Synthesis and characterization of several molybdenum chloride cluster compounds

Investigation into the direct synthesis of Mo(,4)Cl(,8)P((,2)H(,5))(,3)(,4) from Mo(,2)OAc(,4) led to a synthetic procedure that produces yields greater than 80%. The single crystal structure disclosed a planar rectangular cluster of molybdenum atoms. Metal-metal bond distances suggest that the long edges of the rectangular cluster should be considered to be single bonds and the short metal-metal bonds to be triple bonds. This view is reinforced by an extended Huckel calculation;Attempts to add a metal atom to Mo(,4)Cl(,8)PR(,3)(,4) to form Mo(,5)Cl(,10)PR(,3)(,3) led instead to a compound with the composition Mo(,8)Cl(,16)PR(,3)(,4). Solution and reflectance uv-visible spectra and x-ray photoelectron spectra suggest that tetranuclear molybdenum units are present. The facile reaction between Mo(,8)Cl(,16)PR(,3)(,4) and PR(,3) imply that the linkage between tetrameric units is weak;Spectroscopic measurements of Mo(,8)Cl(,16)PR(,3)(,4) revealed similarities to (beta)-MoCl(,2). this observation led to the low temperature synthesis of (beta)-MoCl(,2) from Mo(,2)OAc(,4) and AlCl(,3). (beta)-MoCl(,2) formed by this route is much more reactive than that produced by previous methods. Isolation of Mo(,4)Cl(,8)PEt(,3)(,4) from a room temperature reaction of (beta)-MoCl(,2) with PEt(,3) suggests that (beta)-MoCl(,2) contains tetrameric units;Cyclic voltammetric measurements and chemical redox reactions^in acetonitrile have established that the Mo(,5)Cl(,13)(\u27n-) cluster anion^may be obtained with n = 1, 2, or 3. The Mo(,5)Cl(,13)(\u273-) cluster is stable^for greater than 1 day in the absence of air, but the Mo(,5)Cl(,13)(\u271-) anion^quickly reverts to Mo(,5)Cl(,13)(\u272-). Electronic spectra of solutions in^acetonitrile show related bands at 725-790, 550-580, and 455-490^nm for the three anions. Magnetic susceptibility measurements over^the range 100-295(DEGREES)K for Bu(,4)N(,2)Mo(,5)Cl(,13) yield (mu) = 1.67. The^presence of a dynamic Jahn-Teller effect in the ESR spectrum ofBu(,4)N(,2)Mo(,5)Cl(,13) indicates that the HOMO is doubly degenerate.The crystal structure of C(,6)H(,5)CH(,2)N(CH(,3))(,3)(,2)Mo(,5)Cl(,13) illustrates astatic distortion of the cluster. Susceptibility measurements ofBu(,4)N(,3)Mo(,5)Cl(,13) indicate that it is diamagnetic, from which a singletHOMO is deduced. The Cl 2p photoelectron spectrum forBu(,4)N(,2)Mo(,5)Cl(,13) was resolved into components giving binding;energies for the terminal, edge-bridging, and face-bridging chlorine atoms in the cluster unit; (\u271)DOE Report IS-T-1054. This work was performed under ContractW-7405-eng-82 with the Department of Energy

Microorganisms Found in Field Specimens Of Diseased Corn Borer Larvae

Two hundred and eighty-six abnormal, field collected larvae of the European corn borer were examined for the presence of microorganisms which could have caused the abnormality or death. The most common microorganism found was a microsporidian, Perezia pyraustae Paillot. Next most numerous was a group of enterobacteria. Spore forming rods apparently of the genus Bacillus, and fungi belonging to the genera Beauvaria and Metarrhizium were also isolated. An examination of 100 apparently normal pupae revealed that 82 were hosts to Perezia pyraustae and two contained bacteria

Some Characteristics of Bacteria Isolated From Diseased Larvae of the European Corn Borer

A large proportion of the bacteria isolated from diseased corn borer larvae are pleomorphic, with rods, diplococci, filaments and various transition forms occurring in many cultures. Gram reaction is negative, although the coccoid forms show a tendency to retain gram positivity. In morphology and biochemical characteristics, these isolates resemble certain entomogenous bacteria described by earlier workers, but are similar also to a group of bacteria from human sources which have been designated as members of the tribe Mimeae DeBord. Further studies have been initiated to determine the pathogenicity and the proper taxonomic position of these cultures

Effect of Covalence and Degree of Cation Order on the Luminous Efficacy of Mn4+ Luminescence in the Double Perovskites, Ba2BTaO6 (B = Y, Lu, Sc)

