thus , the invention relates to an oxidation reaction of an organic compound performed in the presence of a formula i salt , as the catalyst . preferred salts of the formula i are those in which substituents r 1 are hydrogen and n = 1 . when a = 3 and b = 0 , l is preferably a ligand of the formula ii . preferred salts of the formula i are also those in which a = 1 and b = 2 and l is a ligand of the formula iii . in the case of salts of the formula i in which l is a ligand of the formula ii , r is preferably c 1 - c 4 - alkyl , more preferably methyl . suitable anions a are f - , cl - , br - , i - , no 3 - , clo 4 - , ncs - , pf 6 - , rso 3 - , rso 4 - , so 4 2 - , bph 4 - , and also anions of organic compounds , e . g ., aliphatic and aromatic alcohols and carboxylic acids such as tosylate , acetate and benzoate . in general as to anions compounds such as aliphatic and aromatic carboxylic acids , reference is made to streitweiser & amp ; heathcock , introduction to organic chemistry ( 1976 ), e . g ., chapter 17 , app . iv ; any of the anions disclosed therein can be used in the invention . preferred anions are pf 6 - , clo 4 - , tosylate , acetate and benzoate . the ligands of the formula iii present in the manganese complex salts of the invention are prepared , for example , by reacting 2 -( chloromethyl )- pyridinium chloride with ethylenediamine in the presence of a phase transfer catalyst ( see synthesis , june 1992 , pp . 539 - 540 ) or in an analogous manner for the substituted other ligands of the formula iii . in a similar manner , the ligands of the formula ii are prepared by reacting 2 -( chloromethyl ) pyridinium chloride or analogous pyridinium compounds with an amine r -- nh 2 . the manganese complex salts of the invention having the formula i are prepared by the method described in inorg . chem . 1989 , 28 , 3606 - 3608 , by oxidizing an aqueous solution containing mncl 2 and the ligand with h 2 o 2 or by a method similar to the process described in inorg . chem . 1994 , 33 , 4105 - 4111 , in which the oxidation is carried out using ammonium peroxodisulfate . accordingly , the method for preparing a formula i salt can comprise oxidizing a solution containing mn 2 + and l . the oxidizing can be with a peroxide or peroxidisulfate , and the peroxide can be h 2 o 2 or the peroxidisulfate can be ammonium peroxodisulfate . the solution can be an aqueous solution . and , the mn 2 + can be in the form of mnay , such as mncl 2 . according to the invention , the resulting manganese complex salts of the formula i are used as catalysts for the oxidation of organic compounds . the organic compounds in the oxidation reaction may be any organic compounds ; however , compounds having at least one electron dense bond , e . g ., at least one double or triple carbon - carbon bond are preferred ; for instance , at least one unsaturated bond , such as an alkene or alkyne . more preferably , the reaction employing the formula i salt is an oxidation of a vinyl compound of the formula r -- ch ═ ch 2 , where r is an aromatic radical , preferably phenyl , or c 1 - c 10 - alkyl , which may be unsubstituted or substituted , e . g ., by a halogen such as f , cl , i , br , oh , or 2 , cn , nh 2 , nhr 2 , n ( r 2 ) ( where r 2 is as defined above ), or the like . thus , the organic compound to be oxidized in the presence of the formula i salt as a catalyst can be a styrene or substituted styrene . the following non - limiting examples are given by way of illustration only and are not to be considered a limitation of this invention . 1 . 74 g ( 8 . 8 mmol ) of mncl 2 . 4h 2 o , 1 . 88 g ( 8 . 8 mmol ) of n , n - bis ( 2 - pyridylmethyl )- n - methylamine and 1 . 75 g ( 9 . 5 mmol ) of kpf 6 were dissolved in 600 ml of a mixture of ethanol and water ( 2 : 1 ). the solution was stirred for 20 minutes at room temperature and then cooled in an ice bath to 5 ° c . 10 ml of h 2 o 2 ( 3 % strength ) and 2 . 6 ml of a 20 % strength aqueous naoh solution were added , with the temperature rising to 10 ° c . and a precipitate being formed . this mixture was stirred for 1 hour at 5 ° c . and one further hour at 20 ° c . the precipitate was filtered off and washed with water . crude yield : 6 . 