Showing papers on "Benzoic acid published in 2011"
TL;DR: Water proved to be essential for the formation of well-ordered Zr-bdc-NH(2) and the first single-crystal structural analysis of a ZR-based metal-organic framework.
Abstract: We present an investigation on the influence of benzoic acid, acetic acid, and water on the syntheses of the Zr-based metal-organic frameworks Zr-bdc (UiO-66), Zr-bdc-NH(2) (UiO-66-NH(2)), Zr-bpdc (UiO-67), and Zr-tpdc-NH(2) (UiO-68-NH(2)) (H(2) bdc: terephthalic acid, H(2) bpdc: biphenyl-4,4'-dicarboxylic acid, H(2) tpdc: terphenyl-4,4''-dicarboxylic acid). By varying the amount of benzoic or acetic acid, the synthesis of Zr-bdc can be modulated. With increasing concentration of the modulator, the products change from intergrown to individual crystals, the size of which can be tuned. Addition of benzoic acid also affects the size and morphology of Zr-bpdc and, additionally, makes the synthesis of Zr-bpdc highly reproducible. The control of crystal and particle size is proven by powder XRD, SEM and dynamic light scattering (DLS) measurements. Thermogravimetric analysis (TGA) and Ar sorption experiments show that the materials from modulated syntheses can be activated and that they exhibit high specific surface areas. Water proved to be essential for the formation of well-ordered Zr-bdc-NH(2) . Zr-tpdc-NH(2), a material with a structure analogous to that of Zr-bdc and Zr-bpdc, but with the longer, functionalized linker 2'-amino-1,1':4',1''-terphenyl-4,4''-dicarboxylic acid, was obtained as single crystals. This allowed the first single-crystal structural analysis of a Zr-based metal-organic framework.
1,249 citations
TL;DR: In this article, the use of different phenolic acids (gallic acid (GA), p-hydroxy benzoic acid (HBA) or ferulic acids (FA)) or flavonoids (catechin (CAT), flavone (FLA) or quercetin (QU)).
178 citations
TL;DR: The reactivity of copper and vanadium catalysts toward the aerobic oxidation of lignin models has been explored in this paper, showing that copper catalyzed reaction afforded benzaldehyde (84%) and methylbenzoate (88%) directly, with no intermediate formation of 4.
Abstract: The reactivity of copper and vanadium catalysts toward the aerobic oxidation of lignin models has been explored. Both (dipic)VV(O)(OiPr) (3) (dipic = dipicolinate) and CuCl/TEMPO (TEMPO = tetramethylpiperidine N-oxide) catalyzed the aerobic oxidation of the lignin model compound 1,2-diphenyl-2-methoxyethanol (2). The vanadium catalyst 3 produced benzoic acid (85%) and methyl benzoate (84%) as the major products via the intermediate ketone benzoin methyl ether (4). The copper catalyzed reaction afforded benzaldehyde (84%) and methylbenzoate (88%) directly, with no intermediate formation of 4. The more complex lignin model system 1-(3,5-dimethoxyphenyl)-2-(2-methoxyphenoxy)propane-1,3-diol-[2,3-13C2] (5-13C2) was oxidized under air by vanadium catalyst 3, affording ketone 7-13C2 (65%), dehydrated ketone 8-13C2 (5%), alkene product 9-13C2 (14%), 3,5-dimethoxybenzoic acid (11%), 3,5-dimethoxybenzaldehyde (2%), 2-methoxyphenol, and formic acid-13C1 (4%). Aerobic oxidation of ketone 7-13C2 using catalyst 3 prod...
167 citations
TL;DR: In this paper, the authors investigated the effect of the chemical nature of the pollutants on the deactivation process of toluene and methylcyclohexane photooxidation on TiO2-ZrO2 thin-films.
Abstract: The main objective of the present study is to gain further insight into the mechanism of toluene and methylcyclohexane photocatalytic oxidation on TiO2–ZrO2 thin-films, in order to understand the influence of the chemical nature of the pollutants on the deactivation process. Despite the significant differences in the physicochemical characteristics of these two molecules, the parallel study of their photocatalytic degradation can contribute to ascertain relevant aspects of the mineralization mechanism. This knowledge could be used for developing feasible solutions for this deactivation problem, which hinders a wider use of photocatalysis for air purification. The operando study of toluene photooxidation, a simultaneous analysis of surface and gas phase during reaction by using two FTIR spectrometers in tandem, allowed us to correlate the deactivation process with the formation of benzoic acid, strongly adsorbed on the surface as benzoate complexes. These species block the access of new organic molecules to the active sites and simultaneously hinder charge transfer from the photoactivated surface. As a consequence, the degradation rate of toluene considerably decreases after a few minutes of reaction. In contrast, intermediate surface complexes can be almost completely removed during the photocatalytic oxidation of methylcyclohexane. Therefore, it seems that the aromaticity of toluene plays a key role in the performance of photocatalysts during its degradation. The high stability of benzyl radicals favors the photocatalytic oxidation of this volatile organic compound (VOC) and the formation of recalcitrant oxygenated aromatic molecules which accumulate on the photoactive surface.
143 citations
TL;DR: In this paper, a batch reactor system was developed in order to perform kinetic studies of toluene removal, organic reaction intermediate formation and removal, and CO and CO 2 formation, at ppbv levels.
Abstract: An investigation of toluene photocatalytic oxidation was conducted with initial concentrations of toluene ranging from 50 to 800 ppbv under dry and wet (50% RH) atmosphere in order to characterize photocatalysis performances close to indoor air conditions. A batch reactor system was developed in order to perform kinetic studies of (i) toluene removal, (ii) organic reaction intermediate formation and removal, (iii) CO and CO 2 formation, at ppbv levels. The monitoring of CO and CO 2 produced by a photocatalytic reaction in the air with ppbv levels of pollutant is reported for the first time. It appears that toluene removal follows, even at ppbv levels, a pseudo first order kinetic slightly improved by the presence of water vapour (50% RH). The determination of reaction intermediate temporal profiles confirmed that oxidized aromatic compounds (benzaldehyde, cresols) are toluene primary reaction intermediates. The fact that no benzoic acid was evidenced in the gas phase, and that benzaldehyde maximum concentration remains below 4 ppbv indicate that several consecutive oxidation steps take place in the adsorbed phase with a low desorption of reaction intermediate. The diversity of aliphatic reaction intermediates obtained after toluene ring opening is coherent with former results obtained at ppmv initial levels of toluene. Nevertheless, the removal of the lightest carbonyls (acetone, acetaldehyde and formaldehyde) is not observed within 14 h of reaction. Carbon mass balance calculations performed with all the quantified gas phase reaction intermediates evidenced that those compounds represent only from 1 to 1.5%. This portion is almost constant during the whole oxidation process. The precise determination of CO and CO 2 concentrations gives a good overview of the oxidation/mineralization process. CO and CO 2 measurements evidenced that the presence of water vapour (50% RH) considerably improves the formation of CO 2 corresponding to a better mineralization of organic matter and an improved conversion of CO into CO 2 . Temporal profiles of CO 2 concentration reveal that CO 2 formation rate is highly dependent on the nature of the compounds to be treated. Between 10 and 12 h of reaction, corresponding to 95% conversion of toluene, CO and CO 2 represent only from 25 to 35% of the carbon mass balance. If the reaction is performed on longer times, the mineralization percentage constantly increases until 23 h of irradiation, mainly corresponding to oxidation of compounds adsorbed on photocatalyst surface. After 22 h of irradiation, the mineralization (CO + CO 2 ) finally exceeds 70% of the carbon mass balance.
107 citations
TL;DR: It was concluded that the transcellular transport of [14C]salicylic acid across Caco‐2 cells is by the pH‐dependent and carrier‐mediated transport mechanism specific for monocarboxylic acids.
Abstract: The transport of monocarboxylic acid drugs such as salicylic acid was examined in the human colon adenocarcinoma cell line, Caco-2 cells that possess intestinal epithelia-like properties. [14C]Salicylic acid transport was pH-dependent and appeared to follow the pH-partition hypothesis. However, 10 mM unlabelled salicylic acid significantly reduced the permeability coefficient of [14C]salicylic acid. Kinetic analysis of the concentration dependence of the permeation rate of salicylic acid across Caco-2 cells showed both saturable (Kt = 5.28 +/- 0.72 mM Jmax = 36.6 +/- 3.54 nmol min-1 (mg protein)-1) and nonsaturable (kd = 0.37 +/- 0.08 microL min-1 (mg protein)-1) processes. The permeation rate of [14C]salicylic acid was competitively inhibited by both acetic acid and benzoic acid, which were demonstrated in our previous studies to be transported in the carrier-mediated-transport mechanism which is responsible for monocarboxylic acids. Furthermore, certain monocarboxylic acids significantly inhibited [14C]salicylic acid transport, whereas salicylamide and dicarboxylic acids such as succinic acid did not. From these results, it was concluded that the transcellular transport of [14C]salicylic acid across Caco-2 cells is by the pH-dependent and carrier-mediated transport mechanism specific for monocarboxylic acids.
