226
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Li Y, Lampkins AJ, Baker MB, Sumpter BG, Huang J, Abboud KA, Castellano RK. Benzotrifuranone: Synthesis, Structure, and Access to Polycyclic Heteroaromatics. Org Lett 2009; 11:4314-7. [DOI: 10.1021/ol901631n] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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227
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Snead DR, Ghiviriga I, Abboud KA, Hong S. A New Route to Acyclic Diaminocarbenes via Lithium−Halogen Exchange. Org Lett 2009; 11:3274-7. [DOI: 10.1021/ol9013156] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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228
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Klosin J, Kruper WJ, Patton JT, Abboud KA. Synthesis and X-ray structure of novel 2- and 3-heteroatom-substituted ansa-zirconocene complexes. J Organomet Chem 2009. [DOI: 10.1016/j.jorganchem.2009.03.049] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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229
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Stamatatos TC, Pringouri KV, Abboud KA, Christou G. High-spin molecules: A mixed-valence Mn6 octahedron with an S=11 ground state. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.10.031] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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230
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Lampropoulos C, Stamatatos TC, Abboud KA, Christou G. A convenient MnIII starting material for the synthesis of homo- and heterometallic manganese carboxylate clusters: Mn9 and Mn10−xFex complexes. Polyhedron 2009. [DOI: 10.1016/j.poly.2008.11.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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231
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Axtell AT, Klosin J, Whiteker GT, Cobley CJ, Fox ME, Jackson M, Abboud KA. Bridging Group Effects in Chelating Bis(2,5-diphenylphospholane) Ligands for Rhodium-Catalyzed Asymmetric Hydroformylation. Organometallics 2009. [DOI: 10.1021/om9000583] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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232
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Palenik RC, Abboud KA, Palenik GJ. Cylindrical hexameric antimony complexes, one with an enclosed hexaaquanickel(II) ion. Inorganica Chim Acta 2009. [DOI: 10.1016/j.ica.2008.05.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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233
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Lampropoulos C, Abboud KA, Stamatatos TC, Christou G. A Nontwisted, Ferromagnetically Coupled MnIII3O Triangular Complex from the Use of 2,6-Bis(hydroxymethyl)-p-cresol. Inorg Chem 2009; 48:813-5. [DOI: 10.1021/ic802084h] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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234
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Stamatatos TC, Mukherjee S, Abboud KA, Christou G. The largest single-strand molecular wheel: Ga20from a targeted, diolate-induced size modification of the Ga10‘gallic wheel’. Chem Commun (Camb) 2009:62-4. [DOI: 10.1039/b812721b] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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235
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Jeletic MS, Jan MT, Ghiviriga I, Abboud KA, Veige AS. New iridium and rhodium chiral di-N-heterocyclic carbene (NHC) complexes and their application in enantioselective catalysis. Dalton Trans 2009:2764-76. [DOI: 10.1039/b819524b] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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236
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Hirsch-Weil D, Snead DR, Inagaki S, Seo H, Abboud KA, Hong S. In situ generation of novel acyclic diaminocarbene–copper complex. Chem Commun (Camb) 2009:2475-7. [DOI: 10.1039/b821169h] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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237
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Stamatatos TC, Abboud KA, Christou G. A mononuclear MnIII/‘bis-tris’ complex and its conversion to a mixed-valence MnII/III5cluster. Dalton Trans 2009:41-50. [DOI: 10.1039/b810701g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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238
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Stamatatos TC, Vinslava A, Abboud KA, Christou G. Azide groups in high oxidation state Mn carboxylate chemistry: a new Mn11 complex and its conversion to a Mn25 azide complex with Me3SiN3. Chem Commun (Camb) 2009:2839-41. [DOI: 10.1039/b902016k] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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239
