1
|
Almubarak T, Ng JHC, Nasr‐El‐Din HA, Almubarak M, AlKhaldi M. Influence of zirconium crosslinker chemical structure and polymer choice on the performance of crosslinked fracturing fluids. CAN J CHEM ENG 2021. [DOI: 10.1002/cjce.24098] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Tariq Almubarak
- Petroleum Engineering Department Texas A&M University College Station Texas USA
| | | | | | - Majed Almubarak
- Civil and Environmental Engineering Department Massachusetts Institute of Technology Cambridge Massachusetts USA
| | | |
Collapse
|
2
|
Ahmad K, Alt HG. Zirconium dichloride complexes with bulky ω-9-methylfluorenylalkyl substituted indenyl ligands as catalysts for homogeneous ethylene polymerization. Inorganica Chim Acta 2016. [DOI: 10.1016/j.ica.2016.07.053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
3
|
Synthesis and reactivity of molybdenum(0) complexes containing sterically expanded arene ligands. Polyhedron 2016. [DOI: 10.1016/j.poly.2016.02.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
4
|
Kohrt S, Dachwitz S, Daniliuc CG, Kehr G, Erker G. Stabilized borata-alkene formation: structural features, reactions and the role of the counter cation. Dalton Trans 2015; 44:21032-40. [DOI: 10.1039/c5dt04058b] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A stable borata-alkene was prepared starting from dimethylbenzofulvene and Piers' borane [HB(C6F5)2]. It undergoes a cycloaddiiton reaction with chalcone.
Collapse
Affiliation(s)
- Sonja Kohrt
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität Münster
- D-48149 Münster
- Germany
| | - Steffen Dachwitz
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität Münster
- D-48149 Münster
- Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität Münster
- D-48149 Münster
- Germany
| | - Gerald Kehr
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität Münster
- D-48149 Münster
- Germany
| | - Gerhard Erker
- Organisch-Chemisches Institut
- Westfälische Wilhelms-Universität Münster
- D-48149 Münster
- Germany
| |
Collapse
|
5
|
Formation of Hydroxyindenyl and Vinylidene Ligands by Reaction of Internal Alkynes with Cp*Fe(CO)(NCMe)Ph. Organometallics 2014. [DOI: 10.1021/om500748v] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
6
|
Kumar Podiyanachari S, Kehr G, Mück-Lichtenfeld C, Daniliuc CG, Erker G. Remarkable Behavior of a Bifunctional Alkynylborane Zirconocene Complex toward Donor Ligands and Acetylenes. J Am Chem Soc 2013; 135:17444-56. [DOI: 10.1021/ja408385h] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
| | - Gerald Kehr
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Correnstrasse 40, D-48149 Münster, Germany
| | - Christian Mück-Lichtenfeld
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Correnstrasse 40, D-48149 Münster, Germany
| | - Constantin G. Daniliuc
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Correnstrasse 40, D-48149 Münster, Germany
| | - Gerhard Erker
- Organisch-Chemisches
Institut, Westfälische Wilhelms-Universität, Correnstrasse 40, D-48149 Münster, Germany
| |
Collapse
|
7
|
Hung-Low F, Bradley CA. Synthesis of a Bis(indenyl) Co(I) Anion: A Reactive Source of a 14 Electron Indenyl Co(I) Equivalent. Inorg Chem 2013; 52:2446-57. [DOI: 10.1021/ic302320w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Fernando Hung-Low
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| | - Christopher A. Bradley
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
| |
Collapse
|
8
|
Wang JW, Tian LJ, Ma ZH, Guo KM, Han ZG, Zheng XZ, Lin J. Crystal structures of dimolybdenum carbonyl complexes containing the cyclopentadienyl-thienyl ligand. J STRUCT CHEM+ 2012. [DOI: 10.1134/s0022476612040233] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
9
|
McGovern GP, Hung-Low F, Tye JW, Bradley CA. Synthesis and Reactivity Studies of Benzo-Substituted Bis(indenyl) Iron and Zirconium Complexes: The Difference a Methyl Group Can Make. Organometallics 2012. [DOI: 10.1021/om2011563] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Gregory P. McGovern
- Department of Chemistry and Biochemistry, Texas Tech University, Box 41061 Lubbock,
Texas 79409-1061,
United States
| | - Fernando Hung-Low
