Patent ID: 6140494
Filing Date: 2000-10-31
Classification: C07H,C09B

Abstract:
A squarate dye of the formula (I) or (II) or (IIa) ##STR15## where each Z is independently O or S or CR.sup.1.sub.2,n=1-3,each of s and m is 0, 1 or 2,R.sup.1 is lower alkyl (1-4 carbon chain),each R.sup.2 is independently selected from electron donating and electron withdrawing groups or is a branched or straight chain of up to 30 carbon atoms incorporating one to five positively charged nitrogen atoms,each R.sup.3 is independently selected from: alkylene, alkenylene and alkynylene (1-20 carbon chain), or is a branched or straight chain of up to 30 carbon atoms incorporating one to five ether oxygen atoms or arylene rings or positively charged nitrogen atoms,at least one X is a nucleophilic functional group, such as OH, SH or NH.sub.2, or alternatively a grouping capable of reacting with a nucleophile,and any other X present is independently selected from H and SO.sub.3.sup.- and the residue of a squarate dye of formula (I) or (II) or (IIa) and another fluorochrome,provided that at least one R.sup.2 is SO.sub.3.sup.- and/or at least one X is phosphoramidite.