Rapid Destruction of Two Types of Chemical Warfare Agent Simulants by Hybrid Polyoxomolybdates Modified by Carboxylic Acid Ligands

Abstract

Four chain-like hybrid compounds based on mixed carboxylic acid ligands-modified polyoxomolybdates,Co, Ni, Zn, Mn; Ala = alanine; PHBA = p-hydroxybenzonic acid), were prepared and characterized by elemental analysis, IR spectroscopy, solid diffuse reflective spectroscopy, TG analysis, powder X-ray diffraction, and single-crystal X-ray diffraction. Four isostructural compounds 1−4 not only represent the extended architectures constructed from two different organic ligands-modified polyoxometalates but also can rapidly catalyze the degradation of two chemical warfare agent simulants, 2-chloroethyl ethyl sulfide (CEES) and diethyl cyanophosphonate (DECP), at room temperature. The catalytic results were analyzed and confirmed by GC-FID, GC-MS, and 1 HNMR techniques. Within 5 min, CEES was high-selectively oxidized to the corresponding nontoxic 2-chloroethyl ethyl sulfoxide (CEESO) using heterogeneous catalyst 1 with the oxidant H 2 O 2 (conversion % = 98.5%, selectivity % > 99.9%). FTIR, PXRD techniques, and the following cycles also ascertained the stability and structural integrity of 1 in the oxidation reaction. Within 10 min, DECP can be almost entirely hydrolyzed to the nontoxic products catalyzed by 1 (conversion % = 99.0%). To our knowledge, they are in the rank of highly active catalysts for the degradation of CEES and DECP to date, accompanied by the advantages of steady reuse.

Catalytic Processes for the Neutralization of Sulfur Mustard

“…Binary systems made of POM (or their alkoxo-d erivatives) and transition metal ion complexes (Figure 7) have also been studied for the oxidation of CEES by H 2 O 2 and the performances of the most successful catalysts from each series are compared in Table 2( entries 2-5). [90][91][92][93] It is worth mentioning that the nature of the metal ions in each of the binary catalyst series have little impact on the reaction rates.P OMs immobilized on solid supports have also been studied for the catalysis of CEES oxidation to CEESO by H 2 O 2 .T hese heterogeneous systemsi nclude ar eticulatedg el materiali ncorporating hexavanadate clusters (entry 6), [94] am ixed Zn/Cr hydroxide layer materialw ith intercalated transition metal-substituted polyoxotungstate (entry 7), [95] and aC u-substituted POM [Si-W 10 O 36 Cu 2 (N 3 ) 2 ] 6À that was bondedt ot he surfaceo fg raphene by an alkyne-azidec ycloaddition( entry 8);t his was also studied as ac atalystf or CEES oxidationb yO 2 (see section 3.4.2). [96] Overall,m any POMs efficiently catalyze the oxidation of CEES by H 2 O 2 ,b ut the gain (in catalytic rates) compared with simple monomeric anionic metal oxidesi sr ather limited.…”

Restricting Polyoxometalate Movement Within Metal-Organic Frameworks to Assess the Role of Residual Water in Catalytic Thioether Oxidation Using These Dynamic Composites

“…One ubiquitous class of materials which has benefitted from heterogenization and immobilization on solid supports is polyoxometalates (POMs) (Long et al, 2007;Frenzel et al, 2016;Hou et al, 2018). POMs are isolated metal oxide clusters, whose tunable size, charge density, and acid strength allow for a wide range of applications, primarily in catalysis (Pope, 1983;Wang and Yang, 2015;Anyushin et al, 2018;Gumerova and Rompel, 2018;Sullivan et al, 2018).…”

Highly stable polyoxometalate‐resorcin[4]arene‐based inorganic‐organic complexes for catalytic oxidation desulfurization

“…[21][22][23] In this facet, POMs-based inorganic-organic hybrid materials, as recycled solid state catalysts of oxidative desulfurization, have received considerable attention due to their intriguing structures and excellent catalytic performances. [1,[24][25][26][27][28][29][30][31] As a result, the rational design of stable POMs-based inorganic-organic hybrid complexes are of particular importance. It is well-established that organic ligands act as a key role in the rational assembly of inorganic-organic hybrid complexes.…”

“…In this facet, POMs‐based inorganic–organic hybrid materials, as recycled solid state catalysts of oxidative desulfurization, have received considerable attention due to their intriguing structures and excellent catalytic performances . As a result, the rational design of stable POMs‐based inorganic–organic hybrid complexes are of particular importance.…”