An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
The $\mathrm{^{25}Al(p,\gamma)^{26}Si}$ reaction is part of a reaction network with impact on the observed galactic $^{26}$Al abundance. A new determination of the proton strength of the lowest $\ell=0$ proton-resonance in $^{26}$Si is required to more precisely calculate the thermal reaction rate. To this end, the $\mathrm{^{25}Al(d,n)^{26}Si}$ proton-transfer reaction is measured in inverse kinematics using an in-flight radioactive beam at the RESOLUT facility. Excitation energies of the lowest $^{26}$Si proton resonances are measured and cross sections are determined for the lowest $\ell=0$ resonance associated with the $3^{+}_{3}$ state at 5.92(2) MeV. Coupled reaction channels (CRC) calculations using FRESCO are performed to extract the $\ell=0$ spectroscopic factor for the $3^{+}_{3}$ state. The proton width for the $3^{+}_{3}$ state in $^{26}$Si is determined to be $\Gamma_{p}$=2.19(45) eV and the $(p,\gamma)$ resonance strength for the $3^{+}_{3}$ state is extracted as 26(10) meV. This resonance dominates the $\mathrm{^{25}Al(p,\gamma)^{26}Si}$ reaction rate above 0.2 GK.
Abstract Das Fe(III)‐Ionophor Ferrichrom des Brandpilzes Ustilago sphaerogena wird aus Eisenkulturen isoliert und durch Anionenaustausch und Silicagel‐Chromatographie gereinigt.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNuclear magnetic resonance studies of phosphorus inversion in and conformational analysis of cis- and trans-4-tert-butyl-1-phenylphosphorinaneG. D. Macdonell, K. D. Berlin, J. R. Baker, S. E. Ealick, Dick Van der Helm, and K. L. MarsiCite this: J. Am. Chem. Soc. 1978, 100, 14, 4535–4540Publication Date (Print):July 1, 1978Publication History Published online1 May 2002Published inissue 1 July 1978https://pubs.acs.org/doi/10.1021/ja00482a036https://doi.org/10.1021/ja00482a036research-articleACS PublicationsRequest reuse permissionsArticle Views123Altmetric-Citations55LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-AlertscloseSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts
Abstract The 13C nmr spectral analysis has been recorded for the title compounds in DCC13, and all data appear to be in a accord with chair forms. Single crystal x-ray diffraction analysis of 1-phenyl-4-phosphorinanone 1-oxide and the corresponding sulfide revealed flattened chair forms in the solid state. Neither the solution data nor the x-ray data provided any evidence for a twist form for either compound as has been suggested for the carbon counterpart, namely, cyclohexane-1,4-dione.
Three tricyclic dilactams were investigated as models for study of chiroptical properties of homoconjugated non-planar cis -amide groups. Racemic 5,8-diazatricyclo[6,3,0,0 1,5 ]undecane-4,9-dione ( I ) was partially resolved into enantiomers by chromatography on acetylcellulose. The 6-isobutyl ( II ) and 6-methyl ( III ) derivatives were prepared in optically pure forms by condensation of diethyl 4-oxoheptanedioate with ( S )-1,2-diamino-4-methylpentane and ( S )-1,2-diamino-propane, respectively. The respective diamines were synthesized starting from ( S )-leucine and ( S )-alanine: this determined the absolute configuration on the C(6) atom in both dilactams. As shown by 1 H and 13 C NMR spectra, the condensation reaction afforded only one of the two possible diastereoisomeric dilactams. The configurational relation between the chiral center at C(6) and the chirality of the tricyclic moiety was derived from coupling constants in the 1 H NMR spectra. The configuration of compound II was confirmed by X-ray diffraction. According to 1 H NMR spectra, the spatial arrangement of II in solution is similar to that in crystal, the only difference being in the local conformation of the isobutyl side chain at C(6). IR spectroscopy identified only minor differences in geometry of the two lactam groupings in II and III . All CD parameters of compounds I-III , measured in various solvents, are very similar. The CD curves show the same absolute configuration (1 S , 6 S ) of compounds II and III and the opposite configuration of the studied enantiomer of I (1 R ). Parameters of the n-π dichroic band indicate a non-planar amide-grouping whose geometry is known from the X-ray analysis. Its sign agrees with the relationship derived for the chiroptical properties of defined pyramidicity on nitrogen atom in non-planar amides. The π-π dichroic bands exhibit an exciton splitting into a couplet as a result of interaction between the amide groups.
