POM Anions Research Articles

A mechanistic study on solar energized degradation of herbicide into value-added product using -SO3H functionalized ionic liquid-polyoxometalate based heterogeneous catalyst in aqueous medium

Two acidic ionic liquid-based hybrids of polyoxometalate, dibutyldisulphoammonium polyoxometalate, [DBDSA]3[PM12O40], (M= Mo, W) were prepared by exchanging labile halide ion of parent ionic liquid with Keggin [PM12O40]3− anions. The incorporation of N-SO3H into the ammonium cation results in intra-molecular H-bonding with POM anion, which is responsible for the preservation of heterogeneity of the catalyst throughout the reaction. Their catalytic activities were investigated for the degradation of metobromuron herbicide in aqueous medium as heterogeneous oxidative catalyst under sunlight using H2O2 as oxidant. The isolated active peroxo intermediate was responsible for the reaction. A detailed mechanistic study on degradation of metobromuron into various products at different time intervals was done. The reaction for 8 h under sunlight removed greater than 70 % of TOC and also resulted in 1‑bromo-4-isocyanatobenzene as the major value-added product for the synthesis of various unsymmetrical disubstituted urea derivatives. The recyclability experiment showed excellent stability and reusability of the catalyst.

Three Anderson and octamolybdate based compounds modified by an asymmetric viologen: Photo-/thermo-chromic and luminescence properties

In this work, POM anions and a viologen ligand were combined to construct appealing electron transfer chromotropic materials. Three kinds of POM-viologen hybrids were obtained in hydrothermal environment, namely [Cu2(1,4-Mbby)2(H2O)6(TeMo6O24)]·H2O (1), [Co2(1,4-Mbby)2(H2O)6(TeMo6O24)]·H2O (2), [Cu2(1,4-Mbby)4(H2O)2(β-Mo8O26)2] (3, 1,4-Mbby·Cl = (1-(4-Methyl-benzyl)-[4,4′]bipyridinyl-1-ium)chloridate). Among them, compounds 1 and 2 are isostructural, showing an infinite inorganic chain with Anderson anions linked by Cu/Co atoms. The 1,4-Mbby suspend on both sides of this chain. Compound 3 exhibits a Mo8 dimer with four 1,4-Mbby as “arms”. POM anions and viologen ligands form a classical donor-acceptor structure, which can promote electron transfer. Therefore, under thermal stimulation, compounds 1–3 show reversible thermochromic properties. Under light stimulation, 1 and 3 have good reversible photochromic properties. Moreover, compound 1 can detect aniline, and 3 can detect ammonia and ethylenediamine through discoloration. Interestingly, compounds 1–3 show luminescence characteristics. Especially, the bright blue fluorescence of 1 can be observed under the irradiation of a 365 nm ultraviolet lamp. Meanwhile, compounds 1–3 have good fluorescence quenching effect under illumination or heating conditions. In other words, these compounds can quickly sense light or heat with color change. This work broadens the applications of POM/viologen compounds in the fields of discoloration and luminescence.

A Series of POM-Viologen Photo-/Electrochromic Hybrids and Hydrogels Acting as Multifunctional Sensors for Detecting UV, Hg2+, and Organic Amines.

In this work, POM anions were introduced into the viologen system in order to synthesize POM-viologen hybrid compounds with excellent properties. Three new POM-viologen compounds, {CdII(tybipy)(DMF)2[β-Mo8O26]0.5Cl} (1), {CoII(tybipy)2(DMF)2[H2(β-Mo8O26)]2}·4C2H7N (2), and (tybipy)4·(β-Mo8O26) (3) (tybipy·Br = 1-thiophen-3-ylmethyl-[4,4']bipyridinyl-1-ium bromide), have been prepared by a solvothermal method, and their structures were characterized. POM anions are modified by mixing organic ligands with transition metals in compounds 1 and 2. However, compound 3 is a supramolecular structure constructed by hydrogen bonding interactions between the dissociative viologen and POM anions. These three compounds have rapid photoresponse and photochromic ability, which can be made into mixed matrix membranes and hydrogels for UV detection. The rigid sandwich devices prepared by compounds 1-3 have achieved ultrafast electrochromism and recovery. In addition, photochromic hydrogels based on compounds 1-3 can achieve ultrafast photochromic recovery. Compounds 1-3 can be used in ink-free printing and Hg2+ fluorescence detecting. Compounds 1 and 2 can also be used as organic amine detectors. Combined with photochromism and fluorescence detection of Hg2+, visual test papers for Hg2+, Cu2+, and Co2+ were successfully realized, which can improve the portability and detection speed of heavy metal ions in the actual environment.