- Department of Chemistry and Biochemistry, Texas Tech University, Box 41061 Lubbock,
Texas 79409-1061,
United States
| | - Jesse W. Tye
- Department of Chemistry, Ball State University, Muncie, Indiana 47306, United
States
| | - Christopher A. Bradley
- Department of Chemistry and Biochemistry, Texas Tech University, Box 41061 Lubbock,
Texas 79409-1061,
United States
| |
Collapse
|
10
|
Maekawa M, Daniliuc CG, Freytag M, Jones PG, Walter MD. Complexes of manganese, iron and cobalt with sterically demanding indenyl ligands. Dalton Trans 2012; 41:10317-27. [PMID: 22772481 DOI: 10.1039/c2dt31136d] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Miyuki Maekawa
- Institut für Anorganische und Analytische Chemie, Technische Universität Braunschweig, Braunschweig, Germany
| | | | | | | | | |
Collapse
|
11
|
Glöckner A, Bauer H, Maekawa M, Bannenberg T, Daniliuc CG, Jones PG, Sun Y, Sitzmann H, Tamm M, Walter MD. How big is a Cp? Cycloheptatrienyl zirconium complexes with bulky cyclopentadienyl and indenyl ligands. Dalton Trans 2012; 41:6614-24. [DOI: 10.1039/c2dt12132h] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
|
12
|
Churakov AV, Krut’ko DP, Below SA, Kirsanov RS, Lemenovskii DA. [η5-C9H5(1,3-SiMe3)2]HfCl3: A monomeric 12-electron half-sandwich complex. RUSS J INORG CHEM+ 2011. [DOI: 10.1134/s0036023611100044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
13
|
Hung-Low F, Bradley CA. Indenyl Ligands as Supports for Reactive, Low-Valent Cobalt(I) Fragments. Organometallics 2011. [DOI: 10.1021/om200139x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Fernando Hung-Low
- Department of Chemistry and Biochemistry, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061, United States
| | - Christopher A. Bradley
- Department of Chemistry and Biochemistry, Texas Tech University, Box 41061, Lubbock, Texas 79409-1061, United States
| |
Collapse
|
14
|
Petrisor CE, Chahboun G, El Amrani MA, Royo E, Cuenca T. Mixed Disilyl‐Substituted Cyclopentadiene Derivatives and Corresponding Zirconium, Molybdenum and Tungsten Compounds. Eur J Inorg Chem 2010. [DOI: 10.1002/ejic.201000394] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Cristina E. Petrisor
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain, Fax: +34‐918854683
| | - Ghaita Chahboun
- Université Abdelmalek Essaâdi, Faculté des Sciences, Departement de Chimie – Laboratoire de Chimie Organique Appliquée, Mhannech II, B.P. 2121, Tétouan, Morocco
| | - Mohamed Amin El Amrani
- Université Abdelmalek Essaâdi, Faculté des Sciences, Departement de Chimie – Laboratoire de Chimie Organique Appliquée, Mhannech II, B.P. 2121, Tétouan, Morocco
| | - Eva Royo
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain, Fax: +34‐918854683
| | - Tomás Cuenca
- Departamento de Química Inorgánica, Facultad de Ciencias, Universidad de Alcalá, 28871 Alcalá de Henares, Madrid, Spain, Fax: +34‐918854683
| |
Collapse
|
15
|
Crisp JA, Meier RM, Overby JS, Hanusa TP, Rheingold AL, Brennessel WW. Indenyl Complexes of Manganese(II). Conformational Flexibility of the Manganese(II)−(RnC9H7−n) Bond. Organometallics 2010. [DOI: 10.1021/om100162j] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jeffrey A. Crisp
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Ryan M. Meier
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Jason S. Overby
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | - Timothy P. Hanusa
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
| | | | | |
Collapse
|
16
|
Chirik PJ. Group 4 Transition Metal Sandwich Complexes: Still Fresh after Almost 60 Years. Organometallics 2010. [DOI: 10.1021/om100016p] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Paul J. Chirik
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| |
Collapse
|
17
|
New 1,3-disubstituted side-chain functionalized indenyl ligands and zirconium complexes derived from them. Russ Chem Bull 2010. [DOI: 10.1007/s11172-010-0083-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
18
|
Xu X, Chen Y, Feng J, Zou G, Sun J. Half-Sandwich Indenyl Rare Earth Metal Dialkyl Complexes: Syntheses, Structures, and Catalytic Activities of (1,3-(SiMe3)2C9H5)Ln(CH2SiMe3)2(THF). Organometallics 2010. [DOI: 10.1021/om900758y] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Xin Xu
