Mechanism of Chrome-free Tanning with Tetra-hydroxymethyl Phosphonium Chloride

Tetra-hydroxymethyl phosphonium chloride （THPC） has been considered as an important chrome-free tanning agent. To understand the THPC tanning mechanism, the structure, charge distribution, activity and tanning ability of each phosphorous compound in THPC tanning system were studied, by ^31p NMR, FT-IR spectroscopy, differential scanning calorimetry （DSC） and computational chemistry method, etc. When pH raised to 6.0, the decomposition of THPC would take place, which results in a production of free formaldehyde, tri-hydroxymethyl phosphonium （TrHP） and tri-hydroxymethyl phosphine oxide （TrHPO）. At pH 9.0, THPC will be converted completely to TrHP and most TrHP is further oxidized into TrHPO. It is possible that, in reaction of phosphorous compounds and collagens, both P-C and C-O bonds would break simultaneously or individually. From molecular charge distribution and bond polar properties, it is deduced that, if P-C bonds break, the activity is in order of TrHPO 〉 THPC 〉 TrHE whereas if C--O bonds break, the order is TrHP 〉 THPC 〉 TrHPO. It is more possible that P--C bonds will break in reaction with collagen, and TrHPO may be more active in the THPC tanning system. The results of tanning and DSC also prove the above conclusion. Furthermore, the fact that the shrinkage temperature of THPC tanned leather was below 70℃ when basified to pH 5.0 or lower suggests that the hydroxymethyl groups of THPC and TrHP are less possible to combine directly with amino groups of collagen.

Transformation of carbon dioxide into valuable chemicals over bifunctional metallosalen catalysts bearing quaternary phosphonium salts

The chemical transformation of CO2under mild conditions remains a great challenge because of itsexceptional kinetic and thermodynamic stability.Two important reactions in the transformation ofCO2are the N‐formylation reaction of amines using hydrosilanes and CO2,and the cycloaddition ofCO2to epoxides.Here,we report the high efficiency of bifunctional metallosalen complexes bearingquaternary phosphonium salts in catalyzing both of these reactions under solvent‐free,mild conditionswithout the need for co‐catalysts.The catalysts’bifunctionality is attributed to an intramolecularcooperative process between the metal center and the halogen anion.Depending on the reaction,this activates CO2by permitting either the synergistic activation of Si–H bond via metal–hydrogen coordinative bond(M–H)or the dual activation of epoxide via metal–oxygen coordinativebond(M–O).The one‐component catalysts are also shown to be easily recovered and reusedfive times without significant loss of activity or selectivity.The current results are combined withprevious work in the area to propose the relevant reaction mechanisms.

Synthesis of Quaternary Phosphonium Salts with Ester Functional Group and Its Application to Improve the Thermal Stability of Modified Montmorillonite

Both of quaternary ammonium and quaternary phosphonium salts of bis-hydroxyethyl terephthalate （BHET） were successfully synthesized and characterized by fourier transform infrared spectroscopy （FT-IR）. These two kinds of salts were used to intercalate Na-MMT to yield two kinds of respective organo-modified MMTs. Basal spacing and thermal stability were investigated by using X-ray diffraction （XRD） and thermogravimetric analysis （TGA）, respectively. The experimental results show that, as compared with Na-MMT, basal spacings of both of MMTs modified by the quaternary phosphonium salt of BHET （BHETPP） and the quaternary ammonium salt of BHET （BHEA）, increase from 12.4 A to 19.7/k and 31.3 A, respec-tively. Thermal stability of BHETPP-modified MMT is much better than that of BHEA-modified MMT, i e, T otof BHETPP-modified MMT is around 400℃ while Tcmset of BHEA-modified MMT is near 250℃. Therefore, with en-larged basal spacing and excellent thermal stability, BHETPP-modified MMT is a promising organo-modified MMT which may be used to prepare polyethylene terephthalate/MMT nanocomposite with high thermal and mechanical performance.

