Metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds and their preparation method and applications for catalyzing the degradation of chemical warfare agent simulants

Abstract

Metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds, and their preparation method and applications in catalyzing the degradation of chemical warfare agent simulants. In the synthesis, Na.sub.2MoO.sub.4, p-hydroxybenzonic acid (PHBA), alanine (Ala), KCl, transition metal cations and As.sub.2O.sub.3 as raw materials and water are used as solvent. At room temperature, 2-chloroethyl ethyl sulfide (CEES) and the prepared polyoxometalate hybrid compounds were mixed together in anhydrous ethanol and stirred, and H.sub.2O.sub.2 was subsequently added into the reaction system. The catalytic reaction for the degradation of CEES was finished within 5 min under stirring. In the catalytic hydrolysis of diethyl cyanophosphonate (DECP), the catalyst, DECP, DMF and H.sub.2O were put together and mixed fully. The prepared polyoxometalate hybrid compounds have the advantages of high conversion, high selectivity and easy recyclability in catalyzing the degradation of two types of chemical warfare agent simulant.

Claims

1. Metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds, wherein the compounds are composed of carboxylic acid modified polyoxomolybdate [AsMo.sub.6O.sub.21(Ala)(PHBA).sub.2].sup.5− covalently linked by metal cations selected from (Co.sup.2+, Ni.sup.2+, Zn.sup.2+, or Mn.sup.2+) to form 1-dimensional (1D) chain structures; a chemical formula is K.sub.2H[(H.sub.2O).sub.4M][AsMo.sub.6O.sub.21(Ala)(PHBA).sub.2].Math.nH.sub.2O; wherein M=Co.sup.2+, Ni.sup.2+, Zn.sup.2+, Mn.sup.2+; Ala=alanine, PHBA=p-hydroxybenzonic acid; n=6.5, 9, 7.5, 7.5, a value of n corresponds to M=Co.sup.2+, Ni.sup.2+, Zn.sup.2+, Mn.sup.2+, respectively; crystals of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds belong to triclinic crystal system and P-1 space group; when M=Co.sup.2+, cell parameters of compound 1 are a=12.0872(8) Å, b=12.5682(8) Å, c=17.2255(13) Å, α=76.700(4)°, β=74.058(4)°, γ=76.399(4)°; when M=Ni.sup.2+, cell parameters of compound 2 are a=11.9612(4) Å, b=12.5318(3) Å, c=17.1943(4) Å, α=76.4990(10) °, β=74.053(2)°, γ=76.535(2)°; when M=Zn.sup.2+, cell parameters of compound 3 are a=12.1425(2) Å, b=12.5739(2)Å, c=17.2226(3)Å, α=76.4430(10) °, β=74.0620(10)°, γ=76.2250(10)°; when M=Mn.sup.2+, cell parameters of compound 4 are a=12.2865(7) Å, b=12.6065(7) Å, c=17.2145(11) Å, α=76.319(3) °, β=73.933(3)°, γ=76.064(3)°; compounds 1-4 are isostructural, and an asymmetric unit of compounds 1-4 contains one crystallographically independent [AsMo.sub.6O.sub.21].sup.3− anion, one Co.sup.2+, Ni.sup.2+, Zn.sup.2+ or Mn.sup.2+ cation, two K.sup.+ cations, two p-hydroxybenzoic acids and one protonated alanine molecule; firstly, the [AsMo.sub.6O.sub.21(Ala)(PHBA).sub.2].sup.5− units are joined together by Co.sup.2+ via Co—O—Mo bond, Ni.sup.2+ via Ni—O—Mo bond, Zn.sup.2+ via Zn—O—Mo bond and Mn.sup.2+ via Mn—O—Mo bond, respectively, to form a 1D linear chain; then strong hydrogen bonds between 1D chains produce a 2-dimensional (2D) supramolecular layer; finally, these 2D layers are linked together to generate a 3-dimensional (3D) supramolecular framework via the hydrogen bonds.

2. A preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds according to claim 1 is as follows: firstly, Na.sub.2MoO.sub.4, PHBA, Ala, KCl and As.sub.2O.sub.3 were dissolved in water, and a pH value of a mixture was adjusted to 3.5-4.5 with 4 M HCl; then an excessive amount of CoCl.sub.2 was added to the reaction mixture; a mole ratio of these materials Na.sub.2MoO.sub.4, PHBA, Ala, KCl, As.sub.2O.sub.3 and CoCl.sub.2 are 6:2:1:2-3:1:1-3; finally, the mixture was heated and stirred in water bath for 1-5 hours at 75-100° C.; a filtrate was kept undisturbed after it cooled under ambient conditions until crystals produced; the crystals are the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds, which were then washed and dried.

