Structure of 2-ethyl-8-methyl-2,8-diazaspiro[4,5]decane-1,3-dione hydrobromide (RS-86)

Crystals of the title compound, C₁₁H₁₈N₂O₂·HBr, are monoclinic, space groupP2₁, witha=7.339(3),b=13.246(7),c=7.340(4) Å,=116.94(5)°, andZ=2. The structure was solved by direct methods and refined by fullmatrix least-squares calculations to anR value of 0.046 for 1218 observed reflections. The piperidine ring, in a chair conformation, is perpendicular (90.6°) to the strictly planar pyrrolidine-2,5-dione ring. Br^– is hydrogen bonded to the positively charged piperidine N1 atom. Bond lengths and valence angles are comparable to those of various related compounds.     

Structure oftrans-methyl 2-phenylhexahydro-2H-isoxazolo (2,3-a)-pyridine-3-carboxylate

The title compound, a 1,3-dipolar cycloaddition product, crystallizes in the monoclinic space groupP2₁/c, witha=8.199(3),b=16.908(1),c=10.248(2)Å,=93.58(2)° andZ=4. The structure was solved by direct methods and refined by full matrix least squares methods toR=0.038 for 1687 observed reflections. The stereochemistry of this compound was found to have the ee conformation in the solid state as well as in solution. The piperidine ring in the molecule is in the chair form and the isoxazolidine ring adopts an envelope conformation.     

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.     

Crystal and molecular structure ofN-[1-(2-phenylethyl)-4-piperidinylium]-N-phenylpropanamide (fentanyl) citrate-toluene solvate

The crystal structure of fentanyl has been determined as part of a structure-activity relationship study on a congeneric series of 4-anilinopiperidines. The compound crystallizes as a citrate toluene solvate, C₂₂H₂₈N₂O · C₆H₈O₇ · C₇H₈, in the monoclinic space groupP2₁/c witha = 18.292(6),b = 9.825(4),c = 19.479(4) Å, = 107.43(3) °, andZ = 4. The structure was solved by direct methods using the program Simpel, and refined by block-diagonal least squares to anR value of 0.092. The torsion angle that describes the conformation of theN-phenyl ring relative to the piperidine ring is 123 ° and differs from that found in other 4-substituted anilinopiperidines (172–177 °).     

Crystal and molecular structure of methylene bis(piperidine-dithiocarbamate), C13H22N2S4

Reaction of anhydrous sodium piperidine dithiocarbamate with methylene chloride yields methylene bis(piperidine dithiocarbamate). The crystals, C₁₃H₂₂N₂S₄ (M=334.57), are monoclinic with space group ,a=6.421(3),b=29.321(7),c=9.022(4)Å,=109.05(3)°,V=1605.6 ų,Z=4,D _c =1.384 g cm^–3,F(000)=712,T=295°K (Mo-K)=0.71069 Å,=5.62 cm^–1 andR=0.032 for 1734 reflections. The molecular structure shows that the methylenic group is bonded to two planar moieties at distances of 1.782(3) and 1.803(3)Å with an S-CH₂-S angle of 114.7(2)°. The configuration about each N atom is planar rather than pyramidal. The two C-N bond lengths adjacent to the C=S bonds are both very short 1.330(4) and 1.336(4) Å indicating the influence of the C=S bond on C-N bond lengths. The six-membered piperidine ring has a classical chair conformation with average C-C distance of 1.511 (5)Å.     

X-ray crystal structures ofcis-bis(diphenylphosphinamide)tetracarbonylmolybdenum(0) andtrans-bis(N-methyl diphenylphosphinamide)tetracarbonylmolybdenum(0)

