5-Benzyl-1-(4-fluorophenyl)-2-phenyl-4,5,6,7-tetrahydro-1H-pyrrolo3,2 -c] pyridine

In the title compound, C26H23FN2, the dihedral angle between the 4-fluorophenyl ring and the adjacent phenyl ring is 62.3 (1)degrees. The crystal structure is stabilized by C-H center dot center dot center dot pi interactions.

Enantiospecific synthesis of tricyclo5.2.1.0(4,8)]decanes via acid catalysed rearrangement of isotwistanes

An acid catalysed rearrangement was employed for the enantiospecific conversion of isotwistanol to tricyclo5.2.1.0(4.8)]-decanes, which provided support for the proposed biosynthesis of allopupukeananes from pupukeananes. The strategy has been further extended to the enantiospecific synthesis of a homobrexane. (c) 2005 Elsevier Ltd. All rights reserved.

Structural and spectral perspectives of a novel thiosemicarbazone synthesized from di-2-pyridyl ketone and 4-phenyl-3-thiosemicarbazide

A new thiosemicarbazone, HL is synthesized from di-2-pyridyl ketone and 4-phenyl-3-thiosemicarbazide and structurally and spectrochemically characterized. H-1 NMR, C-13 NMR, COSY, HMQC and IR spectra of the compound are studied and the proton magnetic resonance spectrum reveals some unprecedented observations. The thione form is predominant in the solid state, as supported by the crystal structure and IR data, while a thiol-thione equilibrium is proposed in the solution state by NMR studies. The compound crystallizes into a monoclinic lattice with space group C2/c and the ZE conformation is exhibited by the thiosemicarbazone. Intra- and intermolecular hydrogen-bonding interactions give rise to a two-dimensional packing in the crystal lattice. (c) 2005 Elsevier B.V. All rights reserved.

Structure of 1 lct-Hydroxyeon-1,4,18-trienine-3-one

C21H27NO2, Mr=325.5 , orthorhombic,P21212,, a = 7.516 (2), b = 13.430 (2), c =18.047 (2) A, U= 1821.79 A 3, Z = 4, D x =1.186 Mg m -a, 2(Cu Ka) = 1.5418 A, # = 0.56 mm -1, F(000) = 704, T= 293 K, final R = 0.04 for 1892 reflections with I _> 3a(I). Ring A is planar, and rings B and C adopt a chair conformation. Rings D and E are envelopes, with C(14) and C(17) displaced from their respective planes by 0.643 (3) and 0.482 (3)A. The ring system A/B shows quasi-trans fusion, whilst ring systems B/C and C/D are trans fused about C(8)-C(9) and C(13)-C(14) respectively. The D/E junction shows cis fusion.

Structure of 1,2,4-oxadiazolidine-3,5-dione monohydrate

C2H2N203.H20, Mr= 120.07, monoclinic,P21/c, a= 5.011 (1), b= 11.796(2), c= 7.689 (2)A,fl= 95.22 (2) ° , V= 452.61 A 3, Z= 4, Dx= 1.76, D m = 1.75 gcm -3, /].(Cu Ks) = 1.5418 A, g = 14-0 cm -l,F(000) = 248, T = 293 K, crystal quality was poor and the final R =0.107, wR =0.090 for 881 observed reflections. The compound is derived from a novel form of the monopropellant oxalohydroxamic acid. The two exocyclic C-O bond lengths of 1.240 (3) and 1.228 (4)A indicate double bonds. The C-N bond lengths of 1.334 (4), 1.390 (4) and 1.359 (4) A are characteristic of the amide bond. The N atom covalently bonded to the two carbonyl C atoms acts as a proton donor in an intermolecular hydrogen bond to the ring O atom: N1...O3i = 2.854 ]k (i =x-- 1,y, z), H...O = 2.15 A, N-H...O = 159 °.

Superconformal transformations of theN=4 supersymmetric Yang-Mills theory

We obtain the superconformal transformation laws of theN=4 supersymmetric Yang-Mills theory and explicitly demonstrate the closure of the algebra.

Syntheses and structural studies of new bicyclic 1,3-diphenyl-1,3,2.lambda.3,4.lambda.3-diazadiphosphetidines

Reactions of cis-[(C6H5N)PC1]z(1 ) with the difunctional reagents HO(CH2)20H,H (CH3)N(CHz)zN(CH3)HH, (CH3)N(CH& OH, and HO(CHz)30Hi n the presence of triethylamine yield the new bicyclic 1,3,2X3,4h3-diazadiphosphetidines[( C6H5- N)PIZ[-O(CHZ)Zo-l (2), [(C6H5N)PlZ[-(CH3)N(CHZ)ZN(CH3)-l (319 [(C6H~N)PlZ~-(CH3)N(cHZ)20 (4), and [(C6H5 N)P],[-Q(CH2),0-] (5), respectively. The products have been characterized by elemental analyses and IR and NMR spectroscopic data. The structures of 4 and 5 have been determined by single-crystal X-ray analysis. Crystal data for 4: monoclinic, P2,/c, a = 9.823 (2) A, b = 8.608 (1) A, c = 18.423 (3) A, i3 = 90.55 (1)O, Z = 4. Crystal data for 5 monoclinic, P2,/c, a = 9.727 (2) A, b = 8.064 (2) A, c = 19.702 (4) A, @ =I 91.31 (l)', 2 = 4. The structures have been solved by direct methods and refined to R = 0.028 for 4 and R = 0.050 for 5. Compound 4 is the first example of an aminoalkoxy-l,3,2X3,4X3-diazadiphosphetidine. The PzNz ring is slightly puckered in both 4 and 5 and the puckering occurs in a manner opposite to that observed for cis-[(RN)PX],structures.

