Multicarboxylic Acids Research Articles

A cluster-of-functional-groups approach for studying organic enhanced atmospheric cluster formation

Abstract. The role of organic compounds in atmospheric new particle formation is difficult to disentangle due to the myriad of potentially important oxygenated organic molecules (OOMs) present in the atmosphere. Using state-of-the-art quantum chemical methods, we here employ a novel approach, denoted the “cluster-of-functional-groups” approach, for studying the involvement of OOMs in atmospheric cluster formation. Instead of the usual “trial-and-error” approach of testing the ability of experimentally identified OOMs to form stable clusters with other nucleation precursors, we here study which, and how many, intermolecular interactions are required in a given OOM to form stable clusters. In this manner we can reverse engineer the elusive structure of OOM candidates that might be involved in organic enhanced atmospheric cluster formation. We calculated the binding free energies of all combinations of donor and acceptor organic functional groups to investigate which functional groups most preferentially bind with each other and with other nucleation precursors such as sulfuric acid and bases (ammonia, methyl-, dimethyl- and trimethylamine). We find that multiple carboxyl groups lead to substantially more stable clusters compared to all other combinations of functional groups. Employing cluster dynamics simulations, we investigate how a hypothetically OOM composed of multiple carboxyl groups can stabilize sulfuric acid–base clusters and provide recommendations for potential atmospheric multi-carboxylic acid tracer compounds that should be explicitly studied in the future. The presented “cluster-of-functional-groups” approach is generally applicable and can be employed in many other applications, such as ion-induced nucleation and potentially in elucidating the structural patterns in molecules that facilitate ice nucleation.

High uptake of citrus essential oil-loaded zein particles into E. coli tuned by the wet-crosslinked folic acid

Zein particles are increasingly used for encapsulation and delivery of hydrophobic bioactive. Conjugation of zein with multi-carboxylic acids by the alkali-catalysed and wet amidation process causes zein crosslinking and enables tuning the characteristics of zein particles. However, little is known about how the conjugation is associated with the crosslinking mode, i.e., intra and/or intermolecular crosslinks. In this study, folic acid (FoA) was conjugated with zein via the wet method, and citrus essential oil (CEO) was encapsulated within the constructed zein-FoA particles. Infra-red spectroscopy and nuclear magnetic resonance analysis indicated amide bond formation between zein and FoA showing that the content of primary amino groups in zein particles decreased due to conjugation. The mole fraction of FoA in the particles (χFoA) was measured as an index of conjugation extent and even though it did not exceed ∼0.1, conjugation influenced several characteristics of the particles. The contents of α-helix and β-turn structures decreased, and that of β-sheets increased with increasing χFoA. We hypothesized based on ζ-potential and hydrodynamic diameter results, as well as gel electrophoresis that conjugation with FoA caused formation of only intramolecular crosslinks at χFoA ≤ 0.035, but it additionally resulted in intermolecular crosslinks at χFoA ≥ 0.037. Conjugation with FoA at χFoA 0.091 resulted in an improvement of the zein particles biological performance. It caused an increase (∼30%) in the particle uptake by E. coli cells, as well as the magnitude of CEO delivery into the bacteria cells compared with non-conjugated particles.

First proof-of-concept of UC/HILIC for extending the versatility of the current art of supercritical fluid separation

Supercritical Fluid Chromatography (SFC), a high-throughput separation technique, has been widely applied as a promising routine method in pharmaceutical, pesticides, and metabolome analysis in the same way as conventional liquid chromatography and gas chromatography. Unified chromatography (UC), an advanced version of SFC, which applied gradient elution with mobile phase changing continuously from supercritical to subcritical and to liquid states, can further extend the SFC applications. UC mostly applying the popular mobile phase of 95%:5%/Methanol:Water with additives allows to analyze many hydrophilic compounds. However, many of phosphorylated metabolites or multi carboxylic acids show very poor peak shapes or even can't be eluted under UC conditions, thus hampering the UC's metabolome coverage. In this study, we proposed the first proof-of-concept of UC/HILIC, a novel strategy to extend the current UC metabolome coverage by employing an aqueous gradient right after the UC gradient on a single packed column in a single measurement. The proposed method showed significant improvement regarding the chromatographic performance and metabolome coverage, while still maintaining the precision and high throughput in comparison with conventional UC methods.

Two-dimensional rare-earth-metal coordination polymers based on biphenyl-3,3',5,5'-tetracarboxylic acid displaying luminescence.

