ph to 4 5 the crude precipitate was filtered and recrystallized from ethanol to give 7 2 g pure furan derivatives 1 as pale or light yellow needles 36w melting point 198 u00b0 c 1 h nmr bruker 250 ppm in chloroform 2 37 s 3h 1 64 s 2h 13 c nmr bruker 250 ppm in chloroform 185 0 177 3 112 2 111 5 110 0 103 6 101 3 23 5 14 2 the synthesis of the donor bridge aldehyde for chromophore ftc 4 followed the procedures established by the inventors of the present invention see f wang design synthesis and characterization of novel organic chromophores and polymers for electro optic modulation ph d thesis university of southern california los angeles 1998 incorporated herein by reference 1 h nmr of intermediates and the detailed procedure for the intermediates is described as follows 3 4 dibromothiophene 1 h nmr bruker 250 cdcl 3 7 28 s 2h 3 4 dibutylthiophene 1 h nmr bruker 250 cdcl 3 6 8 9 s 2h 2 51 t 4h 1 61 m 4h 1 39 m 4h 0 952 t 6h 2 5 dibromo 3 4 dibutylthiophene 1 h nmr bruker 250 cdcl 3 2 52 t 4h 1 43 m 8h 0 952 t 6h 2 bromo 3 4 dibutyl thiophene 5 carbaldehyde 1 h nmr bruker 250 cdcl 3 9 89 s 1h 2 86 t 4h 2 51 m 4h 1 43 m 4h 0 952 t 6h 2 bromo 3 4 dibutyl 5 hydroxymethyl thiophene 1 h nmr bruker 250 cdcl 3 4 68 s 2h 2 51 m 4h 1 69 s 1h 1 42 m 8h 0 952 t 6h 2 bromo 3 4 dibutyl 5 thienylmethyltributylphosphonium bromide 1.