Ultra bright dimeric or polymeric dyes with spacing linker groups

A compound having the following structure (IA):

• or a stereoisomer, salt or tautomer thereof, wherein:
• M comprises aromatic rings selected from aryl and heteroaryl rings, wherein the aromatic rings include multiple degrees of conjugation;
• L1 is at each occurrence, independently either:
• i) an alkylene or heteroalkylene linker;
• or ii) a linker comprising a triazolyl functional group;
• L2 and L3 are, at each occurrence, independently an optional alkylene or heteroalkylene linker;
• R1 is, at each occurrence, independently H;
• R2 and R3 are each independently OH, —OP(═Ra)(Rb)Rc, Q, or a protected form thereof, or L′;
• R4 is, at each occurrence, independently OH, O−, ORd;
• R5 is, at each occurrence, independently oxo;
• Ra is O;
• Rb is OH, O−, or ORd;
• Rc is OH, O−, ORd or OL′;
• Rd is a counter ion;
• Q comprises a sulfhydryl, activated ester, or maleimide functional group;
• L′ is, at each occurrence, independently a linker comprising a covalent bond to Q, a linker comprising a covalent bond to a targeting moiety, a linker comprising a covalent bond to an analyte molecule, a linker comprising a covalent bond to a solid support, a linker comprising a covalent bond to a solid support residue, a linker comprising a covalent bond to a nucleoside or a linker comprising a covalent bond to a further compound of structure (IA);
• m is, at each occurrence, independently an integer of zero to 10, wherein at least one occurrence of m is an integer of one to 10;
• n is an integer of one to 32;
• and
• z is an integer from three to 100.