Crystal structure of 1,3-(N,N′-benzamide)-2-methyl-1-pentene

Crystals of the title compound are monoclinic (C20H22N2O2): space groupP2₁/n,a=11.800(3),b=13.820(2),c=11.004(3) Å,=92.74(3)°. The structure was solved by direct methods and refined by block-matrix least-squares procedure to giveR=0.078 andRw=0.076 for 1960 reflections above 3(I). The two amide groups are not coplanar with respect to their benzene rings. An intramolecular N-HO hydrogen bond was found in the molecules which are joined in chains by other strong N-HO hydrogen bonds.     

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.     

Crystal structure of an intermediate in the synthesis of artemisinin

C₁₄H₂₂O₃,M _r =238.33, P2₁2₁2₁,Z=4,a=6.892(2),b=11.453(1),c=17.159(5) Å. [1R–[1(R^*), 4, 4a, 8a]]–,4-Dimethyl-decahydro-7-oxo-1-naphtaleneacetic acid. The cyclohexane ring adopts a chair conformation and thecis-fused cyclohexanone ring is in a slightly distorted chair conformation. The molecular packing involves an hydrogen bond and C–H...O contacts.     

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.     

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.     

Synthesis and structure of bisiodobis(diisopropyldithiocarbamato)tellurium(IV)

The title mixed ligand complex was synthesized by the controlled oxidative displacement reaction of TeL ₄ by iodine (L is diisopropyldithiocarbamate ion). Its crystals are monoclinic, space group P2₁ withZ=2 in a unit cell of dimensionsa=8.344(4),b=14.113(8),c=10.647(5) Å,=99.884(2)°, andV=1235.15 ų, finalR=0.043 andR _w =0.047 for 3553 unique reflections. The central tellurium atom shows a S₄I₂ six coordination with the two dithiocarbamate groups almost isobidentate, the average Te-S and the Te-I distances being 2.571(3) and 3.011(1) Å, respectively. The structure is monomeric in the solid state. No intermolecular short contacts are observed.     

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.     

Conformations of cyclic disulfides: The crystal structure of (1RS,2RS,7RS,8RS)-1,2,7,8-tetrahydroxy-4,5,10,11-tetrathiacyclododecane

The racemic form of the title compound C₈H₁₈O₄S₄ (TTCD), a twelve-membered cyclic disulfide, has been synthesized and studied by X-ray diffraction. TTCD·H₂O crystallizes in a multiply twinned pseudo-monoclinicC-centered lattice. For convenience aC-centered triclinic unit cell was chosen of dimensionsa=33.855(3),b=5.534(1),c=14.836(2) Å, =90.05(1),=94.76(1), =89.22(1)°,V=2769(1) ų,Z=8, space groupC¯1. The structure, solved by direct methods, was refined to anR of 0.063, using 2769 observed reflections. The two crystallographically independent TTCD molecules in the unit cell have very similar conformations. The distortion from the pseudomonoclinic symmetry is discussed in relation to the hydrogen bonding network.     

Crystallographic and IR spectral study ofcis-bis(creatinine-N)dinitro platinum(II)

Acis-Pt(creat)₂(NO₂)₂ complex was synthesized stereoselectively in a high yield (65%) and characterized by IR spectral and X-ray diffraction analysis. Crystal data: Pt(C₄H₇N₃O)₂(NO₂)₂,M _r=767.55, monoclinic, space groupP2₁/n,a=9.736(1),b=13.433(1),c=12.098(1) Å,=110.55(1)°,V _c=1482(1) ų,Z=2,D _x=3.441 g cm^–3,(MoK)=0.71073 Å,=97.0 cm^–1,F(000)=1504,T=292 K,R=0.026 andR _w=0.028 for 2061 observed reflections with I>2(I). The structure consists of Pt(creat)₂(NO₂)₂ molecules disposed in general positions and joined by N-HO and N-HN hydrogen bonds. The platinum atom has square-planar PtN₄ coordination of twocis disposed pairs of nitro [Pt-N_av 2.023(7) Å] and creatinine [Pt-N(endo)_av 1.991(8) Å] ligands. The creatinine moieties are planar and tilted to the equatorial plane by ~80°.     

