Long stokes shift chromenoquinoline dyes and uses in sequencing applications

A compound of Formula (I), a salt or a mesomeric form thereof:

• wherein each of R1, R4, R5, R7, R8, R9, R10, R11, R12a and R12b is independently H, C1-C6 alkyl, substituted C1-C6 alkyl, C1-C6 alkoxy, C2-C6 alkenyl, C2-C6 alkynyl, C1-C6 haloalkyl, C1-C6 haloalkoxy, (C1-C6 alkoxy) C1-C6 alkyl, optionally substituted amino, amino (C1-C6 alkyl), halo, cyano, hydroxy, hydroxy (C1-C6 alkyl), nitro, sulfonyl, sulfo, sulfino, sulfonate, S-sulfonamido, or N-sulfonamido;
• each of R2 and R3 is independently H, C1-C6 alkyl, or substituted C1-C6 alkyl;
• and
• R6 is C1-C6 alkyl or substituted C1-C6 alkyl;
• alternatively, R1 and R2 together with the atoms to which they are attached form an optionally substituted 5-10 membered heteroaryl or an optionally substituted 5-10 membered heterocyclyl;
• alternatively, R3 and R4 together with the atoms to which they are attached form an optionally substituted 5-10 membered heteroaryl or an optionally substituted 5-10 membered heterocyclyl;
• alternatively, R8 and R9 together with the atoms to which they are attached form an optionally substituted C6-C10 aryl, an optionally substituted 3-10 membered carbocyclyl, an optionally substituted 5-10 membered heteroaryl or an optionally substituted 3-10 membered heterocyclyl;
• provided that when each of R2 and R3 is ethyl;
• each of R1, R4, R5, R7, R8, R10, R11, R12a and R12b is H;
• and R6 is methyl;
• then R9 is a substituted C1-C6 alkyl comprising a carboxyl;
• and
• provided that when R1 and R2 together with the atoms to which they are attached form a piperidinyl and R3 and R4 together with the atoms to which they are attached form a piperidinyl such that the compound has the structure;
• each of R5, R7, R8, R10, R11, R12a and R12b is H;
• and R6 is methyl;
• then R9 is a substituted C1-C6 alkyl comprising a carboxyl;
• wherein at least one of R2, R3, R6, R7, R8, R9, R10 and R11 comprises a carboxyl group.