Two coordination polymers were rationally designed and successfully constructed using the rigid multicarboxylic acid ligand biphenyl-3,3',5,5'-tetracarboxylic acid (H4BPTC) and rare earth metal ions (Eu3+ and Ho3+) under solvothermal conditions. The compounds are poly[[tetra-μ2-acetato-bis(μ6-biphenyl-3,3',5,5'-tetracarboxylato)tetrakis(dimethylacetamide)tetraeuropium(III)] dimethylacetamide disolvate dihydrate], {[Eu4(C16H6O8)2(C2H3O2)4(C4H9NO)4]·2C4H9NO·2H2O}n, and poly[[tetra-μ2-acetato-bis(μ6-biphenyl-3,3',5,5'-tetracarboxylato)tetrakis(dimethylacetamide)tetraholmium(III)] pentahydrate], {[Ho4(C16H6O8)2(C2H3O2)4(C4H9NO)4]·5H2O}n, Single-crystal X-ray diffraction analysis reveals that both polymers possess a two-dimensional structure and they also display good thermal stability up to ca 280 °C and photoluminescence with an orange-red light emission.

Facile membrane preparation from colloidally stable metal-organic framework-polymer nanoparticles

UiO-MOFs are based on zirconium cluster and carboxylic acid linkers. They have excellent chemical and thermal stability, tolerance to linkers of different length and functionalities, making them good candidates for a broad range of applications. However, difficulties of processing the polycrystalline powder of MOFs limit their application. Here, we report for the first time the synthesis of the UiO-66 in the presence of a well-defined poly (methacrylic acid)-b-poly (methyl methacrylate) (PMAA-b-PMMA) nanoparticles (NPs) prepared via Reversible Addition−Fragmentation Chain-transfer Polymerization controlled Polymerization Induced Self-Assembly (RAFT-PISA). The PMAA-b-PMMA NPs with multi carboxylic acid groups on their surface, well defined in shape and size, act as multivalent connecting agent for the synthesis of the UiO-66. The resulting colloidally stable UiO-polymer NPs are crystalline, porous, and with an improved processability as was demonstrated by the preparation of a thin film nanocomposite (TFN) membrane. This membrane was applied in the filtration of Nickel (II) phthalocyanine-tetrasulfonic acid tetrasodium salt aqueous solution obtaining a water permeability circa 20 L m−2 h−1 bar−1 with a rejection of more than 90%. This unprecedented facile synthesis approach could be universally applied to other MOFs, expanding their application in different fields due to their enhanced processability.

Treatment and Nursing Activities of Cu(II)-Based Coordination Polymers on Obstructive Jaundice in Liver Cancer by Regulating Farnesoid X Receptor and Wingless Int1–Catenin Activity

Two novel coordination polymers, namely, [Cu3(qptc)2(H2O)3]·3.5H2O·3Me2NH (1) together with [Cu3(qptc)2(H2O)4]·5H2O (2) (H4qptc is 1,1′:4′,1″:4″,1‴-quaterphenyl-2,4,2″,4″-tetracarboxylic acid), were produced under a hydrothermally condition using the rigid aromatic multicarboxylic acid ligand. Structural analysis results indicated that compound 1 exists in a triclinic space group of P-1 and displays a 4,8-linked 3-D open structure containing the trinuclear nickel Cu3 secondary building units (SBUs), which exists in scu topology with (44 · 62) and (416 · 612) point symbols. And the complex 2 exists in a monoclinic space group of C2/c and displays a 3-D structure involving Cu3 SBUs, which exists in flu topology with (46) and (412 · 612 · 84) point symbols. Moreover, the novel complexes’ bio-activities against obstructive jaundice in liver cancer was investigated, and the specific mechanism was discussed. The expression of the bile acid receptor, farnesoid X receptor, on liver cancer cells was tested by Western blot analysis. Wnt–catenin activity activation in liver cancer cells was tested through exploiting RT-PCR.

Flame Retardancy and Thermal Behavior of Wool Fabric Treated with a Phosphorus-Containing Polycarboxylic Acid.

The compound 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) is an eco-friendly water treatment agent possessing flame-retardant phosphorus element and multi-carboxylic acid groups in its molecular structure. In the present work, PBTCA is employed as a finishing agent to improve the flame retardancy of the wool fabrics by the pad-dry-cure technique. The treated wool (10.2% weight gain) by 100 g/L of PBTCA showed an increased flame retardancy with a limiting oxygen index value (LOI) of 44% with a minimum char length of 40 mm. Importantly, the treated wool can self-extinguish after 30 washing cycles. The PBTCA-treated wool exhibited better stability with obviously increased char residue of 39.7% and 28.7% at 600 °C, while only 25.9% and 13.2% were measured for the control wool in nitrogen and air atmosphere, respectively. In addition, the high thermal stability of the treated wool with astonishing char-forming ability is confirmed by the SEM images of the wool after the isothermal heating treatment at different temperatures. Finally, a two-stage flame-retarding mechanism of enhanced crosslinking and char formability of PBTCA-treated wool is proposed and analyzed by infrared spectroscopy (TG-FTIR) and thermal (DSC and TGA) results of the pyrolytic volatiles of the treated wool.

RETRACTED: Two Cu(II) and Co(II) coordination polymers: Magnetic properties and nutritional support for breast cancer patients by increasing the intestinal epithelial cell microvilli absorption

Abstract In our present investigation, through applying H5L (H5L ​= ​2,4-di(3′,5′-dicarboxylphenyl)benzoic acid), a symmetrical rigid multicarboxylic acid ligand with V-shape, two new coordination polymers containing Co(II) and Cu(II) were assembled, and their chemical formulae respectively were {[Co5(L)2(H2O)12]·6H2O}n (1) and {[H2N(Me)2][Cu2(L)(H2O)]·DMF·H2O}n (2, DMF ​= ​N,N-dimethylformamide), leading to a variety of types of the coordination patterns and multifunctional skeletons of H 5L. Magnetic researches suggest that between neighboring metallic ions, the two compounds possess the antiferromagnetic coupling. Furthermore, the assessment of nutritional support activity was conducted and the detailed mechanism was explored. The results showed that compound 1 was much better than compound 2 on the breast cancer therapy.

Preparation and Properties of Soybean Protein/Compound Carboxylic Acid Modified Cotton Fabric

For exploiting the ecological multifunctional cotton fabric, the citric acid, maleic acid and soybean protein were used to treat the cotton fabric so that the chemical bonding between soybean protein and cotton fabric was formed through the bridging function of multicarboxylic acids. Effects of treating conditions on the weight gain of cotton fabric were analyzed and the optimized process parameters were also obtained. The characterization of infrared spectra showed that the esterification crosslinking occurred between multicarboxylic acids and macromolecules of cotton fiber according to ring-anhydride mechanism, while the soybean protein was combined on cotton fabric with the amido bond by the bridging function of multicarboxylic acids. The breaking strength of soybean protein modified cotton fabric slightly decreased, whereas the anti-ultraviolet property of modified cotton fabric after cactus extract treatment improved remarkably.

Citric acid crosslinked chitosan/poly(ethylene oxide) composite nanofibers fabricated by electrospinning and thermal treatment for controlled drug release

A nontoxic multicarboxylic acid (critic acid) was incorporated into the chitosan/poly(ethylene oxide) composite nanofibers by electrospinning. Critic acid was used to crosslink the chitosan molecules inside the composite nanofibers at elevated temperature, which were characterized by FT-IR and XPS analyses. By increasing the critic acid loading and annealing temperature, the solvent resistance and mechanical properties of these composite nanofibers could be significantly improved. Aspirin, a model drug, has been incorporated into the composite nanofibers and the corresponding drug release performances in PBS solution were evaluated. With the increasing of annealing temperature, the drug release rate of the composite nanofibers was decreasing, which could be ascribed to the reduced swelling ratio and concentration of free volume holes in composite nanofibers. Moreover, the cumulative released aspirin amount in certain release time could be finely tuned by adjusting the initial aspirin loading in the composite nanofibers.

A New Luminescent Zn(II) Complex: Selective Sensing of Cr2O72- and Prevention Activity Against Orthodontic Root Absorption by Suppressing Inflammatory Response.

