Highly fluorescent and photo-stable chromophores for wavelength conversion

A chromophore represented by formula (I):

• wherein Het is
• wherein:
• i is 0;
• X is —N(A0)-;
• Z is —N(Ra)—;
• A0 is selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted heteroalkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted acyl, optionally substituted carboxy, optionally substituted carbonyl,
• Ra is selected from the group consisting of hydrogen, optionally substituted alkyl, optionally substituted alkoxyalkyl, optionally substituted alkenyl, optionally substituted heteroalkyl, optionally substituted heteroalkenyl, optionally substituted aryl, optionally substituted arylalkyl, optionally substituted heteroaryl, optionally substituted cycloalkyl, optionally substituted cycloalkenyl, optionally substituted cycloheteroalkyl, optionally substituted cycloheteroalkenyl, optionally substituted amino, optionally substituted amido, optionally substituted cyclic amido, optionally substituted cyclic imido, optionally substituted alkoxy, optionally substituted carboxy, optionally substituted carbonyl,
• D1 and D2 are independently selected from the group consisting of hydrogen, optionally substituted aryloxy, optionally substituted acyloxy, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, optionally substituted amino, amido, cyclic amido, and cyclic imido;
• provided that D1 and D2 are not both hydrogen, and D1 and D2 are not optionally substituted thiophene or optionally substituted furan;
• and
• wherein when a group is substituted, the group is substituted with one or more substituents selected from the group consisting of C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C7 cycloalkyl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, carboxy, haloalkyl, CN, —SO2-alkyl, —CF3, and —OCF3), cycloalkyl geminally attached, C1-C6 heteroalkyl, C3-C10 heterocycloalkyl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, carboxy, CN, —SO2-alkyl, —CF3, and —OCF3), aryl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, arylalkyl, alkoxy, aryloxy, carboxy, amino, imido, amido, cyclic imido optionally substituted with C1-C6 alkyl, cyclic amido, CN, —NH—C(═O)-alkyl, —CF3, —OCF3, and aryl optionally substituted with C1-C6 alkyl), arylalkyl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, aryl, carboxy, CN, —SO2-alkyl, —CF3, and —OCF3), heteroaryl (optionally substituted with a moiety selected from the group consisting of halo, alkyl, alkoxy, aryl, heteroaryl, aralkyl, carboxy, CN, —SO2-alkyl, —CF3, and —OCF3), halo, cyano, hydroxy, cyclic imido, amino, imido, amido, —CF3, C1-C6 alkoxy (optionally substituted with halo, alkyl, alkoxy optionally substituted with alkoxy, aryl, carboxy, CN, —SO2-alkyl, —CF3, and —OCF3), aryloxy, acyloxy, sulfhydryl, halo(C1-C6)alkyl, C1-C6 alkylthio, arylthio, (C1-C6)alkylamino, di-(C1-C6)alkylamino, quaternary ammonium salts, amino(C1-C6)alkoxy, hydroxy(C1-C6)alkylamino, amino(C1-C6)alkylthio, cyanoamino, nitro, carbamoyl, carboxy, acyl, glycolyl, glycyl, hydrazino, guanyl, sulfamyl, thiocarboxy, sulfonamido, N-carbamate, O-carbamate, and urea.