The X-ray crystal structures ofcis-Mo(CO)₄(Ph₂PNH₂)₂,I, andtrans-Mo(CO)₄(Ph₂PNHMe)₂,II, are presented. ComplexI crystallizes in the monoclinic space groupP2₁/c(a=13.433(1),b=12.2719(8),c=17.318(2)Å;=109.79(1)°;V=2686.1(8)ų;Z=4). ComplexII crystallizes in the triclinic space groupP¯1 (a=6.9986(8),b=10.328(1),c=11.241(2)Å,=107.58(1)°,=91.76(1)°, =101.28(1)°,V=756.1(4)ų,Z=1). The molybdenum coordination geometry in each complex is a slightly distorted octahedron. The molybdenum-carbon bond lengths for the carbonyls trans to phosphorus in complexI are shorter than those the carbonyls trans to other carbonyls. The average molybdenum-phosphorus distance inI (2.525(5)Å) is similar to those in other diphenylphosphinamide complexes and longer than the molybdenum-phosphorus distance inII in 2.4585(7)Å). The distance between two nitrogen atoms incis Mo(CO)₄(Ph₂PNH₂)₂ (3.74(3)Å) is significantly larger than the sum of their van der Waals radii (3.10 Å) indicating that the two nitrogens are not hydrogen bonded.     

Structure and molecular properties of (1)-Centbutindole. Comparison with Haloperidol

The structure and conformation of (1)-Centbutindole, a newly marketed neuroleptic compound, has been investigated by X-ray crystallography. It crystallizes in the monoclinic system and the non-centrosymmetric space group P2₁ (Z=2) with cell dimensionsa=8.434(6),b=6.620(3),c=18.419(9)Å, and =95.07(6)°. The chain conformation istrans extended. The embedded ³ piperidine ring exists in ahalf-chair conformation whereas the embedded piperazine ring exists in achair conformation. The propylene side chain is equatorial relative to the piperazine. A systematic conformational analysis of centbutindole and of a related molecule, Haloperidol, followed by a Monte Carlo search and a stochastic dynamics simulation, have been performed. Electronic and lipophilic properties have been computed and, molecular electrostatic potential (MEP) maps and molecular lipophilicity potential (MLP) maps, have been displayed for two selected conformers satisfying a reported pharmacophore. The two molecules exhibit very similar molecular properties.     

Structure of a platinum(II) complex containing a benzothiazole derivative: [NEt4][Pt(3,4-dsb)Br3]

Tetraethylammoniumtribromo[2-(3.4-dimethoxy)styrylbenzothiazole]platinate(II), [(C₂H₅)₄N]-[PtBr₃(C₁₇H₁₅NO₂S)], monoclinic,P2₁/c,a=13.454(7),b=11.991(3),c=19.004(5) Å, = 108.92(3)°,V=2900(4) ų,Z=4,D _r=1.975 g cm^–3, (MoK)=0.71073 Å, =95.59 cm^–1,F(000)=1656,T=303 K, finalR=0.051 for 2262 unique observed reflections. The structure was solved by heavy atom and Fourier methods. The molecule is nearly planar, with a dihedral angle of only 3.57(7)° between the benzothiazole and phenyl rings. The C–S–C angle in the thiazole ring is 91(1)°.     

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)°.     

Crystal structure of N-(4-nitrophenyl)-N-phenylsulfonamide

The crystal structure of N-(4-nitrophenyl)-N-phenylsulfonamide (C₁₈H₁₄N₂O₄S), a derivative of sulfonamide, has been determined by X-ray diffraction method using CuK radiation. The compound crystallizes in the monoclinic space groupP2₁/n, witha=24.463(1),b=5.745(2),c=11.428(3)Å and=94.39(2)°. The structure was solved by direct methods and refined by full-matrix least squares to a finalR value of 0.045 with 3032 unique reflections. The dihedral angle between the substituents phenyl ring B and the phenyl A is 94.7(3)°. The S atom is in the usual distorted tetrahedral configuration.     

