Biphenyldicarboxylic Acid Research Articles

49‐3: Late‐News Paper: Hybrid Capacitor Type Organic Electrochromic Device for Multicolor Representation

In this paper, we designed a novel multicolor electrochromic (EC) device having hybrid capacitor electrochromic device based on 4,4 ’‐biphenyl dicarboxylic acid diethyl ester and phenothiazine molecule with carbon electrode. The EC properties of the device were analyzed and discussed for the possibility to multicolor representation.

Functional hexanuclear Y(III) cluster-based MOFs supported Pd(II) single site catalysts for aerobic selective oxidation of styrene

Oxidation of styrene is one of the significant reactions in organic synthesis. In this work, a serious of PdCl2 moiety-decorated Y6-MOFs adopting post-synthetic strategy were fabricated as applicable single-site catalysts for oxidation of styrene. Specifically, the functional organic linker, H2bpydc (2,2′-bipyridine-5,5′-dicarboxylic acid), was first incorporated quantitatively into Y6 clusters-based MOF, [(CH3)2NH2]2[Y6(μ3-OH)8(bpdc)6] (bpdc = 4,4′-biphenyl dicarboxylic acid) via post-synthetic ligand exchange. Then post-synthetic Pd(II) metalation was performed to enhance the density of isolated single sites. The obtained Pd(II)-Y-bpydcx/bpdc1-x can be used as highly efficient heterogeneous single-site catalysts to promote selective oxidative cleavage of styrene to benzaldehyde using O2 as a oxidant under solvent-free and mild reaction conditions (1 atm and 80 °C). Importantly, when using Pd(II)-Y-bpydc0.8/bpdc0.2 (0.024 mmol Pd) as catalyst, the high conversion of styrene and the selectivity for benzaldehyde can reach 88.7 % and 82.2 %, respectively.

Synthesis, Crystal Structures and Luminescence Properties of Three New Cadmium 3D Coordination Polymers.

The new rigid planar ligand 2,5-bis(3-(pyridine-4-yl)phenyl)thiazolo[5,4-d]thiazole (BPPT) has been synthesized, which is an excellent building block for assembling coordination polymer. Under solvothermal reaction conditions, cadmium ion with BPPT in the presence of various carboxylic acids including (1,1′-biphenyl)-4,4′-dicarboxylic acid (BPDC), isophthalic acid (IP), and benzene-1,3,5-tricarboxylic acid (BTC) gave rise to three coordination complexes, viz, [Cd(BPPT)(BPDA)](BPPT)n (1), [Cd(BPPT) (IP)] (CH3OH) (2), and [Cd3(BPPT)3(BTC)2(H2O)2] (3). The structures of 1, 2, and 3 were characterized by single crystal X-ray diffraction. The IR spectra as well as thermogravimetric and luminescence properties were also investigated. Complex 1 is a two-dimensional (2D) network and further stretched to a 3D supramolecular structure through π–π stacking interaction. The complexes 2 and 3 show 3D framework. The complexes 1, 2, and 3 exhibited luminescence property at room temperature.

Multiscale Analysis of Phase Transformations in Self-Assembled Layers of 4,4'-Biphenyl Dicarboxylic Acid on the Ag(001) Surface.

Understanding the nucleation and growth kinetics of thin films is a prerequisite for their large-scale utilization in devices. For self-assembled molecular phases near thermodynamic equilibrium the nucleation-growth kinetic models are still not developed. Here, we employ real-time low-energy electron microscopy (LEEM) to visualize a phase transformation induced by the carboxylation of 4,4'-biphenyl dicarboxylic acid on Ag(001) under ultra-high-vacuum conditions. The initial (α) and transformed (β) molecular phases are characterized in detail by X-ray photoemission spectroscopy, single-domain low-energy electron diffraction, room-temperature scanning tunneling microscopy, noncontact atomic force microscopy, and density functional theory calculations. The phase transformation is shown to exhibit a rich variety of phenomena, including Ostwald ripening of the α domains, burst nucleation of the β domains outside the α phase, remote dissolution of the α domains by nearby β domains, and a structural change from disorder to order. We show that all phenomena are well described by a general growth-conversion-growth (GCG) model. Here, the two-dimensional gas of admolecules has a dual role: it mediates mass transport between the molecular islands and hosts a slow deprotonation reaction. Further, we conclude that burst nucleation is consistent with a combination of rather weak intermolecular bonding and the onset of an additional weak many-body attractive interaction when a molecule is surrounded by its nearest neighbors. In addition, we conclude that Ostwald ripening and remote dissolution are essentially the same phenomenon, where a more stable structure grows at the expense of a kinetically formed, less stable entity via transport through the 2D gas. The proposed GCG model is validated through kinetic Monte Carlo (kMC) simulations.

Hydrothermal synthesis of Ni-based metal organic frameworks/graphene oxide composites as supercapacitor electrode materials

Abstract

Characterization of a Holmium 4,4'-Biphenyldicarboxylate Metal-Organic Framework and Its Potential as a Holmium Carrier System.

There is growing interest in Holmium carriers for radiotherapeutic applications. In this work, a holmium-based metal-organic framework (MOF) using the 4,4'-biphenyldicarboxylic acid (H₂BPDC) linker was synthesized and characterized to explore its potential as a radiotherapeutic carrier. The 3D MOF [Ho(BPDC)₂]·(CH₃)₂NH₂ was characterized by single crystal X-ray diffraction, FTIR, TGA and PXRD. A challenge to overcome in lanthanide-based MOFs is the deformation or collapse of the framework that can occur after evacuation of the pores. This structure displays high thermal stability and no collapse was observed when the molecules confined in the pores were removed. The coordination around the holmium center (CN = 8) is the key to this stability since only the organic linker and no solvent molecules coordinate to the metallic center. The porosity of the material was confirmed by high-pressure carbon dioxide (CO₂) adsorption-desorption analysis. The stability of the MOF, its holmium content (28 wt%) and its porosity are features that make this material a potential holmium carrier for radiotherapeutic applications.

Multifunctional naphthalene diimide-based coordination polymers: Photochromism and solventchromism

Naphthalene diimides (NDIs), a class of organic dyes with high photochemical activity and high redox activity, have attracted considerable interest attributing to their photoinduced electron transfer to form stable radical anions upon irradiation in the presence of electron donors. In this study, a naphthalenediimide-based ligand and different aromatic carboxylic acids self-assembled in the presence of zinc ions, forming three novel coordination polymers, [Zn2 (DPMNI) (TPDC)2] (1), [Zn (DPMNI) (BPC)] (2), Zn (DPMNI) (HBTC) (3) (DPMNI = N,N′-bis(4-pyridylmethyl)-1,4,5,8-naphthalene diimide, H2TPDC = thiophene-2,5-dicarboxylic acid, H2BPC = 4,4′-biphenyldicarboxylic acid, H3BTC = 1,3,5-benzenetricarboxylic acid). These coordination polymers characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, powder X-ray diffraction, and theromgravimetric analysis. Because of the presence of electron-deficient NDI moieties, they exhibit reversible photochromic properties. Furthermore, due to the different π–π interactions between the NDI moieties and aromatic carboxylic acid, compounds 1–3 exhibit different photosensitive properties. Moreover, the solvatochromic behaviour of compound 1 was also investigated.

Synthesis of new α‐aminophosphonates using nanoscale nickel‐based metal–organic framework as a heterogeneous catalyst and their antibacterial activity

