Structure and conformation of 6,8-dinitro-2,4-bis(trichloromethyl)-1,3-benzdioxin: X-ray crystallographic determination

6,8-dinitro-2,4-bis(trichloromethyl)-1,3-benzdioxin is monoclinic,P2₁/c,Z=4,a=12.348(2),b=11.575(3),c=12.183(4) Å,=107.48(2)°. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by least-squares to a finalR value of 0.032 using 2192 reflections. The heterocyclic ring is an envelope structure, the dihedral angle between the plane of the aromatic ring and that containing five of the atoms of the heterocycle being 4.98(6)°. One -CCl₃ group is pseudoequatorial while the (Ar-C)CCl₃ group is pseudoaxial. C-C_eq 1.526(3) Å; C-C_ax 1.537(3) Å; C-C(C_ax)-O 112.4(2)°; C(C_ax)-O-C(C_eq) 115.2(2)°.     

Structure and conformation of 6-nitro-2,4-bis(trichloromethyl)-1,3-benzdioxin: X-ray crystallographic determination

6-Nitro-2,4-bis(trichloromethyl)-1,3-benzdioxin is triclinic,P¯1;a=6.604(2),b=7.678(6),c=15.201(4) Å; =91.57(5),=99.39(2), =90.50(5)°;Z=2. The structure was solved by direct methods from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer and refined by least squares to a finalR value of 0.035 using 2092 reflections.The molecule consists of a heterocycle in a distorted screw boat conformation fused to a significantly nonplanar aromatic ring. One-CCl₃ group is pseudoequatorial while the (Ar-C)CCl₃ group is pseudoaxial. The C_Ar-C-O-C side of the ring is much flatter than the C_Ar-C_Ar-O-C side, the distortion being caused by the necessity of the-C_axCl₃ group to bend away from the heterocycle. C-C_eq 1.532(4) Å; C-C_ax 1.550(4) Å; C-C(C_ax)-O 113.0(3)°; C(C_ax)-O-C(C_eq) 115.5(2)°.     

The N,N-diacetylaminobenzene group in the structure of 6-methyl-8-N,N-diacetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin

Crystals of 6-methyl-8-N,N-diacetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin are triclinic, P¯1,Z=2,a=9.586(3),b=9.914(2),c=12.308(5) Å,=67.19(3),=71.95(3), =74.14(2)°. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 difFractometer, and refined by least squares to a finalR value of 0.039 using 3038 reflections. The heterocyclic ring has an envelope conformation. Of thecis-CCl₃ groups one CC1₃ group is pseudoequatorial while the –(C_Ar·C)CCl₃ group is pseudoaxial. (C_Ar)O-C 1.405(4); (C_Ar·O)C-O 1.387(4) Å; C_Ar-C(C_ax)-0 112.3(3); C(C_ax)-O-C(C_eq) 116.1(2)°; (C_Ar)O-C-O-C(C_Ar)58.2(3)°. The configuration of the diacetylamino group (DAA) issyn-anti. The -systems of the DAA and of the aromatic ring are approximately orthogonal, the deviations from orthogonality probably being caused by an intermolecular bifurcated hydrogen bond, each such interaction involving two molecules only, between thesyn O(=C) of the DAA and both hydrogen atoms bonded to the heterocyclic ring in a molecule of the enantiomer. The geometry of the DAA-benzene fragment is compared with those found in the other three published X-ray structures containing this group.     

Crystal and molecular structure of 2,5-dimethyl-3,4-diacetylfuran

The crystal and molecular structure of 2,5-dimethyl-3,4-diacetylfuran has been determined by direct methods using CuK. photographic data. Refinement by full-matrix least-squares methods gave a finalR factor of 0·097. The crystals are monoclinic: space groupP2₁/c,a =14·92(2),b = 4·09(1),c =16·68(3) Å and = 109·7(5) °;Z = 4. The furan ring of the molecule is planar, and the exocyclic atoms bound to the atoms of the ring lie close to the ring plane. The planes of the acetyl groups are tilted by 16 ° and 47 ° with respect to the ring plane. The exocyclic bond angles of this compound are significantly different from the equivalent angles in furan.     

Structure and conformation of 6-nitro-2-trichloromethyl-4-dichloromethylene-1,3-benzdioxin: X-ray crystallographic determination

6-Nitro-trichloromethy1-4-dichloromethylene-1,3-benzdioxin is monoclinic,C2/c,a=12.906(2) Å,b=19.957(2) Å,c=19.992(2) Å,=99.05(1)°,Z=8. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by least squares to a finalR value of 0.032 using 1838 reflections.The compound exhibits a distorted envelope structure in the dioxin ring, and the trichloromethyl group is in the equatorial position. The angle between the planes each containing a group of three atoms from either end of the double bond of the:C(ring)=CCl₂ moiety is 3.8(2)°: a short discussion of deformations found in other compounds which contain:C(ring)=CC1₂ in light atom structures is given. The benzene ring is slightly puckered and planarity has been retained about the carbon atoms which are common to both rings.     

Molecular structures of two conjugated ene-ynes derived from thiophene

The crystal structures of two conjugated ene-yne derivatives of thiophene are described, 2,5-di-(trimethylsilylethynyl)-3,4-dibromothiophene (1), is triclinic P witha=6.3281(4)Å,b=9.7421(6)Å,c=16.3669(9)Å; =80.516(5)°, =84.810(5)°, =74.072(5)°,Z=2,R=0.054; 2,3,4,5-tetra(trimethylsilylethynyl)thiophene (2), is monoclinic, P2₁/c with a=20.928(2)Å b=5.852(1)Å,c=23.907(2)Å; =100.245(6)°,Z=4,R=0.049. The ethynylic C atoms of both compounds lie near the thiophene plane, with deviations in the range 0.010(3)–0.455(4)Å. The phenyl groups of2 form a dihedral angle of 13.0(4)°.     

The crystal and molecular structure of N-(methylsulfonyl)-N-(2,6)-(dimethylphenyl)methanesulfonamide

The title compound, crystallizes in the triclinic space group witha=8.232(4),b=9.159(2),c=10.230(3)Å. =74.07(3)°, =72.50(4)°, =63.65(3)° andZ=2. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.054 for 1817 observed reflections. The plane containing the nitrogen and sulfur atoms is perpendicular to the aromatic plane. One of the S–O bonds in each methanesulfonyl group is in nearly eclipsed conformation with the N–C bond.     

The crystal and molecule structure of tetraphenylphthalic anhydride,C32H20O3

Tetraphenylphthalic anhydride has been structurally characterized by X-ray crystallography: triclinic,P¯1,a=13.386(4),b=13.563(4),c=16.185(6) Å,=71.70(3),=109.32(3), =116.17(3)°,V=2439(1) ų,Z=4,D _x=1.23 g cm^–3,=0.73 cm^–1,T=295 K, andR=0.065 for 3910 observed reflections. The asymmetric unit consists of two crystallographically independent molecules of tetraphenylphthalic anhydride (TPPA). Crowding from four adjacent phenyl substituents produces large average displacements of the substituents from the central ring (av. ~0.08 Å, max. 0.17 Å) and distortions in the central aromatic ring. The torsion angles relating the plane of the substituent phenyl rings to the central ring plane (av. 62°) is consistent with other polyphenylated aromatic structures.     

Structure and conformation of the 6-carboxylic acid and the 6-methylsulfonate of 2,4-bis(trichloromethyl)-1,3-benzdioxin

