Facile Route to the Synthesis of Resorcinarene Nanocapsules

Abstract

Described is a direct method for the fabrication of resorcinarene nanocapsules by photopolymerization of compounds of formula (I), such as resorcinarene tetraalkene tetrathiol (RTATT), in the absence of any template or preorganization. Further, by varying the polymerization media, a variety of other polymeric architectures like lattices, fibrous networks, and nanoparticles were obtained. The morphology and structure were characterized by transmission electron microscopy, energy dispersive spectroscopy, scanning electron microscopy, dynamic light scattering, infrared and nuclear magnetic resonance spectroscopy. These morphologically distinct resorcinarene polymeric architectures contain residual thiol and ene functional groups offering potential functionalization opportunities.

1 . A composition comprising metal nanocapsules encapsulated in a resorcinarene polymer, wherein the resorcinarene polymer is formed by
 (a) the thiol-ene photopolymerization of a compound of formula (I):   
       
         
           
           
               
               
           
         
         wherein:
 X 1 , X 2 , X 3  and X 4  are independently —(CH 2 ) n —; 
 n is from 0-8; and 
 R 1 , R 2 , R 3  and R 4  are independently an alkene, and 
 
         (b) functionalizing a residual thiol moiety or alkene moiety of the resorcinarene polymer produced in step (a) by reacting the residual thiol moiety or alkene moiety with a compound having functional group. 
       
     
     
         2 . The composition of  claim 1 , wherein for the compound of formula (I):
 X 1 , X 2 , X 3  and X 4  are independently —(CH 2 ) n —;   n is from 0-8;   R 1 , R 2 , R 3  and R 4  are independently a C 2 -C 30  alkene.   
     
     
         3 . The composition of  claim 2 , wherein for the compound of formula (I):
 n is 0;   R 1 , R 2 , R 3  and R 4  are independently a C 12 -C 22  alkene.   
     
     
         4 . The composition of  claim 4 , wherein for the compound of formula (I):
 n is 0;   R 1 , R 2 , R 3  and R 4  are independently a C 4 -C 12  alkene.   
     
     
         5 . The composition of  claim 1 , wherein the compound of formula (I) is: 
       
         
           
           
               
               
           
         
       
     
     
         6 . The composition of  claim 1 , wherein the resorcinarene polymer is formed by the thiol-ene photopolymerization of a compound of formula (I) in chloroform, dichloromethane, ethyl actetate, or tetrahydrofuran. 
     
     
         7 . The composition of  claim 1 , wherein the resorcinarene polymer is formed by the thiol-ene photopolymerization of a compound of formula (I) in chloroform. 
     
     
         8 . The composition of  claim 1 , wherein the metal nanoparticles are selected from the group consisting of a metal from Groups 4-12 of the Periodic Table. 
     
     
         9 . The composition of  claim 1 , wherein the metal nanoparticles are selected from the group consisting of a metal Au, Ag, Cd, Hg, Os, Pb, Pt, Pd, Rh, Ru and Zn. 
     
     
         10 . The composition of  claim 1 , wherein the metal nanoparticles are gold nanoparticles. 
     
     
         11 . The composition of  claim 1 , the residual thiol moiety is functionalized with R 5 —CH═CH 2  or R 6 —SH, wherein:
 R 5  and R 6  are independently —C 1 -C 4 -alkyl-OH, —C 1 -C 4 -alkyl-C(O)OH or —C 1 -C 4 -alkyl-C(O)OR 7 , wherein R 7  is H, a —C 1 -C 4 -alkyl or —(C 1 -C 4 -alkyl-O) n H wherein n is 0-4. 
 
     
     
         12 . The composition of  claim 1 , wherein the residual thiol moiety is functionalized with a compound selected from the group consisting of poly(ethylene glycol) methacrylate (PEGMA), 3-mercaptopropionic acid (MPA), 3-butenoic acid and 3-mercaptopropanol. 
     
     
         13 . The composition of  claim 1 , wherein the residual alkene moiety is functionalized with poly(ethylene glycol) methacrylate (PEGMA) or 3-mercaptopropionic acid (MPA).