Molecular structure of P-(2,4,6-tri-tert-buthylphenyl)-phenylmethylene(phenylsulfonylimino)-σ3λ5-phosphorane

The crystal and molecular structure of P-(2,4,6-tri-tert-buthylphenyl)-phenylmethylene (phenylsulfonylimino)-³⁵-phosphorane, 2,4,6-Bu^t ₃-C₆H₂-P(=CHPh)(=N--SO₂Ph), has been determined. Crystal data: triclinic, , a = 9.472(5), b = 11.427(5), c = 13.684(5) Å, = 90.61(3), = 101.21(4), = 97.02(4)°, V = 1441.1 ų, Z = 2, D _c = 1.20 g cm^–3. The observed in 1 noticeable elongation of the P=N bond 1.563(3) Å and shortening of the P=C bond 1.617(3)Å have been discussed in terms of the electron withdrawing ability of substituents on the basis of ab initio (HF/6–31+G**) calculations of the model systems.     

Molecular structure of isopropyl 1-phenyl-4-phenylhydrazono-5-oxo-3-pyrazolecarboxylate

The new azopyrazolone dye has been synthesized and its crystal structure has been investigated. Crystals of C₁₉H₁₈N₄O₃ are triclinic: ,a=7.484(1),b=10.646 (1),c=11.897(1) Å, =82.28(1), =72.86(1), =86.83(1)°,Z=2. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.050 for 2622 unique reflections. The tautomeric form of the molecules has been determined as a hydrazo form. Delocalization of the C5=O3 and C4=N3 -electrons and delocalization of the lone-pair electrons of N1, N3, and N4 atoms has been observed. The intramolecular N–H...O hydrogen bond forms the six-membered ring C₂N₂H...O condensed with the pyrazolone ring. The molecules are connected by intramolecular C–H...O hydrogen bonds.     

Crystal structure of the 1:1 complex formed by 4-nitropyridine N-oxide and 4-nitrophenol

The title complex (C₆H₅NO₃·C₅H₄N₂O₃,M _r =279.21) crystallizes in the orthorhombic space groupPna2₁ witha=18.862(2),b=5.876(1),c=10.803(2) Å,V=1197.3(6) ų,D _c =1.549 g cm^–3 forZ=4,F(000)=576, (MoK)=0.71073 Å,=0.84 mm^–1,T=297 K. The structure was solved by direct methods and refined by block matrix least-squares. FinalR=0.032, wR=0.037 for 904 observed reflections. The complex is held together by an intermediate hydrogen bond between the hydroxyl and the N-oxide group with an OO distance equal to 2.618(3) Å. The stacking of thea glide related complex molecules by translation in theb direction results in a herringbone structure with an overlap of the nitrophenol and 4-nitropyridine N-oxide rings and a mean interplanar distance of 3.4(1) Å between those rings.On leave from Universidad del Valle, Departamento de Quimica, Cali, Colombia.     

Structure of fruticuline B: A new natural anthracene quinodimethide of abietanoid origin

The title compound is C₁₉H₁₈O₄·1/2 CH₃OH, triclinic,P¯1,a=9.891(2),b=13.273(4),c=13.860(4) Å,a=66.47(2),=86.91(2), and =85.59(2)°. The structure was solved by direct methods and refined by least-squares techniques to anR factor of 0.082 for 2282 observed reflections. The X-ray structure uniquely resolves the one remaining ambiguity, namely the assignment of the correct structure4. There are two crystallographically independent molecules (A and B) and one disordered methanol molecule. Both molecular skeletons show small distortions from planarity with inclinations of 1.7 and 4.0° between the outermost rings A/C in molecules A and B, respectively. Intramolecular hydrogen bonds of the form O(3A)-HO(2A) and O(3B)-HO(2B) are observed in molecules A and B, respectively. The molecules are linked by pairs of O(3A)-HO(2B) and O(3B)-HO(2A) hydrogen bonds. The dimerlike structures are stabilized by intermolecular C-HO interactions and van der Waals forces.     

Structure determination and hydrogen bonding of 1-naphthoxyacetic acid, a potential plant growth hormone

1-Napthoxyacetic acid crystallizes in the centrosymmetric space group C2/c (No. 15) with cell dimensions of a=14.273(2)Å, b=5.845(1)Å, c=24.211(1)Å, =105.815(2)°. The structure of the title compound reveals a carboxyl group-naphthalene ring dihedral angle of 4.85(14)°, O—H- - -O hydrogen bonded dimer, hydrogen bond distance of 2.640(2)Å, hydrogen bond angle of 172(2)°, and a cis configuration of O2 (double bond) and O3 relative to the C11—C12 bond all of which indicate that the title compound may be effective as a plant growth hormone.     

