Polymeric tandem dyes with spacing linker groups

A compound having the following structure (I):

• or a stereoisomer, salt or tautomer thereof, wherein:
• M1 and M2 are, at each occurrence, independently a chromophore, provided that M1 is a FRET acceptor and M2 is a corresponding FRET donor, and M1 and M2 form a FRET pair;
• L1a is, at each occurrence, independently a heteroalkylene or heteroarylene linker;
• L1b, L2, L3, L5, L6 and L7 are, at each occurrence, independently optional alkylene, alkenylene, alkynylene, heteroalkylene, heteroalkenylene or heteroalkynylene linkers;
• L4, at each occurrence, has one of the following structures:
• wherein:
• z is an integer from 1 to 100;
• and
• * indicates a bond to the adjacent phosphorous atom;
• R1 and R2 are each independently H, OH, SH, alkyl, alkoxy, alkylether, heteroalkyl, —OP(═Ra)(Rb)Rc, Q, or a protected form thereof, or L′;
• R3 is, at each occurrence, independently H, alkyl or alkoxy;
• R4 is, at each occurrence, independently OH, SH, O−, S−, ORd or SRd;
• R5 is, at each occurrence, independently oxo, thioxo or absent;
• Ra is O or S;
• Rb is OH, SH, O−, S−, ORd or SRd;
• Rc is OH, SH, O−, S−, ORd, OL′, SRd, alkyl, alkoxy, heteroalkyl, heteroalkoxy, alkylether, alkoxyalkylether, phosphate, thiophosphate, phosphoalkyl, thiophosphoalkyl, phosphoalkylether or thiophosphoalkylether;
• Rd is a counter ion;
• Q is, at each occurrence, independently a moiety comprising a reactive group, or protected form thereof, capable of forming a covalent bond with an analyte molecule, a targeting moiety, a solid support or a complementary reactive group Q′;
• 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 (I);
• m is, at each occurrence, an integer of one or greater;
• q is, at each occurrence, an integer of one or greater;
• w is, at least one occurrence, an integer of one or greater, provided that q is an integer greater than w when n is an integer of 1;
• and
• n is an integer of one or greater.