104 citations
TL;DR: Increased adsorption with temperature indicates that the adsorptions of benzoic acid onto Al(OH)-OTMAC-Bent and OTMAC-Bbent are spontaneous and endothermic.
99 citations
TL;DR: A one-pot condensation of isotryptamines and aldehydes that affords enantiomerically enriched 4-substituted tetrahydro-γ-carbolines is reported.
97 citations
TL;DR: TEM measurements and titration analysis by using benzoic acid suggested that the solid basicity of hydrotalcite plays important roles in the precise control of platinum size and metal concentration as well as the initial promotion of alcohol oxidation.
Abstract: A hydrotalcite-supported platinum (Pt/HT) catalyst was found to be a highly active and selective heterogeneous catalyst for glycerol oxidation in pure water under atmospheric oxygen pressure in a high glycerol/metal molar ratio up to 3125. High selectivity toward glyceric acid (78 %) was obtained even at room temperature under air atmosphere. The Pt/HT catalyst selectively oxidized the primary hydroxyl group of 1,2-propandiol to give the corresponding carboxylic acid (lactic acid) as well as glycerol. The activity of the catalyst was greatly influenced by the Mg/Al ratio of hydrotalcite. Glycerol conversion increased with increasing the Mg/Al ratio of hydrotalcite (from trace to 56 %). X-ray absorption fine structure (XAFS) measurements indicated that the catalytic oxidation activity was proportional to the metallic platinum concentration, and more than 35 % of metallic platinum was necessary for this reaction. TEM measurements and titration analysis by using benzoic acid suggested that the solid basicity of hydrotalcite plays important roles in the precise control of platinum size and metal concentration as well as the initial promotion of alcohol oxidation.
94 citations
TL;DR: A series of chalcone derivatives bearing the 2,4-thiazolidinedione and benzoic acid moieties (8a-s) were synthesized, characterized, and evaluated for their anti-bacterial activity, and the most effective compounds were 8a, 8h, 8k, 8n and 8q.
90 citations
TL;DR: Rat caecal contents decarboxylate phenolic benzoic acid derivatives when a free hydroxyl group is in the para position but the presence of substituents adjacent to this group or the carboxyl group reduce or abolish the reaction.
Abstract: Rat caecal contents decarboxylate phenolic benzoic acid derivatives when a free hydroxyl group is in the para position but the presence of substituents adjacent to this group or the carboxyl group reduce or abolish the reaction. Compounds containing a hydroxyl group in the ortho or meta position but lacking one in the para position are not decarboxylated. Some methoxy-derivatives are demethylated. The possible relationship between these findings and urinary phenols is discussed.
TL;DR: In this article, the synthesis, structure, and gas adsorption properties of three metal organic frameworks (MOFs) synthesized from predesigned ligands 4-(1H-tetrazole-5-yl)benzoic acid (4-TBA) and 2-fluoro-4-( 1H-to-hexyl)-4-tohexyl (2F-4-tBA) along with Cu(II) as an metal precursor has been reported.
Abstract: Synthesis, structure, and gas adsorption properties of three Metal Organic Frameworks (MOFs) synthesized from predesigned ligands 4-(1H-tetrazole-5-yl)benzoic acid (4-TBA) and 2-fluoro-4-(1H-tetrazole-5-yl)benzoic acid (2F-4-TBA) along with Cu(II) as an metal precursor has been reported. Among these MOFs, Cu9(4-TBA)10(C2H5OH)2 (Cu-TBA-1) and Cu2(4-TBA)2(DMF)(C2H5OH) (Cu-TBA-2) are structural isomers. Whereas, Cu2(4-TBA)2(DMF)(C2H5OH) (Cu-TBA-2) and Cu2(2-F-4-TBA)2(DMF)2 (Cu-TBA-2F) have similar crystal structure. N2 adsorption isotherms of the activated sample of Cu-TBA-1 and -2 exhibit types-I sorption behavior with a Langmuir and Brunauer–Emmett–Teller (BET) surface area of 686, 402 m2/g and 616, 356 m2/g, respectively. It is noteworthy that Cu-TBA-1 and -2 adsorbs 1.16 and, 1.54 wt % H2, while Cu-TBA-2F adsorbs 0.67 wt % at 77 K and 1 atm. On the other hand, Cu-TBA-1 and -2 adsorb 3.08 and 2.54 mmol/g, while Cu-TBA-2F adsorbs 1.27 mmol/g of CO2 at 298 K and 1 bar pressure. H2 adsorption sites in Cu-TBA...
