Zn-MOFs based luminescent sensors for selective and highly sensitive detection of Fe3+ and tetracycline antibiotic

Either reduced or excessive metal ions level in biological systems might induce serious metabolic diseases, and the abuse of antibiotics has seriously affected the environment. Despite the significant progress in the development of fluorescence probes over the past decade, the ability to sensitively and selectively detect these metal ions and antibiotics remains a pressing problem. Herein, we demonstrated some effective fluorescence probes for sensing metal ions and antibiotics, six novel and stable Zn(II) metal-organic frameworks (Zn-MOFs), namely [Zn₃(L)₂(1,4-bimb)₃]_n (1), [Zn₃(L)₂(4,4'-bbibp)₂(H₂O)₂]_n·2(CH₃CN) (2), [Zn(HL)(4,4'-bidpe)]_n (3), [Zn(HL)(4,4'-bibp)]_n (4), [Zn(HL)(3,5'-bip)]_n (5) and [Zn(HL)(1,3'-bit)]_n (6) (flexible H₃L = 5-(2-carboxylphenoxy)isophthalic acid, semi-flexible 1,4-bimb = 1,4-bis(imidazol-l-ylmethyl) benzene, rigid 4,4'-bbibp = 4,4'-bis(benzoimidazo-1-ly)biphenyl, semi-flexible 4,4'-bidpe = 4,4'-bis(imidazolyl)diphenyl ether, rigid 4,4'-bibp = 4,4'-bis(imidazolyl)biphenyl, rigid 3,5'-bip = bis(1-imidazoly)pyridine and rigid 1,3-bit = 1,3-bis(l-imidazoly)toluene) have been successfully synthesized via solvothermal conditions and further characterized by IR spectra, elemental analysis, powder X-ray diffraction (PXRD), single-crystal X-ray diffraction, and thermogravimetric (TG) analysis. These Zn MOFs have exhibited diversely architectural frameworks via the assistant N-donor ligands: 1, 2, 5 and 6 show unprecedented topological networks, 1 affords a 3-nodal (3, 4, 4)-connect 2-fold interpenetrating topology structure with the Point Schläfli symbol of (5·6·7·9²·10)₂(5·6·7)₂(5·7³·8²), 2 shows a 3-nodal (3, 4, 6)-c topology with (4·8²)₂(4²·8¹¹·10·12)(8⁶), 5 and 6 display 3-nodal (2, 2, 4)-c topology with (2·4⁴·6)(2)(4). 3 and 4 show 4-connected sql topology with (4⁴·6²). As expected, Zn MOFs 1-6 not only revealed a highly sensitive and selective fluorescence quenching effect on Fe³⁺ ions in aqueous solution, but also toughed the interference of a myriad of other metal ions. It is noteworthy that they could also be used as luminescent sensors for detection of tetracycline antibiotic.

Coordination Polymers Based on Highly Emissive Ligands: Synthesis and Functional Properties

Coordination polymers are constructed from metal ions and bridging ligands, linking them into solid-state structures extending in one (1D), two (2D) or three dimensions (3D). Two- and three-dimensional coordination polymers with potential voids are often referred to as metal-organic frameworks (MOFs) or porous coordination polymers. Luminescence is an important property of coordination polymers, often playing a key role in their applications. Photophysical properties of the coordination polymers can be associated with intraligand, metal-centered, guest-centered, metal-to-ligand and ligand-to-metal electron transitions. In recent years, a rapid growth of publications devoted to luminescent or fluorescent coordination polymers can be observed. In this review the use of fluorescent ligands, namely, 4,4'-stilbenedicarboxylic acid, 1,3,4-oxadiazole, thiazole, 2,1,3-benzothiadiazole, terpyridine and carbazole derivatives, naphthalene diimides, 4,4',4''-nitrilotribenzoic acid, ruthenium(II) and iridium(III) complexes, boron-dipyrromethene (BODIPY) derivatives, porphyrins, for the construction of coordination polymers are surveyed. Applications of such coordination polymers based on their photophysical properties will be discussed. The review covers the literature published before April 2020.

Crystal structure of catena-poly[tetraiodido-(μ2-1,4-bis(2-methyl-1H-imidazol-1-yl)benzene-κ2 N:N′)dimercury(II)], C14H14Hg2I4N4

C14H14Hg2I4N4, monoclinic, P21/c, a = 4.3592(11) Å, b = 20.116(5) Å, c = 12.713(3) Å, β = 96.838(5)°, Z = 2, V = 1106.9(5) Å3, R gt(F) = 0.0362, wR ref(F 2) = 0.0863, T = 296(2) K.

Synthesis, structures and magnetic properties of isoreticular polyrotaxane-type two-dimensional coordination polymers

The variable temperature magnetic properties have been investigated for two isoreticular polyrotaxane-type coordination polymers of Co(ii) with bent and two linear dinitrogen spacers.

The mixed-ligand strategy to assemble a microporous anionic metal–organic framework: Ln3+ post-functionalization, sensors and selective adsorption of dyes

A microporous anionic metal–organic framework has been synthesized, which can be used as potential sensor to organic molecules and selective adsorbent to dyes.

Color-tunable entangled coordination polymers based on long flexible bis(imidazole) ligands and phenylenediacetate

Color-tunable coordination polymers with various types of entanglement have been synthesized from flexible phenylenediacetic acid and bis(imidazole) ligands.