Photosensitizing transition metal complex and its use for photovoltaic cell

Abstract

A photosensitizing transition metal complex of the formula (Ia) MLY 1 , (Ib) MLX 3 (Ic) MLY 2 X, (Id) MLY 3 X or (Ie) MLY 4 X in which M is a transition metal selected from ruthenium, osmium, iron, rhenium and technetium, preferably ruthenium or osmium. X is a co-ligand independently selected from NCS—, Cl—, Br—, I—, CN—, H 2 O; pyridine unsubstituted or substituted by at least one group selected from vinyl, primary, secondary or tertiary amine, OH and C 1-30 alkyl, preferably NSC and CN—; L is a tridentate polypyridine ligand, carrying at least one carboxylic, phosphoric acid or a chelating group and one substituted or unsubstituted alkyl group having 1 to 50 carbon atoms, substituted or unsubstituted alkylamide group having 2 to 30 carbon atoms or substituted or unsubstituted aralkyl group having 7 to 50 carbon atoms. A dye-sensitized electrode includes a substrate having an electrically conductive surface, an oxide semiconductor film formed on the conductive surface, and the above sensitizer of formula (Ia), (Ib), (Ic), (Id) or (Ie) as specified above; supported on the film. A solar cell includes the above electrode, a counter electrode, and an electrolyte deposited there between.

1 . A photosensitizing transition metal complex having the general formula (Ic):
   MLY 2 X  (Ic)
   in which M is a transition metal selected from Ru(II), Os(II), Fe(II), Re(I) and Tc(I);   L is a polypyridine ligand having the general formula (II),   
       
         
           
           
               
               
           
         
         wherein A 1 , A 2  and A 3  contain at least one anchoring group selected from —COOH, —COON(C 4 H 9 ) 4 , —PO(OH) 2 , —PO(OR 1 ) 2  (where R 1  is an alkyl group having 1 to 30 carbon atoms), —CO(NHOH), and at least one group selected from an alkyl group having 1 to 50 carbon atoms, an alkylamide group having 2 to 50 carbon atoms or an aralkyl group having 7 to 50 carbon atoms; and 
         X is a ligand selected from NCS—, Cl—, Br—, I—, CN—, NCO—, H 2 O or pyridine group which may be substituted by vinyl, primary, secondary or tertiary amino, alkylthio, arylthio, hydroxyl or C 1-30  alkyl; and 
         Y 2  is a group having the general formula (IVa-1): 
       
       
         
           
           
               
               
           
         
         where R 4 , R 5  and R 6  are independently an alkyl group having 1 to 20 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an aminoalkyl group having 1 to 12 carbon atoms an alkoxycarbonyl group having 2 to 6 carbon atoms, an alkylamide group having 2 to 30 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group, cyano group, hydroxyl group, nitro group, amino group, trifluoro group, halogen atom or hydrogen atom. 
       
     
     
         2 . A photosensitizing transition metal complex of  claim 1  which is a complex of the formula (Ic) in which
 M is Ru(II) or Os(II); 
 L is a polypyridine ligand of the subformula (IIb) 
 
       
         
           
           
               
               
           
         
         where B 1  and B 2  are, the same or different, a hydrogen atom, 
         —COOH, —COON(C 4 H 9 ) 4 , —PO(OH) 2 , provided that any one of B 1  and B 2  is different from a hydrogen atom, and C is an alkyl group having 6 to 30 carbon atoms; 
         X is NCS— or CN—; and 
         R 4 , R 5  and R 6  of the formula (IVa-1) are as follows: 
       
       
         
           
                 
                 
                 
                 
               
                     
                 
                     
                   R 4   
                   R 5   
                   R 6   
                 
                     
                 
                     
                   CH 3   
                   H 
                   CH 3   
                 
                     
                   CH 3    
                   CH3 
                   CH 3   
                 
                     
                   t-Bu 
                   H 
                   t-Bu 
                 
                     
                   Ph 
                   H 
                   CH 3   
                 
                     
                   Ph 
                   H 
                   Ph 
                 
                     
                   CH 3   
                   H 
                   C 1-30  alkyl 
                 
                     
                   CF 3   
                   H 
                   CH 3   
                 
                     
                   CF 3   
                   H 
                   CH 2 CN 
                 
                     
                   CF 3   
                   H 
                   CF 3   
                 
                     
                   CF 3   
                   H 
                   C 1-30  alkyl 
                 
                     
                   CF 3   
                   H 
                   CF 3 —CF 2   
                 
                     
                   CF 3   
                   H 
                   Ph 
                 
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         3 . A photosensitizing transition metal complex having the general formula (Id):
   MLY 3 X  (Id)
   in which M is a transition metal selected from Ru(II),Os(II), Fe(II), Re(I) and Tc(I);   L is a polypyridine ligand having the general formula (II);   
       
         
           
           
               
