Dioxygen Activation by a Macrocyclic Copper Complex Leads to a Cu2O2 Core with Unexpected Structure and Reactivity

Isaac Garcia-Bosch; Ryan E. Cowley; Daniel E. Díaz; Maxime A. Siegler; Wonwoo Nam; Edward I. Solomon; Kenneth D. Karlin

doi:10.1002/chem.201600551

Dioxygen Activation by a Macrocyclic Copper Complex Leads to a Cu₂O₂ Core with Unexpected Structure and Reactivity

Isaac Garcia-Bosch, Ryan E. Cowley, Daniel E. Díaz, Maxime A. Siegler, Wonwoo Nam, Edward I. Solomon, Kenneth D. Karlin

Chemistry & Nanoscience

Research output: Contribution to journal › Article › peer-review

24 Scopus citations

Abstract

We report the Cu^I/O₂ chemistry of complexes derived from the macrocylic ligands 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and 12-TMC (1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). While [(14-TMC)Cu^I]⁺ is unreactive towards dioxygen, the smaller analog [(12-TMC)Cu^I(CH₃CN)]⁺ reacts with O₂ to give a side-on bound peroxo-dicopper(II) species (^SP), confirmed by spectroscopic and computational methods. Intriguingly, 12-TMC as a N4 donor ligand generates ^SP species, thus in contrast with the previous observation that such species are generated by N2 and N3 ligands. In addition, the reactivity of this macrocyclic side-on peroxo-dicopper(II) differs from typical ^SP species, because it reacts only with acid to release H₂O₂, in contrast with the classic reactivity of Cu₂O₂ cores. Kinetics and computations are consistent with a protonation mechanism whereby the TMC acts as a hemilabile ligand and shuttles H⁺ to an isomerized peroxo core.

Original language	English
Pages (from-to)	5133-5137
Number of pages	5
Journal	Chemistry - A European Journal
Volume	22
Issue number	15
DOIs	https://doi.org/10.1002/chem.201600551
State	Published - 4 Apr 2016

Bibliographical note

Funding Information:
This research was supported by the U.S. NIH (GM28962 to K.D.K., DK31450 to E.I.S., NRSA postdoctoral fellowship F32 GM105288 to R.E.C.) and by the NRF of Korea through CRI (NRF 2012R1A3A2048842) and GRL (NRF 2010 00353) (to W.N.). I.G. B. thanks the E.C. for a Marie Curie IOF Fellowship.

Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Keywords

bioinorganic chemistry
copper
dioxygen reduction
macrocyclic ligands
metal-peroxo complexes

Access to Document

10.1002/chem.201600551

Cite this

@article{37ea43219e9245ca92e1b52186eb1bc5,

title = "Dioxygen Activation by a Macrocyclic Copper Complex Leads to a Cu2O2 Core with Unexpected Structure and Reactivity",

abstract = "We report the CuI/O2 chemistry of complexes derived from the macrocylic ligands 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and 12-TMC (1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). While [(14-TMC)CuI]+ is unreactive towards dioxygen, the smaller analog [(12-TMC)CuI(CH3CN)]+ reacts with O2 to give a side-on bound peroxo-dicopper(II) species (SP), confirmed by spectroscopic and computational methods. Intriguingly, 12-TMC as a N4 donor ligand generates SP species, thus in contrast with the previous observation that such species are generated by N2 and N3 ligands. In addition, the reactivity of this macrocyclic side-on peroxo-dicopper(II) differs from typical SP species, because it reacts only with acid to release H2O2, in contrast with the classic reactivity of Cu2O2 cores. Kinetics and computations are consistent with a protonation mechanism whereby the TMC acts as a hemilabile ligand and shuttles H+ to an isomerized peroxo core.",

keywords = "bioinorganic chemistry, copper, dioxygen reduction, macrocyclic ligands, metal-peroxo complexes",

author = "Isaac Garcia-Bosch and Cowley, {Ryan E.} and D{\'i}az, {Daniel E.} and Siegler, {Maxime A.} and Wonwoo Nam and Solomon, {Edward I.} and Karlin, {Kenneth D.}",

