Hole transporting material obtained by reacting: - at least one heteropoly acid containing at least one transition metal belonging to group 5 or 6 of the Periodic Table of the Elements; with - an equivalent amount of at least one salt or one complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand; in the presence of at least one organic solvent selected from alcohols, ketones, esters; characterized in that said at least one salt or a complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand, is selected from: bis(acetylacetonato)dioxomolybdenum (Cas No. 17524-05-9), molybdenum dioxide bis(2,2,6,6-tetramethyl-3,5-heptanedionate) (Cas No. 34872-98-5), bis(tert-butylimido)(bis)(dimethylamino)molybdenum (Cas No. 923956-62-1), 2,6-di-iso-propylphenylimido-neophilidene molybdenum bis(tert-butoxide) (Cas No. 126949-65-3), 2,6-di-iso-propylphenylimidoneophilidene molybdenum bis(hexafluoro-tert-butoxide) ("Schrock's catalyst") (Cas No. 139220-25-0), adduct of 2,6-di-iso-propylphenylimidoneophylidene molybdenum bis(trifluoromethanesulfonate)-dimethoxyethane (Cas No. 126949-63-1), 2,6-di-iso-propylphenylimidoneophylidene-[racemic-BIPHEN] molybdenum ("rac-Schrock's-Hoveyda catalyst") (Cas No. 300344-02-9), 2,6-di-iso-propylphenylimidoneophylidene[R-(+)-BIPHEN]molybdenum [" Schrock's-Hoveyda catalyst"] (Cas No. 329735-77-5), 2,6-di-iso-propylphenylimidoneophylidene [S-(-)BIPHEN]molybdenum [" Schrock's-Hoveyda catalyst"] (Cas No. 205815-80-1), vanadium oxytriisopropoxide (Cas No. 5588-84-1), vanadium oxide acetylacetonate (Cas No. 3153-26-2), acetylacetonate of vanadium, tetrakis(dimethylamino)vanadium (Cas No. 19824-56-7), tetrakis (diethylamino)vanadium (Cas No. 219852-96-7), or mixtures thereof, preferably from bis(acetylacetonato)dioxomolybdenum (Cas No. 17524-05-9), vanadium oxytriisopropoxide (Cas No. 5588-84-1), vanadium oxide acetylacetonate (Cas No. 3153-26-2). - at least one heteropoly acid containing at least one transition metal belonging to group 5 or 6 of the Periodic Table of the Elements; with - an equivalent amount of at least one salt or one complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand; in the presence of at least one organic solvent selected from alcohols, ketones, esters; characterized in that said at least one salt or a complex of a transition metal belonging to group 5 or 6 of the Periodic Table of the Elements with an organic anion, or with an organic ligand, is selected from: bis(acetylacetonato)dioxomolybdenum (Cas No. 17524-05-9), molybdenum dioxide bis(2,2,6,6-tetramethyl-3,5-heptanedionate) (Cas No. 34872-98-5), bis(tert-butylimido)(bis)(dimethylamino)molybdenum (Cas No. 923956-62-1), 2,6-di-iso-propylphenylimido-neophilidene molybdenum bis(tert-butoxide) (Cas No. 126949-65-3), 2,6-di-iso-propylphenylimidoneophilidene molybdenum bis(hexafluoro-tert-butoxide) ("Schrock's catalyst") (Cas No. 139220-25-0), adduct of 2,6-di-iso-propylphenylimidoneophylidene molybdenum bis(trifluoromethanesulfonate)-dimethoxyethane (Cas No. 126949-63-1), 2,6-di-iso-propylphenylimidoneophylidene-[racemic-BIPHEN] molybdenum ("rac-Schrock's-Hoveyda catalyst") (Cas No. 300344-02-9), 2,6-di-iso-propylphenylimidoneophylidene[R-(+)-BIPHEN]molybdenum [" Schrock's-Hoveyda catalyst"] (Cas No. 329735-77-5), 2,6-di-iso-propylphenylimidoneophylidene [S-(-)BIPHEN]molybdenum [" Schrock's-Hoveyda catalyst"] (Cas No. 205815-80-1), vanadium oxytriisopropoxide (Cas No. 5588-84-1), vanadium oxide acetylacetonate (Cas No. 3153-26-2), acetylacetonate of vanadium, tetrakis(dimethylamino)vanadium (Cas No. 19824-56-7), tetrakis (diethylamino)vanadium (Cas No. 219852-96-7), or mixtures thereof, preferably from bis(acetylacetonato)dioxomolybdenum (Cas No. 17524-05-9), vanadium oxytriisopropoxide (Cas No. 5588-84-1), vanadium oxide acetylacetonate (Cas No. 3153-26-2).