There is a need for a blood substitute because of a lack of donors, time consuming blood type and crossmatch tests, immunomodulation to the recipient, viral transmission, and the limited shelf life of donated blood. Perfluorocarbons, modified hemoglobin, and liposome encapsulated hemoglobin are being developed as blood substitutes. However, their capacity to carry oxygen is lower than that of red blood cells. A novel class of compounds, having a high capacity of carrying oxygen, are proposed as blood substitutes. These compounds will be synthesized, purified, and characterized with analytical techniques. The ability of the compounds to carry and release oxygen will be determined. A compound having the maximum capacity to carry oxygen will be selected and the in vitro toxicity of the selected compound will be determined.National Heart, Lung, and Blood Institute (NHLBI)