May 3, 2012  15  US 2012/0108878 Al  [0156]  Polar-protic solvents are favorable for SN! nucleo› philic reactions, while polar aprotic solvents are favorable for  SN2 nucleophilic reactions. In an SN2 reaction, the addition of  a nucleophile and the elimination of a leaving group take  place simultaneously. SN2 reactions can occur when the cen› tral carbon atom is easily accessible to the nucleophile. In  contrast, an SN! reaction involves two steps. SN! reactions  tend to be important when the central carbon atom of the  substrate is surrounded by bulky groups, because such groups  interfere sterically with the SN2 reaction and a highly substi› tuted carbon forms a stable carbocation. Apart from solvent  effects, polar aprotic solvents may also be essential for reac› tions which use strong bases, such as reactions involving  Grignard reagents or n-butyllithium.  If a protic solvent were  to be used, the reagent would be consumed by a side reaction  with the solvent.  [0157]  The organic/aqueous solutions of the present inven› tion comprise one or more organic solvents selected from four  ( 4) separate groups consisting of:  [0162]  Hybrid solvents that have the properties of two or  more groups are included within the scope of the present  invention. Exemplary hybrid solvents include 2-butoxyetha› nol, cyanocarboxylic acids, butanoic acid, and ethyl acetate.  The organic/aqueous solutions of the present invention are  further restricted to solvent mixtures wherein the volume  fraction of water in the solution ranges from about 25% to  about 75%, and the final pH of the solution is less than or  equal to about 8.5. Alternatively, the pH can be maintained at  less than or equal to about 8.0. The invention is active against  all agents as pH values between about 7.0 to about 10.5; the  buffer capacity is more effective at pH values between about  8.0 to about 9.0. However, for maximum active life, the pre› ferred embodiment is maintained a pH values from about 8.0  to about 8.5. The pH can further be maintained at a pH of  about 8.5.  [0163]  Exemplary solutions include the alkanediol/water  solutions, comprising one of the isomers of propanediol,  butanediol, or pentanediol, and solutions made from linear  monoprotic alkanols, such as ethanol or butanol or a hybrid of  two solvent types such as 2-butoxyethanol. The linear or  branched-chain monoprotic alkanols can have from 1 to at  least 15 carbons. Additional properties of the organic/aque› ous solutions of the present invention should preferably  include:  [0169]  Decontamination solutions of the present invention  may be effectively deployed in neutralizing toxants over a  temperature range ofbetween about -25°  F. and about 140°  F.  Preferably, the decontamination solutions may be deployed  and dispersed as aerosolized sprays over the range of tem› peratures of between about -25°  F. and about 140°  F. Other  embodiments within the scope of the invention include  decontaminants with improved hydrolytic activity at about  -25°  F., but which do not rapidly evaporate at temperatures as  high as about 125°  F. Rapid evaporation would limit the  effectiveness of the decontamination solution and thus should  be avoided, if possible. The solutions may also be applied  directly to a surface by pouring or otherwise applying the  solution to the surface. The working temperature range for  decontamination can be adjusted by selection of the type and  relative amounts of polar amphipathic solvents in organic/  aqueous solutions according to the total amount of peroxy› oxidant can vary according to the embodiments of the inven› tion. One skilled in the art having the present specification as  their guide would know that the solutions made using  polyprotic acids, such as the Group IV solvents, will have an  entirely different buffering capacity as compared to solutions  which comprise monoprotic solvents from Group II. Simi› larly, it will be known to one skilled in the art having the  present specification as their guide that all equilibrium con› stants vary with temperature according to the van’t Hoff equa› tion, and that some solvents will be more likely to promote  ionization of a dissolved acidic molecule if the organic/aque› ous solution comprises:  [0173]  Dimtheylsulfoxide (DMSO) has a lower dielectric  constant than water, is less polar, dissolves non-polar, hydro› phobic substances more readily, and has a measurable  pKa  range of about 1 to 30. Acetonitrile is less basic than DMSO.  Also, acids are generally weaker and bases are generally  stronger in this solvent. Some  pKa  values at 25°  C. for aceto› nitrile and dimethyl sulfoxide (DMSO) are shown in the Table  5, where values for water are included for comparison.  [0164]  the ability to dissolve, as a single isotropic solu› tions, full threat loads ofCBW toxants, where a chemi› cal threat load is 10 mg/m$^{2 }$or 10 mg/m$^{3 }$and a biological  threat load is 10 $^{8 }$particles ( cfu or pfu) per mL;  [0165]  the capacity to dissolve sufficient amounts of  polar perhydrolysis agents to enable stoichiometric per› hydrolysis of the dissolved toxant threat load;  [0158]  Polar, aprotic solvents that do not contain oxygen  but have large dipole moments, such as nitriles, haloal› kanes, and amides;  [0159]  polar, monoprotic solvents that contain one (1)  --OH moiety, and have large dipole moments, such as  the linear or branched-chain alcohols;  [0160]  polar, aprotic solvents that contain oxygen but to  not have an acidic proton, such as ketones, aldehydes,  ethers, furans, and dioxins; and  [0161]  polar, polyprotic solvents ( collectively, "poly› ols") that contain two or more -OH moieties, and have  large dipole moments, such as the dials, trials and higher  order polyols.  [0166]  a low fluid viscosity over the temperature range  -25°  F.~T~125°  F.;  [0167]  a low vapor pressure and a high Flash Point at  temperatures >140°  F.; and  [0168]  the ability to be sprayed onto a contaminated  surface without having the composition of the decon› taminant solution change.  [0170]  a protic organic solvent, capable of forming  hydrogen bonds;  [0171]  a solvent with a high donor number, making it a  strong Lewis base; and/or  [0172]  a solvent with a high dielectric constant, making  it a good solvent for ionic species.  TABLES  pKa  values of acids in Group I (acetonitrile),  Group III (DMSO) and Group II solvents  Water  Acetonitrile  DMSO  (for comparison)  HAA-+H•  p-Toluenesulfonic  8.5  0.9  strong  acid  2,4-Dinitrophenol  16.66  5.1  3.9  Benzoic acid  21.51  11.1  4.2  Acetic acid  23.51  12.6  4.756  Phenol  29.14  18.0  9.99 