DOCSLIB.ORG

Synthetic Development and Chemical Reactivity of Transition-Metal

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Synthetic Development and Chemical Reactivity of Transition-Metal Acc. Chem. Res. 2007, 40, 712–719 more stable for the lighter, second period elements.3 Synthetic Development and Further investigation of this concept contributed to the Chemical Reactivity of discovery of silicone polymers and eventually to the discovery of the first compounds with double bonds to Transition-Metal Silylene silicon, silenes and disilenes.4 Whereas much of the exploration of silicon has been patterned after the “blue- Complexes print” of known carbon chemistry, this research has RORY WATERMAN, PAUL G. HAYES, AND consistently revealed marked differences between the two T. DON TILLEY* elements and has led to an appreciation for the novel and Department of Chemistry, University of California, useful properties of silicon-based materials. Berkeley, California 94720-1460 Potential carbon–silicon analogies have also motivated Received February 8, 2007 the development of transition-metal–silicon chemistry. In particular, one such potential relationship has led to height- ABSTRACT ened curiosity over metal silylene complexes, LnMSiR2, A variety of transition-metal complexes with terminal silylene which may possess metal–silicon multiple-bond character ligands have become available in recent years, because of the discovery of several preparative methods. In particular, three and exhibit reactivity patterns analogous to those of the well- general synthetic routes to these complexes have emerged, on the known carbene and alkylidene complexes.5 Transition-metal basis of anionic group abstraction, coordination of a free silylene, silylene complexes are also of interest as postulated inter- and R-hydrogen migration. The direct transformation of organosi- lanes to silylene ligands at a metal center (silylene extrusion) has mediates in a number of metal-catalyzed transformations 6–8 also been observed, and this has further spurred the exploration involving organosilicon compounds. Although metal com- of silylenes as ligands. This Account describes the synthetic plexes of this type have been synthetic targets since the development of silylene ligands in our laboratory and resulting 1960s, they have been realized as definitively isolated investigations of stoichiometric and catalytic chemistry for these species. compounds for only a little less than 15 years. Early, unsuccessful attempts to synthesize silylene complexes produced evidence that these compounds are inherently Introduction very reactive, and heightened interest in the generation of stable examples. Significant progress finally came in 1987 The close relationship of carbon and silicon in the periodic with reports of two so-called base-stabilized silyl- table has inspired many attempts to observe chemical ene complexes, (CO) FeSi(OtBu) [OP(NMe ) ](1) and parallels between these two elements. Thus, some of the 4 2 2 3 [Cp*(Me P) RuSiPh (NCMe)]+ (2).9–11 While such species earliest research on silicon chemistry sought to develop 3 2 2 may reversibly dissociate the base to provide kinetic access pathways to diverse arrays of catenated structures similar to a base-free silylene complex, the ground-state structures to those observed for carbon.1 Whereas this endeavor did not prove fruitful, it established the high reactivity of appear to involve considerable metal–silicon single-bond character (and sp3 silicon), with the positive charge localized simple hydrosilanes, such as SiH4, and foreshadowed the discovery of polysilanes with σ-conjugated silicon back- primarily on the silicon-bound base. Currently, there are bones.2 Early attempts to prepare multiply bonded com- several established routes to base-free silylene complexes pounds of silicon, analogous to those observed for carbon, bearing a variety of substituents at silicon. This synthetic helped fortify the idea that multiple bonds are inherently accessibility to silylene complexes has allowed explorations of their structural, spectroscopic, chemical, and catalytic properties. In this Account, we describe the evolution of Rory Waterman completed his B.S. degree in chemistry at the University of Rochester in 1999. In 2004, he earned a Ph.D. degree in chemistry at The University metal silylene complexes in our laboratories, from a synthetic of Chicago under Professor Gregory L. Hillhouse, studying the organometallic novelty to accessible species that engage in unusual sto- chemistry of three-coordinate nickel complexes. From 2004 to 2006, he was a ichiometric and catalytic transformations. Miller Institute for Basic Research in Science Research Fellow in the laboratories of Professor T. Don Tilley, investigating R elimination and E–H bond activation chemistry. He is currently Assistant Professor of Chemistry at the University of Vermont, with interests in synthetic inorganic and organometallic chemistry, * To whom correspondence should be addressed. E-mail: catalysis, and metal–ligand multiple bonding. [email protected]. Paul G. Hayes was awarded a B.Sc. (honors) degree from Mount Allison T. Don Tilley received his B.S. degree from the University of Texas, Austin, in University in 1999. In 2004, he completed his Ph.D. research on cationic 1977. In 1982, he earned his Ph.D. degree at the University of California, Berkeley, organoscandium complexes under the tutelage of Professor Warren Piers at with R. A. Andersen, studying organometallic lanthanide chemistry. In 1982–1983, the University of Calgary. During his time in Calgary, he was awarded NSERC he participated in a NSF-sponsored postdoctoral exchange program, working and Sir Izaak Walton Killam Doctoral Fellowships as well as a Ralph Steinhauer with Professors Robert Grubbs and John Bercaw at Caltech and with Professors Award of Distinction. In 2004, he undertook a NSERC Postdoctoral Fellowship in Luigi Venanri and Piero Pino at the ETH in Zu¨rich, Switzerland. He started his the laboratories of Professor T. Don Tilley, where he developed new routes to independent career at the University of California, San Diego, in 1983 and rose transition-metal silylyne and stannylyne complexes. He recently joined the to the rank of Professor of Chemistry before moving to his current positions as Department of Chemistry and Biochemistry at the University of Lethbridge as an Professor of Chemistry at the University of California, Berkeley, and Senior Assistant Professor; his current research interests include synthetic and Scientist at Lawrence Berkeley National Laboratory (1994). His research interests mechanistic organometallic chemistry, with a particular focus on the development include synthetic, structural, catalytic, and mechanistic investigations in inorganic of new chemical transformations and catalysis. and organometallic chemistry. 712 ACCOUNTS OF CHEMICAL RESEARCH / VOL. 40, NO. 8, 2007 10.1021/ar700028b CCC: $37.00 2007 American Chemical Society Published on Web 05/03/2007 Transition-Metal Silylene Complexes Waterman et al. Scheme 1. Synthetic Routes to Silylene Complexes Synthetic Routes to Silylene Complexes is tolerant of an array of silicon substituents and has been successfully employed with metals from groups 8, 9, and Transition-metal silylene compounds of the type L MSiRR′ n 10.14 Of course, this approach necessarily produces a possess three-coordinate silicon centers and characteristic cationic (and more electrophilic) silylene complex. low-field 29Si nuclear magnetic resonance (NMR) chemical shifts in the range of δ 200–370. A common feature of silylene A second type of silylene complex has become available compounds is the Lewis acidity of the silicon center. This with the discovery of isolable, free silylenes, in which the π represents an unusual situation, because Lewis acidic centers divalent silicon center is stabilized by donation from are rarely found as donor atoms in transition-metal com- two nitrogen substituents. The coordination complexes plexes. As will be illustrated, this pairing of an acidic silicon of these silylenes appear to be distinct from those men- tioned above, as indicated by their significantly higher center with a transition metal accounts for much of the 29 observed reaction chemistry. An archetypical reaction type field Si NMR chemical shifts (97.5–146.9 ppm), which for silylene complexes is the coordination of a Lewis base are similar to resonances previously observed for base- ) stabilized silylene complexes of the type LnMSiR2(B) (B to the low-valent silicon center. A representative ex- 15,16 ample of such coordination is the reaction of two-electron donor). Also, complexes of stable, free [Cp*(Me P) RudSi(SR) ][BPh ](3a,R) p-tol; 3b,R) Et) silylenes appear to be weakly Lewis acidic at silicon, 3 2 2 4 ′ with acetonitrile to form the base-stabilized silylene com- whereas the previously described LnMSiRR examples 12 usually bind strongly to Lewis bases. These remarkably plex [Cp*(Me3P)2RuSiR2(NCCH3)][BPh4](4a and 4b;eq1). The reverse reaction, whereby a Lewis base is lost from a stable silylenes have been the subject of thorough reviews, and their coordination chemistry will not be discussed base-complexed silylene ligand to afford the terminal silylene 15 ligand has not been directly observed, but there is consider- here. However, it should be noted that the strategy of able kinetic evidence for this dissociation process.13 capturing a thermally unstable silylene fragment with a metal center is also possible. Low-valent platinum species ) i L2Pt (L Pr3P and Cy3P) have been shown to intercept photochemically generated dimesitylsilylene to form the terminal three-coordinate Pt–silylene complexes d ) L2Pt SiMes2 (Scheme 1;
Load more

Recommended publications
  • Studies on Dimethylsilylene James Bailey Kimble III Iowa State University
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1977 Studies on dimethylsilylene James Bailey Kimble III Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Kimble, James Bailey III, "Studies on dimethylsilylene " (1977). Retrospective Theses and Dissertations. 7566. https://lib.dr.iastate.edu/rtd/7566 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS This material was produced from a microfilm copy of the original document. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the original submitted. The following explanation of techniques is provided to help you understand markings or patterns which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting thru an image and duplicating adjacent pages to insure you complete continuity. 2. When an image on the film is obliterated with a large round black mark, it is an indication that the photographer suspected that the copy may have moved during exposure and thus cause a blurred image.
    [Show full text]
  • Synthesis, Structure and Reactivity of Neutral Hydrogen-Substituted
    5082 Organometallics 2009, 28, 5082–5089 DOI: 10.1021/om900348m Synthesis, Structure, and Reactivity of Neutral Hydrogen-Substituted Ruthenium Silylene and Germylene Complexes Paul G. Hayes,† Rory Waterman,‡ Paul B. Glaser,§ and T. Don Tilley* Department of Chemistry, University of California, Berkeley, California 94720-1460. †Current address: Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada, T1K 3M4. ‡ Current address: Department of Chemistry, University of Vermont, Burlington, Vermont 05405. §Current address: General Electric Global Research, Niskayuna, NY 12309. Received May 3, 2009 i Reaction of Cp*( Pr2MeP)RuCl (1) with 0.5 equiv of Mg(CH2Ph)2(THF)2 afforded the benzyl i 3 complex Cp*( Pr2MeP)Ru(η -CH2Ph) (2). Complex 2 readily reacted with primary silanes H3SiR F i F (R = trip, dmp, Mes ; trip = 2,4,6- Pr3-C6H2, dmp = 2,6-Mes2-C6H3,Mes = 2,4,6-(CF3)3-C6H2) i to liberate toluene and afford hydrogen-substituted silylene complexes Cp*( Pr2MeP)(H)RudSiH(R) [R = trip, 3;dmp,4;MesF, 5]. Complexes 3-5 exhibit characteristic SiH 1H NMR resonances downfield 2 of 8 ppm and very small JSiH coupling constants (8-10 Hz). The solid state structures of complexes 3 and 5 feature short Ru-Si distances of 2.205(1) and 2.1806(9) A˚, respectively, and planar silicon centers. In i addition, the silylene complex Cp*( Pr2MeP)(H)RudSiPh(trip) (6) and the unusual, chlorine-substituted i species Cp*( Pr2MeP)(H)RudSiCl(R) [R = trip, 7;dmp,8] were prepared. Hydrogen-substituted i ruthenium germylene complex Cp*( Pr2MeP)(H)RudGeH(trip) (9) was prepared similarly by reaction of 2 with tripGeH3.
    [Show full text]
  • Qt19b5p2m8 Nosplash 248Fed3
    UNIVERSITY OF CALIFORNIA RIVERSIDE The Development of Transition Metal Silylene and Germylene Complexes for Small Molecule Activation A Dissertation submitted in partial satisfaction of the requirements for the degree of Doctor of Philosophy in Chemistry by Marissa Christina Barrientos September 2019 Dissertation Committee: Dr. Hill Harman, Chairperson Dr. Richard Hooley Dr. Yadong Yin Copyright by Marissa Christina Barrientos 2019 The Dissertation of Marissa Christina Barrientos is approved: Committee Chairperson University of California, Riverside Acknowledgments I first and foremost would like to thank my advisor and mentor, Dr Hill Harman. I am forever grateful for the unique experience of being one of your first graduate students. I thank you for all your support and making me the chemist I am now. I would also like to thank the members of my committee, Dr. Richard Hooley and Dr. Yadong Yin. Thank you for all your support and the discussions throughout my time. I would also like to thank the ACIF staff for all their help and support. Thank you to Dr. Dan Borchardt for all your help especially in setting up all those difficult silicon NMR experiments. I would also like to thank Dr. Fook Tham and Dr. Charlene Tsay for their skills and expertise in helping to mount crystals and solving XRD structures. I also want to thank Dr. Richard Kondrat and Dr. Ron New for their expertise in helping to obtain LIFDI results which were invaluable. Last, but certianly not least, I would like to thank Prisciliano Saavedra for all his help in supplying our lab and many solutions to lab issues.
    [Show full text]
  • Reactions of an Isolable Dialkylsilylene with Aroyl Chlorides
    molecules ArticleArticle Reactions of an Isolable Dialkylsilylene with Aroyl ReactionsArticle of an Isolable Dialkylsilylene with Aroyl Chlorides.ReactionsChlorides. of A A anNew New Isolable Route Route Dialkylsilyleneto to Aroylsilanes Aroylsilanes with Aroyl Xu-QiongChlorides.Xu-Qiong Xiao, Xiao, Xupeng Xupeng A NewLiu, Liu, Qiong Qiong Route Lu, Lu, Zhifang Zhifang to Li LiAroylsilanes *, *, Guoqiao Guoqiao Lai Lai and and Mitsuo Mitsuo Kira Kira * * Key Laboratory of Organosilicon Chemistry and Material Technology of Ministry of Education, Xu-QiongKey Laboratory Xiao, Xupeng of Organosilicon Liu, Qiong Chemistry Lu, Zhifang and Material Li *, TechnologyGuoqiao Lai of Ministryand Mitsuo of Education, Kira * HangzhouHangzhou Normal Normal University, University, Hangzhou Hangzhou 311121, 311121, China; China; xqxiao [email protected]@hznu.edu.cn (X.-Q.X.); (X.-Q.X.); [email protected]@163.com Laboratory of Organosilicon (X.L.) (X.L.);; [email protected] [email protected] Chemistry and (Q.L.);Ma (Q.L.);terial [email protected] [email protected] Technology of Mini (G.L.) (G.L.)stry of Education, *Hangzhou * Correspondence:Correspondence: Normal University,[email protected] [email protected] Hangzhou 311121, (Z.L.); (Z.L.); China; [email protected] [email protected] [email protected] (M.K.); (M.K.); (X.-Q.X.); Tel.: +86-571-2886-7825 (Z.L.) [email protected].: +86-571-2886-7825 (X.L.) (Z.L.); [email protected] (Q.L.); [email protected] (G.L.) * AcademicCorrespondence: Editor: Derek [email protected] J. McPhee (Z.L.); [email protected] (M.K.); Academic Editor: Derek J. McPhee Received:Tel.: +86-571-2886-7825 14 September 2016;(Z.L.) Accepted: 8 October 2016; Published: 15 October 2016 Received: 14 September 2016; Accepted: 8 October 2016; Published: date AcademicAbstract: Editor:The reactions Derek J.
    [Show full text]
  • Synthesis of Di- and Trisilanes with Potentially Chelating Substituents
    Journal of Organometallic Chemistry 649 (2002) 25–42 www.elsevier.com/locate/jorganchem Synthesis of di- and trisilanes with potentially chelating substituents Johannes Belzner a,1*, Uwe Dehnert a, Dirk Scha¨r a, Bernhard Rohde a, Peter Mu¨ller b, Isabel Uso´n b a Institut fu¨r Organische Chemie der Georg-August-Uni6ersita¨t Go¨ttingen, Tammannstr. 2, D-37077 Go¨ttingen, Germany b Institut fu¨r Anorganische Chemie der Georg-August-Uni6ersita¨t Go¨ttingen, Tammannstr. 4, D-37077 Go¨ttingen, Germany Received 3 April 2001; received in revised form 29 May 2001; accepted 29 October 2001 Abstract Silylenes 2 or 4, generated by thermolysis of cyclotrisilanes 1 and 3, were inserted into the SiCl or SiH bonds of monosilanes to yield a variety of disilanes, which can be further functionalized subsequently. In a few cases, trisilanes are accessible by the reaction of 1 with disilanes. The reaction of a metalated silane with a chlorosilane is an alternative method for the formation of SiSi bonds, which turned out to be especially useful for the synthesis of bulkily substituted disilanes. Some of the new dichlorodi- and trisilanes themselves serve as thermal precursors of silylenes 2 or 4, the extrusion of which can be catalyzed by 1 or 3 in certain cases. © 2002 Elsevier Science B.V. All rights reserved. Keywords: Silylenes; Oligosilanes; Halosilanes; Siliconsilicon bond formation 1. Introduction crucial intermediate—to the formation of symmetri- cally substituted disilanes [1]. In contrast, geminally Two principal reaction pathways are available for the dihalogenated silanes do not serve as synthetically use- formation of SiSi bonds (Scheme 1).
    [Show full text]
  • The Synthesis of Carbacyclic Silanes Via Organosilicon Reactive Intermediates Michael J
    Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1984 The synthesis of carbacyclic silanes via organosilicon reactive intermediates Michael J. Vuper Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Vuper, Michael J., "The synthesis of carbacyclic silanes via organosilicon reactive intermediates " (1984). Retrospective Theses and Dissertations. 7737. https://lib.dr.iastate.edu/rtd/7737 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. INFORMATION TO USERS Tliis reproduction was made from a copy of a document sent to us for microfilming. While the most advanced technology has been used to photograph and reproduce this document, the quality of the reproduction is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help clarify markings or notations which may appear on this reproduction. 1. The sign or "target" for pages apparently lacking from the document photographed is "Missing Page(s)". If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure complete continuity. 2. When an image on the film is obliterated with a round black mark, it is an indication of either blurred copy because of movement during exposure, duplicate copy, or copyrighted materials that should not have been filmed.
    [Show full text]
  • Facile Access to Dative, Single, and Double Silicon−Metal Bonds
    Full Paper Chemistry—A European Journal doi.org/10.1002/chem.202000866 & Transition Metals |Hot Paper| Facile Access to Dative, Single, and Double Silicon Metal Bonds Through M Cl Insertion Reactions of Base-StabilizedÀ SiII Cations À PhilippFrisch,[a] Tibor Szilvµsi,[b] and Shigeyoshi Inoue*[a] Abstract: Silicon(II) cationscan offer fascinating reactivity 1,2-migration of asilicon-bound NHC to the transition metal patterns due to their unique electronic structure:alone pair takes place after formation of an initial silyliumylidene transi- of electrons,two empty porbitals and apositive charge tion-metal complex.The mechanism could be verified exper- combined on asingle silicon center.Wenow reportthe imentally through characterization of the intermediate com- facile insertion of N-heterocycliccarbene(NHC)-stabilized si- plexes. Furthermore, the obtained chlorosilylene complexes lyliumylidene ions into M Cl bonds (M =Ru, Rh), forming a can be conveniently utilized as synthons to access Si Mand À À series of novel chlorosilylene transition-metal complexes. Si=Mbonding motifs bondsthrough reductive dehalogena- Theoretical investigations revealed areactionmechanism in tion. which the insertioninto the M Cl bond with concomitant À Introduction Hence, both amount anddiversity of reported reactivities lag behind those of silylenes, where common reactivity pat- The presence of alone pair of electrons, two vacant orbitals terns include insertion reactions into varioustypes of (strong) and apositivechargeonthe silicon centermakes silyliumyli- bonds.
    [Show full text]
  • Occurrence and Use of Highly Fluorinated Substances and Alternatives
    REPORT7/15 Occurrence and use of highly fluorinated substances and alternatives Report from a government assignment kemikalieinspektionen.se The Swedish Chemicals Agency is supervisory authority under the Government. We work in Sweden, the EU and internationally to develop legislation and other incentives to promote good health and improved environment. We monitor compliance of applicable rules on chemical products, pesticides and substances in articles and carry out inspections. We review and authorise pesticides before they can be used. Our environmental quality objective is A Non-toxic Environment. © Swedish Chemicals Agency. Print: Arkitektkopia, Stockholm 2015. ISSN 0284-1185. Article number: 361 164. Order print from Arkitektkopia AB, Box 11093, SE-161 11 Bromma. Order tel: +46 8 505 933 35, Order fax: +46 8 505 933 99, e-mail: [email protected]. Preface The Swedish Chemicals Agency (KEMI) has been assigned by the Swedish Government to produce a national action plan for a toxic-free everyday environment: Action plan for a toxic- free everyday environment 2011 – 2014 – protect the children better. The action plan has been extended to 2020. Efforts are going on in several areas, both in Sweden, within the EU and internationally and often in cooperation with other authorities. Reducing chemical risks in the everyday environment is one step towards attaining the Swedish Parliament´s environment quality objective A Non-Toxic Environment, which is the objective that the Swedish Chemicals Agency is responsible for. Within the framework of the action plan, we compile knowledge in the Swedish Chemicals Agency’s report and PM series elaborated by experienced colleagues, researchers or consultants.
    [Show full text]
  • Generation of Bis(Ferrocenyl)Silylenes from Siliranes
    molecules Article y Generation of Bis(ferrocenyl)silylenes from Siliranes Yang Pan 1, Shogo Morisako 2 , Shinobu Aoyagi 1 and Takahiro Sasamori 1,2,* 1 Graduate School of Science, Nagoya City University, Nagoya, Aichi 467-8501, Japan; [email protected] (Y.P.); [email protected] (S.A.) 2 Division of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki 305-8571, Japan; [email protected] * Correspondence: [email protected]; Tel.: +81-29-853-4412 Dedicated to Professor Yosuke Yamamoto on the occasion of his 65th birthday. y Academic Editor: M.-H. Whangbo Received: 23 November 2020; Accepted: 9 December 2020; Published: 14 December 2020 Abstract: Divalent silicon species, the so-called silylenes, represent attractive organosilicon building blocks. Isolable stable silylenes remain scarce, and in most hitherto reported examples, the silicon center is stabilized by electron-donating substituents (e.g., heteroatoms such as nitrogen), which results in electronic perturbation. In order to avoid such electronic perturbation, we have been interested in the chemistry of reactive silylenes with carbon-based substituents such as ferrocenyl groups. Due to the presence of a divalent silicon center and the redox-active transition metal iron, ferrocenylsilylenes can be expected to exhibit interesting redox behavior. Herein, we report the design and synthesis of a bis(ferrocenyl)silirane as a precursor for a bis(ferrocenyl)silylene, which could potentially be used as a building block for redox-active organosilicon compounds. It was found that the isolated bis(ferrocenyl)siliranes could be a bottleable precursor for the bis(ferrocenyl)silylene under mild conditions.
    [Show full text]
  • SILANE, (CH3)2Sicl2
    Naturaleza y Tecnología Enero-Mayo 2021 ISSN 2007-672X Universidad de Guanajuato DISCOVERY OF METHYLCHLOROSILYLENE (CH SiCl:) AS A KEY 3 INTERMEDIATE IN THE DIRECT SYNTHESIS OF DIMETHYLDICHLORO- SILANE, (CH3)2SiCl2 Kenrick M. Lewis, Momentive Performance Materials, 771 Old Sawmill River Rd., Tarrytown, NY 10591. Preambulo sólido-gas catalizada por cobre. El Me2SiCl2 era conocido con anterioridad En uno de los números recientes de la desde antes de la Segunda Guerra revista Organometallics (2021, 40, 459- Mundial, sin embargo, su síntesis, se 462) en la que se incluye una sección basaba en una reacción de metátesis entre dedicada a personalidades pioneras en la tetracloruro de silicio (SiCl4) y un reactivo química organometálica y cuyas de Grignard, por ejemplo, MeMgBr. Se investigaciones han tenido gran influencia conocía que su hidrólisis permitía obtener en el campo industrial, se hace referencia el poli(dimetilsiloxano), por lo que al Dr. Kenrick M. Lewis, cuyos trabajos resultaba muy conveniente y atractiva su son reconocidos al impactar en aspectos síntesis debido a su estabilidad térmica y a fundamentales de la química de muchas aplicaciones que potencialmente organosilanos, entre ellos, la famosa se podrían desarrollar en aislantes para reacción directa de producción de motores eléctricos, radios de vuelo y diclorodimetilsilano (Me2SiCl2), muchas más, motivado a la vez por la compuesto químico esencial para la necesidad de materiales con aplicaciones industria moderna de los polímeros de militares. Sin embargo, la reacción no era
    [Show full text]
  • And Poly(Silylene Dipropargyl Aryl Ether)
    polymers Article Synthesis and Characterization of Block Copolymers of Poly(silylene diethynylbenzen) and Poly(silylene dipropargyl aryl ether) Man Gao 1 , Chengyuan Shang 2, Jixian Li 1, Gang Han 1, Junkun Tang 1, Qiaolong Yuan 1 and Farong Huang 1,* 1 Key Laboratory of Specially Functional Polymeric Materials and Related Technology (Ministry of Education), School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China; [email protected] (M.G.); [email protected] (J.L.); [email protected] (G.H.); [email protected] (J.T.); [email protected] (Q.Y.) 2 Research and Application Center for Structural Composites, Aerospace Research Institute of Materials & Processing Technology, Beijing 100076, China; [email protected] * Correspondence: [email protected] Abstract: Poly(silylene diethynylbenzene)–b–poly(silylene dipropargyloxy diphenyl propane) copoly- mer (ABA-A), poly(silylene diethynylbenzene)–b–poly(silylene dipropargyloxy diphenyl ether) copolymer (ABA-O), and a contrast poly(silylene diethynylbenzene) with equivalent polymeriza- tion degree were synthesized through Grignard reactions. The structures and properties of the copolymers were investigated via hydrogen nuclear magnetic resonance, Fourier transform infrared spectroscopy, Haake torque rheometer, differential scanning calorimetry, dynamic mechanical analy- sis, thermogravimetric analysis and mechanical tests. The results show that the block copolymers possess comprehensive properties, especially good processability and good mechanical properties. Citation: Gao, M.; Shang, C.; Li, J.; ◦ Han, G.; Tang, J.; Yuan, Q.; Huang, F. The processing windows of these copolymers are wider than 58 C. The flexural strength of the cured Synthesis and Characterization of ABA-A copolymer reaches as high as 40.2 MPa.
    [Show full text]
  • Surprising Reactivity for Silylene Coordination Compounds with a Dynamic N.-Si.-N Bonds
    2162 Organometallics 1993,12, 2162-2176 Reversible Intramolecular Base Stabilization in Silylene (Silanediyl) Complexes: Surprising Reactivity for Silylene Coordination Compounds with a Dynamic N.-Si.-N Bonds Hermann Handwerker, Christian Leis, Reiner Probst, Peter Bissinger,t Andreas Grohmann,$ Pavlo Kiprof,t Eberhardt Herdtweck,$ Janet Blumel,? Norbert Auner,’ and Christian Zybill’ Anorganisch-chemisches Institut, Technische Universitat Miinchen, Lichtenbergstrasse 4, 85748 Garching, Federal Republic of Germany Received November 18, 1992 The silane [2-(MezNCHz)C&] ZSiClz (7) shows a new dynamic N**&-N “flip-flop”coordination mode below T,= 233 K (AG* = 46.5 (f0.5) kJ mol-l) with both amine donors displacing each other. 7 is pentacoordinated in the solid state; crystal data: orthorhombic, Paca,a = 13.802(1) A, b = 17.908(1) A, c = 15.544(2) A, Z = 8. Reaction of the silanes C~H~[~-(M~ZNCHZ)C~H~]S~C~P (61, 7, and [~-(M~ZNCHZ)-~-(~-C~H~)C~H~~ZS~C~Z(8) with chromiumpentacarbonyl- metallate yields the silanediyl complexes [~-(M~zNCHZ)C~H~IC~H~S~=C~(CO)B(111, [2-(Mez- NCHZ)C~H~]zSi=Cr(CO)5 (12), and 12- (M~zNCHZ)-~-(~-C~H~)C~H~IzSi=Cr(CO)s (13); 12- (Mez- NCHZ)C~H~]HS~=C~(CO)~(14) was obtained by photolytic methods. Silanediyl complexes with one chelating donor show a rigid coordination of the donor to silicon which can be lifted at higher temperatures (95 ‘C for 11, AG* = 80.4 (*0.5) kJ mol-’). A single crystal X-ray structure determination of 11 reveals a CrSi bond distance of 2.409(1) A and a N-Si bond length of 1.991(2) A.
    [Show full text]