Ligand and complex for catalytically bleaching a substrate

Abstract

The invention relates to catalytically bleaching substrates, especially laundry fabrics, with atmospheric oxygen or air. A method of bleaching a substrate is provided that comprises applying to the substrate, in an aqueous medium, a specified ligand from a selected class which forms a complex with a transition metal, the complex catalysing bleaching of the substrate by atmospheric oxygen. Also provided is an aqueous bleaching composition substantially devoid of peroxygen bleach or a peroxy-based or -generating bleach system.

1 . A monomer ligand or transition metal catalyst thereof of a ligand having the formula (I):  
       
         
           
           
               
               
           
         
       
       wherein each R is independently selected from: hydrogen, F, Cl, Br, hydroxyl, C1-C4-alkylO-, —NH—CO—H, —NH—CO-C1-C4-alkyl, —NH2, —NH-C1-C4-alkyl, and C1-C4-alkyl; 
 R1 and R2 are independently selected from:  
 C1-C4-alkyl,  
 C6-C10-aryl, and,  
 a group containing a heteroatom capable of coordinating to a transition metal, wherein at least one of R1 and R2 is the group containing the heteroatom;  
 R3 and R4 are independently selected from hydrogen, C1-C8 alkyl, C1-C8-alkyl-O-C1-C8-alkyl, C1-C8-alkyl-O-C6-C10-aryl, C6-C10-aryl, C1-C8-hydroxyalkyl, and —(CH2) n C(O)OR5  
 wherein R5 is independently selected from: hydrogen, C1-C6-alkyl, n is from 0 to 4, and mixtures thereof; and,  
 X is selected from C═O, —[C(R6) 2 ] y — wherein Y is from 0 to 3 and each R6 is independently selected from hydrogen, hydroxyl, C1-C4-alkoxy and C1-C4-alkyl; and with the proviso that the following compounds are excluded: dimethyl 2,4-di-(2-pyridyl)-3,7-bis-(pyridin-2-ylmethyl)-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate; 1,5-bis-(hydroxymethylene)-2,4-di-(2-pyridyl)-3,7-bis-(pyridin-2-ylmethyl)-3,7-diazabicyclo[3.3.1]nonan-9-ol; dimethyl 2,4-di-(2-pyridyl)-3,7-bis-(pyridin-2-ylethyl)-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate; dimethyl 2,4-di-(2-pyridyl)-3-(5-carboxypentyl)-7-methyl-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate; dimethyl 2,4-di-(2-pyridyl)-3-(2-methoxyethyl)-7-methyl-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate; diethyl-2,4-dipyridyl-7-picolyl-3,7-diaza-bicyclo-[3.3.1]-nonan-9-one-1,5-dicarboxylate; diethyl-2,4-dipyridyl-7-benzyl-3-hydroxyethyl-3,7-diaza-bicyclo-[3.3.1]-nonan-9-one-1,5-dicarboxylate; and, dimethyl-2,4-dipyridyl-7-benzyl-3-hydroxyethyl-3,7-diaza-bicyclo-[3.3.1]-nonan-9-one-1,5-dicarboxylate.  
 
     
     
         2 . A ligand or catalyst according to  claim 1 , wherein R1 and R2 are both selected from a group containing a heteroatom capable of coordinating to a transition metal.  
     
     
         3 . A ligand or catalyst according to  claim 1 , wherein the group containing the heteroatom is: 
 a heterocycloalkyl: selected from the group consisting of: pyrrolinyl; pyrrolidinyl; morpholinyl; piperidinyl; piperazinyl; hexamethylene imine; 1,4-piperazinyl; tetrahydrothiophenyl; tetrahydrofuranyl; tetrahydropyranyl; and oxazolidinyl, wherein the heterocycloalkyl may be connected to the ligand via any atom in the ring of the selected heterocycloalkyl,    a -C1-C6-alkyl-heterocycloalkyl, wherein the heterocycloalkyl of the -C1-C6-heterocycloalkyl is selected from the group consisting of: piperidinyl; piperidine; 1,4-piperazine, tetrahydrothiophene; tetrahydrofuran; pyrrolidine; and tetrahydropyran, wherein the heterocycloalkyl may be connected to the -C1-C6-alkyl via any atom in the ring of the selected heterocycloalkyl,    a -C1-C6-alkyl-heteroaryl, wherein the heteroaryl of the -C1-C6-alkylheteroaryl is selected from the group consisting of: pyridinyl; pyrimidinyl; pyrazinyl; triazolyl; pyridazinyl; 1,3,5-triazinyl; quinolinyl; isoquinolinyl; quinoxalinyl; imidazolyl; pyrazolyl; benzimidazolyl; thiazolyl; oxazolidinyl; pyrrolyl; carbazolyl; indolyl; and isoindolyl, wherein the heteroaryl may be connected to the -C1-C6-alkyl via any atom in the ring of the selected heteroaryl and the selected heteroaryl is optionally substituted by -C1-C4-alkyl,    a -C0-C6-alkyl-phenol or thiophenol,    a -C2-C4-alkyl-thiol, thioether or alcohol,    a -C2-C4-alkyl-amine, and    a -C2-C4-alkyl-carboxylate.    
     