Structure of a styrylbenzoselenazole platinum(II) complex: [NEt4][Pt(nsbse)Br3]

Tetraethylammonium tribromo[2-(2-chloro-5-nitrostyryl)benzoselenazole] platinate (II), [(C₂H₅)₄N][PtBr₃(C₁₅H₉ClN₂O₂Se)], is monoclinic, in space groupP2₁/c, witha=9.496(2),b=20.321(7),c=15.166(3)Å,=100.18(1)°,V=2880(2)ų,M _r =928.72,Z=4,D _x =2.141 g cm^–3, (MoK)=0.71073 Å,=104.1 cm^–1,F(000)=1752,T=298 K. The structure was solved by direct methods and refined toR=0.032 for 2626 unique observed reflections withI>3(I). The [Pt(nsbse)Br₃)] unit has square-planar geometry about the Pt atom, with the nsbse coordinated to the Pt through the N of the selenazole ring. The ligand molecule is non-planar, with a dihedral angle of 61.6(2)° between the benzoselenazole and phenyl rings. The dihedral angles between the PtBr₃ plane and the benzoselenazole and phenyl planes are 105.2(1) and 80.7(1)°, respectively.     

Crystal and molecular structure of dibromobis(benzimidazole)copper(II)

The reaction of CuBr₂ with benzimidazole and HBr in aqueous solution leads to the formation of Cu(C₇H₆N₂)₂Br₂ as dark-brown, stable monoclinic crystals. Space groupP2₁/c witha=13.794(5),b=7.875(2),c=14.510(6) Å;=105.82(5)°;V _c =1516(5) ų;D _x =2.010(3) Mg m^–3. The structure was refined by a full-matrix least-squares procedure to giveR=R _w =0.045 for 1932 intensities above 3(I). The copper (II) ions are four coordinates in the form of a distorted flattened tetrahedron CuN₂Br₂, with the bond lengths Cu-Br(1)=2.402(1), Cu-Br(2)=2.446(1), Cu-N(1)=1.976(7), and Cu-N(11)=1.946(7) Å. The flattened angles are Br-Cu-Br=139.0(1) and N-Cu-N=154.6(3)°. The geometry of intermolecular and intramolecular hydrogen bonds is discussed.     

Crystal structure of bis(benzimidazolium) tetrabromocuprate(II)

Stable, dark-violet crystals of (C₇H₇N₂)₂CuBr₄ were obtained from an aqueous solution of CuBr₂, HBr, and benzimidazole. The crystal structure was determined by three-dimensional X-ray analysis. The crystals are monoclinic:C2/c, a=15.651(4),b=7.945(1),c=15.775(4) Å,=91.44(2)°,Z=4,V _c=1960.96 ų,D _x=2.105 g cm^–3. The structure was refined by full-matrix least squares to giveR=0.042 andR _w=0.048 for 1254 intensities above 3(I). The copper(II) ions are four-coordinated in the form of a distorted tetrahedron CuBr₄ ofC ₂ symmetry. Two different Cu-Br bond lengths are observed: Cu-Br(1)=2.426(2), Cu-Br(2)=2.330(2) Å. Only one flattened angle [Br(2)-Cu-Br(2)=132.71(9)°] in the CuBr₄ tetrahedron is noted. The angles Br(1)-Cu-Br(1)=108.83(7), Br(2)-Cu-Br(1)=99.92(5) and Br(2)-Cu-Br(1)=107.13(5)° have been found. Hydrogen bonds explain the deformation of the CuBr ₄ ^2– coordination polyhedron. The structure is compared with other CuX ₄ ^2– complexes.     

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 II. Crystal structure and molecular conformation ofdl-methylN-(2,6-dimethylphenyl)-N-(2-furoyl)alaninate

A crystalline modification of the title compound (C₁₇H₁₉NO₄) was determined by three-dimensional X-ray analysis from diffractometer data. Crystal data: monoclinic,Cc,a=15.997(12) Å,b=7.929(7) Å,c=14.664(11) Å,=118.70(5)°,Z=4;D_x=1.227 Mg m^–3,(MoK)=0.094 mm^–1. FinalR=0.068 for 852 observed reflections. The dimethylphenyl ring is strongly twisted (94.9°) with respect to the amidic plane of the molecule, which almost coincides with the furan ring (6.9°).     

