Color sextet scalars in early LHC experiments

We explore the potential for discovery of an exotic color sextet scalar in same-sign top quark pair production in early running at the LHC. We present the first phenomenological analysis at colliders of color sextet scalars with full top quark spin correlations included. We demonstrate that one can measure the scalar mass, the top quark polarization, and confirm the scalar resonance with 1 fb?1 of integrated luminosity. The top quark polarization can distinguish gauge triplet and singlet scalars.     

Simple multiplexing technique for double-exposure hologram interferometry

A simple technique based on spatial division of the hologram plate is described which permits recording a sequence of holograms of an object under different conditions and then reconstructing the images, two at a time, so that the interference patterns between any two images can be studied.     

Deformation Density Study of KMnO4

The electron density distribution of KMnO₄ is studied by the X-ray diffraction method. Potassium permanganate crystalizes in an orthorhombic space group Pbnm with cell parameters a=7.3661(7), b=9.0610(9), c=5.6458(3)Å, Z=4. The molecular symmetry is C_S with the Mn atom and two oxygen atoms located on the plane perpendicular to the c-axis. A set of accurate diffraction data were measured at 115K. Subsequent refinements and Fourier syntheses were performed. The electron density distribution is expressed in terms of the deformation density. The Mn-O bondings are well characterized, the lone pair electron density at the oxygen atoms is also observed. The density near the Mn nucleus seems to be very sensitive to changes of the scale factor and extinction coefficient. Several types of extinction corrections were made. The features of the Mn-O bond are comparable to the theoretical density calculated at the ab-initio level, and to the experimental density of the isoelectronic compound K₂CrO₄. However, the experimental density of KMnO₄ is not so well reproduced in the vicinity of Mn nucleus.     

Photochemical Reaction between Tertiary Allylic Amines and Chromium Carbene Complexes: Synthesis of Lactams via a Zwitterion Aza Cope Rearrangement

Photolysis of chromium carbene complexes in the presence of tertiary allylic amines resulted in a zwitterionic aza Cope rearrangement to produce unsaturated lactams in fair yield.     

Synthesis and properties of cobalt(III) complexes of 4-substituted pyridine-capped dioxocyclams

Cobalt(III) acetate and cyanide complexes of a series of 5,12-dioxocyclams capped across the 1,8-position by 4-substituted pyridines or pyrazine were synthesized and fully characterized. Both the spectroscopic and structural parameters for these complexes were remarkably insensitive to the electronic nature of the capping group, which ranged from the pi-accepting pyrazine group to the sigma-donating 4-[(dimethylamino)phenyl]pyridyl group. All of the complexes underwent an irreversible, one-electron reduction [Co(III)-->Co(II)] at potentials ranging from -0.95 V vs saturated calomel electrode (SCE) for the pyrazine-capped cobalt acetate complex to -1.36 V vs SCE for the pyridine-capped cobalt cyanide complexes. Pyridine-capped cobalt(III) cyanide complex underwent reaction with Rh2(OAc)4 and ruthenium(II) phthalocyanine[bis(benzonitrile)] to form tetrametallic and trimetallic complexes through coordination bridging by the cyanide nitrogen lone pair. These complexes represent two quite different structural types for cyanide-bridged polymetallics. Complex has a relatively long (2.192 A) cyanide N-to-Rh bond, and the CN-Rh bond angle (157.6 degrees) is strongly distorted from linear. In contrast, complex has a substantially shortened cyanide N-to-Ru bond (2.017 A) and an almost linear arrangement along the entire bridging axis of the molecule.     

Reaction of optically active alpha-aminoallenylstannanes with aldehydes formed in situ from the Lewis-acid-catalyzed rearrangement of epoxides

Reaction of optically active alpha-oxazolidinonylallenylstannanes with oxiranes in the presence of BF3.OEt2 produced beta-hydroxypropargylamines with high syn diastereoselectivity and high enantioselectivity through an initial Lewis-acid-catalyzed rearrangement of the oxirane to the corresponding aldehyde via an alkyl, aryl, or hydride shift. This permits the use of readily available oxiranes as alternatives to aldehydes that are difficult to prepare and/or unstable.