Metal–Organic Frameworks Constructed from d-Camphor Acid: Bifunctional Properties Related to Luminescence Sensing and Liquid-Phase Separation

Abstract

Three metal-organic frameworks (MOFs) [M2(d-cam)2(bimb)2]n · 3.5nH2O (M = Mn for 1, Co for 2) and [Cd8(d-cam)8(bimb)4]n (3) (d-H2cam = d-camphor acid, bimb = 4,4'-bis(1-imidazolyl)biphenyl), solvothermally synthesized, exhibit structural diversity. The charming aspect of these frameworks is that compound 3 is the very first MOF-based sensor for quantitatively detecting three different types of analytes (metal ions, aromatic molecules, and pesticides). And also, both compounds 2 and 3 show rapid uptake and ready regeneration for methyl orange (MO) and can selectively bind MO over methylene blue (MB) with high MO/MB separation ratio.

A New 3D 10-Connected Cd(II) Based MOF With Mixed Ligands: A Dual Photoluminescent Sensor for Nitroaroamatics and Ferric Ion

“…The disagreements between quenching of photoluminescent intensity for others NACs except for TNP and their LUMO energy parametersare conducted, in which may contain the electronic migration and/or resonance energy transfer (RET).The correlative factors responsible for photoluminescent intensity quenching process (Hu et al, 2016). Also, the efficiency of energy transfer depend on the extent of overlap between the emission spectrum of MOF and the electronic absorption spectrum of the analyte (Marin et al, 2006; Kent et al, 2010; Saini and Das, 2012; Son et al, 2013; Banerjee et al, 2014; Li et al, 2014; Park and Lee, 2015; Wen et al, 2015; Park et al, 2016; Das and Mandal, 2018). In sharp contrast to other NACs the absorption spectrum for TNP displays good full coverage the emission spectrum of 1 (Figure S29).…”

“…Antagonistically, the emission band at ~475 nm display poor spectral overlap with the electronic absorption spectrum of TNP because of which the quenching of this emission band occurs by a “less efficient” photo-induced electron transfer (PET) mechanism (Banerjee et al, 2014). In addition, there might be electrostatic interactions between TNP and the nitrogen centers of the ligands in 1 (Marin et al, 2006; Kent et al, 2010; Saini and Das, 2012; Son et al, 2013; Banerjee et al, 2014; Li et al, 2014; Park and Lee, 2015; Wen et al, 2015; Park et al, 2016; Das and Mandal, 2018) Hence due to combination of electron-transfer, energy-transfer and electrostatic interaction between TNP 1 , the quenching efficiency for TNP gets significantly enhanced (Marin et al, 2006; Kent et al, 2010; Son et al, 2013; Li et al, 2014; Das and Mandal, 2018).…”

“…Bearing these aspects in mind and in continuation to our efforts in the area of metal-organic frameworks (MOFs) (Li et al, 2016; Liu et al, 2016c; Jin et al, 2017), which were aimed toward the syntheses of multifunctional MOFs we have chosen a flexible 1,4-bis(2-methyl-imidazol-1-yl)butane (bib) ligand (Hou et al, 2014a,b; Shi et al, 2014), and a rigid 1,3,5-benzenetricarboxylic acid (H 3 btc) ligand as well as d 10 transition-metal center (Cd 2+ ) to develop new structures with potential applications as luminescence sensor. The choice of using this strategy has been based on the following considerations (Marin et al, 2006; Kent et al, 2010; Saini and Das, 2012; Son et al, 2013; Banerjee et al, 2014; Li et al, 2014; Park and Lee, 2015; Wen et al, 2015; Park et al, 2016; Das and Mandal, 2018): (1) the binding capacity between bib ligand and metal centers not only induces flexible and diverse structures but also facilitates the surface functionalities of the materials; (2) rigid ligand btc with aromatic rings could effectively favor intra-ligand interactions and induce luminescent character. Herein, we are presenting a new Cd(II) MOF having formula[Cd 2 (btc)(bib)(HCOO)(H 2 O)·H 2 O] n ( 1 ) which have been utilized as dual photoluminescent sensor for the selective detection of nitroaromatics (NACs) especially TNP and ferric ions.…”

Highly Selective Aqueous Phase Detection of Azinphos‐Methyl Pesticide in ppb Level Using a Cage‐Connected 3D MOF

“…They have speculated that electron transfer from the conduction band of the MOF to the LUMO of the analyte is the reason behind the luminescence quenching. The same group also reported another MOF [Cd 8 (D‐cam) 8 (bimb) 4 ] n {where D‐H 2 cam=D‐camphor acid, bimb=4,4′‐bis(1‐imidazolyl)biphenyl)} for parathion‐methyl detection in DMF medium through luminescence quenching . But the real life application demands the pesticide detection in aqueous medium as the agricultural runoff and other source of pesticide toxicity may enter into the living system through aquatic environment.…”

Synthesis, Structure, and Dye Adsorption Properties of a Nickel(II) Coordination Layer Built from d-Camphorate and Bispyridyl Ligands

“…Thus, adsorption, with advantages of simplicity, efficiency, wide-ranging availability, and economic competitiveness, represents one of the most feasible treatment processes for dye removal from water [10,17]. The recent enthusiasm around the use of CPs and MOFs as advanced adsorbents for water purification has been documented in the past couple of years [7,11,12,[18][19][20][21][22][23].…”