The crystal structure of tris(4-methylpyridine) tricarbonylmolybdenum(0)

The title compound, Mo(4-CH₃C₅H₄N)₃(CO)₃, is monoclinic, P2₁/c, with cell dimensionsa=10.385(1),b=13.572(2),c=15.522(2) Å, =105.08(1)°,Z=4. The complex isfac-octahedral with approximate three-fold symmetry. The Mo–C bond lengths are 1.901–1.904(7) Å, distinctly shorter than in the parent Mo(CO)₆, and the Mo–N bond lengths are 2.297–2.331(5) Å.     

Regiospecific ligand addition to the donor–acceptor compound Ru2(CO)6(bpcd): syntheses and X-ray diffraction structures of Ru2(CO)5L(bpcd) and Ru2(CO)5L[μ-C=C(PPh2)C(O)CH2C}(O)](μ2-PPh2) (where L = PMe3 and tBuNC)

Thermal and Me₃NO-assisted activation of the donor–acceptor complex Ru₂(CO)₆(bpcd) (1) [where bpcd = 4,5-bis(diphenylphosphino)-4-cyclopenten-1,3-dione] with PMe₃ or ^tBuNC affords the mono-substituted complexes Ru₂(CO)₅L(bpcd), as a result of regiospecific ligand attack at the diphosphine-substituted ruthenium center. Solution NMR measurements (¹H and ³¹P) reveal that the PMe₃ derivative exists as a noninterconverting mixture of axial (3a) and equatorial (3e) isomers, with the only the equatorial isomer being observed for Ru₂(CO)₅(^tBuNC)(bpcd) (5). Near-UV irradiation of 1 in the presence of added ligand yields Ru₂(CO)₅L(bpcd), in addition to the known ₂-phosphido complex Ru²(CO)⁶ [-C=C(PPh₂)C(O)CH₂C(O)](₂-PPh₂) (2) and the corresponding phosphido-substituted complexes Ru²(CO)_5L[-{C =C(PPh₂)C(O)CH₂C}(O)]₂-PPh₂)[4 (L = PMe₃); 6 (L = ^tBuNC)]. As with compounds 3a, 3e, and 5, both 4 and 6 exhibit ligand attachment at the diphosphine-substituted ruthenium center. The molecular structures of 3e, 4, 5, and 6 were determined by X-ray crystallography. 3e, as the 1/2 C₆H₆ solvate, crystallizes in the monoclinic space group C2/c: a = 40.573(3) Å, b = 10.2663(9) Å, c = 18.347(1) Å, = 95.371(6)°, V = 7609(1) ų and Z = 8; 4, crystallizes in the monoclinic space group P2₁/n: a = 10.8241(8) Å, b = 18.074(1) Å, c = 19.194(1) Å, = 96.968(6)°, V = 3727.3(5) ų, and Z = 4; 5, as the 1/2CH₂Cl₂ solvate, crystallizes in the monoclinic space group C2/c: a = 40.955(3) Å, b = 9.7230(6) Å, c = 20.542(1) Å, = 106.596(5)°, V = 7839.2(9) ų, and Z = 8; 6, as the 1/2C₅H₁₂ solvate, crystallizes in the monoclinic space group P2₁/c: a = 21.773(2) Å, b = 10.907(3) Å, c = 18.744(4) Å, = 114.68(1)°, V = 4045(1) ų, and Z = 4. The site occupied by the PMe₃ and ^tBuNC ligands in these compounds is discussed relative to the steric size/electronic properties of the ancillary ligand and its interaction with the bpcd ligand.     

