Iodine Adsorption in a Redox-Active Metal-Organic Framework: Electrical Conductivity Induced by Host-Guest Charge-Transfer.

ABSTRACT: We report a comparative study of the binding of I2 (iodine) in a pair of redox-active metal-organic framework (MOF) materials, MFM-300(VIII) and its oxidized, deprotonated analogue, MFM-300(VIV). Adsorption of I2 in MFM-300(VIII) triggers a host-to-guest charge-transfer, accompanied by a partial (?30%) oxidation of the VIII centers in the host framework and formation of I3- species residing in the MOF channels. Importantly, this charge-transfer induces a significant enhancement in the electrical conductivity (?? = 700000) of I2@MFM-300(VIII/IV) in comparison to MFM-300(VIII). In contrast, no host-guest charge-transfer or apparent change in the conductivity was observed upon adsorption of I2 in MFM-300(VIV). High-resolution synchrotron X-ray diffraction of I2@MFM-300(VIII/IV) confirms the first example of self-aggregation of adsorbed iodine species (I2 and I3-) into infinite helical chains within a MOF.

SUBMITTER: Zhang X 

PROVIDER: S-EPMC6806328 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature