Six new metal–organic frameworks with multi-carboxylic acids and imidazole-based spacers: syntheses, structures and properties

Abstract

Six new metal-organic frameworks [Cu(obba)(bimb)·(obbaH(2))](n) (1), [Cu(obba)(bimb)](n) (2), [Zn(2)(obba)(2)(bimb)(2)(DMF)(2)(H(2)O)(3.5)](n) (3), [Ni(3)(2,2',4,4'-bptcH)(2)(bimb)(2)(H(2)O)(2)·(H(2)O)(2)](n) (4), [Ni(2)(bimb)(3)(H(2)O)(6)·(aobtc)·(DMF)(2)·(H(2)O)(2)](n) (5) and [Cd(3,3',4,4'-bptcH(2))(H(2)O)·(bimb)](n) (6), were obtained by reactions of 4,4'-bis(1-imidazolyl)biphenyl (bimb) and multi-carboxylic acids of 4,4'-oxybis(benzoic acid) (obbaH(2)), 2,2',4,4'-biphenyltetracarboxylate acid (2,2',4,4'-bptcH(4)), azoxybenzene-3,3',5,5'-tetracarboxylic acid (aobtcH(4)), and 3,3',4,4'-biphenyltetracarboxylate acid (3,3',4,4'-bptcH(4)) with corresponding metal salts under hydro/solvothermal conditions, respectively. Complexes 1-3 have entangled structures with different topologies: 1 is a 3-fold interpenetrating NbO three-dimensional (3D) network; 2 is a 3-fold interpenetrating dmp 3D net; 3 is a 6-fold interpenetrating dia 3D chiral net containing rare 1D helical chains with the same handedness. Complex 4 is an uninodal 6-connected network with a Schäfli symbol of (4(8)6(4)8(3)) based on the trinuclear Ni(II) subunits, while complexes 5 and 6 are 1D chains. Interestingly, compound 6 represents the rare example of MOFs that exhibit high photocatalytic activity for dye degradation under visible light and shows good stability towards photocatalysis. Complexes 3 and 6 exhibit intense blue emissions in the solid state at room temperature whereas 3 appears to be a good candidate of novel hybrid inorganic-organic NLO material.

Optical Properties of Hybrid Organic‐Inorganic Materials and their Applications

“…Theoretical investigation on charge transfer and NLO response of Lindqvist type POMs (hexamolybdate/molybdate anions) functionalized with side chains organic ligands showed that the charge transfer from molybdate central core to the ligands has a central role in the enhancement of the SHG and significant values of second-order polarizability can be obtained in such configuration. [316,317] In the same way, metal polycarboxylates [312,[318][319][320][321] based crystals have shown promising potentialities in terms of second harmonic generation. E. Cariati and co-workers reported several complexes using trans-4-(4-dimethylaminostyryl) - [320] In this case, the very large SHG is mostly explained by the important quadratic polarizability of the ligands DAMS + (much more important than the SHG from the metal-to-ligand charge transfers contribution) combined with their self-organization in a layered structure with an optimized J-type aggregate configuration (Figure 28).…”

A Sensitive Luminescent Acetylacetone Probe Based on Zn‐MOF with Six‐Fold Interpenetration

“…In 1998, aw ide range of interpenetrating frameworks were reported by Batten and Robson. [33] Nevertheless, it is still ac hallenge for us to constructi nterpenetrating networks with novel topology.A sf ar as we know,m ost topology types of sixfold interpenetrating networks reporteda re of either the dia net or chiral net, [34][35][36][37][38][39][40][41] as well as af ew other nets, such as cdl; [42] pts, [43] honeycomb [44] and helical net. [45] Moreover,a lthoughm any sqc networks have been obtained, most of them are three-fold or without interpenetration [46] .H owever,t ot he best of our knowledge, there is no report on six-fold interpenetration with the topology of sqc6.C ompared with the other structures, compound 1 reveals au nique six-foldi nterpenetration with an unusual[ 2 + +2+ +2] mode.…”

Surface assembly of nano-metal organic framework on amine functionalized indium tin oxide substrate for impedimetric sensing of parathion

“…NMOFs are characterized with better dispersive nature than the micsron scale MOFs and they can easily sense small molecules with no loss in their intrigue framework architectures and topologies (Wang et al, 2011a(Wang et al, , 2011b. NMOFs with Eu(III), Zn(II) and Cd (II) as metal ion units have been reported for the detection of nitro aromatic compounds, small molecules and explosives (Kumar et al, 2014b;Wang et al, 2011aWang et al, , 2011bLi et al, 2008;Pramanik et al, 2011). Availability of pendent functional groups on some NMOF structures may be utilized to tag them with biomolecules such as nucleic acid, protein, antibody and enzymes (DeKrafft et al, 2009;McKinlay et al, 2010).…”