Synthesis, characterization and aggregation induced enhanced emission properties of tetraaryl pyrazole decorated cyclophosphazenes

A series of cyclotriphosphazenes N 3 P 3 (O-C 6 H 4 -C 3 N 2 -(C 6 H 5 ) 3 ) 6 ( 3 ), N 3 P 3 (O 2 C 12 H 8 )(O-C 6 H 4 -C 3 N 2 -(C 6 H 5 ) 3 ) 4 ( 4 ), N 3 P 3 (O 2 C 12 H 8 ) 2 (O-C 6 H 4 -C 3 N 2 -(C 6 H 5 ) 3 ) 2 ( 5 ) and N 3 P 3 (OPh) 5 (O-C 6 H 4 -C 3 N 2 -(C 6 H 5 ) 3 ) ( 7 ) decorated with aggregation induced enhanced emission (AIEE) luminogen (tetraaryl pyrazole) are synthesized by the reaction of N 3 P 3 Cl 6 , N 3 P 3 (O 2 C 12 H 8 )Cl 4 , N 3 P 3 (O 2 C 12 H 8 ) 2 Cl 2 and N 3 P 3 Cl 5 (O-C 6 H 4 -C 3 N 2 -(C 6 H 5 ) 3 ) ( 6 ) with 4-(1,3,5-triphenyl-1 H -pyrazol-4-yl)phenol (phenol in the case of 6 ). Intriguingly all the newly synthesized tetraaryl pyrazole decorated cyclotriphosphazenes exhibit the aggregation induced enhanced emission phenomenon. The luminogen decorated cyclophosphazenes have also been investigated as a probe for the detection of explosive picric acid. We report the synthesis, characterization and aggregation induced enhanced emission (AIEE) properties of a series of tetraaryl pyrazole decorated cyclotriphosphazenes. The hexa-substituted cyclotriphosphazene was tested for its usefulness as a probe for the explosive picric acid.