The 6-methylsulfonate (I) and the 6-carboxylic acid (II) of 2,4-bis(trichloromethyl)-1,3-benzdioxin both crystallize in the space groupP2₁/n withZ=4. Unit cell parameters of I are:a=13.398(7),b=14.553(2),c=8.945(2) Å, =99.16(2)°; those of II are:a=6.010(16),b=25.741(16),c=10.505(10) Å, =100.05(16)°. The structures were solved by direct methods and refined by full-matrix least squares, from room-temperature data obtained with an Enraf-Nonius CAD4 diffractometer, to conventionalR factors of 0.035 for I and 0.041 for II. The methylsulfonate group of I is disordered except for the sulfur atom and in II, which forms hydrogen-bonded dimers through the –COOH group, the hydrogen atom of the –COOH group is distributed equally between two positions.The conformation and molecular parameters of the 2,4-bis(trichioromethyl)-1,3-benzdioxin fragment for both compounds is very similar to that in 6-nitro-2,4-bis(trichloromethyl)-1,3-benzdioxin (Irving A., and Irving H. M. N. H. (1986)J. Cryst. Spectrosc. Res. 16, 703). The dioxin ring has an approximate envelope conformation with a pseudoequatorial –CCl₃ group in the 2-position and a pseudoaxial –CC1₃ group in the 4-position. C(ring)-C_eq(Cl₃) is 1.525(5) Å for I and 1.536(6) Å for II, whereas the C(ring)-C_ax(Cl₃) bond length is 1.547(5) Å for I and 1.550(4) Å for II. The chemical shifts of the two protons in the heterocyclic ring do not appear to be altered by these changes in the 6-substituent.     

Crystal structure of tolazoline hydrochloride

The title compound (C₁₀H₁₂N₂ HC1,M _r =196.7) crystallizes in the monoclinic space groupP2₁/c witha=8.997(1),b=9.665(1) andc=12.290(1) Å,=104.41(1)°,V=1035·1 ų,D _x =1.262 g·cm^–3 forZ=4,=29.4 cm^–1, (CuK)=1.54178 Å,F(000)=416. FinalR=0.051 (R _w =0.063) for 1937 reflections collected on a diffractometer. The structure was solved by direct methods. The two N atoms of the imidazoline ring are equivalent due to protonation and they participate in N-HCl hydrogen bonds which join the molecules into infinite chains. The imidazoline ring is approximately planar and is oriented perpendicular to the plane of the benzene ring. The separations of the two N atoms from the center of the aromatic ring are 4.691(3) and 4.598(3) Å, close to the values found in the crystal structures of clonidinelike agents.     

Studies of substituted quinoxaline-di-N-oxides. Part 1. Crystal structure and molecular conformation of 2-[N-(2-hydroxyethyl)carboxamide]-3-methylquinoxaline 1,4-dioxide

A single crystal X-ray investigation of the yellow 2-[N-(2-hydroxyethyl) carboxamide]-3-methylquinoxaline 1,4-dioxide, a commercially available growth promoter used in agricultural stock farming, shows that the molecule is planar. The dihedral angle between the benzene and heterocyclic rings is 0.5°. The N(1)-O(1) and N(2)-O(2) distances are: 1.286(1) and 1.304(1) Å. The C(1)-C(2) bond of the pyrazine ring is not lengthened by substitution at the C(1) and C(2) atoms and is 1.421(2) Å. The atoms O(1) and O(2) deviate by 0.036(2) and 0.123(2) Å from the least-squares plane through the heterocyclic ring. The deviation of the C(12) atom is –0.012(2) Å. The plane through the atoms C(1), C(9), N(3), and O(3) makes an angle of 100.5(2)° with the heterocyclic ring plane. Intermolecular hydrogen bonds O(4)-HO(4)O(3) between the hydroxyl and carbonyl groups generated alternating, antiparalled chains extending in thea direction. The crystals are triclinic,P¯1 (No. 2), witha=7.469(2),b=8.111(2),c=10.357(3) Å,=80.11(2),=88.90(2), =67.73(2)°, andV=571.3(2) ų. The structure was solved by direct phase determination guided by negative quartets and refined by full-matrix least squares to anR value of 0.041 for 2159 observed reflections.Commercially known asOlaquindox.     