TL;DR: In this paper, an investigation into the creation of cocrystals of benzamide and substituted benzoic acids was undertaken and four new cocrystal structures were structurally characterized by single-crystal X-ray diffraction.
Abstract: An investigation into the creation of cocrystals of benzamide and substituted benzoic acids was undertaken and four new cocrystals were structurally characterized by single-crystal X-ray diffraction. The attempted cocrystallizations were only successful in those cases where electron-withdrawing functional groups were present as substituents on the benzoic acid. This experimental observation was supported by computational studies, which indicated that in these cases the intermolecular acid···amide interaction between the acid and benzamide was strengthened. A correlation between the interaction energy and the Hammett substitution constant in the applicable cases was displayed. The calculated energy of interaction between benzamide/salicylic acid dimers and benzamide/benzoic acid dimer are the same, yet only benzamide/salicylic acid forms a cocrystal. Lattice energy calculations on the salicylic acid/benzamide crystal structure and hypothetical benzoic acid/benzamide cocrystal structures indicate a differen...
TL;DR: Lanthanide complexes 2, 4, and 6, which were synthesized from 3,5-bis(pyridine-2-ylmethoxy)benzoic acid, were structurally authenticated by single-crystal X-ray diffraction and found to exist as infinite one-dimensional coordination polymers with the general formula {[Ln(L2)(3)(H(2)O)(2)]·xH( 2)O}(n).
Abstract: Two new aromatic carboxylic acids, namely, 3,5-bis(benzyloxy)benzoic acid (HL1) and 3,5-bis(pyridine-2-ylmethoxy)benzoic acid (HL2), have been prepared by replacing the hydroxyl hydrogens of 3,5-dihydroxy benzoic acid with benzyl and pyridyl moieties, respectively. The anions derived from HL1 and HL2 have been used for the support of a series of lanthanide coordination compounds [Eu3+ = 1–2; Tb3+ = 3–4; Gd3+ = 5–6]. The new lanthanide complexes have been characterized on the basis of a variety of spectroscopic techniques in conjunction with an assessment of their photophysical properties. Lanthanide complexes 2, 4, and 6, which were synthesized from 3,5-bis(pyridine-2-ylmethoxy)benzoic acid, were structurally authenticated by single-crystal X-ray diffraction. All three complexes were found to exist as infinite one-dimensional (1-D) coordination polymers with the general formula {[Ln(L2)3(H2O)2]·xH2O}n. Scrutiny of the packing diagrams for 2, 4, and 6 revealed the existence of interesting two-dimensional m...
TL;DR: In this article, the authors investigated the selective oxidation of benzyl alcohol to benzaldehyde in aqueous solution, under acidic conditions, through the TiO 2 /Cu(II)/solar UV photocatalytic system.
TL;DR: The cytotoxic results indicate that coupling of Hdmpa and Hmef with R(3)Sn(IV) metal center results in complexes with important biological properties and remarkable cytotoxicity activity, since they display IC(50) values in a μΜ range better to that of the antitumor drug cis-platin.
TL;DR: The stability of benzoic acid and three of its derivatives under subcritical water conditions was investigated and the acids became less stable with longer heating time and remained stable at temperatures up to 300°C.
TL;DR: In this paper, an in situ DRIFTS study of toluene oxidation over V-Ti-O catalyst at ambient temperature was presented, where vanadyl species band and XPS characterization were used to illustrate the reaction route.
TL;DR: Docking studies of compound 5 indicated that the phenolic compound with an elongated side chain could possibly penetrate deep into the active site of the enzyme and arrange itself through π-π interaction, H-bonding, and hydrophobic contacts with some critical residues along the complex geometry of the active gorge.