AbstractAn elegant approach was presented for the synthesis of novel α‐aminophosphonates: a three‐component one‐pot condensation of 3‐(trifluoromethyl)aniline, substituted aromatic aldehydes, and diethyl phosphite using a nickel‐based metal–organic framework (Ni‐MOF). The Ni‐MOF was synthesized using 4,4′‐biphenyldicarboxylic acid and further characterized using various techniques such as X‐ray diffraction, Fourier‐transform infrared, thermogravimetry/differential thermal analysis, Brunauer–Emmett–Teller, and field‐emission scanning electron microscopy analyses. Ni‐MOF seems to be an eco‐friendly, an easily recyclable, and heterogeneous catalyst up to the eighth run with minimal reduction in its catalytic activity. The synthesized α‐aminophosphonates were also investigated for antibacterial and antioxidant activities. In few cases, compounds 4a–4x show similar as well as higher antibacterial activity. Among the synthesized α‐aminophosphonates, 4a–4x had more potent antibacterial activity against pathogenic bacteria while compounds 4h, 4m, 4n, 4q, 4u, 4v, and 4w exhibited significant antioxidant activity.

DUT-5 modified Pd metal-nanoparticles: synthesis, chemical stability, and hydrogen sorption studies

The safety and effectiveness of hydrogen storage are important factors in supporting the utilization of hydrogen as fuel. One of the MOFs materials might be potentially used for hydrogen storage is MOF based on Al3+ including ([Al(OH)BPDC]) (BPDC: 4,4′-biphenyl dicarboxylic acid) which well known as Dresden University of Technology (DUT-5). This study aims to investigate the influence of Pd metal nanoparticles embedded into DUT-5 with a variation: 1 and 5 wt% toward the structural feature and hydrogen sorption properties. According to XRD and FTIR spectroscopy, nitrogen sorption isotherm and SEM-EDX analysis, the basic structure of DUT-5 were partially decomposed after the impregnation process. TEM analysis showed Pd nanoparticles were well dispersed into DUT-5. Nitrogen sorption isotherm revealed that Pd loading into DUT-5 lead to decrease surface area and pore volume of DUT-5 up to 85.82%. Based on thermogravimetry analysis, thermal stability of the material did not change after impregnation. Hydrogen sorption measurement revealed the presence of Pd is not able to increase hydrogen storage capacity of DUT-5 due to the framework destruction, however, in Pd/DUT-5 materials, the increasing of Pd concentration can increase the hydrogen storage capacity which might be due to a spillover effect.

Subppm Amine Detection via Absorption and Luminescence Turn-On Caused by Ligand Exchange in Metal Organic Frameworks.

Luminescent metal-organic frameworks (LMOFs) are promising materials for lighting and sensing applications. Herein, exposure of the highly luminescent Zn2(bpdc)2(bpee) MOF (H2bpdc = 4,4'-biphenyldicarboxylic acid and bpee = 1,2-bipyridylethene) to subppm amine contents turns on a new absorption band unambiguously ascribed to free bpee molecules concomitant with the gradual appearance of a new photoluminescence band at shorter wavelengths. These findings combined with Fourier-transform infrared spectra, powder X-ray diffraction and thermogravimetric analysis of exposed LMOF powders confirm that bpee ligands are exchanged by amines and released inside the LMOF, triggering absorption and luminescence features which can be exploited for highly sensitive amine recognition. This principle was demonstrated in mixed matrix membranes (MMMs) prepared by a simple solvent-free method consisting of mixing Zn2(bpdc)2(bpee) with dimethylvinyl-terminated dimethylsiloxane and dimethylhydrogen siloxane. This method enabled the production of free-standing, permeable, and highly transparent MMMs which showed enormous potential and sensitivity to the detection of amines in gas phase and aqueous medium.

A Pr3+-coordination polymer as an adsorbent for neutral red

A luminescent Pr3+-coordination polymer based on functional linear tetrazole-carboxylic acid and an auxiliary ligand, {[Pr(TBCA)(BPA)·2H2O]}n (1) (HTBCA = 4′-(1H-tetrazol-5-yl)-biphenyl-4-carboxylic acid, H2BPA = 2,2′-biphenyldicarboxylic acid), has been solvothermally synthesized and characterized by single crystal XRD, infrared spectroscopy, elemental analysis, and powder X-ray diffraction. Structural analysis reveals that 1 is a 1D coordination polymer with chains approximately parallel to the a-axis, linked by H-bonding interactions to form a 3-D arrangement. The uptake results for six dyes with different size and different charges revealed that 1 can adsorb neutral red and hardly adsorb the other dyes.