- State Key Laboratory of Organometallic Chemistry, Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People's Republic of China
- Laboratory of Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Yaofeng Chen
- State Key Laboratory of Organometallic Chemistry, Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People's Republic of China
| | - Jian Feng
- Laboratory of Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Gang Zou
- Laboratory of Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, People's Republic of China
| | - Jie Sun
- State Key Laboratory of Organometallic Chemistry, Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Road, Shanghai 200032, People's Republic of China
| |
Collapse
|
19
|
Hanna TE, Lobkovsky E, Chirik PJ. Dinitrogen Complexes of Bis(cyclopentadienyl) Titanium Derivatives: Structural Diversity Arising from Substituent Manipulation. Organometallics 2009. [DOI: 10.1021/om900282u] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tamara E. Hanna
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Emil Lobkovsky
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Paul J. Chirik
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| |
Collapse
|
20
|
Pun D, Leopold SM, Bradley CA, Lobkovsky E, Chirik PJ. Bis(indenyl)hafnium Chemistry: Ligand-Induced Haptotropic Rearrangement and Fundamental Reactivity Studies at a Reduced Hafnium Center. Organometallics 2009. [DOI: 10.1021/om900046e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Doris Pun
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Scott M. Leopold
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Christopher A. Bradley
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Emil Lobkovsky
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| | - Paul J. Chirik
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853
| |
Collapse
|
21
|
Xu X, Chen Y, Sun J. Indenyl Abstraction versus Alkyl Abstraction of [(Indenyl)ScR2(thf)] by [Ph3C] [B(C6F5)4]: Aspecific and Syndiospecific Styrene Polymerization. Chemistry 2008; 15:846-50. [DOI: 10.1002/chem.200802220] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
22
|
Ashley AE, Cooper RT, Wildgoose GG, Green JC, O'Hare D. Homoleptic permethylpentalene complexes: "double metallocenes" of the first-row transition metals. J Am Chem Soc 2008; 130:15662-77. [PMID: 18939834 DOI: 10.1021/ja8057138] [Citation(s) in RCA: 84] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The synthesis of the bimetallic permethylpentalene complexes Pn*2M2 (M = V, Cr, Mn, Co, Ni; Pn* = C8Me6) has been accomplished, and all of the complexes have been structurally characterized in the solid state by single-crystal X-ray diffraction. Pn*2V2 (1) and Pn*2Mn2 (3) show very short intermetallic distances that are consistent with metal-metal bonding, while the cobalt centers in Pn*2Co2 (4) exhibit differential bonding to each side of the Pn* ligand that is consistent with an eta(5):eta(3) formulation. The Pn* ligands in Pn*2Ni2 (5) are best described as eta(3):eta(3)-bonded to the metal centers. (1)H NMR studies indicate that all of the Pn*2M2 species exhibit D(2h) molecular symmetry in the solution phase; the temperature variation of the chemical shifts for the resonances of Pn*2Cr2 (2) indicates that the molecule has an S = 0 ground state and a thermally populated S = 1 excited state and can be successfully modeled using a Boltzmann distribution (DeltaH(o) = 14.9 kJ mol(-1) and DeltaS(o) = 26.5 J K(-1) mol(-1)). The solid-state molar magnetic susceptibility of 3 obeys the Curie-Weiss law with mu(eff) = 2.78 muB and theta = -1.0 K; the complex is best described as having an S = 1 electronic ground state over the temperature range 4-300 K. Paradoxically, attempts to isolate the "double ferrocene" equivalent, Pn*2Fe2, led only to the isolation of the permethylpentalene dimer Pn*2 (6). Solution electrochemical studies were performed on all of the organometallic compounds; 2-5 exhibit multiple quasi-reversible redox processes. Density functional theory calculations were performed on this series of complexes in order to rationalize the observed structural and spectroscopic data and provide estimates of the M-M bond orders.
