[ { "id": "authors:hyg9x-0w866", "collection": "authors", "collection_id": "hyg9x-0w866", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141215-141605227", "type": "book_section", "title": "Bis(\u03b7^5-Pentamethylcyclopentadienyl) Complexes of Niobium and Tantalum", "book_title": "Inorganic Syntheses", "author": [ { "family_name": "Min", "given_name": "Endy Y.-J", "clpid": "Min-Endy-Y-J" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Chen", "given_name": "Shujian", "clpid": "Chen-Shujian" }, { "family_name": "Xue", "given_name": "Zi-Ling", "clpid": "Xue-Zi-Ling" } ], "contributor": [ { "family_name": "Girolami", "given_name": "G. S.", "clpid": "Girolami-G-S" }, { "family_name": "Sattelberger", "given_name": "A. P.", "clpid": "Sattelberger-A-P" } ], "abstract": "Bent metallocene derivatives having \u03b7^5-C_5Me_5 ligands (\"permethylmetallocene\" derivatives) offer advantages over their \u03b7^5-C_5H_5 analogs in that they generally display greater thermal stability and are less prone to dimerize through single-atom bridges. These properties have allowed the development of a rich chemistry of group 3 and 4 d-block and f-block transition metal compounds with pentamethylcyclopentadienyl ancillary ligands. Although permethylniobocene and permethyltantalocene derivatives display reactivities similar to the parent niobocene and tantalocene analogs, their increased electron density at niobium and tantalum, their greater steric crowding, and their higher thermal stabilities offer some advantages in probing fundamental transformations such as \u03b1- and \u03b2-migratory insertion and elimination processes. Convenient synthetic entry points to these compounds are (\u03b7^5-C_5Me_5)_2NbCl_2 and (\u03b7^5-C_5Me_5)_2TaCl_2. These compounds can be reduced under dihydrogen to yield (\u03b7^5-C_5Me_5)_2MH_3 (M\u2550Nb, Ta), which catalyzes the exchange of molecular hydrogen with benzene-d^6.", "doi": "10.1002/9781118744994.ch11", "isbn": "9781118744871", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "2014-04-11", "pages": "52-57" }, { "id": "authors:bnzhe-j2f36", "collection": "authors", "collection_id": "bnzhe-j2f36", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141215-144354161", "type": "book_section", "title": "Bis(\u03b7\u2075-Pentamethylcyclopentadienyl) Complexes of Scandium", "book_title": "Inorganic Syntheses", "author": [ { "family_name": "Min", "given_name": "Endy Y.-J", "clpid": "Min-Endy-Y-J" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Kenward", "given_name": "Alyson L.", "clpid": "Kenward-Alyson-L" }, { "family_name": "Piers", "given_name": "Warren", "clpid": "Piers-Warren" } ], "contributor": [ { "family_name": "Girolami", "given_name": "G. S.", "clpid": "Girolami-G-S" }, { "family_name": "Sattelberger", "given_name": "A. P.", "clpid": "Sattelberger-A-P" } ], "abstract": "Use of pentamethylcyclopentadienyl ligands (C\u2085Me\u2085) in place of cyclopentadienyl (Cp) provides reactive, but thermally robust monomelic 14-electron scandocene derivatives. A useful starting material for the synthesis of a variety of derivatives of permethylscandocene is the chloride complex. All experiments discussed in this chapter are conducted under argon in a glove box or a high-vacuum line. The chapter describes the procedures for the preparation and properties of bis(\u03b7\u2075-pentamethylcyclopentadienyl) chloroscandium, bis(\u03b7\u2075-pentamethylcyclopentadienyl) methylscandium, bis(\u03b7\u2075-pentamethylcyclopentadienyl) phenylscandium, and bis(\u03b7\u2075-pentamethylcyclopentadienyl)(o-tolyl) scandium.", "doi": "10.1002/9781118744994.ch09", "isbn": "9781118744871", "publisher": "Wiley", "place_of_publication": "Hoboken, N.J.", "publication_date": "2014-04-11", "pages": "42-47" }, { "id": "authors:0jpz4-hy426", "collection": "authors", "collection_id": "0jpz4-hy426", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170404-100242714", "type": "book_section", "title": "Bis(\u03b7\u2075-Pentamethylcyclopentadienyl) Complexes of Molybdenum", "book_title": "Inorganic Syntheses", "author": [ { "family_name": "Shin", "given_name": "Jun Ho", "clpid": "Shin-Jun-Ho" }, { "family_name": "Churchill", "given_name": "David