Hydrangea‐like NiCo‐based Bimetal‐organic Frameworks, and their Pros and Cons as Supercapacitor Electrode Materials in Aqueous Electrolytes

Hydrangea‐like NiCo‐based bimetal‐organic frameworks (NiCo‐MOF) are synthesized in DMF‐EtOH solution via a solvothermal method, using 4,4′‐biphenyldicarboxylic acid as a ligand. NiCo‐MOF having a highest capacity of 1056.6 F·g–1 at 0.5 A·g–1 and 457.7 F·g–1 even at 10 A·g–1 is achieved at a Ni/Co/BPDC molar ratio of 1:1:1, a temperature of 170 °C and a reaction time of 12 hours. It exhibits secondary 3D microsphere structures assembled by primary 2D nanosheet structures, good crystalline structure and good thermal stability below 350 °C in air. All the electrochemical data show that NiCo‐MOF has the pros and cons as supercapacitor electrode materials in aqueous electrolytes. On the one hand, NiCo‐MOF has a high capacity even at a high current density, low internal resistance, charge‐transfer resistance and ion diffusion impendence, owing to the ordered coordination structure, 2D nanosheet structure and 3D assembled microsphere structure of NiCo‐MOF. On the other hand, the cycling stability and rate capability are not ideal enough due to the hydrolysis of coordination bonds in aqueous electrolytes, especially, in alkaline solution. The good dispersion and high electrochemical activity of metal ions bring a high capacity for NiCo‐MOF, but they result in the poor stability of NiCo‐MOF. In the future work, finding a suitable organic electrolyte is an effective way to enhance the cycling stability of NiCo‐MOF as well as deriving more stable skeleton materials from NiCo‐MOF.

Morphology-Controlled Synthesis of the Metal–Organic Framework-Derived Nanorod Interweaved Lamellose Structure Co3O4 for Outstanding Catalytic Combustion Performance

The linker of metal–organic frameworks is a critical factor in the morphology and physicochemical properties of catalysts, and the influence of the linker was researched in detail. We synthesized a linker (L2) using raw materials of 2-amino-benzimidazole and naphthalene-1,4,5,8-tetracarboxylic acid, which was applied as a linker of bifunctionalized Co–PTA–L2 together with terephthalic acid (PTA). The comparison samples, Co–PTA–PTA and bifunctionalized Co–PTA–BPA, were also synthesized by a solvothermal method using a linker of PTA, 4,4′-biphenyldicarboxylic acid (BPA). Through a series analysis of characterization, the three samples exhibited diverse morphology and physical and chemical properties. After calcination, Co3O4–PTA–PTA, Co3O4–PTA–BPA, and Co3O4–PTA–L2 were obtained, which were used for a catalytic reaction of toluene combustion. The Co3O4–PTA–L2 emerged as having excellent catalytic performance of toluene combustion, which demonstrated outstanding moisture resistance, thermal stability, and st...

Solvothermal synthesis of flower-string-like NiCo-MOF/MWCNT composites as a high-performance supercapacitor electrode material