PW12-M@COFs as efficient photocatalysts for visible-light-driven oxidation of various sulfides and degradation of chemical warfare agent simulant

From sustainable development and application standpoint, visible-light-driven oxidation of sulfides is emerging as sizzling focuses. In this work, a series of novel polyoxometalate-based photocatalysts, PW12-M@COFs 1 − 3 (M = Ag+1, Cu2+2, Ni2+3) were successfully synthesized via the electrostatic interactions between POM anion and cationic porous M@COFs, which were characterized by infrared (IR) spectroscopy, EDS analysis, solid diffuse reflective spectroscopy etc. These compounds exhibit strong visible light adsorption and can be used as excellent photocatalysts for the oxidation of sulfides to sulfoxides and the degradation of chemical warfare agent simulant, 2-chloroethyl ethyl sulfide (CEES). Especially, compound 1 with Ag+ has the best catalytic activity, achieving 98% of methyl phenyl sulfide conversion with 99% of selectivity in 3.5 h illuminated by a 10 W 425 nm light-emitting diode (LED). When extended to other sulfur-containing compounds, it also demonstrates satisfactory yield to sulfoxide and degrade CEES within 2 h. The mechanism reveals that both singlet oxygen and superoxide radicals act as the reactive oxygen species for the visible-light-driven oxidation of various sulfides, corresponding to the photoinduced electron-transfer and energy-transfer pathways. Moreover, these catalysts exhibited excellent catalytic and structural stability.

Three anderson-, mo-capped weakley- and keggin-based compounds modified by viologens acting as photochromic and thermochromic materials

Three viologen compounds were synthesized under hydrothermal conditions based on three kinds of POM anions, namely, [Co2(Cbybpy)2(H2O)6(TeMo6O24)]·5H2O (1), {[Ni(Cbybpy)2(H2O)3]·[Ni4(H2O)2Ge2Mo18O68(MoO2)2]0.5}·7H2O (2), (HCbybpy)2·(SiW12O40) (3), (Cbybpy·Br = 1-(2′-cyano-biphenyl-4-ylmethyl)-[4,4′]bipyridinyl-1-ium bromide). These three viologen compounds are based on Anderson, two {MoO2}-capped Weakley and Keggin anions. When the temperature increased, 1–2 showed excellent reversible thermochromic abilities, and 1–2 showed good fluorescence quenching effect, too. In addition, 2–3 showed photochromic properties when exposed to irradiation of a Xe lamp with filter (300–400 nm), both of which displayed rapid light response and differences in color-changing.

Four Polyoxometalate‐Viologen Discoloration Materials for UV Probing, Inkless and Erasable Printing and Visual Detection of Hg2+

AbstractIn this work, four POM‐based compounds containing viologen ligands were synthesized, namely {CuII(tybipy)2(DMF)2[H2(β‐Mo8O26)]2} ⋅ 4 C2H7N (1), (Htybipy)2 ⋅ (β‐Mo8O26) (2) (tybipy⋅Br=1‐Thiophen‐3‐ylmethyl‐[4,4’]bipyridinyl‐1‐ium bromide), [CuII(nibipy)2(4,4’‐bipy)] ⋅ (SiW12O40) (3), (Hnibipy)2 ⋅ (δ‐Mo8O26) (4) (nibipy⋅Cl=1‐(4‐Nitro‐benzyl)‐[4,4’]bipyridinyl‐1‐ium chloride, 4,4’‐bipy=4,4’‐bipyridine). In compounds 1 and 3, Cu2+ and mixed organic ligands modify POM anions. On the other hand, 2 and 4 are supramolecular structures only containing ligands and anions. Under Xe lamp with filter (300‐400 nm) irradiation, these four compounds showed good photoresponse and photochromic ability, which can be used in mixed matrix films for visible UV detectors. Compounds 1–4 also have photoluminescence property and show good fluorescence quenching effect. A suspension of four compounds can be evenly spread on filter paper as inkless and erasable printing materials. Compounds 1 and 2 were also used as Hg2+ fluorescence detectors. The fluorescence intensity of 1 decreased by ca. 90 % when the concentration of Hg2+ increased to 40 mM. Moreover, we also prepared composites 1/2@Hg2+,1@Cu2+, 1@Co2+ by introducing 1/2 and Hg2+, Cu2+ and Co2+ to detection paper respectively, which can act as photochromic materials with features of fast color recovery.

In-situ growth of polyoxometalate-based metal-organic frameworks on wood as a promising dual-function filter for effective hazardous dye and iodine capture

Environmental contaminants have become a major global issue in recent years. Adsorption has been considered as one of the most effective methods of removing contaminants from the environment. However, there are still some challenges to their practical applications, such as complex preparation, expensive cost, and low efficiency. In this study, we used solvothermal conditions to introduce polyoxometalate-based metal-organic frameworks (POMOFs) into a natural wood (POMOF/wood) for the effective removal of organic dye and iodine capture. The Keggin-type POM anions (PMo12) with a highly negative charge were encapsulated to adjust the charge of the UiO-66 MOF, where the charge overcompensation in the POMOFs allows them to efficiently adsorb cationic dyes. Benefiting from the unique microstructure of wood, the POMOF/wood exhibits up to 94.07% and 95.23% removal efficiency for cationic dyes methylene blue (MB) and gentian violet (GV) with a permeance of 1.0×104 L·m−2·h−1·bar−1. Furthermore, the POMOF/wood has high adsorption capacity for capturing iodine, with a maximum adsorption capacity of 1232.8 mg·g−1 in vapor. We believe that a low-cost and scalable filter is advantageous for environmental remediation and this work provides a promising strategy for developing more multifunctional POMOF/wood materials.

Design of a Polyoxometalate-Based Metal-Organic Framework for Photocatalytic C(sp3)-H Oxidation of Toluene.

A powerful and promising route for developing novel photocatalysts for light-driven toluene oxidation in water under mild conditions is presented. Herein, a novel polyoxometalate-based metal-organic framework (POMOF), {Co4W22-DPNDI}, is prepared by incorporating the unusual Co4-sandwiched POM anion [Co4(μ-OH)2(SiW11O39)2]10- ({Co4W22}) and the photoactive organic bridging link N,N'-bis(4-pyridylmethyl)naphthalene diimide (DPNDI) into a framework. {Co4W22} is a good candidate for photocatalytic water oxidation. DPNDI is easily excited to form the radical species DPNDI* in the presence of an electron donor, which is beneficial for activation of the inert O2. Anion···π interactions and covalent bonds between {Co4W22} and DPNDI facilitate electron-hole separation and electron transfer. {Co4W22-DPNDI} displays high catalytic activity for the activation of the C(sp3)-H bond of toluene using light as a driving force and inexpensive water as an oxygen source under mild conditions. In particular, the yield and selectivity are improved by replacing oxygen with water, which may be ascribed to the release of protons during the water oxidation process that facilitate the generation of •OH.

Photochromic Polyoxometalate/Perylenediimide Donor-Acceptor Hybrid Crystals with Interesting Luminescent Properties.

The self-assembly of electron-deficient protonated N, N'-dipyridyltetrachloroperylenediimide (4Cl-DPPDI) and electron-rich polyoxometalate acids HnXM12O40 (POMs; X = P or Si; M = W or Mo) resulted in four isomorphous donor-acceptor hybrid crystals 1-4 with segregated POM anions and one-dimensional racemic hydrogen-bonded 4Cl-DPPDI networks as electron-donor and -acceptor components, respectively. Because of the compact contacts between the POM anions and 4Cl-DPPDI tectons induced by anion-π interactions, besides enhanced photochromism, these four unique isostructural hybrids exhibited unusual room-temperature phosphorescence (RTP) emissions. More interestingly, owing to the facial compact contacts of two racemic 4Cl-DPPDI tectons induced by lone pair-π-assisted π-π interactions, they also showed unprecedented photon upconversion by triplet-triplet annihilation (TTA).

Cationic Ru complexes anchored on POM via non-covalent interaction towards efficient transfer hydrogenation catalysis

The ionic materials consisting of cationic Ru complexes and Wells-Dawson polyoxometalate anion (POM, K6P2W18O62) have been constructed via a non-covalent interaction. The as-synthesized catalysts have been characterized thoroughly by NMR, XRD, FESEM, and FT-IR, etc. The characterization suggested that a hydrogen bond interaction occurred between the proton of the amine ligand in the cationic Ru complexes and the oxygen atom of the POM anion. The hydrogen bond played an important role in enhancing catalytic activity for the transfer hydrogenation of methyl levulinate (ML) to γ-valerolactone (GVL) under very mild conditions. Especially, the transfer hydrogenation reaction proceeded via a heterogeneous catalysis approach and the heterogenized catalysts even afforded much better catalytic performance than homogeneous analogs. Notably, the catalysts can be recycled without an obvious loss of activity, and further extended to highly selective transfer hydrogenation of α,β-unsaturated ketones and aldehydes, etc. into the corresponding α,β-unsaturated alcohols without any base external additives. The high catalytic performance of these anchored catalysts was highly related to the hydrogen bond interaction and the basicity of the polyanion. The obtained knowledge from this work could lead us to a new catalysis concept of tethering active homogeneous complexes for constructing highly active anchored Ru complex catalysts for hydrogenation reaction.

In Situ Electrochemical Production of Metal‐organic Hybrid Composite Film from Nickel Containing Polyoxometalate and 3,4‐Ethylenedioxy‐thiophene for Sensor Application

AbstractIn situ electrochemical synthesis of an organic‐inorganic hybrid material composed of poly(3,4‐ethylenedioxythiophene) (PEDOT) and nickel‐based Keggin type polyoxometalate, K7[NiIIINiII(H2O)W11O39].15H2O(NiPOM), has been proposed here. The remarkable optical and electrical properties of the PEDOT and the unique redox properties of NiPOM have synergistically combined to make the hybrid structure highly desired multi‐functional materials for a myriad of applications. The driving force for the formation of hybrid structure is thought to be electrostatic interactions between POM anions and cationic polaron/bipolaron structures that in the PEDOT. PEDOT/NiPOM based hybrid composite modified graphite electrode has been used for non‐enzymatic glucose sensor platform as a sample of applications. Furthermore, PEDOT/NiPOM based sensor platform was successfully utilized for detection of glucose content with the lowest detection limit in real samples like honey and milk. These results suggest that PEDOT/NiPOM metal‐organic hybrid composite could be utilized as multi‐functional material for a myriad of applications.

Воздействие наноразмерных анионов кремний-молибденовой кислоты на плазматическую мембрану фибробластов эмбриона человека

Методом времяпролетной масс-спектрометрии вторичных ионов (ToF-SIMS) исследованы изменения состава плазматических мембран (ПМ) фибробластов эмбриона человека под воздействием наноразмерных анионов кремний-молибденовой кислоты (КМК). Измерены и интерпретированы зависимости масс-спектров основных липидов ПМ от концентрации КМК, коррелирующие с их послойными распределениями и со сродством холестерина к фосфолипидам. Обнаружен новый для биохимии клетки эффект – значительное снижение относительного содержания в ПМ холестерина и сфингомиелина под воздействием многозарядных анионов гетерополикислоты (ГПК). Для водных растворов КМК при концентрации С ~ 10мкМ/л и периода воздействия 48 ч обнаружено, что количество холестерина в ПМ снижается в 2–2.5 раза, при этом количество сфингомиелина уменьшается на 20–25%. Предложен новый механизм начального воздействия ГПК на плазматические мембраны, сводящийся к селективному травлению многозарядными анионами. Согласно предлагаемому механизму на первом этапе взаимодействия аниона полиоксометаллата с клеткой осуществляется экстракция из ПМ холестерина и сфингомиелина – основных регуляторов проницаемости и микровязкости ПМ. Как следствие возросшей проницаемости ПМ в клетках возможно ускорение жизненно важных трансмембранных и латеральных процессов.

Self‐Assembly of Hybrid Oxidant POM@Cu‐BTC for Enhanced Efficiency and Long‐Term Stability of Perovskite Solar Cells

AbstractThe controllable oxidation of spiro‐OMeTAD and improving the stability of hole‐transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid polyoxometalate@metal–organic framework (POM@MOF) material, [Cu2(BTC)4/3(H2O)2]6[H3PMo12O40]2 or POM@Cu‐BTC, for the oxidation of spiro‐OMeTAD with Li‐TFSI and TBP. When POM@Cu‐BTC is introduced to the HTM layer as a dopant, the PSCs achieve a superior fill factor of 0.80 and enhanced power conversion efficiency 21.44 %, as well as improved long‐term stability in an ambient atmosphere without encapsulation. The enhanced performance is attributed to the oxidation activity of POM anions and solid‐state nanoparticles. Therefore, this research presents a facile way by using hybrid porous materials to accelerate oxidation of spiro‐OMeTAD, further improving the efficiency and stability of PSCs.

Self-Assembly of Hybrid Oxidant POM@Cu-BTC for Enhanced Efficiency and Long-Term Stability of Perovskite Solar Cells.

The controllable oxidation of spiro-OMeTAD and improving the stability of hole-transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid polyoxometalate@metal-organic framework (POM@MOF) material, [Cu2 (BTC)4/3 (H2 O)2 ]6 [H3 PMo12 O40 ]2 or POM@Cu-BTC, for the oxidation of spiro-OMeTAD with Li-TFSI and TBP. When POM@Cu-BTC is introduced to the HTM layer as a dopant, the PSCs achieve a superior fill factor of 0.80 and enhanced power conversion efficiency 21.44 %, as well as improved long-term stability in an ambient atmosphere without encapsulation. The enhanced performance is attributed to the oxidation activity of POM anions and solid-state nanoparticles. Therefore, this research presents a facile way by using hybrid porous materials to accelerate oxidation of spiro-OMeTAD, further improving the efficiency and stability of PSCs.

Understanding Electrochemical Interface Using Atom-By-Atom Metal Substitution of Redox Species

Molecular-level understanding of electrochemical processes at nanostructured electrode-electrolyte interfaces (EEI) is key to the development of clean and sustainable electrochemical technologies in energy generation and storage as well as water and chemical separation and purification. Herein, we introduced a novel in situ electrochemical cell coupled with ion soft landing to study the precisely defined operating EEI. Ion soft landing is a mass spectrometry based deposition technique which enables to land uniform layers of redox-active ions onto electrode surfaces with precise control over the charge state, composition, and kinetic energy. In this work, we used ion soft landing to study (i) the multi-electron redox activity of Keggin polyoxometalate anions (POMs) to design high-performance EEIs for energy storage (ii) examined how “atom-by-atom” metal substitution affects the redox activity of well-defined mixed addenda POM anions, PMoxW12-xO40 3- (x = 0,1,2,3,6,9,12) at ionic liquid based in situ electrochemical cell. We made a striking observation in in situ experiment and well-supported by theoretical calculation, which is that substantial increase in the first reduction potential obtained by substitution of only few tungsten by molybdenum atoms in the PW12O40 3- anions. More specifically, PMo3W9O40 3- showed the highest redox activity compared to all other mixed-addenda POM anions, which making it as a “super active redox anion” for this class of redox species. This presentation will also focus how these fundamental understanding on the activity of mixed addenda POMs was translated well into achieving device-level supercapacitor performance with superior capacity and capacity retention.

PH-modulated ion transport and amplified redox response of Keggin-type polyoxometalates through vertically-oriented mesoporous silica nanochannels

Cyclic voltammetry has been applied to characterize mass transport of a Keggin-type polyoxometalates ([SiW12O40]4-) through vertically-aligned mesoporous silica thin films in aqueous media. The results indicate a drastic influence of pH and the ionic strength which may be rationalized in terms of electrostatic interactions and confinement effects. Diffusion of such bulky anionic electroactive species is considerably restricted at pH values higher than the point of zero charge of the silica for which the walls of the nanochannels are negatively charged. On the other hand, the positive charge density generated in more acidic solutions favors the ingress of [SiW12O40]4- species through the mesochannels, enhancing considerably the electrochemical response, except at high ionic strength due to competition for the binding sites. The accumulation of POM anions into the silica films can be even promoted by functionalization of the silica surface with propylammonium groups. In summary, pH tuning induced gating of the ionic flux through the silica nanopores, which can be somewhat modulated by the ionic strength by varying the thickness of the electrical double layer generated at the silica walls surface.

Applications of inorganic‐organic hybrid architectures based on polyoxometalates in catalyzed and photocatalyzed chemical transformations

The scope of this article is to reveal the fruitful combination of POM species with metal coordination complexes, leading to the construction of several efficient multifunctional catalysts. In this review, we try to underscore various catalytic and photocatalytic reactions catalyzed by POM‐based inorganic‐organic hybrid. Notably, it has been well established that depending on the type of the reaction, the activity and selectivity of these hybrid catalyst can be drastically improved by the rational and correct choice of the organic metal complex and POM anion providing a marriage of convenience.

