Increased Electric Conductivity upon I 2 Uptake and Gas Sorption in a Pillar‐Layered Metal–Organic Framework

The use of molecular iodine to tune the electrical conductivity in metal–organic frameworks is an effective but seldom investigated strategy. Herein, the single‐crystal‐to‐single‐crystal transformation of [Co 1.5 (bdc) 1.5 (H 2 bpz)] ⋅ DMF ⋅ 4 H 2 O ( 1 ) to [Co 1.5 (bdc) 1.5 (H 2 bpz)] ⋅ 0.5 I 2 ⋅ DMF ( I 2 @1 ) (H 2 bdc=1,4‐benzenedicarboxylic acid, H 2 bpz=3,3′,5,5′‐tetramethyl‐4,4′‐bipyrazole) upon I 2 loading caused a three orders of magnitude enhancement in electrical conductivity of the framework. Single‐crystal X‐ray diffraction revealed that I 2 exists as a single molecule embedded in the channels of framework, and the C−H⋅⋅⋅I hydrogen bonds between I 2 molecules and phenyl units on the porous surface of the framework were suggested to participate in n→σ* host–guest charge transfer, leading to increased electrical conductivity in I 2 @1 . Furthermore, 1 displayed moderate adsorption selectivity for CO 2 over CH 4 and N 2 .