to 6 or u2014 c 12 h 8 n f n u2014 n 0 to 8 the diphenyl containing precursors can have the following general structures iib u2032 wherein each w is fluorinate phenyl u2014 f or u2014 h n u2033 is an integer of at least 2 to a number that is less than total sp 2 c substitutions on p u2032 p u2032 can be u2014 c 6 h 4 n f n u2014 n 0 to 4 u2014 c 6 h 4 n f n u2014 cf 2 u2014 c 6 h 4 n f n u2014 n 0 to 8 u2014 c 10 h 6 n f n u2014 n 0 to 6 or u2014 c 12 h 8 n f n u2014 n 0 to 8 wherein each w is fluorinate phenyl u2014 f or u2014 h n u2032 u2033 is an integer of at least 2 to a number that is less than total sp 2 c substitutions on p u2032 p u2032 can be u2014 c 6 h 4 n f n u2014 n 0 to 4 u2014 c 6 h 4 n f n u2014 cf 2 u2014 c 6 h 4 n f n.