Collapse
Affiliation(s)
- Andrew E Ashley
- Chemistry Research Laboratory, Oxford University, Mansfield Rd, Oxford OX1 3TA, UK
| | | | | | | | | |
Collapse
|
23
|
Belov SA, Kirsanov RS, Krut’ko DP, Lemenovskii DA, Churakov AV, Howard JA. Novel sandwich complexes of zirconium [C9H5(SiMe3)2](C5Me4R)ZrCl2 (R=CH3, CH2CH2NMe2): Synthesis and reduction behavior. J Organomet Chem 2008. [DOI: 10.1016/j.jorganchem.2008.02.019] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
24
|
Bazinet P, Tilley TD. Octa- and Nonamethylfluorenyl Complexes of Zr(II), Zr(IV), and Hf(IV). Investigation of Steric and Electronic Effects. Organometallics 2008. [DOI: 10.1021/om701133e] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Patrick Bazinet
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460, and Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720-1460
| | - T. Don Tilley
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720-1460, and Chemical Sciences Division, Ernest Orlando Lawrence Berkeley National Laboratory, One Cyclotron Road, Berkeley, California 94720-1460
| |
Collapse
|
25
|
Hanna TE, Keresztes I, Lobkovsky E, Chirik PJ. Diazene dehydrogenation follows H2 addition to coordinated dinitrogen in an ansa-zirconocene complex. Inorg Chem 2007; 46:1675-83. [PMID: 17266302 DOI: 10.1021/ic0620539] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
An activated side-on-bound ansa-zirconocene dinitrogen complex, [Me2Si(eta5-C5Me4)(eta5-C5H3-3-tBu)Zr]2(mu2,eta2,eta2-N2), has been prepared by sodium amalgam reduction of the corresponding dichloride precursor under an atmosphere of N2. Both solution spectroscopic and X-ray diffraction data establish diastereoselective formation of the syn homochiral dizirconium dimer. Addition of 1 atm of H2 resulted in rapid hydrogenation of the N2 ligand to yield one diastereomer of the hydrido zirconocene diazenido complex. Kinetic measurements have yielded the barrier for H2 addition and in combination with isotopic labeling studies are consistent with a 1,2-addition pathway. In the absence of H2, the hydrido zirconocene diazenido product undergoes swift diazene dehydrogenation to yield an unusual hydrido zirconocene dinitrogen complex. The N=N bond length of 1.253(5) A determined by X-ray crystallography indicates that the side-on-bound N2 ligand is best described as a two-electron reduced [N2]2- fragment. Comparing the barrier for deuterium exchange with [Me2Si(eta5-C5Me4)(eta5-C5H3-3-tBu)ZrH]2(mu2,eta2,eta2-N2H2) to diazene dehydrogenation is consistent with rapid 1,2-elimination of dihydrogen followed by rate-determining hydride migration to the zirconium. This mechanistic proposal is also corroborated by H2 inhibition and the observation of a normal, primary kinetic isotope effect for dehydrogenation.
Collapse
Affiliation(s)
- Tamara E Hanna
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | | | | | | |
Collapse
|
26
|
Xiang S, Yu G, Liang Y, Wu L. Experimental evidences for stereo-promoted intermolecular C-H···O hydrogen bonding in solution. RUSS J GEN CHEM+ 2007. [DOI: 10.1134/s1070363207010185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
27
|
Pun D, Lobkovsky E, Chirik PJ. Amineborane dehydrogenation promoted by isolable zirconium sandwich, titanium sandwich and N2 complexes. Chem Commun (Camb) 2007:3297-9. [PMID: 17668106 DOI: 10.1039/b704941b] [Citation(s) in RCA: 141] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Catalytic dehydrogenation of R(2)NHBH(3) (R = Me, H) promoted by a family of bis(cyclopentadienyl)titanium and bis(indenyl)zirconium compounds is reported; structure-reactivity relationships as a function of cyclopentadienyl and indenyl substituents have been examined.
