Three new electron‐rich metal–organic frameworks (MOF‐1–MOF‐3) have been synthesized by employing ligands bearing aromatic tags. The key role of the chosen aromatic tags is to enhance the π‐electron density of the luminescent MOFs. Single‐crystal X‐ray structures have revealed that these MOFs form three‐dimensional porous networks with the aromatic tags projecting inwardly into the pores. These highly luminescent electron‐rich MOFs have been successfully utilized for the detection of explosive nitroaromatic compounds (NACs) on the basis of fluorescence quenching. Although all of the prepared MOFs can serve as sensors for NACs, MOF‐1 and MOF‐2 exhibit superior sensitivity towards 4‐nitrotoluene (4‐NT) and 2,4‐dinitrotoluene (DNT) compared to 2,4,6‐trinitrotoluene (TNT) and 1,3,5‐trinitrobenzene (TNB). MOF‐3, on the other hand, shows an order of sensitivity in accordance with the electron deficiencies of the substrates. To understand such anomalous behavior, we have thoroughly analyzed both the steady‐state and time‐resolved fluorescence quenching associated with these interactions. Determination of static Stern–Volmer constants (KS) as well as collisional constants (KC) has revealed that MOF‐1 and MOF‐2 have higher KS values with 4‐NT than with TNT, whereas for MOF‐3 the reverse order is observed. This apparently anomalous phenomenon was well corroborated by theoretical calculations. Moreover, recyclability and sensitivity studies have revealed that these MOFs can be reused several times and that their sensitivities towards TNT solution are at the parts per billion (ppb) level. Competing size and electronic effects: Luminescent Zn‐MOFs can be prepared by employing π‐electron‐rich isophthalic acid derivatives bearing fluorescent tags. These MOFs can be used for sensing nitroaromatic explosives on the basis of fluorescence quenching (see graphic; 4‐NT=4‐nitrotoluene; TNT=trinitrotoluene). For the more porous MOFs, the fluorescence quenching is dictated by size selection. For MOFs in which the pores are blocked by pyrenyl tags, the fluorescence quenching thus occurs on the surface and conforms to the electronic properties of the analytes.