31,602 research outputs found
Complexes (R=Organyl): Stepwise versus Concerted Mechanism in Copper‐Mediated Trifluoromethylation
No full textIntramolecular Phenyl Transfer from Boron to Lithium, Sodium, and Copper: Defining the Limits of Transmetalation
No full textAbstract Transmetalation is a key elementary step in organometallic chemistry, for which reason there is a keen interest in better understanding the factors governing this reaction. We have previously reported the unusual transfer of a phenyl anion from boron to lithium in the gas‐phase dissociation of [LiBr( t Bu)(Ph)Bpin] − ( Chem. Eur. J . 2024 , 43 , e202303653). Here, we use a combination of gas‐phase fragmentation experiments and quantum chemical calculations to probe the reactivity of the related adducts [MX(R)(Ph)Bpin] − (R= n Bu, t Bu, Ph; X=Cl, Br, I, BF 4 , BPh 4 ; M=Li, Na, K, Cu). We find the transfer of Ph − to be much favored over that of n Bu − and t Bu − . The tendency toward transmetalation is decreased for anions X − that strongly bind to the metal center M. Likewise, it is diminished for more electropositive/less electronegative metals M. According to our theoretical calculations, the coordination of a single molecule of tetrahydrofuran to the metal M also lowers the propensity for transmetalation, thereby approaching the behavior in solution. Thus, our results reveal a subtle interplay of different effects influencing the tendency toward transmetalation.Deutsche Forschungsgemeinschaft https://doi.org/10.13039/50110000165
Thomas Grisell letter to Thomas Rotch, 2nd mo 19th 1823
No full textThomas Grisell's letter reached the Rotch household several months before the unexpected death of Thomas Rotch in August, 1823. This is the last letter of the series and presumably the author learned of his friend's death before another letter was penned. 7.95" x 10" (20.2 by 25.5 cm
Failed Censures: Ecclesiastical Regulation of Women’s Clothing in Late Medieval Italy
No full textChurchmen in the late thirteenth and early fourteenth centuries tried to regulate the costume of Italian women. These efforts failed, and regulation was largely left thereafter to civic authorities.The published version was published as Chapter 3 in Medieval Clothing and Textiles 5Izbicki, Thomas M. (2009), "Failed Censures: Ecclesiastical Regulation of Women’s Clothing in Late Medieval Italy" in Netherton, Robin and Owen-Crocker, Gale R., eds., Medieval Clothing and Textiles 5 (Boydell Press), 37-53ISBN: 9781843834519 (published book)Peer reviewe
Modular Ion Mobility Calibrants for Organometallic Anions Based on Tetraorganylborate Salts
No full textThe Thomas Iron Company, 1854-1904 : chartered under the laws of Pennsylvania
No full textThis book presents the history of the Thomas Iron Company. It was prepared for the stockholders of the Company in commemoration of the company\u27s 50th anniversary. The history of the company and its founders, as well as other notable figures are described. Also, the expansion of the company and its development in the area is also provided in detail
Western medieval legal manuscripts in the collections of the University of Pennsylvania
No full textWestern legal manuscripts of the Middle Ages in North American collections are among the least known to scholars. The University of Pennsylvania has a rich collection of these texts, several of which were in the collection of the historian Henry Charles Lea. Included are works of civil law and canon law, as well as collections of papal letters and guides to pastoral care. The descriptions of most of these manuscripts in the catalog of Norman P. Zacour and Rudolf Hirsch are perfunctory, sometimes erring or omitting valuable information. Other manuscripts were added in recent years in the Lawrence J. Schoenberg Collection. Much of this material is being added to the Franklin online catalog of the University’s libraries, but researchers frequently do not search these digital resources. This article provides more complete guidance to the University’s medieval legal manuscripts than any of the existing catalogs offers, whether in print or online. It also provides updated bibliographic information in print or online. Every manuscript has been examined by the author in situ. Among the important works represented in the collection is the Panormia (a work of canon law often attributed to Ivo of Chartres). Authors present include the curialist Thomas of Capua, canonists Petrus de Braco, William of Pagula, Bernardus Raimundi, Adam of Aldersbach, Raymond of Peñafort, and civil lawyers Baldus de Ubaldis, and Bartolus de Saxoferrato. Three of these manuscripts were owned in the past by Sir Thomas Phillipps
Forbidden Colors in the Regulation of Clerical Dress from the Fourth Lateran Council (1215) to the Time of Nicholas of Cusa (d. 1464)
No full textMedieval canon law attempted to distinguish clergy from the laity by restricting their dress choices. The article focuses on prohibition of wearing red or green on the street. Both colors were identified with the nobility.The published version was published as Chapter 7 in Medieval Clothing and Textiles 1Izbicki, Thomas M. (2005), "Forbidden Colors in the Regulation of Clerical Dress from the Fourth Lateran Council (1215) to the Time of Nicholas of Cusa (d. 1464)" in Netherton, Robin and Owen-Crocker, Gale R., eds., Medieval Clothing and Textiles 1 (Boydell Press),105-114ISBN: 9781843831235 (published book
Dissecting Transmetalation Reactions at the Molecular Level: Phenyl Transfer in Metal Borate Complexes
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