+ Site Statistics
References:
54,258,434
Abstracts:
29,560,870
PMIDs:
28,072,757
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

Ligand noninnocence of thiolate/disulfide in dinuclear copper complexes: solvent-dependent redox isomerization and proton-coupled electron transfer



Ligand noninnocence of thiolate/disulfide in dinuclear copper complexes: solvent-dependent redox isomerization and proton-coupled electron transfer



Journal of the American Chemical Society 135(50): 18912-9



Copper thiolate/disulfide interconversions are related to the functions of several important proteins such as human Sco1, Cu-Zn superoxide dismutase (SOD1), and mammalian zinc-bonded metallothionein. The synthesis and characterization of well-defined synthetic analogues for such interconversions are challenging yet provide important insights into the mechanisms of such redox processes. Solvent-dependent redox isomerization and proton-coupled electron transfer mimicking these interconversions are observed in two structurally related dimeric μ,η(2):η(2)-thiolato Cu(II)Cu(II) complexes by various methods, including X-ray diffraction, XAS, NMR, and UV-vis. Spectroscopic evidence shows that a solvent-dependent equilibrium exists between the dimeric μ-thiolato Cu(II)Cu(II) state and its redox isomeric μ-disulfido Cu(I)Cu(I) form. Complete formation of μ-disulfido Cu(I)Cu(I) complexes, however, only occurs after the addition of 2 equiv of protons, which promote electron transfer from thiolate to Cu(II) and formation of disulfide and Cu(I) via protonation of the coordinating ligand. Proton removal reverses this reaction. The reported unusual reductive protonation/oxidative deprotonation of the metal centers may serve as a new chemical precedent for how related proteins manage Cu ions in living organisms.

(PDF emailed within 0-6 h: $19.90)

Accession: 054124596

Download citation: RISBibTeXText

PMID: 24279864

DOI: 10.1021/ja409603m


Related references

Carboxamidate Ligand Noninnocence in Proton Coupled Electron Transfer. Inorganic Chemistry 2019, 2019

A copper thiolate centre for electron transfer: mononuclear vs. dinuclear complexes. Dalton Transactions 41(11): 3130-3133, 2012

Hydrogen bonding, solvent exchange, and coupled proton and electron transfer in the oxidation and reduction of redox-active tyrosine Y(Z) in Mn-depleted core complexes of photosystem II. Biochemistry 37(51): 17931-17943, 1999

Hydrogen bonding, solvent exchange, and coupled proton and electron transfer in the oxidation and reduction of redox-active tyrosine YZ in Mn-depleted core complexes of photosystem II. Biochemistry (American Chemical Society) 37(51): 931-43, 1998

Dinuclear copper(I) thiolate complexes with a bridging noninnocent PNP ligand. Chemistry 17(14): 3850-3854, 2011

Solvent-dependent transition from concerted electron-proton to proton transfer in photoinduced reactions between phenols and polypyridine Ru complexes with proton-accepting sites. Dalton Transactions 47(44): 15917-15928, 2018

Selective 4e-/4H+ O2 reduction by an iron(tetraferrocenyl)porphyrin complex: from proton transfer followed by electron transfer in organic solvent to proton coupled electron transfer in aqueous medium. Inorganic Chemistry 52(24): 14317-14325, 2014

Reductive Termination of Cyanoisopropyl Radicals by Copper(I) Complexes and Proton Donors: Organometallic Intermediates or Coupled Proton-Electron Transfer?. Inorganic Chemistry 2019, 2019

Trigonal planar copper(I) complex: synthesis, structure, and spectra of a redox pair of novel copper(II/I) complexes of tridentate bis(benzimidazol-2'-yl) ligand framework as models for electron-transfer copper proteins. Inorganic Chemistry 40(10): 2246-2255, 2001

Carbon disulfide binding at dinuclear and mononuclear nickel complexes ligated by a redox-active ligand: iminopyridine serving as an accumulator of redox equivalents for the activation of heteroallenes. Chemical Communications 48(77): 9595-9597, 2013

Observation of redox-induced electron transfer and spin crossover for dinuclear cobalt and iron complexes with the 2,5-di-tert-butyl-3,6-dihydroxy-1,4-benzoquinonate bridging ligand. Journal of the American Chemical Society 131(17): 6229-6236, 2009

J-Dependent Curie or Anti-Curie Behavior of Proton NMR Resonances for Antiferromagnetically Coupled Dinuclear Copper(II) Complexes. Journal of Magnetic Resonance, Series A 119(1): 125-128, 1996

Activation of C-H, N-H, and O-H Bonds via Proton-Coupled Electron Transfer to a Mn(III) Complex of Redox-Noninnocent Octaazacyclotetradecadiene, a Catenated-Nitrogen Macrocyclic Ligand. Journal of the American Chemical Society 2019, 2019

Solvent-slaved protein motions accompany proton coupled electron transfer reactions catalysed by copper nitrite reductase. Chemical Communications 2019, 2019

Controlled Interconversion of a Dinuclear Au Species Supported by a Redox-Active Bridging PNP Ligand Facilitates Ligand-to-Gold Electron Transfer. Chemistry 23(23): 5585-5594, 2017