Abstract: A process is described for the preparation of a compound having the formula: ##STR1## wherein Mn is manganese in a III or IV oxidation state; X is independently selected from a coordinating or bridging species selected from the group consisting of:H.sub.2 O, O.sub.2.sup.2-, O.sub.2-, OH.sup.-, HO.sub.2.sup.-, SH.sup.-, S.sup.2-, SO, Cl.sup.-, N.sub.3.sup.-, SCN.sup.-, N.sup.3-, HCOO.sup.-, NH.sub.2.sup.- and NH.sub.3 ;L is an organic ligand that is at least a nine-membered ring wherein at least two nitrogen atoms form part of the ring and coordinate with the Mn;z is an integer ranging from -4 to +4;Y is a monovalent or multivalent counterion leading to charge neutrality selected from the group consisting of halides, sulphates, sulphonates, nitrates, boron and phosphorus salt counterions; andq is an integer from 1 to 4;the process comprising the steps of:(i) reacting in an aqueous medium a manganese (II) salt with the ligand L to form a manganese coordinated substance, a counterion salt M.sub.z Y.sub.

Abstract: A process is described for the preparation of a manganese complex catalyst having the formula: ##STR1## wherein Mn is manganese in a III or IV oxidation state;X is independently selected from a coordinating or bridging species selected from the group consisting of: H.sub.2 O, O.sub.2.sup.2-, O.sup.2-, OH.sup.-, HO.sub.2.sup.-, SH.sup.-, S.sup.2-, >SO, Cl.sup.-, N.sub.3.sup.-, SCN.sup.-, N.sup.3-, RCOO.sup.-, NH.sub.2.sup.- and NR.sub.3 ;R is a radical selected from the group consisting of H, alkyl and aryl radicals;L is an organic ligand containing at least two nitrogen atoms that coordinate with the Mn;z is an integer ranging from -4 to +4;Y is a monovalent or multivalent counterion leading to charge neutrality; andq is an integer from 1 to 4;the process comprising the steps of:(i) reacting in an aqueous medium a manganese (II) salt with the ligand L to form a manganese coordinated substance, a counterion salt M.sub.z Y.sub.