Collapse
Affiliation(s)
- Doris Pun
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA
| | | | | |
Collapse
|
28
|
Bradley CA, Veiros LF, Pun D, Lobkovsky E, Keresztes I, Chirik PJ. Carbon−Oxygen Bond Cleavage with η9,η5-Bis(indenyl)zirconium Sandwich Complexes. J Am Chem Soc 2006; 128:16600-12. [PMID: 17177409 DOI: 10.1021/ja065456g] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Treatment of the eta9,eta5-bis(indenyl)zirconium sandwich complex, (eta9-C9H5-1,3-(SiMe3)2)(eta5-C9H5-1,3-(SiMe3)2)Zr, with dialkyl ethers such as diethyl ether, CH3OR (R=Et, nBu, tBu), nBu2O, or iPr2O resulted in facile C-O bond scission furnishing an eta5,eta5-bis(indenyl)zirconium alkoxy hydride complex and free olefin. In cases where ethylene is formed, trapping by the zirconocene sandwich yields a rare example of a crystallographically characterized, base-free eta5,eta5-bis(indenyl)zirconium ethylene complex. Observation of normal, primary kinetic isotope effects in combination with rate studies and the stability of various model compounds support a mechanism involving rate-determining C-H activation to yield an eta5,eta5-bis(indenyl)zirconium alkyl hydride intermediate followed by rapid beta-alkoxide elimination. For isolable eta6,eta5-bis(indenyl)zirconium THF compounds, thermolysis at 85 degrees C also resulted in C-O bond cleavage to yield the corresponding zirconacycle. Both mechanistic and computational studies again support a pathway involving haptotropic rearrangement to eta5,eta5-bis(indenyl)zirconium intermediates that promote rate-determining C-H activation and ultimately C-O bond scission.
Collapse
Affiliation(s)
- Christopher A Bradley
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA
| | | | | | | | | | | |
Collapse
|
29
|
Xiang S, Yu G, Liang Y, Wu L. 1H NMR and DFT studies of steric effects on intermolecular C–H···O hydrogen bonding in solution. J Mol Struct 2006. [DOI: 10.1016/j.molstruc.2005.12.020] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
30
|
Bradley CA, Lobkovsky E, Keresztes I, Chirik PJ. Synthesis of Bis(indenyl)zirconium Dihydrides and Subsequent Rearrangement to η5,η3-4,5-Dihydroindenediyl Ligands: Evidence for Intermediates during the Hydrogenation to Tetrahydroindenyl Derivatives. J Am Chem Soc 2006; 128:6454-67. [PMID: 16683811 DOI: 10.1021/ja060472z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Exposure of eta9,eta5-bis(indenyl)zirconium sandwich complexes to 4 atm of H2 resulted in facile oxidative addition to furnish the corresponding zirconocene dihydrides, (eta5-C9H5-1,3-R2)2ZrH2 (R = SiMe3, SiMe2Ph, CHMe2). Continued hydrogenation completed conversion to the tetrahydroindenyl derivatives, (eta5-C9H9-1,3-R2)2ZrH2. Deuterium labeling studies established that dihydrogen (dideuterium) addition to the benzo rings is intramolecular and stereospecific, occurring solely from the endo face of the ligand, proximal to the zirconium. In the absence of dihydrogen, the bis(indenyl)zirconium dihydrides rearranged to new zirconium monohydride complexes containing an unusual eta5,eta3-4,5-dihydroindenediyl ligand, arising from metal-to-benzo ring hydrogen transfer. Mechanistic studies, including a normal, primary kinetic isotope effect measured at 23 degrees C, are consistent with a pathway involving regio- and stereoselective insertion of a benzo C=C bond into a zirconium hydride. The stereochemistry of the insertion reaction, and hence the eta5,eta3-4,5-dihydroindenediyl product, is influenced by the presence of donor ligands and controlled by the preferred conformation of the indenyl rings. Exposure of the zirconium hydrides containing the eta5,eta3-4,5-dihydroindenediyl rings to 1 atm of dihydrogen afforded the tetrahydroindenyl zirconium dihydride complexes, establishing the intermediacy of this unusual coordination environment during benzo ring hydrogenation.