A novel luminescent coordination polymer (CP) based on Zn(II) ions as nodes [Zn(OPY)1.5(Hbtc)]n (1), [H3btc = trimesic acid and OPY = 4,4'-(oxybis(4,1-phenylene))dipyridine] has been prepared via the solvothermal assembly of a tripodal multicarboxylic acid ligand, a bis-pyridyl ligand with V-shape containing two diverse coordination patterns as well as Zn2 + ion. The experiments of photoluminescence also reflect that the coordination polymer 1 has high sensitivity to potassium dichromate, and its quenching efficiency is Ksv of 2.12 × 104L·mol- 1. Furthermore, its treatment activity on orthodontic root absorption was evaluated in vivo. Firstly, the CCK-8 assay was performed in this research to evaluate the biotoxicity of the synthetic compound. Next, the TNF-α and Cbfα1 released by the periodontal ligament fibroblast was determined via the ELISA test kit. In addition to this, the signaling pathway of NF-κB activation after treated with compound was measured by the RT-PCR.

Two ternary Co(II) coordination polymers induced by bis(benzimidazole) and multicarboxylic acids ligands: Dual-function detection of Fe3+ and benzaldehyde

Two water-stable cobalt(II) coordination polymers, namely, [Co(BTA)0.5(L)(H2O)]n (1) and {[Co(HBTC)(L)1.5]·0.25H2O}n (2) (L ​= ​1,2-bis(benzimidazol-1-ylmethyl)benzene, H4BTA ​= ​1,2,4,5 -benzenetetracarboxylic acid, H3BTC ​= ​1,3,5-benzenetricarboxylic acid) were synthesized under hydrothermal routes. 1 exhibits a 2D 3,4L13 framework which is further packed a 3D supramolecular network via π–π stacking interactions and 2 forms a 2D hcb layer. 1 and 2 are the sensitive and selective luminescent sensors for detecting benzaldehyde and Fe3+ ions with excellent recyclable behaviors.

Polynuclear and coordination polymers of copper(II) complexes assembled by flexible polyamines and bridging rigid N-heterocyclic multicarboxylates

Four trinuclear Cu(II) complexes bridged by N-heterocyclic multicarboxylic acids: [Cu3(dien)2(μ2-Pz3,5-dc)2(H2O)2]·4H2O (1), [Cu3(pmdien)2(μ2-Py2,5-dc)2(ClO4)2(H2O)2] (2), [Cu3(trpn)2(μ2-Py2,5-dc)2(ClO4)2] (3) and [Cu3(ip3tren)2(μ2-Py2,4-dc)2(H2O)](ClO4)2 (4) and the coordination polymer: catena-[Cu2(bedmpza)2(μ2-Py2,4-dc)](ClO4)2·H2O (5) as well as the monomeric [Cu(bdmpzpy)(Py2,6-dc)]2·3H2O (6), where H3Pz3,5-dc = 3,5-pyrazole dicarboxylic acid, H2Py2,4-dc = 2,4-pyridine dicarboxylic acid, H2Py2,5-dc = 2,5-pyridine dicarboxylic acid, H2Py2,6-dc = 2,6-pyridine dicarboxylic, dien = diethylenetriamine, pmedien = N,N,N′,N″,N″-pentamethyldiethylene-triamine, bedmpza = bis(3,5-dimethylpyrazolyl-1H-ethyl)amine, trpn = tris(3-aminopropyl)amine, ip3tren = tris(2-isopropyl-2-ethyl)amine and bdmpzpy = 2,6-bis[(3,5-dimethyl-1H-pyrazolyl)methyl]pyridine were synthesized. The compounds were structurally characterized by elemental microanalyses, IR and UV–Vis spectra as well as by single crystal X-ray crystallography for 1–3, 5 and 6. In 1–3 and 5, the N-heterocyclic multicarboxylate dianion linkers are simultaneously bound by at least one N,O chelating hetero-aromatic dicarboxylato anions via ring-N atom and one O-atom of the adjacent carboxylato group and an O-atom of the carboxylates located at the other side of the heteroxyclic ring. In complex 6 the adjacent bdmpzpy ligands constitute π-π interactions through the central pyridine rings with separation of the centers of gravities = 3.666(2) Å. The degree of nuclearity in the polynuclear species depends entirely on the skeletal structure of the linker N-heterocyclic multicarboxylic acids and the amine coligands.

