Ion plated indium oxide : infrared and optical study

The high optical transparency of ion plated indium oxide combined with their mechanical hardness and good environmental stability have opened up numerous applications in the line of sophisticated optoelectronic devices. Indium is evaporated at a low oxygen pressure on to an ordinary glass substrate mounted under the cathode and biased by a r.f. generator at 13,6 M Hz. Infrared spectra are recorded in the range 5000–200 cm^?1 by A.T.R. and reflexion-absorption spectroscopy, and show between 800 and 200 cm^?1 bands due to stretching and bending modes predicted by a factor group analysis. A tentative assignment is made of the highest frequency. Last U.V. and visible spectra are discussed.     

Different interaction motifs of dipolar S=O...C=O contacts that associate diastereomers of 2,4(6)‐di‐O‐benzoyl‐6(4)‐O‐{[(1S)‐7,7‐dimethyl‐2‐oxobicyclo[2.2.1]heptan‐1‐ylmethyl]sulfonyl}‐myo‐inositol 1,3,5‐orthoacetate

Diastereomeric mixtures of 2,4(6)‐di‐O‐benzoyl‐6(4)‐O‐[(1S)‐10‐camphorsulfonyl]‐myo‐inositol 1,3,5‐orthoesters associate in their crystal structures via different geometries of S=O...C=O short contacts, depending upon the substitution. A comparison of the dimeric association in the orthoacetate and orthoformate (solvated) derivatives shows a sheared parallel motif of dipolar S=O...C=O contacts bridging the former, whereas perpendicular S=O...C=O contacts occur in the latter. The title compound, C₃₂H₃₄O₁₁S, is chiral, owing to the presence of the camphor moiety.     

Synthesis and characterisation of the methylene-inserted mixed-chalcogenide compounds Fe2(CO)6(μ-SeCH2Te) and Fe2(CO)6(μ-SCH2Te)

The methylene-bridged, mixed-chalogen compounds Fe₂(CO)₆(μ-SeCH₂Te) (1) and Fe₂(CO)₆(μ-SCH₂Te) (3) have been synthesised from the room temperature reaction of diazomethane with Fe₂(CO)₆(μ-SeTe) and Fe₂(CO)₆(μ-STe), respectively. Compounds 1 and 3 have been characterised by IR, ¹H, ¹³C, ⁷⁷Se and ¹²⁵Te NMR spectroscopy. The structure of 1 has been elucidated by X-ray crystallography. The crystalsare monoclinic,space group P2₁/n, A = 6.695(2), B = 13.993(5), C = 14.007(4)Å, β = 103.03(2)°, V = 1278(7) ų, Z = 4, D_c = 2.599 g cm⁻³ and R = 0.030 (R_w = 0.047).     

X-ray crystal structure analysis of nitroxazepine: 10-(3-dimethylaminopropyl)-2-nitro-10,11-dihydrodibenz [b,f][l,4]oxazepin-11-one

The title compound, C₁₈H₁₉O₄N₃,M _r=341, the base (I) of the dibenzoxazepine anti-depressant drug Sintamil, crystallizes in the orthorhombic space group,Pbca withZ=8 in a cella=8.636(2),b=23.687(3),c=16.787(3)Å,V _c=3434 ų. The structure was solved by direct methods and refined toR=0.102 (R _w=0.093) with 1348 observed CuK reflections. The tricyclic framework takes up a saddle shape with the heterocyclic ring in boat conformation; the flanking planar aromatic rings make angles 148.2(3), 150.8(3)° with the central ring plane, compared with 143.5(5), 158.1(5)° in Sintamil monohydrate (II). BothI andII have extended-CNMe₂ side chains (with appreciable thermal motion); this conformation, and the distances of the -N(CH₃)₃ nitrogen to the centers of aromatic rings (6.4 and 7.8 Å inI), are consistent with inhibition of uptake mechanisms underlying the pharmacological action.     

Gel- and Solid-State-Structure of Dialanine and Diphenylalanine Amphiphiles: Importance of C⋅⋅⋅H Interactions in Gelation

To investigate the role of the capping group in the solution and solid-state self-assembly of short peptide amphiphiles, dialanine and diphenylalanine have been linked via the N-terminus to a benzene (phenyl) and 3-naphthyl capping groups using three different methylene linkers; (CH₂)_n, n=0–4 for the benezene and 0, 1 and 2 for the naphthalene capping group. Atomic force microscopy (AFM), oscillatory rheology, circular dichroism (CD), and IR analysis have been employed to understand the properties of these peptide-based hydrogels. Several X-ray structures of these short peptide gelators give useful conformational information regarding packing. A comparison of these solid state structures with their gel state properties yielded greater insights into the process of self-assembly in short peptide gelators, particularly in terms of the important role of C⋅⋅⋅H interactions appear to play in determining if a short aromatic peptide does form a gel or not.     

Concerning hypophyllanthin

The structure (1) for hypophyllanthin was confirmed by X-ray crystallography.