and the methyl group at C(20). The stereochemistry at C(13) is S. Apart from van der Waals forces the structure is stabilized by hydrogen bonds.     

Synthesis and characterization of ternary L-histidine complexes. Crystal structure of (2,2′-dipyridyl)-(L-histidinato-N,N′,O)copper(II) perchlorate 1.5 hydrate

A series of ternary complexes of copper(II), cobalt(II) and zinc(II) with L-histidine, 1,10-phenanthroline, 2,2-dipyridyl or imidazole having perchlorate or acetate as counterions were synthesized and characterized by conventional methods and for [Cu(bipy)(L-hist)]ClO₄·1.5H₂O and X-ray crystal structure was determined. The crystals belong to the monoclinic space groupC2 witha=18.843(3),b=10.582(2),c=11.020(2), =115.20(10)°,Z=4,R=0.0535. The structure is consistent of [Cu(bipy)(L-hist)]⁺ cations, perchlorate ions and water molecules. The geometry around copper is trigonal bipyramidal with one N,N,O tridentate L-histidine molecule and one 2,2-dipyridyl ligand, the apical sites are occupied by the -amino nitrogen [Cu–N(71) 1.995(8)] and by N(11) of 2,2-dipyridyl [Cu–N(11) 1.983(7)], the equatorial plane is formed by the N(3) imidazole -nitrogen [Cu–N(3) 2.140(6)], O(82) carboxylic oxygen [Cu–O(82) 2.009(5)] and N(22) [Cu–N(22) 2.010(7)].     

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 .     

Reaction of trimethylaluminum and trimethylgallium with bifunctional amines: Syntheses and molecular structures of [Me2Al−N(CH2CH2)2−C−(OCH2)2]2 and [Me2Ga−N(Si(H)Me2)2]2

The crystalline products [Me₂Al–N(CH₂CH₂)₂–C–(OCH₂)₂]₂ (I) and [Me₂Ga–N(Si(H)Me₂)₂]₂ (II) were prepared from reactions of trimethylaluminum and trimethylgallium with 1,4-dioxa-8-azaspiro[4.5]-decane and 1,1,3,3-tetramethyldisilazane, respectively, in toluene. The organoaluminum dimer crystallizes in the monoclinic space groupP2₁/c with unit cell parametersa=8.970(2) ,b=9.683(2) ,c=12.833(3) , =103.18(2)°,V=1085.3(3) ³, andD _calcd=1.22 g cm^–3 forZ=2. Least-squares refinement based on 935 observed reflectionsI>3(I) in the range 3.5°<2<45.0° led to a finalR factor of 0.033 (R _w =0.041). The dimeric organosilazagallium crystallizes in the triclinic space group with unit cell parametersa=7.636(2) ,b=9.168(2) ,c=9.466(3), =72.81(2)°, =87.94(2)°, =69.90(2)°,V=593.0(3) ³, andD _calcd=1.30 g cm^–3 forZ=1. Least-squares refinement based on 1661 observed reflectionsI>3(I) in the range 3.5°<2<48.0° led to a finalR factor of 0.055 (R _w =0.070). Both compoundsI andII reside about a crystallographic center of symmetry and contain a planar M₂N₂ (M=Al forI, Ga forII) four-membered ring withI having an Al...Al contact of 2.801 .     

Synthesis and structural characterization of 2,6-bis-(N-methylenemorpholino)-4-methylphenol (MMP) and 2,6-bis-(N-methylenemorpholino)-4-bromophenol (MBrP)

MMP: C₁₇H₂₆N₂O₃,M _r =306.40, monoclinic, space groupP2₁/c,a=10.927(2),b=10.777(2),c=14.197(2) , =94.04(2)°,V=1667.7(5) ³,D _cal=1.22 Mgm^–3,Z=4,F(000)=664, =5.93 cm^–1,T=293K. FinalR=0.049 andwR=0.063 for 2724 observed reflections. MBrP; C₁₆H₂₃N₂O₃Br,M _r =371.27, monoclinic, space groupP2₁/c,a=10.955(1),b=10.785(1),c=14.213(1) , =94.54(2)°,V=1674.0(4) ³,D _cal=1.48 Mgm^–3,Z=4,F(000)=768, =32.35 cm^–1,T=293K. FinalR=0.055 andwR=0.069 for 2886 observed reflections. MMP and MBrP are isostructural and in both the molecules the morpholino rings assume a chair conformation.DCB Contribution No. 824.     

Crystal structures of [(η5-C5H4COOH)W(CO)3R] (R=Me,I)

The crystal structures of [(₅-C₅H₄COOH)W(CO)₃R] (R=Me, I) have been determined. They crystallize in two different monoclinic space groups. R=Me isP2₁/c,a=10.4833(6),b=8.0144(7),c=13.0731(6) , =93.147(4)°, andD(calc)=2.374 g-cm^–3 forZ=4. R=I isP2₁/n,a=7.814(2),b=13.075(4),c=11.097(4) , =91.75(2)°, andD(calc)=2.953 g-cm^–3 forZ=4. Both possess a four-legged piano stool geometry. The methyl ligand in the R=Me complex is disordered between two positions insyn oranti relative to the substituted carbon of the cyclopentadienyl ligand. The iodo ligand in the R=I complex is, however, exclusively insyn-position.     

Crystal structure of cesium sodium hexathiocyanatobismuthate Cs2Na[Bi(SCN)6] and characterization of Cs2Na[Bi(SCN)6−x Cl x ] and Cs2Na[Bi2(SCN)9−x Cl x ] complexes by X-ray powder diffraction

Cs₂Na[Bi(SCN)₆] crystallizes in the trigonal space group with one formal molecule per unit cell.M=846.25,a=7.189(1),c=10.580(2) ,V=473.5(1) ,D _x =2.967 g cm^–3, (MoK)=13.70 mm^–1,F(000)=378. FinalR=0.029 for 917 absorption-corrected reflections. The structure consists of infinite[Bi(SCN)₆Na] ^2– anionic chains along thec axis with slightly distorted octahedral Bi–6S and Na–6N coordination and Cs⁺ ions surrounded by three anionic chains with irregular coordination by six N and three S atoms. X-ray powder diffractograms of three complexes, Cs₂Na[Bi(SCN)_6–x Cl _x ] withx=2, 3 and 4, indicate that the mixed complexes are not isostructural and can be indexed in different orthorombic unit cells witha=14.617(8),b=12.32(1),c=10.769(6) forx=2;a=15.37(1),b=10.81(1),c=10.287(6) forx=3 anda=14.662(7),b=14.366(7),c=7.932(4) forx=4. The two dinuclear complexes Cs₂Na[Bi₂(SCN)_9–x Cl _x ] withx=2 and 3, despite the large similarity of their diffractograms, are not isostructural and can be indexed in different orthorombic unit cells witha=14.79(1),b=13.72(1),c=10.591(5) forx=2 anda=18.423(8),b=15.657(7),c=7.410(7) forx=3.     

Crystal and molecular structures of tri(o-tolyl)phosphinegold(I) purine-6-thiolate ethanol solvate (1/1) and tri(c-hexyl)phosphinegold(I) 6-methyl-2-thiouracilate

The crystal and molecular structures of the title compounds, [(o-tol)₃PAu(6-MP)]·EtOH and [(c-hexyl)₃PAu(6-Me-2-TU)], have been determined and each show the presence of a linear geometry about the Au atom; both of the thionucleobases function as thiolate ligands. Important interatomic parameters for [(o-tol)₃PAu(6-MP)] are Au–S 2.266(2), Au–P 2.239(2) and S–Au–P 177.03(8)° and for [(c-hexyl)₃PAu(6-Me-2-TU)]: Au–S 2.299(3), Au–P 2.244(3) and S–Au–P 176.1(1)°. Crystals of [(o-tol)₃PAu(6-MP)]·EtOH are monoclinic with space groupP2₁/n, and unit cell dimensionsa=10.067(2),b=10.518(2),c=25.416(4) , =98.42(2)°,Z=4. The structure was refined to finalR=0.040 for 4183 data withI3.0(I). Crystals of [(c-hexyl)₃PAu(6-Me-2-TU)] are monoclinic with space groupP2₁/c, and unit cell dimensionsa=9.692(4),b=15.822(4),c=15.775(3) , =94.00(2)°,Z=4,R=0.033 for 2666 data.     

Antimony(III) fluoride: inclusion complexes with crown ethers

Four crystalline molecular complexes between antimony(III) fluoride and 18-membered crown ethers have been obtained and their structures investigated by single crystal X-ray diffraction techniques: [18-crown-6·SbF₃], C₁₂H₂₄F₃O₆Sb,P2₁2₁2₁,a=8.328(4),b=11.573(4),c=18.094(4),V=1744(1)³,Z=4; [benzo-18-crown-6·SbF₃], C₁₆H₂₄F₃O₆Sb,P2₁/n,a=10.490(2),b=13.714(1),c=13.442(2), =101.94(1)°,V=1892(1)³,Z=4; [cis-syn-cis-dicyclohexano-18-crown-6·SbF₃·CH₃OH], C₂₁H₄₀F₃O₇Sb,P2₁/n,a=8.270(4),b=23.386(3),c=12.772(1), =96.31(2)°,V=2455(1)³,Z=4; [cis-anti-cis-dicyclohexano-18-crown-6·SbF₃], C₂₀H₃₆F₃O₆Sb,Pna2₁,a=21.091(8),b=12.829(5),c=8.437(3),V=2283(2)³,Z=4. All species are the perching-type complexes with the antimony fluoride above the cavity and the metal lone pair pointed toward the center of the crown ring. The antimony atom interacts with all six crown oxygen atoms with Sb–O distances of 2.837(2)–3.344(2) . The antimony atom is displaced from the least square plane of the crown oxygen atoms at the distances of 1.288–1.383 .     