               
           
         
         wherein at least one of A 1 , A 2  and A 3  is an anchoring group selected from —COOH, —COON(C 4 H 9 ) 4 , —PO(OH) 2 , —PO(OR 1 ) 2  (where R 1  is an alkyl group having 1 to 30 carbon atoms), —CO(NHOH), and when there is the remaining A 1 , A 2  and A 3  being not said anchoring group, it may be a hydrogen atom, an alkyl group having 1 to 50 carbon atoms, an alkylamide group having 2 to 50 carbon atoms or an aralkyl group having 7 to 50 carbon atoms; 
         X is a ligand selected from NCS—, Cl—, Br—, I—, CN—, NCO—, H 2 O or pyridine group which may be substituted by vinyl, primary, secondary or tertiary amino, alkylthio, arylthio, hydroxyl or C 1-30  alkyl; and 
         Y 3  is a group having the formula (IVa-2): 
       
       
         
           
           
               
               
           
         
         where R 7  is 4 trifluoro or perfluoroalkyl group having 1 to 12 carbon atoms, R 9  and R 9  are independently an alkyl group having 1 to 20 carbon atoms, an alkoxyalkyl group having 2 to 12 carbon atoms, an aminoalkyl group having 1 to 12 carbon atoms an alkoxycarbonyl group having 2 to 6 carbon atoms, an alkylamide group having 2 to 30 carbon atoms, a perfluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an aryl group, cyano group, hydroxyl group, nitro group, amino group, trifluoro group, halogen atom or hydrogen atom. 
       
     
     
         4 . A photosensitizing transition metal complex of  claim 3 , which is a complex of the formula (Id) in which
 M is Ru(II) or Os(II);   L is polypyridine ligand of the formula (IIa)   
       
         
           
           
               
               
           
         
         where B 1 , B 2  and B 3  are H, —COOH, —COON(C 4 H 9 ) 4  or —PO(OH) 2  provided that at least one of B 1 , B 2  and B 3  is different from hydrogen atom; 
         X is NCS— or CN—; and 
         R 7 , R 8  and R 9  of the formula (IVa-2) are as follows: 
       
       
         
           
                 
                 
                 
                 
               
                     
                 
                     
                   R 7   
                   R 8   
                   R 9   
                 
                     
                 
                     
                   CF 3   
                   H 
                   4-F 
                 
                     
                   CF 3   
                   H 
                   4-Cl 
                 
                     
                   CF 3   
                   H 
                   4-CN 
                 
                     
                   CF 3   
                   H 
                   4-CF 3   
                 
                     
                   CF 3   
                   H 
                   4-CH 3   
                 
                     
                   CF 3   
                   H 
                   4-NO 2   
                 
                     
                   CF 3 —CF 2   
                   H 
                   4-F 
                 
                     
                   CF 3 —CF 2   
                   H 
                   4-Cl 
                 
                     
                   CF 3 —CF 2   
                   H 
                   4-CN 
                 
                     
                   CF 3   
                   F 
                   4-F 
                 
                     
                   CF 3   
                   F 
                   4-Cl 
                 
                     
                   CF 3   
                   F 
                   4-CN 
                 
                     
                   CF 3   
                   F 
                   4-CF 3   
                 
                     
                   CF 3   
                   F 
                   4-CH 3   
                 
                     
                   CF 3   
                   H 
                   H 
                 
                     
                   CF 3 —CF 2   
                   H 
                   4-CF 3   
                 
                     
                   CF 3 —CF 2   
                   H 
                   4-CH 3   
                 
                     
                   CF 3 —CF 2   
                   H 
                   H 
                 
                     
                 
             
                
                
                
               
               
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
                
               
            
           
         
       
     
     
         5 . A photosensitizing transition metal complex of the  claim 3 , which is a complex of the formula (Id) in which
 M is Ru(II) or Os(II);   L is a polypyridine ligand of the subformula (IIb)   
       
         
           
           
               
               
           
         
         where B 1  and B 2  are, the same or different, a hydrogen atom, —COOH, —COON(C 4 H 9 ) 4 , —PO(OH) 2 , provided that any one of B 1  and B 2  is different from a hydrogen atom, and C is an alkyl group having 6 to 30 carbon atoms; 
         X is NCS— or CN—; and 
         R 7 , R 8  and R 9  of the formula (IVa-2). 
       
     
     
         6 . A photovoltaic cell comprising a support, a conductive layer formed on the support, and a porous semiconductor layer formed on the conductive layer, a counter electrode, and an electrolyte deposited there between wherein the porous semiconductor layer carries a photosensitizing transition metal complex as claimed in  claim 1 . 
     
     
         7 . A photovoltaic cell comprising a support, a conductive layer formed on the support, and a porous semiconductor layer formed on the conductive layer, a counter electrode, and an electrolyte deposited there between wherein the porous semiconductor layer carries a photosensitizing transition metal complex as claimed in  claim 3 .