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Butler RS, Cohn P, Tenzel P, Abboud KA, Castellano RK. Synthesis, Photophysical Behavior, and Electronic Structure of Push−Pull Purines. J Am Chem Soc 2008; 131:623-33. [DOI: 10.1021/ja806348z] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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240
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Stamatatos TC, Abboud KA, Wernsdorfer W, Christou G. {Mn6}n Single-Chain Magnet Bearing Azides and Di-2-pyridylketone-Derived Ligands. Inorg Chem 2008; 48:807-9. [DOI: 10.1021/ic8020645] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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241
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Lampropoulos C, Stamatatos TC, Abboud KA, Christou G. Initial Use of Dioximate Ligands in 3d/4f Cluster Chemistry: Synthesis, Structure, and Magnetic Studies of an Unusual [GdIII2MnIVO]8+ Complex. Inorg Chem 2008; 48:429-31. [DOI: 10.1021/ic802005a] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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242
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Park J, Lang K, Abboud KA, Hong S. Self-Assembled Dinuclear Cobalt(II)-Salen Catalyst Through Hydrogen-Bonding and Its Application to Enantioselective Nitro-Aldol (Henry) Reaction. J Am Chem Soc 2008; 130:16484-5. [PMID: 19554722 DOI: 10.1021/ja807221s] [Citation(s) in RCA: 167] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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243
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Sarkar S, Abboud KA, Veige AS. Addition of Mild Electrophiles to a Mo≡N Triple Bond and Nitrile Synthesis via Metal-Mediated N-Atom Transfer to Acid Chlorides. J Am Chem Soc 2008; 130:16128-9. [DOI: 10.1021/ja805629x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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244
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Lowry RJ, Veige MK, Clément O, Abboud KA, Ghiviriga I, Veige AS. New Constrained-Geometry C2-Symmetric Di-N-heterocyclic Carbene Ligands and Their Mono- and Dinuclear Rhodium(I) Complexes: Design, Synthesis, and Structural Analysis. Organometallics 2008. [DOI: 10.1021/om800471m] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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245
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Murugesu M, Takahashi S, Wilson A, Abboud KA, Wernsdorfer W, Hill S, Christou G. Large Mn25 Single-Molecule Magnet with Spin S = 51/2: Magnetic and High-Frequency Electron Paramagnetic Resonance Spectroscopic Characterization of a Giant Spin State. Inorg Chem 2008; 47:9459-70. [DOI: 10.1021/ic801142p] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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246
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Stamatatos TC, Christou AG, Mukherjee S, Poole KM, Lampropoulos C, Abboud KA, O’Brien TA, Christou G. High-Yield Syntheses and Reactivity Studies of Fe10 “Ferric Wheels”: Structural, Magnetic, and Computational Characterization of a Star-Shaped Fe8 Complex. Inorg Chem 2008; 47:9021-34. [DOI: 10.1021/ic801038r] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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247
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Ogle JW, Zhang J, Reibenspies JH, Abboud KA, Miller SA. Synthesis of Electronically Diverse Tetraarylimidazolylidene Carbenes via Catalytic Aldimine Coupling. Org Lett 2008; 10:3677-80. [DOI: 10.1021/ol8012765] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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248
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Zuccaccia C, Macchioni A, Busico V, Cipullo R, Talarico G, Alfano F, Boone HW, Frazier KA, Hustad PD, Stevens JC, Vosejpka PC, Abboud KA. Intra- and intermolecular NMR studies on the activation of arylcyclometallated hafnium pyridyl-amido olefin polymerization precatalysts. J Am Chem Soc 2008; 130:10354-68. [PMID: 18613668 DOI: 10.1021/ja802072n] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Pyridyl-amido catalysts have emerged recently with great promise for olefin polymerization. Insights into the activation chemistry are presented in an initial attempt to understand the polymerization mechanisms of these important catalysts. The activation of C1-symmetric arylcyclometallated hafnium pyridyl-amido precatalysts, denoted Me2Hf{N(-),N,C(-)} (1, aryl = naphthyl; 2, aryl = phenyl), with both Lewis (B(C6F5)3 and [CPh3][B(C6F5)4]) and Brønsted ([HNR3][B(C6F5)4]) acids is investigated. Reactions of 1 with B(C6F5)3 lead to abstraction of a methyl group and formation of a single inner-sphere diastereoisomeric ion pair [MeHf{N(-),N,C(-)}][MeB(C6F5)3] (3). A 1:1 mixture of the two possible outer-sphere diastereoisomeric ion pairs [MeHf{N(-),N,C(-)}][B(C6F5)4] (4) is obtained when [CPh3][B(C6F5)4] is used. [HNR3][B(C6F5)4] selectively protonates the aryl arm of the tridentate ligand in both