Four alkaline earth metal (Mg, Ca, Sr, Ba)-based MOFs as multiresponsive fluorescent sensors for Fe3+, Pb2+ and Cu2+ ions in aqueous solution

A series of new alkaline earth-metal organic frameworks (AE-MOFs), i.e. {[Mg2(μ6-L)(μ2-OH2)(H2O)4]·DMF}n (1), [Ca2(μ10-L)(EtOH)]n (2), [Sr(μ6-H2L)(MeOH)]n (3) and {[Ba1.5(μ5-H2L)(μ4-H3L)(H2O)3]·2(H2O)}n(4) were synthesized under solvothermal reaction by employing a symmetrical V-shaped multicarboxylic acid ligand H4L (H4L = 5,5′-oxydiisophthalic acid), resulting in versatile coordination modes as well as various topologies. 1 forms a uninodal 4-connected (66)-dia 3D topology based on dinuclear Mg2(COO)2(μ2-OH2) clusters. 2 displays an unprecedented 3-nodal (5,5,10)-connected 3D net with (424·621)(48·62)2 topology based on 1D [Ca(COO)]n chains and dinuclear Ca2(COO)2 clusters. 3 indicates a uninodal 6-connected 3D net with (410·65)-sma topology based on 1D [Sr(COO)]n chains. 4 features a new 4-nodal (4,5,6,6)-connected net with (43·63)2(46·64)2(46·68·8)(46·69)2 topology based on two types of 1D chains. 1-4 show solid-state fluorescent properties at ambient temperature. Especially, 1 and 2 have multiresponsive recognition of Fe3+ and Pb2+ ions, Fe3+ and Cu2+ ions, respectively, while 3 and 4 show single selective detection for Fe3+ ion, signifying that they could be potential fluorescent sensors for specific heavy metal ions in water system. The sensing mechanism has also been discussed in detail.

SORPTION OF LEAD ION FROM AQUEOUS SOLUTION BY CARBOXYLIC ACID GROUPS CONTAINING ADSORBENT POLYMER

Novel method to synthesize of p -(2,2,3,3-tetracarboxylic acid cyclopropyl)phenyl acrylate( P- TCP) was disclosed. In this study,3-(4-hydroxyphenyl)cyclopropane-1,1,2,2-tetracarboxylicacid was synthesized by the new method and reacted with acryloyl chloride to preparation of P -TCP monomer. Then the resulting monomer was polymerized by free-radical polymerization initiated with benzoyl peroxide in ethyl acetate a solvent to obtain a poly-(2,2,3,3- tetra carboxylic acid cyclopropyl)phenyl acrylate (PTCP)with multicarboxylic acid cyclopropane functionalities in the pendant group as a new polymer and applied to remove Pb(II) from aqueous solution. The sorption experiments under different experimental conditions such as, contact time, temperature and pH were investigated. The functionalized polymer showed strong adsorption ability to the Pb(II), with the maximum adsorption capacities of 553 mgg -1 at pH of 5.The high adsorption rate (<50 min) was seen. The removal of Pb(II) by polymer followed the pseudo-second-order rate better than the pseudo-first-order. The removal mechanisms was described as a metal-binding organic ligand (-COOH) and the electrostatic attractions between Pb(II) and oxygenic functional groups. The synthesized monomer, polymer and its metal chelates were characterized by FT-IR, 1 H-NMR spectroscopy, scanning electronic microscopy (SEM) and atomic absorption techniques (AAS).

Fluorescent sensing properties of Cd(II)/Zn(II) metal–organic frameworks based on 3,5-di(2′,5′-dicarboxylphenyl)benozoic acid

Three 3D metal–organic frameworks (MOFs), namely, {[Cd2(HL)(4,4-bipy)(H2O)]n·H2O} (1), {Zn2(HL)(phen)}n (2) and {Zn2(HL)(2,2-bipy)}n (3) have been synthesized by the V-pattern multi-carboxylic acid ligand H5L (H5L = 3,5-di(2′,5′-dicarboxylphenyl)benozoic acid) and Cd(II)/Zn(II) salts under solvothermal conditions and characterized by X-ray single-crystal diffraction analysis, IR spectrum analysis, thermogravimetric analysis and powder X-ray diffraction analysis. Complex 1 reveals a 3D 4,6-connected net with the point symbol of {43·5·62}{43·53·67·72}. 2 and 3 display a 3D 3-connected net with the point symbol of {103}, respectively. Furthermore, the solid-state luminescence properties of three complexes were researched, 1 and 3 present highly sensitive detection for Fe3+ and Cr2O72− ions in aqueous solution.

Modulating proton diffusion and conductivity in metal-organic frameworks by incorporation of accessible free carboxylic acid groups.

Three multi-carboxylic acid functionalised ligands have been designed, synthesised and utilised to prepare the new barium-based MOFs, MFM-510, -511, and -512, which show excellent stability to water-vapour. MFM-510 and MFM-511 show moderate proton conductivities (2.1 × 10-5 and 5.1 × 10-5 S cm-1, respectively) at 99% RH and 298 K, attributed to the lack of free protons or hindered proton diffusion within the framework structures. In contrast, MFM-512, which incorporates a pendant carboxylic acid group directed into the pore of the framework, shows a two orders of magnitude enhancement in proton conductivity (2.9 × 10-3 S cm-1). Quasi-elastic neutron scattering (QENS) suggests that the proton dynamics of MFM-512 are mediated by "free diffusion inside a sphere" confirming that incorporation of free carboxylic acid groups within the pores of MOFs is an efficient albeit synthetically challenging strategy to improve proton conductivity.

Tunable Physicochemical and Bactericidal Activity of Multicarboxylic‐Acids‐Crosslinked Polyvinyl Alcohol Membrane for Food Packaging Applications

AbstractThe present study demonstrates the role of multicarboxylic acids as crosslinkers to polyvinyl alcohol (PVA) films were fabricated by solution casting method for food packing applications. Effect of incorporating different carboxylic acids namely oxalic acid (OA), succinic acid (SA) and citric acid (CA) on physicochemical and bioactive properties of PVA were investigated in detail. The crystalline phase, optical absorptions and the functional group were analyzed through X‐Ray diffraction (XRD), UV‐Vis and Fourier Transform Infrared (FTIR) Spectroscopy. Thermal, microstructure and surface analysis were studied by Differential thermal analysis (TG/DTA) and Scanning Electron Microscope (SEM) analysis and the chief anti‐bacterial activity. The rheological study was carried out using precursor polymer solutions with different crosslinkers reveal that viscosity of PVA/CA solution is higher. Surface topography and roughness exert a strong influence on bactericidal properties of films as evidenced by Atomic Force Microscope (AFM) analysis. Among they studied films, PVA/CA exhibits higher bacterial inhibition efficiency mainly due to the ability of CA to alter local pH and cause an alteration in the permeability of microbial membrane by disrupting bacterial substrate transport. In addition to this food quality analysis results of microbial tests revealed an increase in the microbial shelf life of sliced carrot from 1 to 5 days for PVA/CA film compared to the control and commercial.

Compatibilization of starch/poly(butylene adipate‐co‐terephthalate) blown films using itaconic acid and sodium hypophosphite

ABSTRACTItaconic acid (IA) has potential as a compatibilizing agent in polymeric blends due to its unique chemical characteristics. Sodium hypophosphite (SHP) has been studied as a catalyst in esterifying reactions using multicarboxylic acids. Starch/poly(butylene adipate‐co‐terephthalate) blown films containing IA, with and without SHP, were produced. The film containing IA presented higher tensile strength (8.166 MPa) and elongation (891.473%) than the control film (5.548 MPa and 487.637%, respectively). When SHP was added (sample IA‐SHP), tensile strength increased even more (9.215 MPa); however, elongation (636.821%) was lower than in the IA film. This behavior was attributed to crosslinking between two starch itaconoate molecules intermediated by SHP. The increase in the compatibility between the polymeric phases justified the lower permeability to water vapor of the IA‐SHP films and was responsible for the production of films with a more compact and homogeneous structure. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46629.

Ligand-controlled formation of covalently modified antimoniomolybdates and their photochromic properties

Four inorganic–organic hybrids based on multicarboxylic acids and antimoniomolybdates, namely, (NH4)4(C3N2H5)4H4[(SbMo6O21)2{OOC(CH2)4COO}3]·7H2O (1), (NH4)8(C3N2H5)2H2[(SbMo6O21)2{OOC(CH2)6COO}3]·8H2O (2), (NH4)24[(SbMo6O21)4{C6H3(COO)3}4]·8H2O (3), and (NH4)6[(SbMo6O21){C9H9(COO)3}]·3H2O (4) have been synthesized under conventional solution conditions. Studies reveal that these compounds are monomers, dimers or tetramers, depending on the structures of the coordinated carboxylic acids. Also, the photochromic properties of these compounds were studied and compared, and based on the different carboxylic acids they displayed great disparities in the coloration speed under irradiation; the speed sequence is: 4 {benzene-1,3,5-triacetic acid (BTA)} > 2 (suberic acid) > 1 (adipic acid). It is indicated that compared to the applied aliphatic acids, the aromatic carboxylic acid ligands will facilitate the enhancement of the coloration speed of organic-POM hybrids.