Thermal stability and long-acting antibacterial activity of phosphonium montmorillonites

Na-montruorillonite （Na-MMT） was exchanged with three quaternary atkylphosphonium salts： decyl tributylphosphonium bromide （DTBPBr）, dodecyl tributylphosphonium bromide （DDTBPBr） and hexadecyl tributylphosphonium bromide （HDTBPBr）, to investigate the effects of phosphonium salts species and relative molecular mass on the characteristics, morphology, thermal stability and long-acting antibacterial property of phosphonium montmorillonites. The resulting modified montmorillonites were characterized by the FTIR, XRD, TEM, and TG/DTG techniques. And minimum inhibitory concentration （MIC） was used to investigate antibacterial activity. The results show that the phosphonium salts are intercalated into Na-MMT, and the basal spacing of P-MMTs is enlarged with the increase of phosphonium salt content or the growth of alkyl chain length. DDTBP-MMT-3 with 19.83% （mass fraction of dodecyl tributylphosphonium salts, displays excellent thermal stability and long-acting antibacterial activity.

Synthesis, Characterization and Performance of a New Type of Alkylene Triphenyl Double Quaternary Phosphonium Salt

ByBimolecular Nucleophilic Substitution, four new types of alkylene triphenyl double quaternary phosphonium salt were synthesized respectively by using triphenylphosphine, 1,3-dibromopropane, 1,6-dibromohexane,1,10-dibromo- decane, 1,12-dibromododecane as raw materials and using DMAC as the solvent, under a certain temperature and reac- tion time. The productivity is 58% - 83%. The molecular structures of the products were characterized by IR, NMR and elemental analysis. The sterilizing effect of 1,6-hexylidene triphenyl double phosphonium bromide(HTDPB) and 1,12- dodecylidene triphenyl double phosphonium bromide(DoTDPB) was evaluated by using extinct dilution method.The experimental result shows that the sterilizing effect of DoTDPB is better than the effect of HTDPB under the same drug concentration and contact time. When the concentration of DoTDPB was 20 mg/L and the contact time was 0.5 h, the sterilizing rate of DoTDPB used to kill saprophytic bacteria (TGB), sulfate-reducing bacteria (SRB) and iron bacteria (IB) was 95.56%, 84% and 99.58% respectively.

Efficient and recyclable Rh-catalytic system with involvement of phosphine-functionalized phosphonium-based ionic liquids for tandem hydroformylation—acetalization

The phosphine-functionalized phosphonium-based ionic liquids(dppm-Q, dppe-Q, dppp-Q and dppb-Q) as the bi-functional ligands enable the efficient one-pot tandem hydroformylationeacetalization. It was found that, in dppm-Q, dppe-Q, dppp-Q and dppb-Q, the incorporated phosphino-fragments were responsible for Rh-catalyzed hydroformylation and the phosphoniums were in charge of the subsequent acetalization as the Lewis acid catalysts. Moreover, the diphosphonium-based ionic liquid of dppb-DQ could be applied as a co-solvent to immobilize the Rh/dppb-Q catalytic system with the advantages of the improved catalytic performance, the available catalyst recyclability, and the wide generality for the substrates.

Novel Stereoselective Synthesis of (E)-a,b-Unsaturated Esters by the Tandem Reaction of Deprotonation-Oxidation-Wittig Reaction from Phosphonium and Arsonium Salt

Phosphonium or arsonium salt 1 can undergo the tandem reaction of deprotonation -oxidation-Wittig reaction with alcohol 2 in the presence of sodium hydroxide and manganese dioxide, which affords a general simplified method for the stereoselective synthesis of (E)- a, b-unsaturated esters 3.