G.", "clpid": "Churchill-David-G" }, { "family_name": "Parkin", "given_name": "Gerard", "clpid": "Parkin-Gerard" }, { "family_name": "Roggan", "given_name": "Stefan", "clpid": "Roggan-Stefan" }, { "family_name": "Jankowski", "given_name": "Christel", "clpid": "Jankowski-Christel" }, { "family_name": "Limberg", "given_name": "Christian", "clpid": "Limberg-Christian" }, { "family_name": "Tonks", "given_name": "Ian", "clpid": "Tonks-Ian-A" }, { "family_name": "Bercaw", "given_name": "John", "clpid": "Bercaw-J-E" } ], "contributor": [ { "family_name": "Girolami", "given_name": "Gregory S.", "clpid": "Girolami-G-S" }, { "family_name": "Sattelberger", "given_name": "Alfred P.", "clpid": "Sattelberger-A-P" } ], "abstract": "Molybdenocene and tungstenocene complexes have played a prominent role in the development of organometallic chemistry. This chapter describes the synthesis of (\u03b7\u2075-C\u2085Me\u2085)\u2082MoCl\u2082 and (\u03b7\u2075-C\u2085Me\u2085)\u2082MoH\u2082. (\u03b7\u2075-C\u2085Me\u2085)\u2082MoCl\u2082 is obtained by a two-step sequence involving (i) the reaction of MoCl\u2085 with a mixture of KC\u2085Me\u2085 and NaBH\u2084 to give crude (\u03b7\u2075-C\u2085Me\u2085)\u2082MoH\u2082, followed by (ii) addition of CHCl\u2083. (\u03b7\u2075-C\u2085Me\u2085)\u2082MoCl\u2082 is a useful precursor for a variety of other permethylmolybdenocene derivatives, which include hydride, alkyl, carbonyl, and oxo complexes.", "doi": "10.1002/9781118744994.ch12", "isbn": "9781118744871", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "2014-04-11", "pages": "58-62" }, { "id": "authors:kbs67-18484", "collection": "authors", "collection_id": "kbs67-18484", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20141215-151719573", "type": "book_section", "title": "Bis(\u03b7^5-Pentamethylcyclopentadienyl) Complexes of Titanium, Zirconium, and Hafnium", "book_title": "Inorganic Syntheses", "author": [ { "family_name": "Min", "given_name": "Endy Y.-J.", "clpid": "Min-Endy-Y-J" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Bernskoetter", "given_name": "Wesley", "clpid": "Bernskoetter-Wesley" }, { "family_name": "Chirik", "given_name": "Paul J.", "clpid": "Chirik-Paul-J" } ], "contributor": [ { "family_name": "Girolami", "given_name": "G. S.", "clpid": "Girolami-G-S" }, { "family_name": "Satterberger", "given_name": "A. P.", "clpid": "Satterberger-A-P" } ], "abstract": "The chemistry of organometallic derivatives of titanium and zirconium bearing two pentamethylcyclopentadienyl groups as ancillary ligands has proven to be rich and varied, whereas that for hafnium is still in its formative stages. Derivatives of permethyltitanocene, permethylzirconocene, and permethylhafnocene offer a number of advantages over their (\u03b75-C5H5) analogs. Generally, they exhibit higher thermal stability, solubility, and crystallinity. Furthermore, the steric bulk of the pentamethylcyclopentadienyl group discourages oligomerization through singleatom bridges (H, O, N), thus rendering permethylmetallocene derivatives monomeric. Such properties have facilitated the development of a rich and diverse reaction chemistry for compounds of the group 4 transition metals with pentamethylcyclopentadienyl ancillary ligands.", "doi": "10.1002/9781118744994.ch10", "isbn": "9781118744871", "publisher": "Wiley", "place_of_publication": "Hoboken, NJ", "publication_date": "2014-04-11", "pages": "47-51" }, { "id": "authors:q0zsn-en450", "collection": "authors", "collection_id": "q0zsn-en450", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20110826-140851864", "type": "book_section", "title": "The Role of Higher Oxidation State Species in Platinum-Mediated C\u2013H Bond Activation and Functionalization", "book_title": "Higher Oxidation State Organopalladium and Platinum Chemistry", "author": [ { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" } ], "contributor": [ { "family_name": "Canty", "given_name": "Allan J.", "clpid": "Canty-A-J" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" } ], "abstract": "The Shilov system, a mixture of di- and tetravalent chloroplatinate salts in aqueous solution, provided the first indication of the potential of organotransition\nmetal complexes for activating and functionalizing alkanes under mild conditions; the participation of higher-valent species plays a crucial role. In this chapter, we discuss the experimental and computational studies that have led to detailed mechanistic understanding of C\u2013H activation and functionalization by both the original Shilov system and the many subsequent modifications that have been developed, and assess the prospects for practical, selective catalytic oxidation of alkanes using this chemistry.", "doi": "10.1007/978-3-642-17429-2_2", "isbn": "978-3-642-17428-5", "publisher": "Springer", "place_of_publication": "Berlin", "publication_date": "2011", "pages": "29-59" }, { "id": "authors:t4t9j-7vx41", "collection": "authors", "collection_id": "t4t9j-7vx41", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161206-102601857", "type": "book_section", "title": "C\u2014H Bond Activation at Pt(II): A Route to Selective Alkane Oxidation?", "book_title": "Activation and Functionalization of C\u2014H Bonds", "author": [ { "family_name": "Heyduk", "given_name": "Alan F.", "clpid": "Heyduk-A-F" }, { "family_name": "Zhong", "given_name": "H. Annita", "clpid": "Zhong-H-Annita" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" } ], "contributor": [ { "family_name": "Goldberg", "given_name": "Karen I.", "clpid": "Goldberg-K-I" }, { "family_name": "Goldman", "given_name": "Alan S.", "clpid": "Goldman-A-S" } ], "abstract": "A hypothetical catalytic cycle for the selective oxidation of alkanes to alcohols by dioxygen may be based on the activation of C-H bonds at Pt(II) centers, coupled with additional known organoplatinum chemistry. Mechanistic studies on the C-H activation process offer guides for designing potential catalytic species.", "doi": "10.1021/bk-2004-0885.ch015", "isbn": "9780841238497", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "2004-07-12", "pages": "250-263" }, { "id": "authors:r8w3w-zjb82", "collection": "authors", "collection_id": "r8w3w-zjb82", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161206-104838539", "type": "book_section", "title": "C-H Bond Activation with Neutral Platinum Methyl Complexes", "book_title": "Activation and Functionalization of C\u2014H Bonds", "author": [ { "family_name": "Iverson", "given_name": "Carl N.", "clpid": "Iverson-Carl-N" }, { "family_name": "Carter", "given_name": "Charles A. G.", "clpid": "Carter-Charles-A-G" }, { "family_name": "Scollard", "given_name": "John D.", "clpid": "Scollard-John-D" }, { "family_name": "Pribisko", "given_name": "Melanie A.", "clpid": "Pribisko-Melanie-A" }, { "family_name": "John", "given_name": "Kevin D.", "clpid": "John-Kevin-D" }, { "family_name": "Scott", "given_name": "Brian L.", "clpid": "Scott-Brian-L" }, { "family_name": "Baker", "given_name": "R. Tom", "clpid": "Baker-R-Tom" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" }, { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-Jay-A" } ], "contributor": [ { "family_name": "Goldberg", "given_name": "Karen I.", "clpid": "Goldberg-Karen-I" }, { "family_name": "Goldman", "given_name": "Alan S.", "clpid": "Goldman-Alan-S" } ], "abstract": "The selective metal-catalyzed oxidation of alkanes to alcohols offers immense opportunities for saving energy and reducing waste in the petroleum and chemical manufacturing industries. Robust transition metal complexes with chelating nitrogen ligands show great promise as homogeneous catalysts for this reaction, but a practical system has yet to be identified. In this work a variety of neutral platinum methyl complexes with bidentate anionic N,N- and N,C-donor ligands were prepared. Ligand backbones included one, two, and three-atom bridges between the donor atoms. Redox properties of the new complexes were investigated using competition studies with I_2 and evaluating equilibrium constants between divalent methyl complexes and their tetravalent diiodides. The ease of oxidation was amidinate > \u03b2-diketiminate > iminopyrrolide. Studies of benzene C-H bond activation using iminopyrrolide platinum complexes were consistent with rate determining benzene association and revealed a novel geometric effect on the rate for iminopyrrolide ligands.", "doi": "10.1021/bk-2004-0885.ch019", "isbn": "9780841238497", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "2004-07-12", "pages": "319-333" }, { "id": "authors:43b3d-38363", "collection": "authors", "collection_id": "43b3d-38363", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20161130-153120635", "type": "book_section", "title": "Reactivity and Mechanistic Studies of Stereocontrol for Ziegler\u2014Natta Polymerization Utilizing Doubly-Silylene Bridged Group 3 and Group 4 Metalocenes", "book_title": "Olefin Polymerization", "author": [ { "family_name": "Zubris", "given_name": "D. L.", "clpid": "Zubris-D-L" }, { "family_name": "Veghini", "given_name": "D.", "clpid": "Veghini-D" }, { "family_name": "Herzog", "given_name": "T. A.", "clpid": "Herzog-T-A" }, { "family_name": "Bercaw", "given_name": "J. E.", "clpid": "Bercaw-J-E" } ], "contributor": [ { "family_name": "Arjunan", "given_name": "Palanisamy", "clpid": "Arjunan-P" }, { "family_name": "McGrath", "given_name": "James E.", "clpid": "McGrath-J-E" }, { "family_name": "Hanlon", "given_name": "Thomas L.", "clpid": "Hanlon-T-L" } ], "abstract": "A family of zirconocene, yttrocene, and scandocene complexes have been prepared utilizing an easily modified doubly bridged ligand array, (1,2-SiMe_2)_2{\u03b7^5-C_5H_2-4-R}{\u03b7^5-C_5H-3,5-CHMe_2)_2}, developed in our laboratories. Variations in ligand array substitution and metal center provide complexes that exhibit a range of stereoselectivities and activities in \u03b1-olefin polymerizations. A series of C_(s-) and C_(1-) symmetric metallocenes have been utilized for the preparation of polypropylene and polypentene under various polymerization conditions. Analysis of the resulting polymer microstructures has provided valuable information about the factors that dictate syndiospecificity, as well as common error forming mechanisms for these systems.", "doi": "10.1021/bk-2000-0749.ch001", "isbn": "9780841236141", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1999-12-29", "pages": "2-14" }, { "id": "authors:g0bd5-96n86", "collection": "authors", "collection_id": "g0bd5-96n86", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-131938956", "type": "book_section", "title": "Selective Hydroxylation of Hydrocarbons by Platinum Salts in Aqueous Media Direct Conversion of Ethanol to Ethylene Glycol", "book_title": "Homogeneous Transition Metal Catalyzed Reactions", "author": [ { "family_name": "Labinger", "given_name": "Jay A.", "orcid": "0000-0002-1942-9232", "clpid": "Labinger-J-A" }, { "family_name": "Herring", "given_name": "Andrew M.", "clpid": "Herring-A-M" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" } ], "abstract": "Water-soluble organic compounds are hydroxylated by aqueous solutions of chloroplatinum(II) and chloroplatinum(IV) salts. p-Toluenesulfonic acid is converted stepwise to the corresponding alcohol and aldehyde, the first step being somewhat faster than the second. No further conversion to the carboxylic acid is observed. Ethanol shows substantial selectivity for attack at a C-H bond of the methyl group, affording ethylene glycol and 2-chloroethanol, as well as more expected products such as acetaldehyde and acetic acid. The origin of the unusual selectivity patterns is discussed in terms of the mechanism of activation of C-H bonds by Pt(II) species.", "doi": "10.1021/ba-1992-0230.ch015", "isbn": "9780841220072", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1992-03-01", "pages": "221-232" }, { "id": "authors:306ej-18508", "collection": "authors", "collection_id": "306ej-18508", "cite_using_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180405-083658013", "type": "book_section", "title": "Vacuum Line Techniques for Handling Air-Sensitive Organometallic Compounds", "book_title": "Experimental Organometallic Chemistry", "author": [ { "family_name": "Burger", "given_name": "Barbara J.", "clpid": "Burger-B-J" }, { "family_name": "Bercaw", "given_name": "John E.", "clpid": "Bercaw-J-E" } ], "abstract": "Vacuum line techniques for handling air sensitive oganometallic compounds are described. The vacuum line is discussed in six sections: (i) the pumps and main traps, (ii) the main manifold with pressure gauges, (iii) work stations, (iv) the cryogenic traps and Toepler pump, (v) the inert gas purifiers and inlet system, and (vi) the specialty gas inlet system. Use of a swivel frit assembly in the synthesis of air sensitive compounds is described along procedures for the addition of gases, volatile and nonvolatile liquids and solutions to reaction mixtures. High temperature and pressure reactions are discussed in terms of the use of sealed NMR tubes and heavy walled reaction vessels. The procedure for molecular weight determination using the Signer method is also included.", "doi": "10.1021/bk-1987-0357.ch004", "isbn": "9780841214385", "publisher": "American Chemical Society", "place_of_publication": "Washington, DC", "publication_date": "1987-11-24", "pages": "79-115" } ]