TL;DR: The solid-state chiral optical properties of a 4-(2-arylethynyl)-benzoic acid/amine supramolecular organic fluorophore can be controlled by changing the arylethunyl group of the achiral 4-( 2-aryllynyl-2,3,4,5-triple-triethylene)-benzosic acid component molecule rather than the chirality of the amine component molecule.
Abstract: The solid-state chiral optical properties of a 4-(2-arylethynyl)-benzoic acid/amine supramolecular organic fluorophore can be controlled by changing the arylethynyl group of the achiral 4-(2-arylethynyl)-benzoic acid component molecule rather than the chirality of the amine component molecule.
TL;DR: A sensitive method of online preconcentration followed by capillary electrophoresis with capacitively coupled contactless conductivity detection (CE-C(4)D) with a great potential for the proposed method as a tool for the fast screening of benzoic acid and sorbic acid in a complex matrix.
TL;DR: In this paper, a 1:1 mixture of D2O/CD3OD was used for catalytic H/D exchange reactions of benzene and benzoic acid with deuterated solvents.
TL;DR: A limited life cycle assessment was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process, and a decrease in the CO2eq emission was especially achieved when the N2O emission was restricted.
Abstract: A limited life cycle assessment (LCA) was performed on a combined biological and chemical process for the production of adipic acid, which was compared to the traditional petrochemical process. The LCA comprises the biological conversion of the aromatic feedstocks benzoic acid, impure aromatics, toluene, or phenol from lignin to cis, cis-muconic acid, which is subsequently converted to adipic acid through hydrogenation. Apart from the impact of usage of petrochemical and biomass-based feedstocks, the environmental impact of the final concentration of cis, cis-muconic acid in the fermentation broth was studied using 1.85% and 4.26% cis, cis-muconic acid. The LCA focused on the cumulative energy demand (CED), cumulative exergy demand (CExD), and the CO(2) equivalent (CO(2) eq) emission, with CO(2) and N(2) O measured separately. The highest calculated reduction potential of CED and CExD were achieved using phenol, which reduced the CED by 29% and 57% with 1.85% and 4.26% cis, cis-muconic acid, respectively. A decrease in the CO(2) eq emission was especially achieved when the N(2) O emission in the combined biological and chemical process was restricted. At 4.26% cis, cis-muconic acid, the different carbon backbone feedstocks contributed to an optimized reduction of CO(2) eq emissions ranging from 14.0 to 17.4 ton CO(2) eq/ton adipic acid. The bulk of the bioprocessing energy intensity is attributed to the hydrogenation reactor, which has a high environmental impact and a direct relationship with the product concentration in the broth.
TL;DR: The metal-free preparation of benzoic acid derivatives from phenols provides a potentially useful alternative to metal-catalyzed carbonylation of aryl triflates.
Abstract: We report a metal-free procedure for transformation of phenols into esters and amides of benzoic acids via a new radical cascade. Diaryl thiocarbonates and thiocarbamates, available in a single high-yielding step from phenols, selectively add silyl radicals at the sulfur atom of the C═S moiety. This addition step, analogous to the first step of the Barton−McCombie reaction, produces a carbon radical which undergoes 1,2 O→C transposition through an O-neophyl rearrangement. The usually unfavorable equilibrium in the reversible rearrangement step is shifted forward via a highly exothermic C−S bond scission in the O-centered radical, which furnishes the final benzoic ester or benzamide product. The metal-free preparation of benzoic acid derivatives from phenols provides a potentially useful alternative to metal-catalyzed carbonylation of aryl triflates.
TL;DR: The AKR1C3 inhibitory potency of the 4'-substituted 3-(phenylamino)benzoic acids shows a linear correlation with both electronic effects of substituents and the pK(a) of the carboxylic acid and secondary amine groups, which are interdependent.
TL;DR: The absorption is shown to be the passive entry into a lipid phase and there is an increase in absorption of the acids due to alterations in partition characteristics with increasing chain length of n‐fatty acids from butyric to dodecanoic.
Abstract: A method to determine the passage of acids into the buccal membrane of man is presented. The absorption is shown to be the passive entry into a lipid phase. There is an increase in absorption of the acids due to alterations in partition characteristics with increasing chain length of n-fatty acids from butyric to dodecanoic. Methyl substitution of benzoic acid increases the absorption with mono- and di-substituents, but decreases the absorption with the tri- and tetra-substituents by lowering the pKa. Predictions of the relative absorption and excretion in man of these acids is included.