precatalysts 1 and 2. A remarkably stable [Me2Hf{N(-),N,C2}][B(C6F5)4] (5) outer-sphere ion pair is formed when the naphthyl substituent is present. The stability is attributed to a hafnium/eta(2)-naphthyl interaction and the release of an eclipsing H-H interaction between naphthyl and pyridine moieties, as evidenced through extensive NMR studies, X-ray single crystal investigation and DFT calculations. When the aryl substituent is phenyl, [Me2Hf{N(-),N,C2}][B(C6F5)4] (10) is originally obtained from protonation of 2, but this species rapidly undergoes remetalation, methane evolution, and amine coordination, giving a diastereomeric mixture of [MeHf{N(-),N,C(-)}NR3][B(C6F5)4] (11). This species transforms over time into the trianionic-ligated [Hf{N(-),C(-),N,C(-)}NR3][B(C6F5)4] (12) through activation of a C-H bond of an amido-isopropyl group. In contrast, ion pair 5 does not spontaneously undergo remetalation of the naphthyl moiety; it reacts with NMe2Ph leading to [MeHf{N(-),N}NMe2C6H4][B(C6F5)4] (7) through ortho-metalation of the aniline. Ion pair 7 successively undergoes a complex transformation ultimately leading to [Hf{N(-),C(-),N,C(-)}NMe2Ph][B(C6F5)4] (8), strictly analogous to 12. The reaction of 5 with aliphatic amines leads to the formation of a single diastereomeric ion pair [MeHf{N(-),N,C(-)}NR3][B(C6F5)4] (9). These differences in activation chemistry are manifested in the polymerization characteristics of these different precatalyst/cocatalyst combinations. Relatively long induction times are observed for propene polymerizations with the naphthyl precatalyst 1 activated with [HNMe3Ph][B(C6F5)4]. However, no induction time is present when 1 is activated with Lewis acids. Similarly, precatalyst 2 shows no induction period with either Lewis or Brønsted acids. Correlation of the solution behavior of these ion pairs and the polymerization characteristics of these various species provides a basis for an initial picture of the polymerization mechanism of these important catalyst systems.
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Nielsen CB, Angerhofer A, Abboud KA, Reynolds JR. Discrete photopatternable pi-conjugated oligomers for electrochromic devices. J Am Chem Soc 2008; 130:9734-46. [PMID: 18593166 DOI: 10.1021/ja7112273] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Three discrete oligomeric systems including an all-thiophene ( T6) system, a thiophene/phenylene ( TPTTPT) system, and a thiophene/EDOT/phenylene ( TPEEPT) system have been constructed and characterized with emphasis on structural, optical, electrochemical, and spectroelectrochemical properties. For all three chromophores, the radical cation, the dication, and the pi-dimer have been identified and characterized. EPR spectroscopy reveals that the radical cations of TPTTPT and TPEEPT have g values of 2.008-2.012 and peak-to-peak widths in the range 4.2-5.3 G. Formation of the radical cation takes place at a lower potential for TPEEPT than for TPTTPT and T6, whereas subsequent oxidation to the dication occurs more easily for TPTTPT than for TPEEPT and T6. We ascribe this observation to more localized charges in the oxidized species of TPEEPT, which is supported by our finding that the radical cation of TPEEPT is less prone to undergo pi-dimerization than the radical cations of TPTTPT and T6. All the oxidized species are sufficiently stable to allow for optical characterization, and the relative positions of all absorption bands are found to be in agreement with the electrochemical data. For further solid-state modifications of these materials, we have effectively modified the synthetic design and grafted terminal functionalities (e.s. acrylates) onto the discrete oligomers. Of these novel materials, TPEEPT proves to be the most promising anodically coloring material for electrochromics, and it undergoes reversible switching between two different colored states (bright yellow and clear blue) and one almost transparent and color neutral state. Contrast ratios, measured as Delta% T at lambda max, are as high as 62.5%, and switching times are in the range 2-5 s for the coloration process, though significantly longer for the bleaching process. As a proof of concept, we have successfully constructed a simple photopatterned electrochromic device by exploiting the terminal acrylate functionalities of the oligomers in a UV-initiated cross-linking process. To the best of our knowledge, this is the first oligomer-based photopatterned electrochromic device reported in the literature.
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Stamatatos TC, Poole KM, Foguet-Albiol D, Abboud KA, O’Brien TA, Christou G. Spin Maximization: Switching of the Usual S = 11 State of MnII4MnIII3 Disklike Complexes to the Maximum S = 16. Inorg Chem 2008; 47:6593-5. [DOI: 10.1021/ic801024d] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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