Acute Toxicity and Bactericidal Property of Tetrakis Hydroxymethyl Phosphonium Sulfate in Japanese Eel

[ Objective] To understand the toxicity and sterilization effects of the tetrakis hydroxmethyl phosphonium sulfate （THPS） as a novel quatemary phosphonium biocide. [ Method] Under hydrostatic conditions, the acute toxicity and bactericidal property of THPS on the Fiexibacter coiumnaris （ F. columnaris） were observed in Japanese eel. The semi-lethal concentration （LCso）, safe concentration （Sc）, minimum inhibitory concentration （MIC）, minimum bactericidal concentration （MBC） and the sterilization rate of THPS were calculated, respectively. [ Result ] The LCso of THPS at 24, 48 and 96 h were 11.9, 9.9 and 9.1 mg/L, respectively. The Sc of THPS at 24 h was 2.1 mg/L; the MIC and MBC of THPS to the F. columnaris were 0.36 and 0.72 mg/L; and the sterilization rate was 100% at a concentration of 0.7 mg/L at 12 h. The sterilization rate of THPS had no great change with pH values varying from 5.5 to 9.5. [ Condusion] The THPS is a novel, safe and effective biocide for prevention and treatment of bacterial diseases of Japanese eel.

Synthesis, Kinetics and Mechanism of Terpolymerization of Styrene, Vinyl Acetate with Acrylonitrile Initiated by P-Nitrobenzyl Triphenyl Phosphonium Ylide

Synthesis of terpolymers consisting of two electron-donating monomers, viz. styrene and vinyl acetate with one electron-accepting monomer, i.e. acrylonitrile, initiated by p-nitrobenzyl triphenyl phosphonim ylide in dioxane as diluent at 65°C for 150 min has been studied. The kinetic expression is Rpα[I]0.8[Sty] 1.2[VA] 1.4 [AN]1.2. The terpolymer composition was determined by the Kelen-Tüdos method. The values of reactivity ratios using r1 (Sty + VA) = 0.1 and r2 (AN) = 0.005. The overall activation energy is 46 kJ●mol●L–1. The formation of terpolymer is confirmed by the FTIR spectra showing bands at 3030 cm–1, 1598 cm–1, and 2362 cm–1, confirming the presence of phenyl, acetoxy and nitrile group respectively. The terpolymer has been characterized by 1H-Nuclear Magnetic Resonance, 13C-Nuclear Magnetic Resonance. The Differential Scanning Calorimetric curve shows the Tg of the polymer as 149.5°C. A scanning electron microscope confirms the polymer to be phosphorus free. Electron.Spin.Resonance spectra confirms phenyl radical responsible for initiation.

A NEW KIND OF SURFACTANT:LONG-CHAIN ALKYLTRIPHENYLPHOSPHONIUM HALIDES Ⅲ.AN“ABNORMAL”QUENCHING OF PYRENE FLUORESCENCE BY PHOSPHONIUMS WITH DIFFERENT LENGTHS OF ALKYL CHAIN

A study of the quenching of pyrene fluorescence by a series of alkyltriphenylphosphonium bromides indi- cated the coiling conformation of ionic surfactant in aqueous solution.Formation of pyrene excimer in cetyltriph- enylphosphonium solution strengthened the conclusion.

AN EFFICIENT SYNTHESIS OF PROPARGYLIC PHOSPHONIUM SALTS

Alkylated propargyl bromides react with phosphiaes in acidic tetrahydrofuran solution to give propargylic phosphonium salts in good yield.

Synthesis and Antibacterial Performance of Quaternary Phosphonium Salts with Reactive Hydroxyl Group

Quaternary phosphonium salts （QPS） with reactive groups used as antibacterial agents are promising which could be covalently linked to inert polymer surfaces by in situ polymerization. In this work, two kinds of quaternary phosphonium salts with hydroxyl groups were synthesized successfully. Characterization of these two quaternary phosphonium salts was performed by the Fourier transform infrared spectroscopy （FT-IR） and nuclear magnetic resonance （NMR） spectrometry. The thermal stability and antibacterial activity of antibacterial agents were also investigated by using thermo-gravimetric analysis, differential scanning calorimetry （TG-DSC） and agar diffusion method. The test results showed that these two QPS exhibited good thermal stability and excellent antibacterial activity against both bacteria： Staphylococcus aureus and Escherichia coll.

