Inclusion Chemistry of Thiazyl and Selenazyl Radicals in MIL-53(Al)

Host-guest interactions have recently become a growing area of study within the scientific community, where the intrinsic chemistry affiliated with the binding and activity of these interactions can be directly correlated to the applications these complexes possess, such as gas storage materials, sensors, activators, and in heterogeneous catalysis. In particular, inclusion complexes possessing radical guests offer the potential for strong communication between both the host and guest and/or the guest molecules themselves, where the nature of the host-guest interactions lead to the effects in which the host can modify the guest properties, or conversely, the guest affects the host structure. This presentation will describe the inclusion chemistry of 4-phenyl-1,2,3,5-dithiadiazolyl (PhDTDA) radical, and its selenium analogue (PhDSDA), into the porous metal-organic framework host MIL-53(Al). The inclusion of the PhDTDA and PhDSDA radicals into MIL-53(Al) was achieved through gas phase diffusion, and led to a colour change in the host from white to red and purple, respectively. The characterization of these inclusion complexes was confirmed through powder X-Ray diffraction and EPR spectroscopy. Reactivity studies of these radicals within the host framework will be discussed

Exploring through-bond and through-space magnetic communication in 1,3,2-dithiazolyl radical complexes

Reaction of the methyl-benzodithiazolyl radical (MBDTA) with M(hfac)2 complexes (M = Mn, Co, Zn) affords the complexes M(hfac)2(MBDTA)2. Strong antiferromagnetic exchange interactions are observed between M(ii) ions and the two S = 1/2 radicals (M = Mn, Co), whereas weak antiferromagnetic interactions are observed between radicals when using the diamagnetic Zn(ii) ion. Strong intermolecular exchange coupling is also evident in Mn(hfac)2(MBDTA)2 and attributed to π*-π* contacts between MBDTA radicals which are absent for the Co and Zn derivatives.J. M. R. would like to thank NSERC for financial support. A. A. and J. C. acknowledge support from grant PGC-2018-099024-B100 from the Ministry of Science, Innovation and Universities of Spain. Additional support from Diputacioń General de Aragoń (DGA-M4) is also acknowledged.Peer reviewe

Inclusion and reactivity of main group radicals in the porous framework MIL-53(Al)

Inclusion of the dithiadiazolyl and diselenadiazolyl radicals PhCNEEN (E = S, Se) into the porous framework, Al(bdc)(OH) [MIL-53(Al); bdc = 1,4-benzenedicarboxylate] was achieved by vacuum sublimation. PXRD studies reveal the inclusion complexes adopt the orthorhombic space group Imma. Variable temperature PXRD studies coupled with thermal analysis reveal that for PhCNSSN@MIL-53(Al), radical elimination from the pores at elevated temperatures is accompanied by an opening of the pore channels. Radicals can also be extracted from the framework using an appropriate solvent. Oxidation of the radical guest within the host framework has been achieved with Cl2 or Br2 and led to complete radical oxidation (based on EPR studies) whereas the milder oxidant I2 leads to incomplete oxidation.NTS thanks Dr J. Auld for HRMS measurements, as well as Dr K. Pringouri and L. Watanabe for CHN data. JMR would like to thank NSERC for an operating grant (RGPIN-2015-245402) and CFI and ORF for infrastructure grants. AA and JC acknowledge support from grant PGC-2018-099024-B100 from the Ministry of Science, Innovation and Universities of Spain and the European Regional Development Fund. Additional support from Diputacion General de Aragon (DGA-M4) is also acknowledged.Peer reviewe