Molecular structure of [(tBu)2Al(μ-NHtBu)]2

The crystal and molecular structure of [(^tBu)₂Al(-NH^tBu)]₂ has been determined. The unit cell contains two independent molecules with only slight variation in the orientation of thetert-butyl ligands. Crystal data: Triclinic, ,a=9.0138(6),b=10.2944(8),c=15.791(1) , =91.262(6), =89.822(6), =106.141(6)°,V=1407.2(2) ų,Z=2,R=0.039,R _w=0.041.     

Crystal and molecular structure of nitrito-bis(1,3-propanediamine) nickel(II) tetraphenylborate

The title compound is orthorhombic,M _r =590.2,P2₁2₁2₁ (No. 19),a=9.865(2),b=9.924(2),c=31.202(7) Å,V=3055(2) ų,Z=4,D _x =1.283 g cm^–3, (MoK );F(000)=1256; (MoK )=6.76 cm^–1, finalR=0.052 for 1441 reflections I2.5(I). The nitrite group is chelated via the two oxygen atoms; the two six-membered rings resulting from the coordination of the 1,3-propanediamine ligands to the nickel(II) atom are in the chair conformation. The Ni-N and Ni-O distances average 2.07(1) and 2.14(2) Å respectively. The two Ni-O distances are nearly equivalent.     

Synthesis and X-ray crystal structure of three polyazamacrocycles having sulfonate pendant groups: Piperazinyl-monomethanesulfonic acid,sodium hydrogen 1,4,7-triazacyclononane-N,N′-di(methanesulfonate) and 1,4,7,10-tetraazacyclododecane-N,N′-di(methanesulfonic acid)

C₅H₁₀N₂O₃S,1, monoclinicC2/c,a=17.545(5),b=6.822(8),c=13.928(2),=108.36(7),Z=8, MoK, =0.7107 Å,=3.56cm^–1,R=0.061,R _w =0.099. C₈H₁₆N₃O₆S₂Na·2H₂O,2, orthorhombicPna2₁,a=17.964(8),b=10.157(1),c=8.263(4),Z=4, MoK, =0.7107 Å,=4.07 cm^–1,R=0.040,R _w =0.043. C₁₀H₂₀N₄O₆S₂·2H₂O,3, monoclinicP2₁/n,a=9.142(9),b=13.576(7),c=14.028(8),=94.096(8),Z=4, MoK, =0.7107 Å,=3.37 cm^–1,R=0.063,R _w =0.074. Compounds1, 2, and3 were prepared from the pH-dependent sulfomethylation of the di- and polyazamacrocycles.     

Cl⋯π(Ar), Cl⋯Cl,and other intermolecular interactions in the crystal structure of 8-nitro-6-methyl-2-trichloromethyl-4-dichloromethylene-1,3-benzodioxin

Crystals of the title compound are monoclinic,P2₁,a=9.791(4),b=7.129(3),c=10.428(3)Å,=91.84(3)°,V=727.50ų,Z=2. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by full matrix least squares to a finalR value of 0.045 using 2466 reflections. The molecules form stacks along theb axis of the formA, B, A, B(A=dichloromethylene group; B=aromatic ring in the molecule at –x, 1/2+y, –z to the molecule atx, y, z containing A). Cl(Ar),, ClCl, ClO(N), (Cl₃C)HO intermolecular interactions are also present. An inverse correlation between the (C)ClCl(C) distance and the difference in the corresponding pairs of C-ClCl angles is observed and is interpreted in terms of incipient nucleophile: electrophile attack.     

Structures of three isomeric ring-brominated PEA β-blockers: [C13H21BrNO3]+·Cl−, [C13H21BrNO3]+·[CH3SO3]−, and [C13H21BrNO3]+·[C2HO4]−

The X-ray crystal structures of three-blockers of the phenylethanolamine (PEA) class have been determined by single crystal techniques. They are (I): (±)-2-(2-bromo-3,4-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine hydrochloride; (II): (±)-2-(3-bromo-4,5-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine methylsulphonate; (III): (±)-2-(2-bromo-4,5-dimethoxyphenyl)-2-hydroxy-N-isopropylethylamine hydrogen oxalate. A conformational energy map of a partially hydrated model cation as a function of the principal torsion angles ₁ and ₂ shows the transperpendicular conformer (₁90°, ₂180°) to be the most stable. This conformation is adopted by cations of (II) and (III) in their crystals, but for (I), ₁=52.3(6)° is observed. Non-bonded pharmacophoric distances lie within the expected ranges.     