3. The preparation method according to claim 2, wherein CoCl.sub.2 is replaced by NiCl.sub.2, ZnCl.sub.2, or MnCl.sub.2.

4. The preparation method according to claim 2, wherein CoCl.sub.2 is replaced by Co(NO.sub.3).sub.2 or CoSO.sub.4.

5. An application of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds according to claim 1 in catalyzing the degradation of 2-chloroethyl ethyl sulfide (CEES), wherein the operation is as follows: CEES and the metal ion-directed carboxylic acid modified polyoxometalates were mixed together in anhydrous ethanol; then, H.sub.2O.sub.2 was subsequently added in this reaction system under stirring; the catalytic degradation was finished after 5 minutes; mole ratio of CEES, the metal ion-directed carboxylic acid modified polyoxometalates and oxidant is 200:3:200-300; the catalytic degradation route is as follow: ##STR00003##

6. An application of the metal ion-directed carboxylic acid modified polyoxometalate hybrid compounds according to claim 1 in catalyzing the degradation of diethyl cyanophosphonate (DECP), wherein the operation is as follows: DECP, N N-dimethylformamide (DMF) and H.sub.2O were mixed together under stirring, and then the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds were subsequently added into the catalytic mixture; the catalytic degradation was completed after 10 minutes; a mole ratio of DECP and catalyst is 1000:1; the catalytic degradation route is as follow: ##STR00004##

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 shows the asymmetric unit of compound 1 in the present invention.

(2) FIG. 2 shows the 1D chain structure of compound 1 in the present invention.

(3) FIG. 3 shows the 2D supramolecular sheet of compound 1 in the present invention.

(4) FIG. 4 shows the results for the oxidation of CEES catalyzed by compounds described in example 1, a) time profile of conversion of CEES oxidation catalyzed by compounds 1-4; b) GC-FID signals for the oxidation progress of CEES catalyzed by compound 1.

(5) FIG. 5 shows .sup.1H NMR spectra for the oxidation process of CEES catalyzed by compound 1 in example 1.

(6) FIG. 6 shows the recycling of conversion and selectivity for the oxidation of CEES catalyzed by compound 1 in example 1.

(7) FIG. 7 shows a FT-IR spectra comparison plot of compound 1 in example 1 before and after the catalytic reaction.

(8) FIG. 8 shows a comparison plot of powder X-ray diffraction (PXRD) patterns of compound 1 in example 1 before and after the catalytic reaction.

(9) FIG. 9 shows the proposed mechanism of the catalytic oxidation of CEES catalyzed by compound 1 in example 1.

(10) FIG. 10 shows the result for the hydrolysis of DECP catalyzed by compound 1 in example 1.

(11) FIG. 11 shows the recycle test for the hydrolytic degradation of DECP by compound 1 in example 1.

DETAILED DESCRIPTION OF THE INVENTION

(12) This invention is further illustrated by the following detailed description of some embodiments, which only explain the invention, but not limit this invention.

Example 1

(13) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(14) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0224 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0714 g CoCl.sub.2 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

(15) The described 0.0714 g CoCl.sub.2 can be replaced by 0.0678 g NiCl.sub.2 or 0.0861 g ZnCl.sub.2 or 0.0486 g MnCl.sub.2.

Example 2

(16) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(17) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0224 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0873 g Ni(NO.sub.3).sub.2 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 3

(18) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(19) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0224 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0893 g Zn(NO.sub.3).sub.2 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 4

(20) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(21) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0149 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0843 g CoSO.sub.4 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 5

(22) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(23) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0149 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then 0.0788 g NiSO.sub.4 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 6

(24) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(25) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0149 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0863 g ZnSO.sub.4 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 7

(26) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(27) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0149 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0669 g MnSO.sub.4 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

Example 8

(28) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(29) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0224 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 4.2 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0714 g CoCl.sub.2 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

(30) The described 0.0714 g CoCl.sub.2 can be replaced by 0.0678 g NiCl.sub.2 or 0.0861 g ZnCl.sub.2 or 0.0486 g MnCl.sub.2.

