Synthesis, crystal structure, and magnetic properties of hexanuclear [{MnL2}4{Nb(CN)8}2] and Nonanuclear [{MnL2}6{Nb(CN)8}3] heterometallic clusters (L=bpy, phen)

A hexanuclear cyano-bridged {MnII4NbIV2} cluster (1) bearing 2,2'-bipyridine (bpy) as the blocking ligand at manganese is obtained from the reaction of cis-[MnCl2(bpy)2] and K4[Nb(CN)8]. When the blocking ligand is 1,10-phenanthroline (phen), a nonanuclear cluster {MnII6NbIV3} (2) is obtained. The structure of [{Mn(bpy)2}4{Nb(CN)8}2] has been solved by single-crystal X-ray crystallography, whereas the phen derivative has been confirmed by means of the structure analysis of the corresponding WIV analogue [{Mn(phen)2}6{W(CN)8}3(H2O)2]. Magnetic measurements revealed S=9 and 27/2 spin ground states for these aggregates as a result of antiferromagnetic Nb-Mn interaction with JNb-Mn=-18.1 cm(-1) (1) and -13.6 cm(-1) (2).     

Interatomic potential-based semiclassical theory for Lennard-Jones fluids

An interatomic potential based semiclassical theory is proposed to predict the concentration and potential profiles of a Lennard-Jones (LJ) fluid confined in a channel. The inputs to the semiclassical formulation are the LJ parameters of the fluid and the wall, the density of channel wall atoms, and the average concentration of the fluid inside the channel. Using the semiclassical formulation, fluid confinement in channel with widths ranging from 2sigma ff to 100sigma ff, where sigma ff is the fluid-fluid LJ distance parameter, is investigated. The concentration and potential predicted by the semiclassical formulation are found to be in good agreement with those from equilibrium molecular dynamics simulations. While atomistic simulations in large channels are computationally expensive, the proposed semiclassical formulation can rapidly and accurately predict the concentration and potential profiles. The proposed semiclassical theory is thus a robust and fast method to predict the interfacial and "bulk" fluid phenomena in channels with widths ranging from the macroscale down to the scale of a few atomic diameters.     

Stereoselective synthesis of oxazolidine, hexahydropyrrolo [2,1-b] oxazole, and tetrahydro-2H-oxazolo [3,2-c] thiazole grafted macrocycles through intramolecular 1,3-dipolar cycloaddition reaction

A facile one-pot synthesis of oxazolidine, hexahydropyrrolooxazole and tetrahydro-2H-oxazolothiazole grafted macrocycles through intramolecular 1,3-dipolar cycloaddition reaction (1,3-DC reaction) is reported. X-ray diffraction studies and 2D NOESY experiments of the cycloadducts proved the stereo- and regiochemistry of the cycloaddition.     

3′,4′‐Bis(4‐chloro­phenyl)­spiro­[chroman‐3,5′(4′H)‐isoxazol]‐4‐one

The title compound, C₂₃H₁₅Cl₂NO₃, crystallizes with two independent mol­ecules in the asymmetric unit. The chroman­one moiety consists of a benzene ring fused with a six‐membered heterocyclic ring which adopts a sofa conformation. The five‐membered spiro­isoxazoline ring is in an envelope conformation. The p‐chloro­phenyl rings bridged by the five‐membered ring are nearly perpendicular to each other. The chromanone moiety of one mol­ecule packs into the cavity formed by the p‐chloro­phenyl rings of a second mol­ecule through the formation of C—H?π interactions. The structure is stabilized by weak C—H?O, C—H?Cl and C—H?π interactions.     

Study on using high injection voltage and spiral inflector in the central region of VEC

A feasibility study of using high injection voltage and spiral inflector in the present heavy ion central region of VEC is described. Conditions necessary for waist-to-waist transfer of the ion beam in the hole lens of main magnet have been obtained. The results of orbit studies of a variety of heavy ions indicate that a spiral inflector can be used in the central region.     

Orientational Order Parameter in 1-Hexyl-4-(4-Isothiocyanatophenyl) Bicyclo [2,2,2] Octane using X-Rays

Abstract

1-Hexy1-4-(4-isothiocyanatophenyl)bicyclo[2,2,2]octane (HIPBO), a nematic liquid crystal which shows nematic phase in the temperature range 52.8 to 90.2°C, has been used along with imaging plate system to record X-ray Laue type diffraction pattern at different temperatures. For this purpose oriented sample was used. Orientational order parameter was obtained using Fourier method, recently reported by us, and has been compared with that of other existing methods.     

Topological central extensions ofSL 1 (D)

Supported in part by NSF at MSRI, Berkeley, and IAS, Princeton