note = "Funding Information: This research was supported by the U.S. NIH (GM28962 to K.D.K., DK31450 to E.I.S., NRSA postdoctoral fellowship F32 GM105288 to R.E.C.) and by the NRF of Korea through CRI (NRF 2012R1A3A2048842) and GRL (NRF 2010 00353) (to W.N.). I.G. B. thanks the E.C. for a Marie Curie IOF Fellowship. Publisher Copyright: {\textcopyright} 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.",

year = "2016",

month = apr,

day = "4",

doi = "10.1002/chem.201600551",

language = "English",

volume = "22",

pages = "5133--5137",

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TY - JOUR

T1 - Dioxygen Activation by a Macrocyclic Copper Complex Leads to a Cu2O2 Core with Unexpected Structure and Reactivity

AU - Garcia-Bosch, Isaac

AU - Cowley, Ryan E.

AU - Díaz, Daniel E.

AU - Siegler, Maxime A.

AU - Nam, Wonwoo

AU - Solomon, Edward I.

AU - Karlin, Kenneth D.

N1 - Funding Information: This research was supported by the U.S. NIH (GM28962 to K.D.K., DK31450 to E.I.S., NRSA postdoctoral fellowship F32 GM105288 to R.E.C.) and by the NRF of Korea through CRI (NRF 2012R1A3A2048842) and GRL (NRF 2010 00353) (to W.N.). I.G. B. thanks the E.C. for a Marie Curie IOF Fellowship. Publisher Copyright: © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

PY - 2016/4/4

Y1 - 2016/4/4

N2 - We report the CuI/O2 chemistry of complexes derived from the macrocylic ligands 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and 12-TMC (1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). While [(14-TMC)CuI]+ is unreactive towards dioxygen, the smaller analog [(12-TMC)CuI(CH3CN)]+ reacts with O2 to give a side-on bound peroxo-dicopper(II) species (SP), confirmed by spectroscopic and computational methods. Intriguingly, 12-TMC as a N4 donor ligand generates SP species, thus in contrast with the previous observation that such species are generated by N2 and N3 ligands. In addition, the reactivity of this macrocyclic side-on peroxo-dicopper(II) differs from typical SP species, because it reacts only with acid to release H2O2, in contrast with the classic reactivity of Cu2O2 cores. Kinetics and computations are consistent with a protonation mechanism whereby the TMC acts as a hemilabile ligand and shuttles H+ to an isomerized peroxo core.

AB - We report the CuI/O2 chemistry of complexes derived from the macrocylic ligands 14-TMC (1,4,8,11-tetramethyl-1,4,8,11-tetraazacyclotetradecane) and 12-TMC (1,4,7,10-tetramethyl-1,4,7,10-tetraazacyclododecane). While [(14-TMC)CuI]+ is unreactive towards dioxygen, the smaller analog [(12-TMC)CuI(CH3CN)]+ reacts with O2 to give a side-on bound peroxo-dicopper(II) species (SP), confirmed by spectroscopic and computational methods. Intriguingly, 12-TMC as a N4 donor ligand generates SP species, thus in contrast with the previous observation that such species are generated by N2 and N3 ligands. In addition, the reactivity of this macrocyclic side-on peroxo-dicopper(II) differs from typical SP species, because it reacts only with acid to release H2O2, in contrast with the classic reactivity of Cu2O2 cores. Kinetics and computations are consistent with a protonation mechanism whereby the TMC acts as a hemilabile ligand and shuttles H+ to an isomerized peroxo core.

KW - bioinorganic chemistry

KW - copper

KW - dioxygen reduction

KW - macrocyclic ligands

KW - metal-peroxo complexes

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U2 - 10.1002/chem.201600551

DO - 10.1002/chem.201600551

M3 - Article

C2 - 26919169

AN - SCOPUS:84959419442

SN - 0947-6539

VL - 22

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EP - 5137

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

IS - 15

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