Abstract: Compositions of matter according to the present invention comprise a carrier compound immobilized in or on a solid phase. The carrier compound is reactive to bind a ligand such as molecular oxygen and includes a complex formed from a transition metal ion and a multidentate organic chelate. The solid phase is substantially immiscible in or separated from a ligand-containing environment, and the compositions are utilized by contacting the immobilized carrier compounds with the ligand-containing environment. Desirably, the compositions may be maintained in an inactive state (i.e., unable to bind ligand) where the transition metal ion is separated from the chelate. By allowing the complex to form at a preselected time, premature ligand binding can be avoided.

Abstract: Oxygen is extracted from a fluid mixture feedstock by circulating a carrier fluid from an oxygen loading station to an electrochemical cell. The carrier fluid includes a carrier compound capable of reversibly binding oxygen, with oxygen binding dependent on the oxidation state of the compound. Oxygen bound to the carrier compound in a first oxidation state is released as the oxidation state is altered at the first electrode of the electrochemical cell. The carrier compound is then returned to the first oxidation state at the second electrode at the electrochemical cell. The loading station typically comprises an oxygen-permeable membrane which prevents bulk mixing of the fluid mixture and the carrier fluid.