Crystal and molecular structure of inner-chelatecis-1,7-dioxa-4,10-diazacyclododecane-4,10-diacetatocopper(II) dihydrate

cis-1,7-Dioxa-4,10-diazacyclododecane-4,10-diacetato-copper(II) dihydrate crystallizes in the monoclinic space groupP2₁/n witha=11.318(2),b=12.129(2),c=12.160(2) Å,=110.09(1)°, andZ=4. The structure was solved by the heavy-atom technique, followed by full-matrix least-squares refinement with anisotropic thermal parameters for non-H atoms. The Cu(II) atom is in a very distorted octahedral environment, with two nitrogen and two oxygen atoms located approximately coplanar with Cu(II), and the two remaining oxygen atoms in apical positions forming an angle of about 147° at Cu(II). The 12-membered ring has noncrystallographicmm2 symmetry. Two five-membered rings containing acetato groups are located in acis arrangement relative to the macrocyclic ring.     

X-ray structural and spectroscopic investigation of 1-piperidine-2,4-dinitrobenzene

The crystal structure of the title compound (C₁₁H₁₃N₃O₄) has been determined by single-crystal X-ray diffraction. The compound is monoclinic, space group P2₁/n, witha=9.968(2),b=9.156(2),c=13.249(2)Å, =102.05(2)°, andD _x=1.563 gcm^–3 forZ=4. The aromatic ring shows a slight boat deformation. Theo- andp-NO₂ groups are twisted out of the plane of the phenyl ring by 39.0(2)° and 4.4(1)°, respectively. The piperidine ring exhibits a slightly deformed chair conformation. Short C–H...O intermolecular contacts stabilize the three dimensional structure. UV and NMR data indicate that the molecule in solution presents a conformation similar to that of the the solid state.     

Structural investigation on hexasubstituted benzene derivatives. Part 2: The structure of metadinitrotetramethylbenzene and molecular mechanics analysis on meta and ortho derivatives

C₁₀H₁₂N₂O₄ (M r=224.2) crystallizes in the monoclinic system, space groupP2₁/mwitha=15.462(4),b=7.926(3),c=8.972(3) Å;=90.2(1)°;V=1099.5(6) ų;Z=4;D _c=1.35 gcm^–3;(Cu-K)=8.6 cm^–1; =1.5418 Å;F(000)=472. The position of the molecule on a crystallographic mirror plane forces the NO₂ plane to be normal to the benzene ring. The-electron-withdrawing character of the NO₂ groups induces a deformation on the geometry of the benzene.     

Crystal structure of 1,1-diphenyl-2,4-dimethyl-5-(N-benzamide)-1,3-pentadiene

Crystals of the title compound are monoclinic (C₂₆H₂₅NO): space groupP2₁/c,a=16.565(3),b=10.328(2),c=12.621(3) Å,=104.02(3)°. The structure was solved by direct methods and refined by block-matrix least-squares to giveR=0.056 andR _w =0.061 for 1613 reflections above 2(I). The amide moiety is tilted by 19.3(2)° with respect to the mean aromatic ring plane. The two othergem phenyl rings subtend a dihedral angle of 112.2(4)° to each other. The molecules are joined in the solid by N-HO hydrogen bonds.     

Studies of systemic acylanilide fungicides. Part IV. Crystal structure and molecular conformation ofN-(2-methoxyacetyl)-N-(2,6-xylyl)-α-amino-γ-butyrolactone

The crystal structure of the title compound (C₁₅H₁₉NO₄, MW 277.3 amu) was determined by three-dimensional X-ray analysis from diffractometer data. Crystal data are: monoclinic,P2₁/n,a=9.600(3) Å,b=11.964(6) Å,c=12.802(4) Å,=101.25(3)°,V=1442.1(16) ų,Z=4;D _x =1.277 Mg m^–3;(MoK)=0.10 mm^–1. FinalR=0.055 for 1686 observed reflections having 2 (MoK)<50° andI>2.5 (I). The compound is isostructural withN-(2-methoxyacetyl)-N-(2,6-xylyl)-3-amino-1,3-oxazolidin-2-one. The dimethylphenyl ring is almost perpendicular to the amidic plane of the molecule (dihedral angle 81.9°); the butyrolactone ring is in the typical envelope conformation.     

