Synthesis, Characterization, and Redox Behavior of New Selenium Coronands and of Copper(I) and Copper(II) Complexes of Selenium Coronands

Rj, Batchelor; Fw, Einstein; Jh, Gu; Mehta, Seema; Bm, Pinto; Zhou, Xin

doi:10.1021/ic991345p

Cited by 49 publications

(22 citation statements)

References 75 publications

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“…Dicationic 1,5-diselenacyclooctane trifluoromethane sulfonate (structure shown in Fig. 16a), possesses two three-coordinate selenonium environments that, not surprisingly, show very similar selenium chemical shift tensor principal components [120]. Similarly, the selenium coronand complexes with copper and mercury demonstrate three-coordinate selenium species with at least a partial positive charge.…”

Section: Miscellaneous Organoselenium Systemsmentioning

confidence: 97%

“…Isotropic 77 Se chemical shifts measured by solidstate NMR in coronands ranging from 1,5,9-triselenacyclododecane, 12Se3, to 1,5,9,13,17,21-hexaselenacyclotetracosane, 24Se6 (see Fig. 6 for structures), cover between 113 and 327 ppm [117][118][119][120]. Through electrochemical oxidation of 1,5,9,13-tetraselenahexadecane, 16Se4, the complex [16Se4][SO 3 CF 3 ] 2 is afforded yielding four very different 77 Se NMR peaks at 173, 420, 505, and 737 ppm [121,122], which have been assigned to the four unique Se atoms in the asymmetric unit based on estimated contributions to the 77 Se line width from SeAF dipolar couplings [122].…”

Section: Bridging Selenium Systemsmentioning

confidence: 99%

“…Through electrochemical oxidation of 1,5,9,13-tetraselenahexadecane, 16Se4, the complex [16Se4][SO 3 CF 3 ] 2 is afforded yielding four very different 77 Se NMR peaks at 173, 420, 505, and 737 ppm [121,122], which have been assigned to the four unique Se atoms in the asymmetric unit based on estimated contributions to the 77 Se line width from SeAF dipolar couplings [122]. To date, only two selenium chemical shift tensors involving a selenium coronand, those for 1,5,9,13-tetraselenacyclohexadecan-3-ol, 16Se4(OH), have had their principal components characterized [120].…”

Section: Bridging Selenium Systemsmentioning

confidence: 99%

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Solid-state selenium-77 NMR

Demko

Wasylishen

2009

Progress in Nuclear Magnetic Resonance Spectroscopy

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Section: Miscellaneous Organoselenium Systemsmentioning

confidence: 97%

Section: Bridging Selenium Systemsmentioning

confidence: 99%

Section: Bridging Selenium Systemsmentioning

confidence: 99%

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Solid-state selenium-77 NMR

Demko

Wasylishen

2009

Progress in Nuclear Magnetic Resonance Spectroscopy

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“…The CuÀSe bond lengths in 1±3 are roughly 2.30 ä, about 0.11 ä shorter than CuÀSe bond lengths in Cu II selenium coronands. [27] In complexes 4 and 5, the CuÀS bond lengths are 2.18 ä, about 0.10 ä shorter than those of other Cu II bis-dithiolene complexes. [22a, 28] The latter structural changes also argue in favor of an important contribution of the metal to the oxidative processes of complexes 1±5.…”

Section: àmentioning

confidence: 99%

Novel Cu^III Bis‐1,2‐dichalcogenene Complexes with Tunable 3D Framework through Alkaline Cation Coordination: A Structural and Theoretical Study