In view of the poor electronic conductivity and inferior structural stability, the direct application of Metal-Organic Frameworks (MOFs) as an electrode material is limited. Herein, the carboxylated multi-wall carbon nanotubes (MWCNT) are utilized as a substrate for the in-situ growth of bimetallic NiCo-based MOFs (NiCo-MOF). The flower-string-like NiCo-MOF/MWCNT composites are successfully synthesized using 4, 4′-biphenyldicarboxylic acid (BPDC) as a ligand via a simple solvothermal approach. In the composites, MWCNT is wrapped with 2D NiCo-MOF nanosheets through some bonds or affinity between MWCNT and NiCo-MOF. Meanwhile, the MWCNT presence does not affect the formation of the NiCo-MOF crystals. Compared with the hydrangea-like NiCo-MOF microspheres, the flower-string-like composite structures are more loosely assembled by NiCo-MOF nanosheets. Owing to the guiding effect of MWCNT on the NiCo-MOF growth, many well-dispersed flower-string-like structures can be achieved by adjusting MWCNT dosages. Due to the unique hierarchical structure and good synergistic effect, the NiCo-MOF/MWCNT composites exhibit excellent capacitance performances. The optimal composites demonstrate a large specific capacitance of 1010 F g−1 at 0.5 A g−1, a good rate capability (760 F g−1 even at 10 A g−1), a good cycling stability and reversibility with the capacitance retention of 828 F g−1 (100% of the initial capacitance) and coulombic efficiency of approximate 98% at 5 A g−1 after 3000 cycles, a low internal resistance and charge transfer resistance. The asymmetric supercapacitor assembled by NiCo-MOF/MWCNT composites as electrode materials has high energy density even at high power density, good rate capability, excellent cycling stability and reversibility. Hence, the as-synthesized NiCo-MOF/MWCNT composites are a promising high-performance electrode material for supercapacitors.

Expanding the Variety of Zirconium-based Inorganic Building Units for Metal-Organic Frameworks.

Two new zirconium-based metal-organic frameworks with the composition [Zr6 O4 (OH)4 (OAc)6 (BDC)3 ] (CAU-26) and [Zr5 O4 (OH)4 (OAc)4 (BDC)2 ] (CAU-27) are reported, which were synthesized from acetic acid, a rarely utilized but green and sustainable solvent (BDC2- : 1,4-benzenedicarboxylate). Structure determination aided by automated electron diffraction tomography revealed that CAU-26 is composed of layers of well-known {Zr6 O8 } clusters interconnected by terephthalate ions. In contrast CAU-27 exhibits a three-dimensional structure with a so far unknown type of one-dimensional inorganic building unit (IBU), which can be rationalized as condensed polyhedron-sharing chains of {Zr6 O8 } clusters. CAU-26 occurs as an intermediate of the CAU-27 synthesis and can be isolated easily, when reaction temperature and time are decreased. We were also able to synthesize two isoreticular derivatives of CAU-27 with extended linker molecules by implementing 4,4'-biphenyldicarboxylic acid (H2 BPDC) and 5,5'-dicarboxy-2,2'-bipyridine (H2 BIPY). All materials show high thermal and chemical stability as well as permanent microporosity. The excellent stability of CAU-27-BIPY was exploited to synthesize a performant iridium-supported heterogeneous MOF-based catalyst for the direct C-H borylation of arenes.

Expanding the Variety of Zirconium‐based Inorganic Building Units for Metal–Organic Frameworks

AbstractTwo new zirconium‐based metal–organic frameworks with the composition [Zr6O4(OH)4(OAc)6(BDC)3] (CAU‐26) and [Zr5O4(OH)4(OAc)4(BDC)2] (CAU‐27) are reported, which were synthesized from acetic acid, a rarely utilized but green and sustainable solvent (BDC2−: 1,4‐benzenedicarboxylate). Structure determination aided by automated electron diffraction tomography revealed that CAU‐26 is composed of layers of well‐known {Zr6O8} clusters interconnected by terephthalate ions. In contrast CAU‐27 exhibits a three‐dimensional structure with a so far unknown type of one‐dimensional inorganic building unit (IBU), which can be rationalized as condensed polyhedron‐sharing chains of {Zr6O8} clusters. CAU‐26 occurs as an intermediate of the CAU‐27 synthesis and can be isolated easily, when reaction temperature and time are decreased. We were also able to synthesize two isoreticular derivatives of CAU‐27 with extended linker molecules by implementing 4,4′‐biphenyldicarboxylic acid (H2BPDC) and 5,5′‐dicarboxy‐2,2′‐bipyridine (H2BIPY). All materials show high thermal and chemical stability as well as permanent microporosity. The excellent stability of CAU‐27‐BIPY was exploited to synthesize a performant iridium‐supported heterogeneous MOF‐based catalyst for the direct C−H borylation of arenes.

