Pyrazole metal complex for absorbing carbon dioxide, method for preparing pyrazole metal complex, and method for absorption of carbon dioxide

Abstract

A pyrazole metal complex for absorption of carbon dioxide, a method for preparing the pyrazole metal complex, and a method for absorbing carbon dioxide are provided; wherein the product produced by reacting pyrazole metal complex and carbon dioxide may be transformed into several economically valuable compounds.

1 . A pyrazole metal complex for absorbing carbon dioxide, having the structure: 
       
         
           
           
               
               
           
         
         wherein each of R 1 , R 2 , and R 3  is independently selected from a group consisting of hydrogen, substituted or unsubstituted C 1 -C 6  alkyl group, and substituted or unsubstituted aryl group; and 
         M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + , Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Ni 2+ , Cu 2+ , Cu + , and Zn 2+ . 
       
     
     
         2 . The pyrazole metal complex of  claim 1 , wherein R 1  is selected from a group consisting of hydrogen, methyl group, and benzyl group; each of R 2  and R 3  is independently hydrogen. 
     
     
         3 . The pyrazole metal complex of  claim 1 , wherein M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + . 
     
     
         4 . A preparing method of the pyrazole metal complex of  claim 1 , comprising the steps of:
 step (a): providing a pyrazole compound having the structure:   
       
         
           
           
               
               
           
         
       
       and
 step (b): reacting a metal hydride with the pyrazole compound of formula (I-1) to obtain the pyrazole metal complex. 
 
     
     
         5 . The preparing method of  claim 4 , wherein step (b) further comprising a tetrahydrofuran as a solvent. 
     
     
         6 . A method for absorbing carbon dioxide, comprising:
 step (1): providing a pyrazole metal complex of formula (I):   
       
         
           
           
               
               
           
         
         wherein each of R 1 , R 2 , and R 3  is independently selected from a group consisting of hydrogen, substituted or unsubstituted C 1 -C 6  alkyl group, and substituted or unsubstituted aryl group; and 
         M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + , Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Ni 2+ , Cu 2+ , Cu + , and Zn 2+ ; and 
         step (2): reacting the pyrazole metal complex with carbon dioxide for absorbing carbon dioxide, wherein a product obtained by reacting the pyrazole metal complex and carbon dioxide is a pyrazole amide formate of formula (II): 
       
       
         
           
           
               
               
           
         
       
     
     
         7 . The method of  claim 6 , wherein step (1), R 1  is selected from a group consisting of hydrogen, methyl group, and benzyl group; each of R 2  and R 3  is independently hydrogen. 
     
     
         8 . The method of  claim 6 , wherein step (1), M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + . 
     
     
         9 . The method of  claim 6 , wherein step (2), the reaction of the pyrazole metal complex and carbon dioxide is carried out under an inert gas environment. 
     
     
         10 . method for absorbing carbon dioxide, comprising:
 step (i): providing a pyrazole metal complex of formula (I)   
       
         
           
           
               
               
           
         
         wherein each of R 1 , R 2 , and R 3  is independently selected from a group consisting of hydrogen, substituted or unsubstituted C 1 -C 6  alkyl group, and substituted or unsubstituted aryl group; and 
         M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + , Mn 2+ , Fe 2+ , Fe 3+ , Co 2+ , Co 3+ , Ni 2+ , Cu 2+ , Cu + , and Zn 2+ ; and 
         step (ii): reacting the pyrazole metal complex with carbon dioxide for absorbing carbon dioxide, wherein a product obtained by reacting the pyrazole metal complex and carbon dioxide is a pyrazole amide formate of formula (II): 
       
       
         
           
           
               
               
           
         
       
       and
 step (iii): providing a double nitroso iron complex of formula (III) for reacting with the pyrazolamide formate of formula (II) to obtain a metal complex having structure of formula (IV): 
 
       
         
           
           
               
               
           
         
       
     
     
         11 . The method of  claim 10 , wherein step (i), R 1  is selected from a group consisting of hydrogen, methyl group, and benzyl group; each of R 2  and R 3  is independently hydrogen. 
     
     
         12 . The method of  claim 10 , wherein step (i), M 1   n+  is selected from a group consisting of Na + , K + , and [K-18-crown-6 ether] + . 
     
     
         13 . The method of  claim 10 , wherein step (ii), the reaction of the pyrazole metal complex and carbon dioxide is carried out under an inert gas environment. 
     
     
         14 . The method of  claim 10 , further comprising:
 step (iv): providing a calcium trifluoromethanesulfonate (Ca(OTf) 2 ) for reacting with the metal complex of formula (IV) to obtain a calcium oxalate (CaC 2 O 4 ).   
     
     
         15 . The method of  claim 10 , further comprising:
 step (v): providing a bis(pinacolato)diboron ((PinB) 2 ) for reacting with the metal complex of formula (IV) to obtain a carbon monoxide.   
     
     
         16 . The method of  claim 10 , further comprising:
 step (vi): providing a 9-Borabicyclo(3.3.1)nonane (9-BBN) for reacting with the metal complex of formula (IV) to obtain a formic acid.   
     
     
         17 . The method of  claim 10 , further comprising:
 step (vii): providing a triethyl boride for reacting with the metal complex of formula (IV) to obtain a propionate.   
     
     
         18 . The method of  claim 10 , further comprising:
 step (viii): providing a zinc trifluoromethanesulfonate for reacting with the metal complex of formula (IV) to obtain a carbon dioxide reduction product.