Collapse
Affiliation(s)
- Christopher A Bradley
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | | | | | | |
Collapse
|
31
|
Bradley CA, Keresztes I, Lobkovsky E, Chirik PJ. The “Indenyl Effect” in Zirconocene Dihydride Chemistry. Organometallics 2006. [DOI: 10.1021/om060035t] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher A. Bradley
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Ivan Keresztes
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Emil Lobkovsky
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Paul J. Chirik
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| |
Collapse
|
32
|
Curnow OJ, Fern GM, Jenkins EM. Electrochemistry and UV/visible spectroscopy of phosphino-substituted bis(η5-indenyl)iron(II) complexes. J Organomet Chem 2006. [DOI: 10.1016/j.jorganchem.2005.09.044] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
33
|
Diekmann M, Bockstiegel G, Lützen A, Friedemann M, Saak W, Haase D, Beckhaus R. Chiral Bis(η5:η1-pentafulvene)titanium Complexes. Organometallics 2005. [DOI: 10.1021/om050815m] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mira Diekmann
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Geert Bockstiegel
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Arne Lützen
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Marion Friedemann
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Wolfgang Saak
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Detlev Haase
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| | - Rüdiger Beckhaus
- Institute of Pure and Applied Chemistry, University of Oldenburg, D-26111 Oldenburg, Germany
| |
Collapse
|
34
|
Bernskoetter WH, Lobkovsky E, Chirik PJ. Ancillary Ligand Effects on C−H Bond Activation Reactions Promoted by β-Diiminate Iridium Complexes. Organometallics 2005. [DOI: 10.1021/om050705f] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Wesley H. Bernskoetter
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Emil Lobkovsky
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| | - Paul J. Chirik
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853
| |
Collapse
|
35
|
Losio S, Zecchi G, Bertini F, Sacchi MC, Bertolasi V, Polo E. Unbridged Zirconium and Titanium Metallocenes with Seven- or Eight-Saturated Fused-Ring Ligands: a Route for the Synthesis of Stereoblock Polypropene. Macromolecules 2005. [DOI: 10.1021/ma050599t] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Simona Losio
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| | - Gaetano Zecchi
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| | - Fabio Bertini
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| | - Maria Carmela Sacchi
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| | - Valerio Bertolasi
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| | - Eleonora Polo
- Università dell'Insubria, Dipartimento di Scienze Chimiche e Ambientali, via Valleggio 11, 22100 Como, Italy, ISMACCNR via E. Bassini 15, 20133 Milano, Italy, Centro di Strutturistica Diffrattometrica, Dipartimento di Chimica, Università di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy, and ISOFCNR Sezione di Ferrara, via L. Borsari 46, 44100 Ferrara, Italy
| |
Collapse
|
36
|
Bradley CA, Lobkovsky E, Keresztes I, Chirik PJ. Ligand-Induced Haptotropic Rearrangements in Bis(indenyl)zirconium Sandwich Complexes. J Am Chem Soc 2005; 127:10291-304. [PMID: 16028941 DOI: 10.1021/ja052033q] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Addition of principally sigma-donating ligands such as THF, chelating diethers, or 1,2-bis(dimethyl)phosphinoethane to eta(9),eta(5)-bis(indenyl)zirconium sandwich complexes, (eta(9)-C(9)H(5)-1,3-R(2))(eta(5)-C(9)H(5)-1,3-R(2))Zr (R = alkyl or silyl), induces haptotropic rearrangement to afford (eta(6)-C(9)H(5)-1,3-R(2))(eta(5)-C(9)H(5)-1,3-R(2))ZrL adducts. Examples where L = THF and DME have been characterized by X-ray diffraction and revealed significant buckling of the eta(6) benzo ring, consistent with reduction of the arene, and highlight the importance of the zirconium(IV) canonical form. For the THF-induced haptotropic rearrangements, the thermodynamic driving force for ring migration has been measured as a function of indenyl substituent and demonstrates silylated sandwiches favor THF coordination and the eta(6),eta(5) bonding motif over their alkylated counterparts. In the case of chelating diethers, measurement of the corresponding equilibrium constants establish more stable eta(6),eta(5) adducts with five- over four-membered chelates and with smaller oxygen and carbon backbone substituents. Kinetic studies on both THF and DME addition to (eta(9)-C(9)H(5)-1,3-(SiMe(3))(2))(eta(5)-C(9)H(5)-1,3-(SiMe(3))(2))Zr established a first-order dependence on the incoming ligand, consistent with a mechanism involving direct attack of the incoming nucleophile on the eta(9),eta(5) sandwich. These results further highlight the ability of the indenyl ligand to smoothly adjust hapticity to meet the electronic requirements of the metal center.