A series of metal–organic loops templated by [SiMo12O40]4− and [β-Mo8O26]4− anions using double chelating ligands: amperometric sensing and selective photocatalytic properties

By changing the POM anions and TM ions, a series of compounds with multi-nuclear loops was formed.

A series of Keggin- and Wells-Dawson-polyoxometalate-based compounds constructed from oxygen-functional imidazole derivatives

Abstract Through the use of two kinds of imidazole derivatives containing different O-functional units, three new Keggin- and one Wells-Dawson-polyoxometalate (POM)-based compounds, namely [Cu2 La 4(HPW12O40)] (1), [CuLa 4(H2O)2(HPMo12O40)] (2), [Cu2 La 7(H2O)(H2P2W18O62)]·La (3), [Ag2(Lb 4)(HPMo12O40)]·Lb ·H2O (4)(La= (4-(2,5-dihydro-1H-imidazol-1-yl)benzaldehyde), and Lb =(4-(2,5-dihydro-1H-imidazol-1-yl)benzoic acid), were synthesized and characterized using single-crystal X-ray diffraction, elemental analyses, and infrared spectroscopy. The polyoxoanions occupy holes framed by two symmetrically oriented CuLa 2 units in 1. In compound 2, the square-planar CuLa 4 units form a two-dimensional (2D), supramolecular grid through π···π stacking interactions. The POMs occupy vacancies in this grid. In compound 3, the CuLa 3 subunits connect the neighboring P2W18 units and an “S”-type chain is formed. Through hydrogen bonding interactions, the chains are connected to form a layer. In compound 4, the POM anions are linked by AgLb 2 subunits to form a chain. All the chains are tied together to construct a layer structure with weak hydrogen bonding interactions between the terminal carboxylic acid functional groups of ligands Lb . The electrocatalytic and photocatalytic activities of all these four compounds were also studied.

A series of pH-dependent POM-based compounds as photocatalysts and electrochemical sensors

By tuning pH, a Zn complex and five POM-based compounds decorated by a pyrazole derivative 1,1′-bis(3,5-dimethyl-1H-pyrazol-4-yl)methane (H2bdpm), [Ag4(H2bdpm)4(SiW12O40)]·4H2O (1), [Ag3(H2bdpm)3(PMo12O40)] (2), [Cu(H2bdpm)2(H2O)2(HPMo12O40)] (3), [Zn(H2bdpm)2(β-Mo8O26)0.5]·3H2O (4), [(ZnO)2(H2O)2(H2bdpm)] (5) and [(γ-Mo8O26)(H2bdpm)2]·2H4bdpm·4H2O (6), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction analysis, IR spectra and elemental analyses. In compound 1, the infinite wave-like metal–organic chains are linked by POM anions to form a 3D framework. In the compound 2, the H2bdpm ligands are linked by Ag+ ions to construct a chain with [PMo12O40]3− anions suspending up and down this chain by hydrogen bonding interactions. In compound 3, there is a mono-supporting [PMo12O40]3− anion with one [Cu(H2bdpm)2(H2O)2]2+ subunit. By tuning pH of [Mo7O24]6−/Zn2+/H2bdpm system with three values, three distinct structures 4–6 were constructed. In compound 4, two Zn ions and two H2bdpm form a bi-nuclear [Zn2(H2bdpm)2]4+ cycle. Adjacent cycles connect each other vertically to build a cycle-connecting-cycle chain. The discrete [β-Mo8O26]4− anions exist hydrogen bonding interactions with metal–organic chains. In compound 5, the cycle-like [(ZnO)4(H2O)4] subunits are linked by a pair of H2bdpm alternately to form a 1D chain. Compound 6 contains only a [γ-Mo8O26]4− anion functionalized by two H2bdpm through Mo-N bonds. The pH factor is essential for construction of this series. The 1-, 3- and 4-CPEs not only possess excellent multifunctional electrocatalytic activities but also can be used as electrochemical sensors for the detection of hydrogen peroxide, bromate and nitrite. Photocatalytic investigation indicates that compounds 1–4 and 6 are active for the degradation of methylene blue under UV irradiation.