POLYMER-SUPPORTED SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS AS CATALYSTS FOR PHASE-TRANSFER REACTIONS

In this study was to investigate, by phase-transfer catalysis, the activity of single and mixed ammonium and phosphonium salts grafted on a 揼el-type?styrene-7% divinylbenzene copolymer in the oxidation of benzyl alcohol with hydrogen peroxide. A wide variety of catalysts with different quaternary groups and different quaternary chain length substituents were examined. The activity of single 搊nium?salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support. The activity of polymer-supported ammonium and phosphonium salts increases with the number of carbon atoms contained in the alkyl radicals of the onium and of the functionalization degree with phosphonium groups.

ANTIBACTERIAL ACTIVITY OF SINGLE AND MIXED AMMONIUM AND PHOSPHONIUM SALTS GRAFTED ON "GEL-TYPE" STYRENE-DIVINYLBENZENE COPOLYMERS

A systematic study on the synthesis and antibacterial activity of the quaternary "onium" salts grafted on an insoluble "gel-type" styrene-7% divinylbenzene copolymer by polymer-analogous reactions is showed. Antibacterial activity of quaternary ammonium and/or phosphonium salts grafted on polymer-supports has been studied against Staphylococcus aureus and Escherichia coli. A wide variety of "onium" salts bound to macromolecular supports with different quaternary groups and different quaternary chain length substituents were examined. The antibacterial activity of mixed "onium" salts increases as a consequence of the association of ammonium and phosphonium salts grafted on the same polymeric support.

Antibacterial performance of cationic quaternary phosphonium-modified chitosan polymer in water

Microbial contamination in water has emerged as a critical concern and thus developing biocide materials for controlling microbial contamination is crucial.Removing all pathogenic bacteria in water is difficult when using traditional water treatment technologies.Moreover,these bacteria can easily reproduce during pipeline distribution.In this work,a facile and effective chitosan derivative biocide denoted as PCC was developed by grafting with quaternary phosphonium salt(QPS).PCC became positively charged with a wide range of p H and demonstrated antibacterial activity up to 95%and 100%against Escherichia coli and Staphylococcus aureus as model pathogens,respectively.The grafting of QPS may disrupt the cell membrane and lead to bacterial inactivation,as demonstrated by the scanning electron microscopy image and the concentration of intracellular substance leakage.MTT assay results indicate that PCC achieved good biocompatibility with negligible in vitro cytotoxicity.These findings introduce a promising approach for bacterial decontamination due to its low cytotoxicity and high biocidal activity.

Chemoselective and Living/Controlled Polymerization of Alkenyl Methacrylates by the Phosphonium Ylide/Organoaluminum Lewis Pairs

Chemoselective,living/controlled polymerizations of allyl methacrylate(AMA) and vinyl methacrylate(VMA) with/without methyl methacrylate(MMA) by using the phosphonium ylide/organoaluminum based Lewis pairs(LPs) have been realized.The P-ylide-2/AIMe(BHT)_(2)(Pylide-2=Ph_(3)P=CHMe and BHT=2,6-iBu_(2)-4-MeC_(6)H_(2)O) was demonstrated to be superior by which homopolymers PAMAs(M_(n)=27.6-111.5kg/mol and ■=1.14-1.25) and PVMAs(M_(n)=28.4-78.4 kg/mol and ■=1.12-1.18) and block copolymers PMMA-b-PAMA,PAMA-b-PVMA,PAMA-bPMMA,PMMA-b-PAMA-b-PMMA,PAMA-b-PMMA-b-PAMA,and PAMA-b-PVMA-b-PAMA were synthesized.In the polymerizations,all of the monomers were reacted by the conjugated ester vinyl groups leaving intactly the nonconjugated acryloxy groups.The pendant acryloxy groups attached to the main chain enable further to post-functionalization by the AIBN-induced radical "thiol-ene" reaction using PhCH_(2)SH.The thiolether side group-containing polymers PAMA-SCH_(2)Ph and PAMA-SCH_(2)Ph-b-PMMA-b-PAMA-SCH_(2)Ph were thus prepared.

