title: A Mononuclear Co(II) Coordination Complex Locked in a Confined Space and Acting as an Electrochemical Water-Oxidation Catalyst: A "Ship-in-a-Bottle" Approach.
abstract: Preparing efficient and robust water oxidation catalyst (WOC) with inexpensive materials remains a crucial challenge in artificial photosynthesis and for renewable energy. Existing heterogeneous WOCs are mostly metal oxides/hydroxides immobilized on solid supports. Herein we report a newly synthesized and structurally characterized metal-organic hybrid compound [{Co3 (μ3 -OH)(BTB)2(dpe)2} {Co(H2O)4(DMF)2}0.5]n ⋅n H2O(Co-WOC-1) as an effective and stable water-oxidation electrocatalyst in an alkaline medium. In the crystal structure of Co-WOC-1, a mononuclear Co(II) complex {Co(H2O)4(DMF)2}(2+) is encapsulated in the void space of a 3D framework structure and this translationally rigid complex cation is responsible for a remarkable electrocatalytic WO activity, with a catalytic turnover frequency (TOF) of 0.05 s(-1) at an overpotential of 390 mV (vs. NHE) in 0.1 m KOH along with prolonged stability. This host-guest system can be described as a "ship-in-a-bottle", and is a new class of heterogeneous WOC.
authors.affiliation: School of Chemistry, University of Hyderabad, P.O. Central University, Hyderabad, 500046, India.
authors.forename: Paulami
authors.initials: P
authors.lastname: Manna
authors.affiliation: School of Chemistry, University of Hyderabad, P.O. Central University, Hyderabad, 500046, India.
authors.forename: Joyashish
authors.initials: J
authors.lastname: Debgupta
authors.affiliation: School of Chemistry, University of Hyderabad, P.O. Central University, Hyderabad, 500046, India.
authors.forename: Suranjana
authors.initials: S
authors.lastname: Bose
authors.affiliation: School of Chemistry, University of Hyderabad, P.O. Central University, Hyderabad, 500046, India. skdas@uohyd.ac.in, samar439@gmail.com.
authors.forename: Samar K
authors.initials: SK
authors.lastname: Das
keywords: cobalt complexes; electrocatalyst; metal-organic frameworks; oxygen evolution; water oxidation