Crystal and molecular structure of 15-oxosparteine-N(1)-oxide perchlorate

[C₁₅H₂₅N₂O₂ ⁺·ClO ₄ ^– ,M _r =364.83, is monoclinic:P2₁,a=7.885(1),b=10.685(1),c=10.658(1) Å,=105.63(1)°,V _c =864.8(2) ų,Z=2,D _x =1.39(1)g cm^–3, (CuK)=1.54178 Å,(CuK)=21.4 cm^–1,F(000)=388 e,T=292K,R=0.066 for 1205 unique reflections. The piperidine ringsA, B, C, andD have chair, chair, boat, and half-chair conformations, respectively. The quinolizidine system (ringsA/B) has atrans configuration. The cations are interconnected by a hydrogen bond O(N1)O(C15) of 2.552(10) Å into chains along [010]. Atoms C(12) and C(13) from ringD of the cation are disordered. Very high thermal parameters of the oxygen atoms of the perchlorate anion may indicate its orientational disorder.     

Crystal and molecular structure of 5-bromo-pentacyclo[4.3.0.02,5.03,8.04,7]nonane-4-carboxylic acid,C10H9BrO2

The structure of the title compound, C₁₀H₉BrO₂, was determined by X-rays.M _r =241.08, triclinic, space groupP¯1,a=5.800(1),b=6.441(1),c=12.030(1) Å,=92.90(1)°,=95.65(2)°, =95.69(2)°,V _c =444.2 ų,Z=2,D _x =1.80 Mg m^–3, MoK radiation (graphite crystal monochromator, =0.71069 Å),(MoK)=48.58 cm^–1,T=290 K. Final conventionalR-factor=0.037,R _w =0.044 for 1863 observed reflections and 145 variables. The structure was solved usingMultan andDirdif. The results show that the 5-bromo substituent has a marked effect on the geometry of the homocubane skeleton. Its presence prevents a complete release of geometrical strain and induces a shortening of the bond distances to the apex carbon atom.     

Complexes of azobisindoles with π-organic acceptors

Complexes of azobisindoles with tetracyanoethylene and tetracyanoquinodimethane were studied by UV-Vis, FT-IR, Raman, NMR and X-ray spectroscopies. FT-IR and Raman spectra, as well as X-ray analysis, gave useful information on the participation of various sites to the association, through analysis of CN and N=N vibrational modes, while UV-Vis and NMR spectra were less helpful. The crystal structure of complexes 1-ethyl-2-phenyl-3-(1-ethyl-2-phenyl-3-azoindole)indole/TCNE,3a and 1,2-diphenyl-3-(1,2-diphenyl-3-azoindole)indole/TCNQ,5b are reported. In the two complexes, the distances between donor and acceptor planes range between 3.4 and 3.5 Å; in3a tetracyanoethylene faces the phenyl ring of the indole, while in5b the superposition of tetracyanoquinodimethane with the donor is negligible. Compound3a,P–1,a=9.504(2),b=9.513(3),c=8.941(2) Å, =97.81(4), =103.38(3), =84.14(2)°,Z=2,D _calc=2.55 g cm^–3; compound5b,P–1,a=12.648(3),b=12.205(2),c=7.263(3) Å, =103.69(2), =91.23(3), =110.61(2)°,Z=2,D _calc=2.53 g cm^–3.     

Role of water molecules in protein-nucleic acid interactions: visualization of a model highly hydrated complex structure of Inosine 5′-monophosphate and L-Serine (2C10H13N4O8P·C3H7NO3·12H2O) at atomic resolution

The crystal structure of a dodecahydrated co-complex between two Inosine 5-monophosphate (IMP) and one L-serine, the first of its kind reported, has been determined at atomic resolution by X-ray crystallographic methods. The crystal belongs to a monoclinic space group, P2₁, with the cell dimensionsa=8.695(7),b=21.898(6),c=12.374(3)Å, =110.59(3)°. This structure reveals the recognition mechanism of serine to the nucleotides through direct and water-mediated hydrogen bonds. The phosphate oxygen (O22) seems to prefer the nonspecific interaction with the functional sites of serine (N...O22=2.735, OG...O22=2.970, O1...O22 =3.121 Å), whereas the bases prefer specific (N17...N=3.199, N23...O2=2.784 Å) bondings. The solvent-mediated hydrogen bonds N17...W3...N27 endow extra stabilization to the stacked bases. The presence of hydrogen-bonded water spines and their interplay in the specific and nonspecific bindings with potential ligands indicate the functional involvement of solvent molecules through cooperative donor-acceptor network and could act as viable centers of intricate interactions in protein-DNA complexation processes.