Fluorescent Cadmium Bipillared‐Layer Open Frameworks: Synthesis, Structures, Sensing of Nitro Compounds, and Capture of Volatile Iodine

Abstract

Fluorescent Cd metal-organic frameworks (MOFs), [Cd 2 (dicarboxylate) 2 (NI-bpy-44) 2 ]( dicarboxylate = benzene-1,4-dicarboxylate (1,4-bdc, 1), 2-bromobenzene-1,4-dicarboxylate (Br-1,4-bdc, 2), 2-nitrobenzene-1,4-dicarboxylate (NO 2 -1,4-bdc, 3), biphenyl-4,4'-dicarboxylate (bpdc, 4); NI-bpy-44 = N-(pyridin-4-yl)-4-(pyridin-4-yl)-1,8-naphthalimide)),f eaturing non-and twofold interpenetrating pcu-type bipillared-layer open structures with sufficient free voids of 58.4, 51.4, 51.5, and 41.4 %, respectively,h ave been hydro(solvo)thermally synthesized.M OFs 1-4 emitted solid-state blue or cyan fluorescence emissions at 447 AE 7nm, which mainly arose from NI-bpy-44 and are dependento nt he incorporated solvents. After immersing the crystalline samples in different solvents, that is, H 2 Oa nd DMSO (1 and 2)a sw ell as nitrobenzene and phenol (1-4), they exhibited ar emarkable fluorescenceq uenching effect, whereas o-xylene and pxylene( 4)c aused significant fluorescencee nhancement. The sensing abilityo fM OFs 1-4 towardn itroc ompoundsc arried out in the vapor phase showed that nitrobenzenea nd 2-nitrophenol displayed detectable fluorescence quenching with 1, 2,a nd 4 whereas 4-nitrotoluenew as an effective fluorescenceq uencher for 1 and 2;t his is most likely attributed to their electron-deficient properties and higherv apor pressures.M oreover,MOFs 1-4 are highlyr eusablefor quick capture of volatile iodine, as supported by clear crystal color change and also by immense fluorescenceq uenching responses owing to the donor-acceptor interaction. Low-pressure CO 2 adsorption isothermsi ndicatet hat activated materials 1'-4' are inefficient at taking up CO 2 .[a] T.

Engineered Bifunctional Luminescent Pillared‐Layer Frameworks for Adsorption of CO2 and Sensitive Detection of Nitrobenzene in Aqueous Media

“…Naphthalimide (NI) derivatives with a large, planar, π‐conjugated arene core(s) are attractive fluorophores in optoelectronics due to their adjustable photoluminescence properties through substitute modifications [28–30] . Upon immobilization with donating functions, such as pyridine and carboxyl, the highly emissive properties of NI derivatives encourage their use in the construction of luminescent MOFs as potential sensor materials [24, 31–33] . Therefore, we have designed a NI‐based bis‐pyridyl ligand, namely, N ‐(pyridin‐4‐yl)‐4‐(pyridin‐4‐yl)‐1,8‐naphthalimide (NI‐bpy‐44), [24] with remarkable fluorescence as a potential provider of luminescence properties in isoreticular pillared‐layer MOFs of various aromatic dicarboxylic acids (Scheme 2).…”

“…From a topological point of view, a pillared‐layer MOF is usually composed of 2D metal–carboxylate layered nets and (rigid) linear bis‐pyridyl N‐tethering pillars [19–25] . Hence, the formation of (luminescent) isoreticular pillared‐layer MOFs can be reasonably achieved by applying a dual‐ligand synthetic approach (Scheme 1), [19] which is an alternative and effective approach to generate well‐designed porous frameworks with adjustable pore sizes and tunable structural features by simply adjusting the length of the linear bis‐pyridyl pillars [20–22, 26] or by changing the polycarboxylate moieties [23, 24, 27] . Of particular note, as the length of the bridging ligands is increased, MOFs usually possess network interpenetration, which tends to diminish the porosity [19, 25] .…”

Dicarboxylate‐Induced Structural Diversity of Luminescent Zn(II)/Cd(II) Metal–Organic Frameworks Based on the 2,5‐Bis(4‐pyridyl)thiazolo[5,4‐d]thiazole Ligand

“…Among various organic ligands, rigid dicarboxylic acids are extensively utilized to construct intriguing structures because of their strong coordination ability and diverse coordination mode . Among the different kinds of N‐containing linkers, bipyridine and their derivatives are widely employed in the construction of versatile MOFs with promising properties . In addition, it has been reported that some MOFs were constructed from rigid dicarboxylate and functionalized bipyridine by the mixed‐ligand strategy, which have intriguing structures and excellent properties .…”

“…Among the different kinds of N‐containing linkers, bipyridine and their derivatives are widely employed in the construction of versatile MOFs with promising properties . In addition, it has been reported that some MOFs were constructed from rigid dicarboxylate and functionalized bipyridine by the mixed‐ligand strategy, which have intriguing structures and excellent properties . 2,5‐Bis(4‐pyridyl)thiazolo[5,4‐ d ]thiazole (Py 2 TTz) with rigid π‐conjugated system has good luminescence property , .…”

A Novel Supramolecular Silver Coordination Complex Based on a Triazole Carboxylate Ligand: Synthesis and Fluorescence Sensing of Colchicine and a Series of Nitro Explosives

“…Thus, it is imperative to detect these nitro compounds. Despite a large number of efforts have been applied to detecting nitro explosives, it is still challenging to detect nitro compounds in practical applications . Therefore, we explored the ability of coordination complex 1 to detect some nitro compounds such as 2, 4, 6‐trinitrophenol (TNP), p‐nitroaniline (PNA), p‐nitrophenol (PNP), p‐nitrotoluene (PNT) and nitrobenzene (NB).…”