Collapse
Affiliation(s)
- Christopher A Bradley
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, New York 14853, USA
| | | | | | | |
Collapse
|
37
|
Silver S, Puranen A, Sjöholm R, Repo T, Leino R. Chiral Indenes and Group‐4 Metallocene Dichlorides Containing α‐ and β‐Pinenyl‐Derived Ligand Substituents: Synthesis and Catalytic Applications in Polymerization and Carboalumination Reactions. Eur J Inorg Chem 2005. [DOI: 10.1002/ejic.200400882] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Satu Silver
- Department of Organic Chemistry, Åbo Akademi University, 20500 Åbo, Finland, Fax: +358‐2‐215‐4866
| | - Arto Puranen
- Department of Chemistry, Laboratory of Inorganic Chemistry, University of Helsinki, P. O. Box 55, 00014 University of Helsinki, Finland
| | - Rainer Sjöholm
- Department of Organic Chemistry, Åbo Akademi University, 20500 Åbo, Finland, Fax: +358‐2‐215‐4866
| | - Timo Repo
- Department of Chemistry, Laboratory of Inorganic Chemistry, University of Helsinki, P. O. Box 55, 00014 University of Helsinki, Finland
| | - Reko Leino
- Department of Organic Chemistry, Åbo Akademi University, 20500 Åbo, Finland, Fax: +358‐2‐215‐4866
| |
Collapse
|
38
|
Bradley CA, Keresztes I, Lobkovsky E, Young VG, Chirik PJ. Zirconium Sandwich Complexes with η9 Indenyl Ligands: Well-Defined Precursors for Zirconocene-Mediated Coupling Reactions. J Am Chem Soc 2004; 126:16937-50. [PMID: 15612732 DOI: 10.1021/ja045072v] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
A family of isolable, well-defined bis-indenyl zirconium sandwich complexes, (eta(5)-C(9)H(5)-1,3-R(2))(eta(9)-C(9)H(5)-1,3-R(2))Zr (R = silyl, alkyl), have been prepared by either alkane reductive elimination or alkali metal reduction of a suitable zirconium(IV) dihalide precursor. Crystallographic characterization of two of these derivatives, R = SiMe(2)CMe(3) and CHMe(2), reveals unprecedented eta(9) coordination of one of the indenyl ligands. Variable-temperature and EXSY NMR studies establish that the eta(5) and eta(9) rings are rapidly interconverting in solution. The sandwich complexes serve as effective sources of low-valent zirconium reacting rapidly with both olefins and alkynes at ambient temperature. In contrast to bis-cyclopentadienyl chemistry, the olefin adducts of the bis-indenyl zirconium sandwiches undergo preferential C-H activation to yield the corresponding allyl hydride compounds, although reaction with excess olefin proceeds through the eta(2)-olefin adduct, forming the corresponding zirconacyclopentane.
Collapse
Affiliation(s)
- Christopher A Bradley
- Department of Chemistry and Chemical Biology, Baker Laboratory, Cornell University, Ithaca, NY 14853, USA
| | | | | | | | | |
Collapse
|