Metal-organic frameworks cavity size effect on the extraction of organic pollutants

Zirconium Metal-organic frameworks (MOFs, UiO-66 and UiO-67) have been used for the removal from aqueous solutions of persistent fluorinated pollutants, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The two isostructural materials differ in cavity size, defined by the ligand, bdc (benzene-dicarboxylic acid) or bpdc (biphenyl-dicarboxylic acid) for UiO-66 and UiO-67 respectively. Both materials enable efficient sorption of PFOA and PFOS. Sorption kinetics and isotherms have been experimentally determined, and thermodynamic parameters ΔH°, ΔS° and ΔG° have been determined. UiO-67 shows higher sorption capacities (up to 743 mg·g−1 for PFOA and 585 mg·g−1 for PFOS) compared to these of UiO-66 (388 and 160 mg·g−1 for the sorption of PFOA and PFOS respectively) with a change in the sorption mechanism.

MOF matrix doped with rare earth ions to realize ratiometric fluorescent sensing of 2,4,6-trinitrophenol: Synthesis, characterization and performance

2,4,6-trinitrophenol (PA) is a well-known aromatic compound, due to their higher explosive energy than TNT and their wide utilization when producing organic dyes, medicines and antiseptics. The following paper constructed a composite optical sensing system (denoted as Tb:Eu@MOF) for PA detection using [Zn8(ad)4(BPDC)6O·2 Me2NH2]·G, ad = adenine, BPDC = 4,4′-biphenyl dicarboxylic acid, G = DMF and water, as supporting matrix and two rare earth ions, Tb(III) and Eu(III), as dopant. Tb:Eu@MOF was carefully characterized by means of micromorphology, XRD, N2 adsorption and desorption. Detailed analysis on its photophysical performance indicated weak Tb emission and strong Eu emission, owing to the energy competing between two kinds of rare earth ions in Tb:Eu@MOF. After meeting PA, such energy competing was blocked, leading to enhanced Tb emission and decreased Eu emission. Ratiometric fluorescent sensing for PA detection was thus constructed with good selectivity and low LOD (limit of detection) of 0.87 μM. Linear sensing response was achieved. Its practical sensing application and naked eye detection for PA were tentatively discussed as well.

Two solvent-induced variable host–guest two-dimensional binary frameworks mediated by hydrogen bonding

Two-dimensional binary hydrogen-bonded organic frameworks constructed from 1,3,5-benzenetricarboxylic acid (TMA) and 4,4'-biphenyldicarboxylic acid (BDA) on highly oriented pyrolytic graphite (HOPG) were investigated by scanning tunneling microscopy (STM) in heptanoic acid and octanoic acid solvents. High-resolution STM observations demonstrated that various assemblies of hydrogen-bonded networks are strongly dependent on the nature of the solvent. Well-ordered porous rectangular flowerlike networks were revealed at the heptanoic acid/HOPG interface, whereas two different coexisting densely packed guest-host BDA/TMA structures were observed at the octanoic acid/HOPG interface. It is suggested that the stabilization of the binary networks is possibly associated with the solvent chain length, and longer-chain solvents favored the formation of porous polymorphic networks.

Imidazole-containing Cd Metal-Organic Framework with Selective Adsorption Properties

Metal-organic framework material [Cd(tib)(dnbpdc) (H2O)]·2DMF·2H2O (1) [tib = 1, 3, 5-tris(1-imidazolyl)benzene, H2dnbpdc = 2, 2′-dinitro-4, 4′-biphenyldicarboxylic acid] was synthesized and characterized by Thermogravimetric analyses (TGA), Powder X-ray diffraction (PXRD) analyses and Bruker D8 Advance X-ray diffractometer. The results showed that 1 was a 1D chain structure to be joined together by hydrogen bonds to generate a 3D supramolecular structure. CO2 and N2 adsorption behavior of the material was studied. It is significative that 1 can selective sorption of CO2.