Example 9

(31) The preparation method of the metal ion-directed carboxylic acid functionalized polyoxometalate hybrid compounds is as follows:

(32) 0.145 g Na.sub.2MoO.sub.4, 0.0197 g As.sub.2O.sub.3, 0.0224 g KCl, 0.0089 g Ala, and 0.0274 g PHBA, were dissolved in 20 mL water. The pH value of the mixture was adjusted to 3.5 by HCl and the solution was stirred for 1 h at room temperature. Then, 0.0476 g CoCl.sub.2 was added to the reaction system. Finally, the solution was heated and stirred for 1 h at 80° C. The filtrate was kept undisturbed after it cooled under ambient conditions until the crystals produced.

(33) The described 0.0476 g CoCl.sub.2 can be replaced by 0.0452 g NiCl.sub.2 or 0.0574 g ZnCl.sub.2 or 0.0324 g MnCl.sub.2.

(34) The products of the above embodiments were tested. The chemical formulas of these compounds are K.sub.2H[(H.sub.2O).sub.4M][AsMo.sub.6O.sub.21(Ala)(PHBA).sub.2].Math.nH.sub.2O 1-4 (M=Co.sup.2+1, Ni.sup.2+2, Zn.sup.2+3, Mn.sup.2+4; n=6.5, 9, 7.5, 7.5; Ala=alanine, PHBA=p-hydroxybenzonic acid). The crystal structues of these compounds are displayed in FIGS. 1, 2 and 3.

(35) The catalytic results of compounds described in example 1 were confirmed by GC. FIG. 4a displayed the time profiles of the conversion of CEES oxidation, which indicated that CEES can be almost entirely converted to CEESO within 5 min. FIG. 4b further illustrated CEES was almost completely oxidized to the only product CEESO within 5 min through the comparisons of GC signals of different substances at different time.

(36) .sup.1HNMR spectroscopy was also utilized to monitor the conversion and ascertain the product to demonstrate the accuracy of the reaction. The comparison of .sup.1HNMR spectroscopy at different reaction time indicated nearly entire CEES was degraded by compound 1 described in example 1 within 5 min in FIG. 5.

(37) The stability of compounds described in example 1 before and after the catalytic reaction was proved by the IR spectra. FIG. 7 displayed the IR spectra comparison of the compound in the present invention before and after the catalytic reaction. The characteristic peaks showed no obvious changes, indicating the structure of compound keeps intact as the heterogeneous catalyst before and after the catalytic reaction.

(38) The stability of compounds described in example 1 was also proved by the XRD patterns of before and after the catalytic reaction. FIG. 8 displayed the comparison of simulated and experimental XRD pattern of the compound in the present invention before and after the catalytic reaction. The results indicate the structure of compound keeps intact as the heterogeneous catalyst.

(39) The catalytic result for compounds described in example 1 was detected by GC. FIG. 10 displayed the time profiles of the conversion of DECP hydrolysis, which indicated that DECP was almost completely converted to the corresponding products within 10 min.

(40) TABLE-US-00001 TABLE 1 Comparison of CEES decomposition by different materials in recent years Sulfoxide Time Temperature Conversion selectivity catalyst (min) Oxidant (° C.) (%) (%) Compound 1 5 H.sub.2O.sub.2 25 98.5 >99.9% Compound 2 5 H.sub.2O.sub.2 25 97.3 >99.9% Compound 3 5 H.sub.2O.sub.2 25 95.4 >99.9% Compound 4 5 H.sub.2O.sub.2 25 94.3 >99.9% PNb.sub.12V.sup.VV.sup.IV.sub.4 60 H.sub.2O.sub.2 25 100 67 PW.sub.12@NU-1000 20 H.sub.2O.sub.2 45 98 57 TBA-polyV.sub.6 30 H.sub.2O.sub.2 25 99 100 fb-PCN-222/MOF-545 60 O.sub.2 25 93 100

(41) TABLE-US-00002 TABLE 2 Comparison of DECP decomposition by different materials in recent years. Time Conversion t.sub.1/2 Catalyst (min) (%) (min) Compound 1 10 99 3.8 Compound 2 10 97 4.2 Compound 3 10 95 4.7 Compound 4 10 96 4.8 MOF-808 30 50 24 UiO-66 30 32 78 MgO 30 90 12 TiO.sub.2 30 87 12 KGeNb 30 100 6 PNb.sub.12V.sup.VV.sup.IV.sub.4 30 98 10 K.sub.8Nb.sub.6O.sub.19 30 90 12