The catalysts comprise {HEAD ~ a metalatable particle}, such as {TAIL ~ a bound rubber}, a thermoplastic polymer or a cured elastomer, that is multiply metalated with Group IA alkali metal atoms 
such as
The catalysts comprise { HEAD ~ a metalatable particle } , such as { TAIL ~ a bound rubber } , a thermoplastic polymer or a cured elastomer , that is multiply metalated with Group IA alkali metal atoms
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH