TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preparation (Claimed): Preparation of (I) comprises: either metathesis reaction of ion between salt of formula (Q+A-) (IV) and thiophosphate of formula ((R1aO-P(-OR1b)(=O)-S-)(1/nM(n+))) or ((R1aO-P(-OR1b)(=S)-O-)(1/nM(n+))) to give (I); or reacting the salt (IV) and an acid compound of formula (R1aO-P(-OR1b)(=O)-SH) (V) or (R1aO-P(-OR1b)(=S)-OH) (VI) to give (I).A- = organic or inorganic anion, preferably chloride, bromide, iodide, nitrate, formate, acetate, alkyl carbonate, acetate, formate or hydroxide anion;Mn+ = alkali metal cation or alkaline earth metal cation; andn = 1 or 2, preferably lithium, sodium, potassium, magnesium or calcium cation.Preferred Process: The reaction of (IV) with the acid (V) or (VI) is carried out at -78 degrees C to 150 degrees C, preferably -20 degrees C to 80 degrees C in air or under inert gas atmosphere, in the absence of solvent or an organic solvent. Preferred Components: The organic cation (Q+) is quaternary ammonium, phosphonium, guanidinium and/or sulfonium cation. The guanidinium cation has the structure of formula (C(NR1R2)(NR3R4)(NR5R6)+). The sulfonium cation has the structure of formula (SR1R2R3+). The quaternary ammonium cation has the structure of formula (NR1R2R3R4+), (R1R2N=CR3R4+) or (R1R2N+=CR3-R7-R3C=N+R1R2). The phosphonium cation has the structure of formula (PR1R2R3R4+), (R1R2P=CR3R4+) or (R1R2P+=CR3-R7-R3C=P+R1R2). The quaternary ammonium cations and/or phosphonium cations are derived from nitrogen containing heterocycle compound of formula (a) or (b) and/or phosphorus containing heterocycle compound of formula (c) or (d) having 1, 2 or 3 nitrogen atoms and/or phosphorus atoms. (I) is a mixture of cations and anions. The solvent is hydrocarbons such as pentane, hexane, heptane or cyclohexane; aromatic solvents such as benzene, toluene, and xylene; chlorinated solvents such as chloroform or dichloromethane; oxygenated solvents such as diethyl ether, tetrahydrofuran (THF), methyl-THF, dioxane or dimethoxyethane; and nitrogenated solvents such as acetonitrile, dimethylformamide, N-methyl-2-pyrrolidone or pyridine.R1-R6 = optionally substituted 1-30C hydrocarbyl group, preferably optionally saturated alkyl groups, cycloalkyl or aromatic groups, aryl or aralkyl groups, where the hydrocarbyl group optionally carries one or more -CO2R, -C(O)R, -OR, -C(O)NRRaa, -C(O)N(R)NRaaRbb,-NRRaa, -SR, -S(O)R, -S(O)2R, -SO3R, -CN, -N(R)P(O)RaaRaa, -PRRaa-, -P(O)RRaa, -P(OR)(ORaa), or -P(O)(OR)(ORaa); andR7 = alkylene, preferably methylene, ethylene, propylene or phenylene group. SPECIFIC COMPOUNDS - 15 Compounds (I) are specifically claimed e.g. allyl-3-methyl-1-imidazolium diethylthiophosphate of formula (Ia), vinyl-3-methyl-1-imidazolium diethylthiophosphate, ethyl-3-methyl-1-imidazolium diethylthiophosphate, butyl-3-methyl-1-imidazolium diethylthiophosphate, and allyl-3-methyl-1-imidazolium diphenylthiophosphate.    EXAMPLE - Sodium diethylthiophosphate (20.96 g) was added to a solution of allyl-3-methyl-1-imidazolium chloride (15.64 g) in anhydrous dichloromethane (150 ml) under argon atmosphere. The suspension was stirred for 2 hours at room temperature. Then, diethyl ether (20 ml) was added and the solution was filtered. The filtrate was then evaporated under vacuum to obtain an orange-brown liquid of allyl-3-methyl-1-imidazolium diethylthiophosphate (26.06 g, 90%).