title: Photochemistry of framework-supported M(diimine)(CO)3X complexes in three-dimensional lithium carboxylate metal-organic frameworks: monitoring the effect of framework cations.
abstract: The structures and photochemical behaviour of two new metal-organic frameworks (MOFs) are reported. Reaction of Re(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Cl or Mn(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Br with LiCl or LiBr, respectively, produces single crystals of {Li2(DMF)2[(2,2'-bipy-5,5'-dicarboxylate)Re(CO)3Cl]}n( RELI: ) or {Li2(DMF)2[(2,2'-bipy-5,5'-dicarboxylate)Mn(CO)3Br]}n( MNLI: ). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations that are cross-linked by units of Re(2,2'-bipy-5,5'-dicarboxylate)(CO)3Cl ( RELI: ) or Mn(2,2'-bipy-5,5'- dicarboxylate)(CO)3Br ( MNLI: ). The photophysical and photochemical behaviour of both RELI: and MNLI: are probed. The rhenium-containing MOF, RELI: , exhibits luminescence and the excited state behaviour, as established by time-resolved infrared measurements, is closer in behaviour to that of unsubstituted [Re(bipy)(CO)3Cl] rather than a related MOF where the Li(I) cations are replaced by Mn(II) cations. These observations are further supported by density functional theory calculations. Upon excitation MNLI: forms a dicarbonyl species which rapidly recombines with the dissociated CO, in a fashion consistent with the majority of the photoejected CO not escaping the MOF channels.This article is part of the themed issue 'Coordination polymers and metal-organic frameworks: materials by design'.
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Reade
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Thomas S
authors.initials: TS
authors.lastname: Murphy
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: James A
authors.initials: JA
authors.lastname: Calladine
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: Raphael
authors.initials: R
authors.lastname: Horvath
authors.affiliation: STFC Rutherford Appleton Lab, Central Laser Facility, Didcot OX11 0QX, UK.
authors.forename: Ian P
authors.initials: IP
authors.lastname: Clark
authors.affiliation: STFC Rutherford Appleton Lab, Central Laser Facility, Didcot OX11 0QX, UK.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Greetham
authors.affiliation: STFC Rutherford Appleton Lab, Central Laser Facility, Didcot OX11 0QX, UK.
authors.forename: Michael
authors.initials: M
authors.lastname: Towrie
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK.
authors.forename: William
authors.initials: W
authors.lastname: Lewis
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK mike.george@nottingham.ac.uk.|Department of Chemistry and Environmental Engineering, University of Nottingham Ningbo China, Ningbo 315100, Zhejiang, People's Republic of China.
authors.forename: Michael W
authors.initials: MW
authors.lastname: George
authors.affiliation: School of Chemistry, University of Nottingham, Nottingham NG7 2RD, UK neil.champness@nottingham.ac.uk.
authors.forename: Neil R
authors.identifier: http://orcid.org/0000-0003-2970-1487
authors.initials: NR
authors.lastname: Champness
keywords: metal–organic frameworks; photochemistry; supramolecular chemistry