Structures of three halo(tetramethylethylenediamine)copper(I) complexes

The X-ray crystal structures of three halo(tetramethylethylenediamine)copper(I) complexes have been determined. (TMED)₂Cu⁺CuCl ₂ ^– (I) crystallizes in monoclinic space groupP2₁/n with lattice constantsa=9.332(9),b=15.126(7),c=14.49(1) Å,=96.95(7)°. (TMEDCuBr)₂ (II) crystallizes in monoclinic space groupP2₁/c with lattice constantsa=12.064(5),b=11.888(6),c=15.841(6) Å,=113.97(3)°. (TMED CuI)₂ (III) crystallizes in monoclinic space groupP2₁/c with lattice constantsa=12.401(6),b=12.159(6),c=15.412(9) Å,=109.12(4)°. Compound (I) is a molecule exhibiting two discrete environments for copper(I). The cation is a pseudotetrahedral monomer and the anion a linear monomer. Both (II) and (III) are dimers with asymmetrically bridging bromine and iodine atoms, respectively. Distortions from tetrahedral geometry are observed about the copper atoms in (II) and (III).     

Crystal structure of 4,6-dinitro-1-(5-tetrazolyl)-1H-indazole trihydrate

The title compound, C₈H₄N₈O₄·3H₂O, crystallizes in space groupP¯1 with cell constantsa=7.022(1),b=9.507(2),c=10.906(2) Å,=84.99(1),=71.89(1),=72.56(1)°,Z=2, andV _c =660.2 ų. The structure was solved by direct methods using diffractometer data and was refined by full-matrix least-squares methods to anR value of 0.060 for 2112 observed reflections. The molecule, consisting of a phenyl ring fused to a pyrazole ring with a tetrazole ring connected to it equatorially, is planar except for the N(7) nitro-group oxygen atoms. The structure is stabilized by a three-dimensional network of O-HO, O-HN, and N-HO hydrogen bonds through the water molecules.     

Stereochemistry and hydrogen bonding of cytokinins: Crystal and molecular structure of 6-(4-hydroxy-3-methyl-cis-2-butenyl) aminopurine (cis-zeatin)

The title compound is C₁₀H₁₃N₅O, monoclinic,P2₁/a,a=13.829 (7),b=7.834 (7),c=20.138 (9) Å, and =100.75 (6)°. The structure was solved by direct methods and refined by least-squares techniques to anR factor of 0.079 for 1581 observed reflections. There are two crystallographically independent molecules (I andI). The N⁶-substituent is distal to the imidazole ring of the adenine moiety. It is interesting to note that the conformation of the N⁶-substituent relative to the adenine ring base in these two crystallographically independent molecules shows considerable resemblance with the preferred one usually adopted in other cytokinins. The angles between the mean planes of the adenine base and the N⁶-substituent are 65.6 and 63.3° for theI andI molecules, respectively. The molecules are linked by pairs of N(9)-H·N(3) hydrogen bonds. The dimer-like structures are stabilized by a three-dimensional network of O-H·O, O-H·N, N-H·O, and C-H·N hydrogen bonds.     

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 and molecular structures of two polymorphic forms of dimethyl-N-(2-ethylphenyl)-phosphoramidate (I) and dimethyl-N-(2,6-dimethylphenyl)-phosphoramidate (II)

The crystal structures of the phosphoric amides dimethyl-N-(2-ethylphenyl)-phosphoramidate (I) and dimethyl-N-(2,6-dimethylphenyl)-phosphoramidate (II) have been determined by direct methods and refined by full-matrix least squares. Compound (I) crystallizes in two polymorphic forms, both monoclinicP2₁/c, but with different cell parameters. Parameters for compound (I) are: FormA:a=10.878(5),b=8.890(4),c=25.11(1) Å,=92.18(2)°; FormB:a=7.071(4),b=17.059(9),c=10.221(5) Å,=97.07(2)°. Compound (II) is also monoclinicP2₁/c witha=8.453(4),b=14.231(7),c=10.283(5) Å,=108.95(2)°. Compound (I) exists as a hydrogen-bonded dimer, whereas compound (II) exists as a hydrogen-bonded polymeric species.