Crystal and molecular structure of (±)-1-phenyl-2-amino-1-propanol,C9H13NO

The crystal structure of (±)-phenylpropanolamine has been determined by single-crystal X-ray diffraction methods. The structure was solved by direct methods and refined by least-squares toR=0.055 andR _w=0.045 for 2000 reflections (I2 (I)). The molecule was found to adoptgauche geometry. Inter- and intramolecular N-HO and O-HN hydrogen bonds were observed in the crystal structure.     

Crystal structure of 6-nitrobenzo(a)pyrene

In 6-nitrobenzo(a)pyrene, an environmental pollutant, the nitro substituent lies at 69.5(1) to the mean plane of the aromatic moiety. The C–C bond distances range from 1.341(3) to 1.443(3) Å. The crystal is in the monoclinic space group, P2₁/c, with a = 8.3239(3) Å, b = 8.9530(3) Å, c = 18.0678(5) Å, = 99.264(2) and Z = 4. Molecules are assembled in sheets in the unit cell through stacking and alternating C–H O interactions.     

Structure of (Z)-1-p-methoxyphenyltelluro-1,4-diphenyl but-1-en-3-yne

C₂₃H₁₈TeO,M _r=437.97, ,a=9.940(2),b=13.664(3),c=7.895(2) Å, =80.60(1), =69.71(2), =75.95(1)°,V=972.0(4) ų,Z=2,R=0.041 for 2668 observed reflections. The Te–C bond distances are 2.109(5)Å and the C–Te–C angle is 96.0(2)°. The phenyl rings are planar to within experimental accuracy, making dihedral angles of 64.6(2), 65.3(2) and 31.1(3)°.     

“Trimethyl lock” facilitated spirocyclizations: A structural analysis

A trimethyl lock was shown earlier to significantly facilitate certain cyclization reactions. Our renewed interests in such facile cyclization systems stemmed from their potential applications in the preparation of redox-, esterase-, and phosphatase-sensitive prodrugs. Furthermore, such systems have also been used for the development of redox-sensitive protecting groups for amines and alcohols. However, there is an undesirable spirocyclization reaction associated with certain trimethyl lock facilitated cyclization systems. In an effort to probe factors important for the controlling of the undesirable spirocyclization reaction, we undertook the X-ray crystallographic studies of the such trimethyl lock facilitated spirocyclization systems. The spirocyclization product was crystallized from ethyl acetate/hexane mixture (space group: P2₁/c,a=13.467(1),b=13.297(2),c=13.626(8) Å, =92.120(6)°. It was found that spirocyclization results in release of steric congestion caused by the trimethyl lock to a larger degree than the desired lactonization. However, this release of steric congestion itself is not enough to bring about the cyclization. A kinetically reactive nucleophile is also essential for the initiation of the spirocyclization reaction. This is consistent with the fact that such spirocyclization reactions require specific base catalysis.     

Structure and spectroscopic properties of the 1∶2 complex of 3,5-dimethylpyridine with 3,5-dinitrobenzoic acid and its deuterated analog

The structure of the nondeuterated and deuterated complexes of 3,5-dimethylpyridine with 3,5-dinitrobenzoic acid in a stoichiometric ratio 12 have been determined by X-ray diffraction methods. The crystals of the nondeuterated complex are triclinic, space groupP¯1 witha=9.409(9),b=10.813(7),c=12.310(7)Å,a=95.75(5),=108.17(7), =91.46(7)° andZ=2. The crystals of the deuterated complex are monoclinic, space groupP2₁/c, witha=11.680(6),b=8.451(4),c=24.382(9)Å,=102.94(4)° andZ=4. Both structures have been solved by direct methods and refined toR=0.035 for 2235 and toR=0.044 for 1938 independent reflections for nondeuterated and deuterated crystal, respectively. The structures consist of 3,5-dimethylpyridinium cations and hydrogen (or deuterium) bis(3,5-dinitrobenzoate) anions. The N(1)⁺-H(N1)O(1)^–, O(7)-H(7)O(2), N(1)⁺-D(1)O(l)^– and O(7)-D(7)O(2) bond lengths are 2.644(4), 2.499(3), 2.739(5), and 2.526(5)Å, respectively. The IR spectra of both complexes within the proton (or deuteron) absorption range have been studied.