Author: David John ZalewskiPublisher:
ISBN:
Category : Metal-metal bonds
Languages : en
Pages : 416
Book Description
Reaction Pathways in Polynuclear Metal Carbonyls
Author: David John ZalewskiPublisher:
ISBN:
Category : Metal-metal bonds
Languages : en
Pages : 416
Book Description
Competing Reaction Pathways in the Photochemical Reactions of Metal Carbonyl Compounds
Author: Richard Joseph SullivanPublisher:
ISBN:
Category :
Languages : en
Pages : 952
Book Description
The photochemical reaction of Mn$\sb2$(CO)$\sb{10}$ with HSnBu$\sb3$ has been studied by continuous photolysis. Sunlamp irradiation of a CO-saturated hexane solution of Mn$\sb2$(CO)$\sb{10}$ and HSnBu$\sb3$ results in formation of HMn(CO)$\sb5$ and Bu$\sb3$SnMn(CO)$\sb5$ in equimolar quantities. The rate of disappearance of Mn$\sb2$(CO)$\sb{10}$ and formation of products exhibit an inverse (CO) dependence. When the reaction of Mn$\sb2$(CO)$\sb{10}$ with HSnBu$\sb3$ is performed under 1 atm AR, the rate of disappearance of Mn$\sb2$(CO)$\sb{10}$ is much faster than when CO is present, HMn(CO)$\sb5$ forms in much greater quantities than Bu$\sb3$SnMn(CO)$\sb5$, and a third product, identified as HMn(CO)$\sb4$(SnBu$\sb3$)$\sb2$, forms as the other major product. The above observations are consistent with a mechanism involving oxidative addition of HSnBu$\sb3$ to Mn$\sb2$(CO)$\sb9$. The reactions of HSnBu$\sb3$ with Mn(CO)$\sb4$L$\cdot$ (L = CO or PR$\sb3$) and Mn$\sb2$(CO)$\sb7$L$\sb2$ were studied by flash photolysis. In every case examined, HSnBu$\sb3$ undergoes oxidative addition with Mn$\sb2$(CO)$\sb7$L$\sb2$. However, H-atom transfer to Mn(CO)$\sb4$L$\cdot$ does not occur. For L = CO, PMe$\sb3$, P(i-Bu)$\sb3$, and P(O-i-Pr)$\sb3$, the initial product of oxidative addition, Mn$\sb2$(CO)$\sb7$L$\sb2$(H)(SnBu$\sb3$), is observed. At longer time intervals, this intermediate disappears by reductive elimination of HMn(CO)$\sb4$L. Mn$\sb2$(CO)$\sb7$L$\sb2$(H)(SnBu$\sb3$) is not observed when the metal center is crowded as in the cases of L = P(i-Pr)$\sb3$ and P(C$\sb6$H$\sb{11}$)$\sb3$ because oxidative addition is slow relative to reductive elimination. The transient absorbance decay of Mn$\sb2$(CO)$\sb7$L$\sb2$ in the presence of HSnBu$\sb3$ obeys pseudo-first-order kinetics. Plots of K$\sb{\rm obs}$ vs. (HSnBu$\sb3$) are linear for L = P(i-Bu)$\sb3$, P(i-Pr)$\sb3$, and P(C$\sb6$H$\sb{11}$)$\sb3$. However, for L = PMe$\sb3$ and P(n-Bu)$\sb3$, the k$\sb{\rm obs}$ vs (HSnBu$\sb3$) plot is non-linear throughout the entire (HSnBu$\sb3$) range. A mechanism involving a rate determining equilibrium between unbridged Mn$\sb2$(CO)$\sb7$L$\sb2$ and semi-bridged Mn$\sb2$(CO)$\sb7$L$\sb2$ prior to oxidative addition of HSnBu$\sb3$ accounts for the experimental observations.
