Abstract: Provided herein are modified hemoglobin (Hb) comprising at least two subunits of a Hb intramolecularly crosslinked with a compound of formula (I), or salt, stereoisomer, or deuterated form thereof, wherein X, R1, and R2 are defined herein. The modified Hb can further comprise residues functionalized with reactive groups. Also provided herein are multimerized hemoglobin (Hb) compositions comprising a reaction product of: the modified Hb comprising a residue functionalized with one or more first reactive groups for click reaction and a reactant molecule comprising second reactive groups complementary to the first reactive group for the click reaction.

Abstract: Provided herein are compounds of formula (I), or salt, stereoisomer, or deuterated form thereof, wherein X, R1, and R2 are defined herein. Also provided herein are conjugated compositions comprising reacted units of a molecule (e.g., a protein) and a compound of formula (I), or salt, stereoisomer, or deuterated form thereof.