Thermodynamic measurements of b.c.c. Cr-Mn solid solutions at 1373 K

Thermodynamics of Cr-Mn alloys have been studied by Eremenko et al (l) using a fused salt e.m.f.technique. Their results indicate positive deviations from ideality at 1023 K. Kaufman (2) has independently estimated negative enthaipy and excess entropy for the b.c.c. Cr-Mn alloys, such that at high temperatures, the entropy term predominates over the enthalpy term giving positive deviations from ideality. Recently the thermodynamic properties of the alloys have been measured by 3acob (3) using a Knudsen cell technique in the temperature range of 1200 to 1500 K. The results indicate mild negative deviations from ideality over the entire composition range. Because of the differences in the reported results and Mn being a volatile component in the alloys which leads to surface depletion under a dynamic set up, an isopiestic technique is used to measure the properties of the alloys.

The structure of 11[alpha]-hydroxycon-1,4-dienine-3-one monohydrate

C22H31NO2.H2 O, M r = 359" 5, orthorhombic,P2~212 ~, a= 10.032 (1), b= 11.186 (1), C = 17.980 (1)/~,, U= 2017.48/~3, Z = 4, D x = 1.276 Mg m -a, 2(Cu Kct) = 1.5418/~, # = 0.69 mm -~,F(000) = 784, T = 293 K. Final R = 0.05 for 1972 unique reflections with I > 3o(/). Ring A is planar, and rings B and C adopt a chair conformation. Rings D and E are envelopes, with C(14) and C(20) displaced from their respective ring planes by 0-616 (2) and 0.648 (3)/~. The A/B ring junction is quasi-trans,whilst ring systems B/C and C/D are trans fused about the bonds C(8)-C(9) and C(13)-C(14) respectively.The D/E junction shows cis fusion.

Non-periodic tilings in 2-dimensions: 4- and 7-fold symmetries

By inflating basic rhombuses, with a self-similarity principle, non-periodic tiling of 2-d planes is possible with 4, 5, 6, 7, 8, … -fold symmetries. As examples, non-periodic tilings with crystallographically allowed 4-fold symmetry and crystallographically forbidden 7-fold symmetry are presented in detail. The computed diffraction patterns of these tilings are also discussed.

Synthesis and characterization of metal substituted AlxCr1-x(acetylacetonate)(3) single-source precursors for their application to MOCVD of thin films

A detailed study, involving the synthesis of a single-source precursor containing two metal ions sharing the same crystallographic site, has been undertaken to elucidate the use of such a single-source precursor in a CVD process for growing thin films of oxides comprising these two metals, ensuring a uniform composition and distribution of metal ions. The substituted complexes Cr1-xAlx(acac)(3), where acac = acetyl-acetonate, have been prepared by a co-synthesis method, and characterized using UV-Vis spectroscopy. TGA/DTA measurements, and single crystal X-ray diffraction at low temperature. All the studied compositions crystallize in the monoclinic space group P2(1)/c with Z = 4 in the unit cell. It was observed that the ratio (Al:Cr) of the site occupancy for the metal ions, obtained from single crystal refinement, is in agreement with the results obtained from complexometric titrations. All the solid state structures have the metal in an octahedral environment forming six-membered chelate rings. M-O acac bond lengths and disorder in the terminal carbon have been studied in detail for these substituted metal-organic complexes. One composition among these was chosen to evaluate their suitability as a single-source precursor in a LPMOCVD process (low-pressure metal-organic chemical vapour deposition) for the deposition of a substituted binary metal oxide thin film. The resulting thin films were characterized by X-ray diffraction, scanning electron microscopy, and infrared spectroscopy. (C) 2010 Elsevier Ltd. All rights reserved.

Structure of (4-chloro-2-methylphenoxy) acetamide

C9H10ClNO2, Mol · wt = 199.69, monoclinic, C2/c, Z = 8, a = 15.782(2) Å, b = 3.958(1) Å, c = 29.448(2) Å, β = 92.08°, ν = 1838.35 Å3, ϱc = 1.443 g cm−3, ϱ0 = 1.438(2) g cm−3. The structure of (4-chloro-2-methylphenoxy) acetamide (2M4ClPA) was determined by direct methods and refined by full-matrix least-squares methods to R = 0.079. The molecules dimerize about a centre of symmetry and the N – H⋯O distance is = 2.909(3) Å.