Crystal structure of two cocrystallized complexes obtained from the reaction of magnesium chloride with 2,4-pentanedione

The crystal structures of two cocrystallized complexes of MgCl₂ with 2,4-pentanedione have been determined. The conglomerate crystallizes in the monoclinic system, space groupP 2₁/c (No. 14);a=7.835(2),b=18.169(4),c=13.303(3) Å, =90.70(2)°,Z=4. The former complex is a dimer which consists of two octahedra sharing one edge by two chlorine bridges between the metal atoms. The chelate ring in the equatorial plane and two apical water molecules realize the coordination polyhedron around each Mg atom. In the latter complex the metal lies at the center of a slightly distorted octahedron formed by six oxygens, four from two chelate ligands and two from apical water molecules.     

Crystal structure of bis-(thiophene-2-carboxaldehyde-4-phenyl-thiosemicarbazonato)-palladium(II)

The structure of bis-(thiophene-2-carboxaldehyde-4-phenyl-thiosemicarbazonato)-palladium(II) has been established by X-ray crystallography. C₂₄H₂₀N₆S₄Pd is monoclinic, space groupP2₁/a (No. 14). Unit-cell parametersa=9.112(1),b=14.494(2),c=10.194(1) Å, and=111.88(1)°;V=1249.3(5) ų,M _r=627.14,Z=2,D _x=1.67 cm^–3,F(000)=632,T=293 K,R=0.053 for 1254 observed reflections. Two sulfurs and two nitrogens are involved in planar coordination with the palladium. A five-membered thiophene ring is almost parallel to this coordination plane while the phenyl ring makes an angle of 31° with it.NCL Communication No. 4969.     

X-ray crystal structure of the 1:1 dimethylpicric acid–acenaphthene complex

The dimethylpicric acid–acenaphthene complex is orthorhombic, space group P2₁2₁2₁; at 24° a = 7.3685(1), b = 15.4159(1), c = 16.1296(3) Å, D _x = 1.491(2) g cm^–3, V = 1832.19(4) ų, Z = 4. The phenolic OH group in the dimethylpicric acid is intramolecularly hydrogen bonded to one of the ortho nitro groups with an OO distance of 2.500(2) Å. This nitro group is twisted out of the plane of the benzene ring by 8.2°; the twist angles of the other nitro groups are 52.6 and 83.5°. The acenaphthene molecule deviates slightly from planarity as a consequence of the torsion angle at CH ₂-CH ₂ being 1.8 rather then 0°. The molecules pack in stacks of alternating picric acid and acenaphthene molecules. Each stack is surrounded by a close-packed arrangement of six other stacks. The acenaphthene molecules are 2.7° away from being parallel to the benzene ring in the picric acid. The distances from the benzene ring to the acenaphthene carbon atoms range from 3.26 to 3.49 Å on one side of the ring and from 3.30 to 3.54 Å on the other.     

The crystal structure of 5-methyl-1-(octahydro-1-iodo-1H-1-inden-4-yl)-1H-tetrazole

The title compound is C₁₁H₁₇N₄I, F.W.=330.20, monoclinic, space groupP2₁/a,a=11.586(2),b=10.617(1),c=10.417(1) Å, =94.567(2)°,Z=4,F(000)=652, (MoK)=0.7107 Å, (MoK)=2.31 mm^–1,V=1277.31 Å₃,D _C=1.71 gcm^–3,D _m=1.70 gcm^–3. The structurewassolved by Patterson and Fourier methods and refined to anR value 0.031 for 1620 observed reflections. The connectivity and conformation of the addition product ofcis-1,5-cyclononadiene and iodine azide was determined by X-ray analysis. The reaction product contains a chair-conformation cyclohexane ring that iscis fused to a cyclopentane ring. The cyclopentane ring has an envelope conformation and an equatorially oriented iodine substituent. A planar tetrazole ring is axially substituted on the cyclohexane ring. The plane of the tetrazole ring makes a dihedral angle of 69.6° with the average plane of the carbon atoms of the cyclohexane ring.