Surface Organometallic Chemistry: Molecular Approaches to Surface Catalysis
Author: Jean-Marie BassetPublisher: Springer Science & Business Media
ISBN: 9400929714
Category : Science
Languages : en
Pages : 340
Book Description
Surface organometallic chemistry is a new field bringing together researchers from organometallic, inorganic, and surface chemistry and catalysis. Topics ranging from reaction mechanisms to catalyst preparation are considered from a molecular basis, according to which the "active site" on a catalyst surface has a supra-molecular character. This. the first book on the subject, is the outcome of a NATO Workshop held in Le Rouret. France, in May. 1986. It is our hope that the following chapters and the concluding summary of recommendations for research may help to provide a definition of surface organometallic chemistry. Besides catalysis. the central theme of the Workshop, four main topics are considered: 1) Reactions of organometallics with surfaces of metal oxides, metals. and zeolites; 2) Molecular models of surfaces, metal oxides, and metals; 3) Molecular approaches to the mechanisms of surface reactions; 4) Synthesis and modification of zeolites and related microporous solids. Most surface organometallic chemistry has been carried out on amorphous high-surf ace-area metal oxides such as silica. alumina. magnesia, and titania. The first chapter. contributed by KNOZINGER. gives a short summary of the structure and reactivity of metal oxide surfaces. Most of our understanding of these surfaces is based on acid base and redox chemistry; this chemistry has developed from X-ray and spectroscopic data, and much has been inferred from the structures and reactivities of adsorbed organic probe molecules. There are major opportunities for extending this understanding by use of well-defined (single crystal) oxide surfaces and organometallic probe molecules.
Progress in Inorganic Chemistry, Volume 29
Author: Stephen J. LippardPublisher: John Wiley & Sons
ISBN: 0470166800
Category : Science
Languages : en
Pages : 412
Book Description
This comprehensive series of volumes on inorganic chemistry provides inorganic chemists with a forum for critical, authoritative evaluations of advances in every area of the discipline. Every volume reports recent progress with a significant, up-to-date selection of papers by internationally recognized researchers, complemented by detailed discussions and complete documentation. Each volume features a complete subject index and the series includes a cumulative index as well.
Chemistry and Structures of Some Polynuclear Metal Carbonyl Complexes
Author: Glenn Richard WilkesPublisher:
ISBN:
Category : Carbonyl compounds
Languages : en
Pages : 356
Book Description
Reactions of Polynuclear Transition Metal Carbonyls with Alkynes
Author: Stephen R. FinnimorePublisher:
ISBN:
Category :
Languages : en
Pages : 448
Book Description
Ultrafast Phenomena XI
Author: Thomas ElsässerPublisher: Springer Science & Business Media
ISBN: 364272289X
Category : Science
Languages : en
Pages : 706
Book Description
This volume contains papers presented at the Eleventh International Conference on Ultrafast Phenomena held at Garmisch-Partenkirchen, Germany, from July 12 to 17, 1998. The biannual Ultrafast Phenomena Conferences provide a forum for dis cussion of the latest advances in ultrafast optics and their applications in science and engineering. The Garmisch conference brought together a multidisciplinary group of 440 participants from 27 countries, including 127 students. The enthu siasm of this large number of Participants, the high quality of the papers they presented and the magnificent conference site resulted in a successful and pleasant conference. Progress was reported in the technology of generating ultrashort pulses, in cluding new techniques for improving laser-pulse duration, tunability over broad wavelength ranges, output power and peak intensity. Ultrafast spectroscopy con tinues to provide new insight into fundamental processes in physics, chemistry, biology, and engineering. In addition to analyzing ultrafast phenomena, control of ultrafast dynamics now represents an important topic. Ultrafast concepts and tech niques are being applied in imaging and microscopy, high speed optoelectronics, mat~rial diagnostics and processing, reflecting the maturing of the field. Acknowledgements. Many people contributed to the success of the conference.
New Pathways In Inorganic Chemistry
Author: Report
Author: Robert A. Welch FoundationPublisher:
ISBN:
Category : Chemistry
Languages : en
Pages : 52
Book Description
Author: George Hansen Young