The spectroscopic properties of the Mn4+ ion are investigated in the series of isostructural double perovskite compounds, Ba2BTaO6 (B = Y, Lu, Sc). A comparison of these properties highlights the influence of covalent bonding within the perovskite framework and the degree of order between the B3+–Ta cations on the energy and intensity of the Mn4+2E → 4A2 emission transition (R-line). These two parameters of the emission spectrum are of importance for practical application since they determine the phosphor luminous efficacy. The influence of covalent bonding within the corner shared BO6/2 and TaO6/2 perovskite framework on the energy of the R-line energy is investigated. From the spectroscopic data, we have derived information on the influence of the degree of order between the B3+ and Ta5+ cations on the intensity of the R-line. The lowest energy and the highest intensity of the R-line are found in the double perovskite, Ba2ScTaO6. The purpose of this work is to propose for first time an explanation of these effects in the considered double perovskites. The obtained results are useful guidelines for practical improvement and tuning of key parameters of phosphors to the desired values

‘Daddy, I'm falling for a monster’: Women, Sex, and Sacrifice in Contemporary Paranormal Romance

This paper examines a key trope within much contemporary paranormal romance: the absence, or ineffectiveness, of the father. The first part of the essay develops an analysis of this aspect of the genre (in the Twilight Saga especially) through the work of René Girard, Luce Irigaray, and Juliet MacCannell. Of particular importance here is the extent to which Twilight and similar narratives stage female self-sacrifice as a pre-condition for the redemption of the hero and the restoration of patriarchal bonds initially compromised by some crisis in the effective functioning of paternal authority. The second section extends this analysis to consider ways in which paranormal romances featuring werewolves and vampires shift away from this conservative and reductivist romance paradigm so as to affirm and contest heteronormative, paternalistic models of masculinity and sexual desire

Adenosine Transporter ENT4 Is a Direct Target of EWS/WT1 Translocation Product and Is Highly Expressed in Desmoplastic Small Round Cell Tumor

Background: Desmoplastic Small Round Cell Tumor (DSRCT) is a highly aggressive malignancy that affects mainly adolescents and young adults. A defining characteristic of DSRCT is a specific chromosomal translocation, t(11;22)(p13;q12), that fuses EWS with WT1, leading to a production of two isoforms of chimeric transcription factor, EWS/WT1(−KTS) and EWS/WT1(+KTS). The chimeric proteins are thought to play critical roles in various stages of oncogenesis through aberrant transcription of different genes, but only a few of these genes have been identified. Methodology/Principal Findings: We report the identification of a new target of EWS/WT1, ENT4 (equilibrative nucleoside transporter 4) which encodes a pH-dependent adenosine transporter. ENT4 is transcriptionally activated by both isoforms of EWS/WT1 as evidenced by promoter-reporter and chromatin immunoprecipitation (ChIP) analyses. Furthermore, ENT4 is highly and specifically expressed in primary tumors of DSRCT as well as in a DSRCT cell line, JN-DSRCT-1. Treatment of JN-DSRCT-1 cells with adenosine analogs, such as 2-chloro-2′-deoxyadenosine (2-CdA), resulted in an increased cytotoxic response in dose- and pH-dependent manner. Conclusions/Significance: Our detailed analyses of a novel target of EWS/WT1 in DSRCT reveal an insight into the oncogenic mechanism of EWS-fusion chromosomal translocation gene products and provide a new marker for DSRCT. Furthermore, identification of ENT4 as a highly expressed transcript in DSRCT may represent an attractive pathway for targeting chemotherapeutic drugs into DSRCT

Proper Motions in Kapteyn Selected Area 103: A Preliminary Orbit for the Virgo Stellar Stream

We present absolute proper motions in Kapteyn Selected Area (SA) 103. This field is located 7 degrees west of the center of the Virgo Stellar Stream (VSS, Duffau et al. 2006), and has a well-defined main sequence representing the stream. In SA 103 we identify one RR Lyrae star as a member of the VSS according to its metallicity, radial velocity and distance. VSS candidate turnoff stars and subgiant stars have proper motions consistent with that of the RR Lyrae star. The 3D velocity data imply an orbit with a pericenter of 11 kpc and an apocenter of ~90 kpc. Thus, the VSS comprises tidal debris found near the pericenter of a highly destructive orbit. Examining the six globular clusters at distances larger than 50 kpc from the Galactic center, and the proposed orbit of the VSS, we find one tentative association, NGC 2419. We speculate that NGC 2419 is possibly the nucleus of a disrupted system of which the VSS is a part.Comment: ApJL accepte