Every MOF property surveyed so far, porosity, stability, selectivity, tolerates the materials being electrical insulators, which they overwhelmingly are: carboxylate linkages are poor electron highways. Sheberla, Dinca and colleagues broke the pattern by swapping oxygen donors for nitrogen, condensing hexaaminotriphenylene with nickel into stacked two-dimensional honeycomb sheets, a deliberate structural rhyme with graphene.
The conductivity numbers rewrote expectations: about 2 S/cm through pressed pellets and 40 S/cm across thin films, records for MOFs at the time and respectable against many conducting polymers. Extended pi-d conjugation across the nickel-diimine planes, plus graphite-like interlayer stacking, provides genuine band transport rather than the hopping conduction of doped insulators. A crystalline, porous, synthetically tunable conductor is a strange and useful object.
Critical notes: pellet measurements convolve grain boundaries with intrinsic transport, so the true single-crystal conductivity remained uncertain here, and the material sacrifices the large pores and diverse chemistry that make classical MOFs attractive, its channels are narrow and its linker options constrained. Air stability of the reduced states also required later care.
The descendants justify the hype: Ni3(HITP)2 and its relatives have since appeared in chemiresistive sensors, supercapacitor electrodes and electrocatalysts, applications structurally impossible for insulating frameworks. When a single paper creates a property axis where none existed, it belongs on any list of the field's essentials.