The specific aims of this proposal are directed toward development of highly selective organic cross-linking reagents for hemoglobins that would lead to modified hemoglobins that could be used as blood substitutes. The effectiveness of the organic cross-linking reagents is expected to be a complex function of "linker" length, chemical reactivity, and solubility properties of the agent. The title compounds constitute a new class of bifunctional organic reagents that are expected to show a high level of selectivity toward ammonium groups in proteins. The structural design of the reagents allows us to alter chemical properties and molecular dimensions in a systematic way.