Increase in Electrical Conductivity of MOF to Billion-Fold upon Filling the Nanochannels with Conducting Polymer

Redox-active pyrrole (Py) monomers were intercalated into 1D nanochannels of [Cd(NDC)(0.5)(PCA)]center dot G(x) (H2NDC = 2,6-napthalenedicarboxylic acid, HPCA = 4-pyridinecarboxylic acid, G = guest molecules) (1) - a fluorescent 3D MOF (lambda(em) = 385 nm). Subsequent activation of 1 superset of Py upon immersing into iodine (I-2) solution resulted in an increment of the bulk electrical conductivity by similar to 9 orders of magnitude. The unusual increase in conductivity was attributed to the formation of highly oriented and conducting polypyrrole (PPy) chains inside ID nanochannels and specific host-guest interaction in 1 superset of PPy thereof. The Hall-effect measurements suggested 1 superset of PPy to be an n-type semiconductor material with remarkably high-carrier density (eta) of similar to 1.5 x 10(17) cm(-3) and mobility (mu) of similar to 8.15 cm(2) V-1 s(-1). The fluorescence property of 1 was almost retained in 1 superset of PPy with concomitant exciplex-type emission at higher wavelength (lambda(em) = 520 nm). The here-presented results on [MOF superset of Conducting Polymer] systems in general will serve as a prototype experiment toward rational design for the development of highly conductive yet fluorescent MOF-based materials for various optoelectronic applications.