1 g . after drying , the solid was treated with acetone to leave mno 2 as solid . the acetone solution was filtered from the insoluble mno 2 and the acetone was distilled off . this gave 1 . 25 g of a gray - green solid . ______________________________________calc . : c 40 . 9 % h 3 . 8 % n 10 . 9 % found : c 39 . 5 % h 3 . 6 % n 10 . 4 % ______________________________________ a mixture of 25 . 5 ml of ethanol and 4 . 5 ml of water was degassed by applying a vacuum three times and was then treated with argon in order to remove all residual oxygen which would otherwise oxidize mn ( ii ) to mn ( iv ). to this mixture was added 2 . 47 g ( 5 . 82 mmol ) of n , n , n &# 39 ;, n &# 39 ;- tetrakis ( 2 - pyridylmethyl ) ethylenediamine . this gave a yellow solution having a ph of 8 . 8 . 0 . 96 g ( 3 . 6 mmol ) of manganese triacetate ( mn ( oac ) 3 . 3h 2 o ) was then added . the solution became brown and had a ph of 6 . 2 . subsequently , 2 g ( 14 . 58 mmol ) of sodium acetate was added ( ph 6 . 5 ), then perchloric acid ( 55 drops ) to a ph of 5 was added . after addition of 3 g ( 24 . 48 mmol ) of sodium perchlorate , a precipitate was formed at ph 6 . 1 . this reaction mixture was left for 4 hours . the precipitated crystals were filtered off under nitrogen . this gave 3 . 08 g of crude product of the compound ( μ - oxo )- bis -( μ - acetato )- bis [ n , n , n &# 39 ;, n &# 39 ;-( 2 - pyridylmethyl ) ethylenediamine ] dimanganese -( iii , iii ) perchlorate . 1 . 15 g ( 0 . 823 mmol ) of this compound was dissolved in 40 ml of a 1 : 1 mixture of ethanol and water . after half an hour , 4 ml of triethylamine was added . the ph of the reaction mixture was 11 . 3 . 89 g ( 21 . 12 mmol ) of kpf 6 was then added . after 15 minutes , the reaction mixture was filtered to remove insoluble manganese dioxide . the solvent was distilled from the filtrate and the residue was treated with acetone in order to remove residual amounts of manganese dioxide , since the desired complex salt is readily soluble in acetone , unlike manganese dioxide . after separating off the manganese dioxide , the acetone was removed by distillation . this gave the title compound in the form of a white powder . 2 . 47 g ( 5 . 82 mmol ) of n , n , n &# 39 ;, n &# 39 ;- tetrakis ( 2 - pyridylmethyl )- 1 , 2 - ethylenediamine was dissolved in 30 ml of a mixture of ethanol and water ( 5 : 1 ) and then mn ( oac ) 3 . 2h 2 o ( 0 . 96 g ; 3 . 6 mmol ) was added thereto . subsequently , 2 . 2 g ( 20 mmol ) of sodium butyrate were added and then 2 ml of hclo 4 ( 70 % strength ). a ph of 7 . 5 was established . 3 g ( 24 . 48 mmol ) of naclo 4 was then added and this mixture was stirred for 4 hours at room temperature . a precipitate was formed and this was filtered off , washed with an ethanol / water mixture ( 85 % of etoh / 15 % of h 2 o ) and dried . crude yield : 2 . 3 g . the solid was treated with 70 ml of acetone and the acetone solution was filtered from the insoluble inorganic salts . distilling off the acetone and recrystallization from ethanol / water ( 5 : 1 ) gave the above - mentioned complex salt . ______________________________________calc . : mn 7 . 5 % c 49 . 17 % h 4 . 95 % n 11 . 47 % found : mn 8 . 0 % c 44 . 8 % h 4 . 5 % n 12 . 1 % ______________________________________ 0 . 425 g ( 1 mmol ) of n , n , n &# 39 ;, n &# 39 ;- tetrakis ( 2 - pyridylmethyl )- 1 , 2 - ethylenediamine and 0 . 198 g ( 1 mmol ) of mncl 2 . 4h 2 o were dissolved in 6 ml of water . the solution was stirred for 30 minutes at room temperature . 4 drops of h 2 o 2 were then added and the mixture was stirred for one hour at room temperature . subsequently , 0 . 13 g ( 1 mmol ) of naclo 4 was added and the mixture was stirred for 3 . 5 hours at room temperature . the precipitated manganese complex salt was filtered off and washed with a 1 molar solution of naclo 4 ______________________________________calc . : mn 8 . 4 % c 47 . 77 % h 4 . 47 % cl 8 . 14 % n 12 . 86 % found : mn 8 . 4 % c 45 . 1 % h 4 . 3 % cl 8 . 6 % n 11 . 9 % ______________________________________ the ligand n , n , n &# 39 ;, n &# 39 ;- tetrakis ( 2 - pyridylmethyl ) ethylenediamine used in the above examples was prepared as described in synthesis , 1992 , p . 539 . a mixture of 4 . 6 g ( 10 . 5 mmol ) of n , n , n &# 39 ;, n &# 39 ;- tetrakis -( 2 - pyridylmethyl )- 1 , 2 - ethylenediamine and 1 . 98 g of mncl 2 - 4h 2 o was stirred for one hour in 15 ml ( 1 . 5 mmol ) of 0 . 1 m hcl . the water was then distilled off and a solution of 7 . 5 g ( 32 . 8 mmol ) of ( nh 4 ) 2 so 8 in 20 ml of water was added . this mixture was stirred for one hour at room temperature . a precipitate was formed and this was filtered off and washed with water . drying under reduced pressure gave 7 . 9 g of the crude product . this crude product was treated with 100 ml of acetone for 30 minutes . the manganese dioxide remaining as a solid was filtered off and the acetone solution was evaporated under reduced pressure . drying under reduced pressure gave 6 . 30 g of the abovementioned manganese complex salt . ______________________________________calc : mn 8 . 47 %; c 48 . 15 %; h 4 . 5 %; n 12 . 96 % found : mn 8 . 1 %; c 43 . 9 %; h 3 . 7 %; n 11 . 9 %. ______________________________________ 0 . 0178 g ( 0 . 02 mmol ) of the complex salt as described in preparative example 1 was added to a mixture of 0 . 208 g ( 2 mmol ) of styrene in 20 ml of ch 2 cl 2 and 1 . 68 g ( 20 mmol ) of sodium hydrogen carbonate in 20 ml of water . after a reaction time at room temperature of 10 minutes , 20 ml of h 2 o 2 ( 30 % strength ) was added slowly over a period of 2 . 5 hours , with the temperature rising to 28 ° c . after a further 22 hours , the reaction was complete . the layers were separated and the organic phase was evaporated under reduced pressure . the product obtained was purified by column chromatography giving styrene oxide in a yield of 54 % based on styrene . 2 mmol of 3 - chlorostyrene in 20 ml of ch 2 cl 2 was oxidized in the presence of 0 . 0178 g ( 0 . 02 mmol ) of the complex salt as described in preparative example 1 and 1 . 68 g ( 20 mmol ) of sodium hydrogen carbonate using a method similar to that in use example 1 . this gave 3 - chlorostyrene oxide in a yield of 49 % based on 3 - chlorostyrene . 0 . 0178 g ( 0 . 02 mmol ) of the complex salt described in preparative example 1 was added to a mixture of 0 . 208 g ( 2 mmol ) of styrene in 20 ml of ch 2 cl 2 and 1 . 68 g ( 20 mmol ) of sodium hydrogen carbonate in 20 ml of water . after a reaction time at room temperature of 10 minutes , 1 . 5 g ( 20 mmol ) of naocl was added slowly over a period of 15 minutes , with the temperature rising to 28 ° c . after a further 6 hours , the reaction was complete . the layers were separated and the organic phase was evaporated under reduced pressure . the product obtained was purified by column chromatography . this gave 1 - chloro - 2 - phenylethanol in a yield of 40 % based on styrene . a mixture of 0 . 208 g of styrene ( 2 mmol ) in 10 ml of ch 2 cl 2 and 1 . 68 g ( 20 mmol ) of sodium hydrogen carbonate in 20 ml of water together with 0 . 026 g ( 0 . 02 mmol ) of the complex salt described in preparative example 5 was stirred for 10 minutes at room temperature . 20 ml ( 200 mmol ) of h 2 o 2 ( 30 % strength ) was added slowly over a period of 2 . 5 hours , with the temperature rising to 28 ° c . the reaction mixture was stirred for a further 22 hours and the organic phase was then separated from the aqueous phase . the organic phase was evaporated under reduced pressure and the residue was purified by column chromatography . this gave styrene oxide in a yield of 49 . 6 %. a mixture of 0 . 208 g of styrene in 2 ml of methanol and 40 ml of an aqueous solution of sodium carbonate was stirred together with 0 . 26 g ( 0 . 2 mmol ) of the complex salt described in preparative example 5 for 10 minutes at room temperature . the amount of sodium carbonate was such that the ph of the reaction mixture was 6 . 5 . 20 ml ( 200 mmol ) of h 2 o 2 ( 30 % strength ) was then added slowly over a period of 5 hours , with the temperature rising to 28 ° c . the reaction mixture was stirred for a further 24 hours and the aqueous phase was then separated from the organic phase . the organic phase was evaporated under reduced pressure and the residue was purified by column chromatography . this gave benzaldehyde in a yield of 48 %. having thus described in detail preferred embodiments of the present invention , it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope thereof .