title: Tailoring porosity and rotational dynamics in a series of octacarboxylate metal-organic frameworks.
abstract: Modulation and precise control of porosity of metal-organic frameworks (MOFs) is of critical importance to their materials function. Here we report modulation of porosity for a series of isoreticular octacarboxylate MOFs, denoted MFM-180 to MFM-185, via a strategy of selective elongation of metal-organic cages. Owing to the high ligand connectivity, these MOFs do not show interpenetration, and are robust structures that have permanent porosity. Interestingly, activated MFM-185a shows a high Brunauer-Emmett-Teller (BET) surface area of 4,734 m2g-1for an octacarboxylate MOF. These MOFs show remarkable CH4and CO2adsorption properties, notably with simultaneously high gravimetric and volumetric deliverable CH4capacities of 0.24 g g-1and 163 vol/vol (298 K, 5-65 bar) recorded for MFM-185a due to selective elongation of tubular cages. The dynamics of molecular rotors in deuterated MFM-180a-d16and MFM-181a-d16were investigated by variable-temperature2H solid-state NMR spectroscopy to reveal the reorientation mechanisms within these materials. Analysis of the flipping modes of the mobile phenyl groups, their rotational rates, and transition temperatures paves the way to controlling and understanding the role of molecular rotors through design of organic linkers within porous MOF materials.
authors.affiliation: School of Chemistry, University of Manchester, Manchester M13 9PL, United Kingdom.
authors.forename: Florian
authors.initials: F
authors.lastname: Moreau
authors.affiliation: Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.|Novosibirsk State University, Novosibirsk 630090, Russia.
authors.forename: Daniil I
authors.initials: DI
authors.lastname: Kolokolov
authors.affiliation: Boreskov Institute of Catalysis, Siberian Branch, Russian Academy of Sciences, Novosibirsk 630090, Russia.|Novosibirsk State University, Novosibirsk 630090, Russia.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Stepanov
authors.affiliation: School of Chemistry, Cardiff University, Cardiff CF10 3AT, United Kingdom.
authors.forename: Timothy L
authors.initials: TL
authors.lastname: Easun
authors.affiliation: Chemical and Environmental Sciences Laboratory, General Motors Corporation, Warren, MI 48090.
authors.forename: Anne
authors.initials: A
authors.lastname: Dailly
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: William
authors.identifier: 0000-0001-7103-6981
authors.initials: W
authors.lastname: Lewis
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Blake
authors.affiliation: Diamond Light Source, Oxon, OX11 0DE, United Kingdom.
authors.forename: Harriott
authors.initials: H
authors.lastname: Nowell
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Lennox
authors.affiliation: School of Chemistry, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom.
authors.forename: Elena
authors.identifier: 0000-0002-9910-7603
authors.initials: E
authors.lastname: Besley
authors.affiliation: School of Chemistry, University of Manchester, Manchester M13 9PL, United Kingdom; Sihai.Yang@manchester.ac.uk M.Schroder@manchester.ac.uk.
authors.forename: Sihai
authors.initials: S
authors.lastname: Yang
authors.affiliation: School of Chemistry, University of Manchester, Manchester M13 9PL, United Kingdom; Sihai.Yang@manchester.ac.uk M.Schroder@manchester.ac.uk.|Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, 630090, Russia.
authors.forename: Martin
authors.initials: M
authors.lastname: Schröder
keywords: CH4; CO2; copper; metal-organic framework; molecular rotors