TL;DR: Information is provided that can be used to formulate safer acid and acidified food products and insights are provided about the mode of action of weak acids against EHEC.
TL;DR: In this article, a comparative study on titanium dioxide (TiO2) catalyzed photocatalytic degradation (PCD) of aqueous aromatic carboxylic acids (phthalic acid, o-nitrobenzoic acid (ONA), o-chlorobenzoic (OBA), and benzoic acids) was carried out in the presence of UV radiation using air.
TL;DR: The acid-base chemistry of 2-mercaptobenzoic acid immobilized on a polycrystalline silver surface was investigated by surface-enhanced Raman spectroscopy under potential control and shows a significant increase in the intrinsic pK(a) of the immobilized ligand compared to 2-MBA in free solution.
Abstract: The acid−base chemistry of 2-mercaptobenzoic acid (2-MBA) immobilized on a polycrystalline silver surface was investigated by surface-enhanced Raman spectroscopy under potential control. The COO− bending mode of the benzoate form and the C−COOH stretching mode of the benzoic acid form of 2-MBA were used to determine the relative deprotonated and protonated populations of the bound ligand, respectively. In addition, shifts in the symmetric carboxylate stretching mode of 2-MBA reveal interactions between the benzoate group and the silver surface, interactions which could be displaced by acetate and other buffer anions from solution. It was found that the applied potential has a significant effect on the proton dissociation equilibrium of immobilized 2-MBA. This effect arises from the surface potential governing the activity of protons at the interface, which changes the interfacial pH relative to bulk solution. The results are fit to a Poisson−Boltzmann model, corrected for potential distribution across the...
TL;DR: In this paper, the reaction of oxidovanadium(IV)-exchanged zeolite-Y with N,N′-ethylenebis(pyridoxyliminato) (H2pydx-en, I), N, N′-propylenebis(polypropylene) (Pyridoxylinato, II) and H2pYDx-1,2-pn (III) in methanol heated at reflux leads to the formation of the corresponding complexes, abbreviated herein as [VIVO(p
Abstract: The reaction of oxidovanadium(IV)-exchanged zeolite-Y with N,N′-ethylenebis(pyridoxyliminato) (H2pydx-en, I), N,N′-propylenebis(pyridoxyliminato) (H2pydx-1,3-pn, II) and H2pydx-1,2-pn (III) in methanol heated at reflux leads to the formation of the corresponding complexes, abbreviated herein as [VIVO(pydx-en)]-Y (4), [VIVO(pydx-1,3-pn)]-Y (5) and [VIVO(pydx-1,2-pn)]-Y (6) in the supercages of zeolite-Y. The neat complexes [VIVO(pydx-en)] (1), [VIVO(pydx-1,3-pn)] (2) and [VIVO(pydx-1,2-pn)] (3) were also prepared. Spectroscopic studies (IR, UV/Vis and EPR), elemental analyses, thermal studies, field-emission scanning electron micrographs (FESEM) and X-ray diffraction patterns were used to characterize these complexes. Oxidations of styrene, cyclohexene and methyl phenyl sulfide were investigated using these complexes as catalyst precursors in the presence of H2O2 as oxidant. Under the optimized reaction conditions, a maximum of 85.5 % conversion of styrene was obtained with 4, 84.6 % conversion with 5 and 82.9 % conversion with 6 in 6 h of reaction time. The selectivity of the various products was similar for the catalyst precursors 4–6 and followed the order: benzaldehyde > 1-phenylethane-1,2-diol > benzoic acid > phenyl acetaldehyde. With cyclohexene, a maximum conversion of 95.9 % was achieved with 4, 94.5 % with 5 and 94.2 % conversion with 6, also in 6 h of reaction time. The selectivity of the various products was similar for the three catalysts: 2-cyclohexen-1-one > 2-cyclohexen-1-ol > cyclohexane-1,2-diol. The oxidation of methyl phenyl sulfide was achieved with 4, 5 and 6 in 2.5 h of reaction time with 85.5, 82.1 and 80 % conversion, with higher selectivity towards sulfoxide. Overall, the encapsulated catalysts were significantly more active than their neat counterparts and have the further advantage of being recyclable. No relevant difference in activity was found due to a change in the diamine in the Schiff base ligands I–III. UV/Vis and 51V NMR spectroscopic experiments with 1 confirmed the plausible formation of VVO(O2)L as intermediates in the catalytic oxidations.