     
         4 . A ligand or catalyst according to  claim 1 , wherein: each R is the same; and R3=R4.  
     
     
         5 . A ligand or catalyst according to  claim 1 , wherein R3 and R4 are the same and are —(CH2) n C(O)O-C1-C4-alkyl.  
     
     
         6 . A ligand or catalyst according to  claim 1 , wherein R3 and R4 are selected from the group consisting of —CH2OH, —C(O)O-C1-C6-alkyl, and phenyl.  
     
     
         7 . A ligand or catalyst according to  claim 1 , wherein at least one R1 and R2 is a 3-C0-C6-alkyl-pyridin-2-yl—C0-C 6 -alkyl.  
     
     
         8 . A ligand or catalyst according to  claim 1 , wherein Y=1.  
     
     
         9 . A ligand or catalyst according to  claim 1 , wherein R3 and R4 are —C(O)O-C1-C6-alkyl.  
     
     
         10 . A ligand or catalyst according to  claim 1 , wherein at least one of R1 and R2 is selected from the group consisting of: 3-ethyl-pyridin-2-ylmethyl, pyridin-2-ylmethyl, 3-methyl-pyridin-2-ylmethyl, and 6-amide-pyridin-2-ylmethyl.  
     
     
         11 . A ligand or catalyst according to  claim 10 , wherein at least one of R1 and R2 is pyridin-2-ylmethyl.  
     
     
         12 . A ligand or catalyst according to  claim 1 , wherein both R1 and R2 are pyridin-2-ylmethyl and R is H.  
     
     
         13 . A ligand or catalyst according to  claim 1 , wherein X is C═O.  
     
     
         14 . A ligand or catalyst according to  claim 1 , wherein the bleaching composition comprises the free ligand.  
     
     
         15 . A bleaching composition catalyst according to  claim 1 , wherein the transition metal catalyst is of the general formula (A1):  
         [M a L k X n ]Y m   (A1) 
       in which: 
 M represents a metal selected from Mn(II)-(III)-(IV)-(V), Cu(I)-(II)-(III), Fe(II)-(III)-(IV)-(V), Co(I)-(II)-(III), Ti(II)-(III)-(IV), V(II)-(III)-(IV)-(V), Mo(II)-(III)-(IV)-(V)-(VI) and W(IV)-(V)-(VI);  
 X represents a coordinating species selected from any mono, bi or tri charged anions and any neutral molecules able to coordinate the metal in a mono, bi or tridentate manner;  
 Y represents any non-coordinated counter ion;  
 a represents an integer from 1 to 10;  
 k represents an integer from 1 to 10;  
 n represents an integer from 1 to 10;  
 m represents zero or an integer from 1 to 20; and  
 L represents a ligand as defined in  claim 1 , or its protonated or deprotonated analogue.  
 
     
     
         16 . A catalyst according to  claim 15 , wherein M represents a metal selected from Fe(II)-(III)-(IV)-(V).  
     
     
         17 . A catalyst according to  claim 16 , wherein M represents a metal selected from Fe(II) and Fe(III).  
     
     
         18 . (canceled)  
     
     
         19 . A ligand of formula (I) according to  claim 18  or a transition metal catalyst thereof, wherein at least one of R1 or R2 is pyridin-2-ylmethyl and the other is selected from —CH3, —C2H5, —C3H7, and —C4H9.  
     
     
         20 . A perchlorate salt of dimethyl 2,4-di-(2-pyridyl)-3,7-di(pyridin-2-ylmethyl)-3,7-diaza-bicyclo[3.3.1]nonan-9-one-1,5-dicarboxylate (N2Py4).