Ribas

Dias

Morgado

et al. 2004

Chemistry A European J

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The deprotonated form of the ligands pyrazine-2,3-diselenol (pds) and pyrazine-2,3-dithiol (pdt) react with Cu(ClO(4))(2).6 H(2)O to form different Cu(III) complexes Na[Cu(III)(pds)(2)].2 H(2)O (1), Li[Cu(III)(pds)(2)].3 H(2)O (2), and Na[Cu(III)(pdt)(2)].2 H(2)O (4) depending on the countercation compound used as deprotonating agent (NaOH, LiOH). Two other Cu(III) complexes were obtained by replacement of the alkali metal cations with tetrabutylammonium (TBA(+)), namely, TBA[Cu(III)(pds)(2)] (3), and TBA[Cu(III)(pdt)(2)] (5). All complexes were characterized by (1)H and (13)C NMR and IR spectroscopy, electronic absorption, elemental analysis, cyclic voltammetry (CV), and X-ray crystallography. Electrical conductivity measurements on single crystals show that these salts exhibit insulating behavior. The crystal structure of these species revealed a lateral coordination capability of the N atoms of the pyrazine ring of both pds and pdt ligands towards the alkali metal ions, which leads to the build up of a net of coordinative bonds, hydrogen bonds, and contacts that result in the final 3D structure. Two parameters control the crystal engineering of the final 3D structures: the nature of the alkali metal countercation and the nature of the chalcogen atom (Se/S), which allow fine-tuning of complex 3D crystal lattice. Density functional calculations were performed on the [Cu(pds)(2)] and [Cu(pdt)(2)] systems to investigate the electronic structure of the complexes and understand their electronic and electrochemical behavior by studying the frontier molecular orbitals. This study also reveals whether the redox processes take place on the ligands or on the metal center, a question under continuous discussion in the literature.

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“…57 In other oxidases, a positively charged residue is present around the flavin N5, 58 and is postulated to stabilize the superoxide anion (formed during the first stepwise electron transfer to dioxygen) via electrostatic interactions. [58][59][60][61][62][63] In vanillyl alcohol oxidase-type flavoproteins, it was observed that a covalent linkage between the flavin cofactor and the protein increases the redox potential of the flavin significantly, limiting the number of feasible electron acceptors. 32,64 It was also observed that bicovalently linked flavin cofactors have a very open active site, while retaining the cofactor in position for catalysis, allowing them to accept bulky substrates.…”

Section: ]mentioning

confidence: 99%

Electrochemistry of flavins

Tan¹

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A thesis submitted to the Nanyang Technological University in fulfillment of the requirements for the degree of Doctor of Philosophy of Chemistry First and foremost, I would like to thank Nanyang Technological University (NTU) for awarding me the Nanyang President's Graduate Scholarship, and giving me opportunities to attending 2 conferences which has broadened my horizons both scientifically and personally. I would also like to thank my PhD supervisor, Assoc. Prof. Richard David Webster, for accepting me into his group without prior experience, for providing guidance over these 4 years, for giving me space and freedom to explore the field, for understanding, for never having any harsh words and being really great to talk to even for non-electrochemistry topics. Much love to my lunch buddies, Gwen, Shu Jun, Novi, for being the best part of these 4 years, making me look forward to school every day. Also, I am really thankful to my student Jiamin, for being so reliable, meticulous and determined. I could not have done it without you, and could not have asked for a better student! To all Gwen's ex-students and my ex-lunch buddies (Marcus, Shu Jun, Li Zhen, Li Lin and Wen Hui), it has been great knowing all of you! Special thanks to Shu Jun and Novi for the last few months, starving yourselves till 2 pm to lunch with me, to Novi for stepping up without complaints to help me with data collection, to Yanni for always being so kind and sweet, and to Diane for understanding! Also, thanks to Shu Hui for our dinners, for working late together and for the trips home. To Colin, thanks for your friendship and "thanks" for scaring me while making sure I am not holding any glassware. To Weejian, thanks for your kind notes of encouragement during my FYP days, and being the kind of friend that sticks around. To Boon Hong, thanks for being mature and understanding, for helping me with ithenticate II and so much more, you are truly a much better person than you are given credit for! You are friends I wish I knew earlier and hope to keep for many years to come! To my other labmates,

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Synthesis, Characterization, and Redox Behavior of New Selenium Coronands and of Copper(I) and Copper(II) Complexes of Selenium Coronands

Cited by 49 publications

References 75 publications

Solid-state selenium-77 NMR

Solid-state selenium-77 NMR

Novel Cu^III Bis‐1,2‐dichalcogenene Complexes with Tunable 3D Framework through Alkaline Cation Coordination: A Structural and Theoretical Study

Electrochemistry of flavins

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Synthesis, Characterization, and Redox Behavior of New Selenium Coronands and of Copper(I) and Copper(II) Complexes of Selenium Coronands

Cited by 49 publications

References 75 publications

Solid-state selenium-77 NMR

Solid-state selenium-77 NMR

Novel CuIII Bis‐1,2‐dichalcogenene Complexes with Tunable 3D Framework through Alkaline Cation Coordination: A Structural and Theoretical Study

Electrochemistry of flavins

Contact Info

Product

Resources

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Novel Cu^III Bis‐1,2‐dichalcogenene Complexes with Tunable 3D Framework through Alkaline Cation Coordination: A Structural and Theoretical Study