Charge transfer complex enabled photoreduction of ether phosphonium salts for the selective oxyalkylation of enamides

A charge transfer complex(CTC)-enabled photoreduction of ether phosphonium salts for the generation of oxyalkyl radicals was described.The photoreduction provides a convenient method to achieve selective oxyalkylation of enamides with broad substrate scope.The method features operational simplicity,mild and inherent green conditions.

Access to Enantioenriched Allylic Alcohols via Peptide-Mimic Phosphonium Salt-Catalyzed Asymmetric Aerobic Hydroxylation

The development of catalytic asymmetric methods that enable access to value-added functionalities or structures,exemplified by allylic alcohols,is a highly interesting yet challenging topic from both academic and industrial perspectives.However,before recent advances in chemical catalysis,there were scarce protocols toward constructing enantioenriched tertiary allylic alcohol scaffolds.In this context,peptide-mimic phosphonium salts were found to be highly efficient in catalytic asymmetricα-hydroxylation ofα,β-unsaturated and/orβ,Y-unsaturated compounds with satisfactory regio-and stereochemical outcomes(up to 97%yield and 95%ee).This methodology tolerates a broad array of substrates and thus provides an expeditious and unified platform for the assembly of enantioenriched tertiary allylic alcohols by avoiding the use of additional reductants and expensive metal catalysts.Furthermore,the power of this protocol is enlarged by simple conditions and the use of air as a source of hydroxyl functionality.

Effects of tetrakis (hydroxymethyl) phosphonium sulfate pretreatment on characteristics of sewage sludge

Recently, tetrakis(hydroxymethyl)phosphonium sulfate(THPS) was found to play an important role in the sludge pretreatment process. However, the effects of THPS pretreatment on the characteristics of sewage sludge are still insufficiently understood.The properties of sludge after pretreatment with different concentrations of THPS were investigated in this study. The results showed that pH, dewatering ability, and particle size of sludge decreased with increase in THPS concentration. The volatile suspended solids(VSS) and total suspended solids(TSS) of sludge also decreased slightly with increase in THPS concentration. The specific oxygen uptake rate(SOUR) results suggested that lower THPS concentrations(≤ 1.87 mg/g VSS) enhanced the activity of sludge, but higher concentrations(≥ 1.87 mg/g VSS) inhibited it. Gram-negative bacteria with peritrichous flagellation(such as Pseudomonas, Escherichia, and Faecalibacterium) were extremely sensitive to THPS. The decrease in specific most probable numbers(MPNs) of pathogens(total coliforms and Escherichia coli) with the increase in THPS concentration also proved the sterilization ability of THPS in the sludge pretreatment process. Pretreatment of sludge with concentrations of THPS higher than 37.41 mg/g VSS would meet the pathogen requirements for land application of Class A biosolids.

Poly(aryl ether nitrile)s containing flexible side-chain-type quaternary phosphonium cations as anion exchange membranes

In order to effectively improve the properties of anion exchange membrane(AEM)materials,a series of novel poly(aryl ether nitrile)s with flexible side-chain-type quaternary phosphonium cations(PAEN-TPP-x)were designed and prepared on the basis of considering the influences of polymer backbone,cationic group species and the connection way between the cations and polymer chains.The synthetic method,structure and ion-exchange capacity,water absorption,swelling,hydroxide conductivity and alkaline stability of the obtained AEMs were studied.A comparative study with other reported AEMs was also performed for further exploration of the relationship between the structure and properties.These AEMs with flexible side-chain-type quaternary phosphonium cations displayed good comprehensive properties.Their water uptakes and swelling ratios were in the range of 11.6%–22.7%and 4.4%–7.8%at 60℃,respectively.They had hydroxide conductivity in the range of 28.6–45.8 mS cm^-1 at 60℃.Moreover,these AEMs also exhibited improved alkaline stability,and the hydroxide conductivity for PAEN-TPP-0.35 could remain 82.1%and 80.6%of its initial value at 60 and 90℃in 2 mol L^-1 NaOH solution for480 h,respectively.