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71.
Silvestri MA Miles D Rothwell AP Wood KV Cushman M 《Rapid communications in mass spectrometry : RCM》2003,17(15):1703-1708
Electrospray ionization (ESI) mass spectrometry was employed to obtain both molecular weight confirmation and structural information for a series of novel alkenyldiarylmethane (ADAM) analogs. The mass spectral data were intended for use during the structure elucidation of ester hydrolysis products formed during an in vitro metabolism study of a series of novel ADAM analogs. The data on the precursor molecules show the presence of the molecular ion peak, [M+H](+), as well as a peak consistent with the hydrolysis product of the original ester ([MH-ROH+H(2)O](+)). However, chemical ionization mass spectrometry, elemental analysis and (1)H NMR data indicated the presence of only the intact diester compounds, suggesting that the formation of the hydrolysis product was an instrumental artifact, i.e., in-beam hydrolysis during ESI or a result of longer ion residence times of the ion trap mass analyzer. 相似文献
72.
Stephan Klaus Maximilian W. Lehenmeier Carly E. Anderson Bernhard Rieger 《Coordination chemistry reviews》2011,255(13-14):1460-1479
The catalytic copolymerization of CO2 with epoxides has been known for over 40 years. Even though many heterogeneous and homogeneous catalyst systems have been developed, catalyst activity and selectivity still remain too low for large scale industrial application.Recent investigations have identified new copolymerization pathways with strong evidence for cooperative (bifunctional) mechanisms. At high dilutions, traditional discrete mononuclear single-site catalyst systems generally show a loss in activity. This effect can be overcome with the help of recently developed dinuclear and binary linked systems that involve cooperative mechanisms and thus permit high catalyst efficiency.This review gives an overview on the most recent advances in CO2/epoxide copolymerization, new mechanistic studies and strategies for future catalyst developments. 相似文献
73.
We analyze the time evolution describing a quantum source for non-interacting particles, either bosons or fermions. The growth
behavior of the particle number (trace of the density matrix) is investigated, leading to spectral criteria for sublinear
or linear growth in the fermionic case, but also establishing the possibility of exponential growth for bosons. We further
study the local convergence of the density matrix in the long time limit and prove the semi-classical limit. 相似文献
74.
Maximilian Popper 《Monatshefte für Chemie / Chemical Monthly》1898,19(1):268-279
Ohne Zusammenfassung 相似文献
75.
76.
Ohne Zusammenfassung 相似文献
77.
Dr. Sara Sabater Dr. David Schmidt Dr. Heidi Schmidt Dr. Maximilian W. Kuntze-Fechner Dr. Thomas Zell Connie J. Isaac Dr. Nasir A. Rajabi Harry Grieve Dr. William J. M. Blackaby Dr. John P. Lowe Prof. Stuart A. Macgregor Dr. Mary F. Mahon Prof. Dr. Udo Radius Prof. Michael K. Whittlesey 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(52):13221-13234
The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction. 相似文献
78.
79.
Dr. Maximilian Samec 《Monatshefte für Chemie / Chemical Monthly》1907,28(6):739-765
Ohne ZusammenfassungSchließlich spreche ich Herrn Hofrat Prof. Dr. Adolf Lieben für die Anregung zu dieser Arbeit sowie für die gütige Unterstützung derselben meinen wärmsten Dank aus. 相似文献
80.
Joost Vercruysse 《数学学报(英文版)》2008,24(10):1655-1674
We show the close connection between apparently different Galois theories for comodules introduced recently in [J. Gomez-Torrecillas and J. Vercruysse, Comatrix corings and Galois Comodules over firm rings, Algebr. Represent. Theory, 10 (2007), 271 306] and [Wisbauer, On Galois comodules, Comm. Algebra 34 (2006), 2683-2711]. Furthermore we study equivalences between categories of comodules over a coring and modules over a firm ring. We show that these equivalences are related to Galois theory for comodules. 相似文献