Polyalkylamine complexes for ligand extraction and generation

A metallic complex of a polyalkylamine of the general formula ##STR11## where, each of R.sub.1 and R.sub.2 is independently selected from the group consisting of 2-pyridyl and amino;

• each of m, n, o, and p is independently 1, 2, 3, or 4;
• X is 2,6-pyridyl;
• and
• M is a transition metal ion;
• wherein at least two of m, n, o, and p are unequal.

A metallic complex of a polyalkylamine of the general formula ##STR12## where, each of R.sub.1 and R.sub.2 is independently an organic group including a nitrogen coordinated to M;

• each of m, n, o, and p is independently 1, 2, 3, or 4;
• X is selected from the group consisting of 2,6-pyridyl, substituted 2,6-pyridyl, 2,4-imidazolyl, substituted 2,4-imidazolyl and >N-H;
• and
• M is transition metal ion;
• and
• wherein n and o are unequal.

A composition of matter for use in electrochemical ligand extraction and generation processes comprising:

• an aqueous solution of greater than about 10 millimoles per liter of a metallic complex of a polyalkylamine having the general formula:
• ##STR14## where, each of R.sub.1 and R.sub.2 is independently an organic group including a nitrogen atom coordinated to M;
• each of m, n, o, and p is independently 1, 2, 3, or 4;
• X is selected from the group consisting of 2,6-pyridyl, substituted 2,6-pyridyl 2,4-imidazolyl, substituted 2,4-imidazolyl, and;
• ##STR15## and M is a transition metal ion.

A method for extracting a ligand from a first fluid environment, the method comprising the steps of:

• contacting the first fluid environment containing ligand with a first surface of a first ligand-permeable membrane having a first surface and a second surface wherein the membrane separates the environment from an interior space of a container;
• contacting an aqueous carrier fluid with the second surface of the membrane wherein the carrier fluid is confined in the container and the carrier fluid contains a carrier compound, whereby at least a portion of a ligand which diffuses through the membrane binds to the carrier compound to give bound ligand complex;
• transporting the carrier fluid containing the bound ligand complex to a first electrode compartment of an electrochemical cell which forms a second portion of the container;
• electrochemically modulating the carrier compound to an oxidation state having relatively less binding affinity for ligand, thereby releasing free ligand into the carrier fluid and producing a non-binding state carrier compound;
• removing ligand from the carrier fluid to give a ligand depleted carrier fluid;
• transporting the ligand depleted carrier fluid containing the non-binding state carrier compound to a second electrode compartment of an electrochemical cell which forms a third portion of the container;
• and
• electrochemically modifying the non-binding state carrier compound to reform the binding state carrier compound;
• wherein, the carrier compound comprises a metallic complex of a polyalkylamine having the general formula:
• ##STR17## where, each of R.sub.1 and R.sub.2 is independently an organic group including a nitrogen atom coordinated to M;
• each of m, n, o, and p is independently 1, 2, 3, or 4;
• X is selected from the group consisting of 2,6-pyridyl, substituted 2,6-pyridyl, 2,4-imidazolyl, substituted 2,4-imidazolyl and;
• ##STR18## and M is a transition metal ion.

A method for extracting a ligand from a first fluid environment and releasing the ligand to a second fluid environment, the method comprising the steps of:

• providing an electrochemical cell including an anode, a cathode and an electrolyte comprising a transition metal carrier compound having the general formula:
• ##STR19## where, each of R.sub.1 and R.sub.2 is independently an organic group including a nitrogen atom coordinated to M;
• each of m, n, o, and p is independently 1, 2, 3, or 4;
• X is selected from the group consisting of 2,6-pyrdiyl, substituted 2,6-pyridyl, 2,4-imidazolyl, substituted 2,4-imidazolyl, and;
• ##STR20## and M is a transition metal ion;
• providing a potential across the cell sufficient to convert the transition metal ion of the carrier compound to a binding valance state at the cathode and convert, at the anode, the transition metal ion of the carrier compound ligand complex to a non-binding valence state;
• communicating the ligand from the first fluid environment to the electrolyte at the cathode so that the carrier compound ligand complex is formed between the ligand and the binding valence state carrier compound;
• transporting the carrier compound ligand complex to the anode for release of the ligand;
• and
• electrochemically releasing the ligand from the carrier compound ligand complex to the second fluid environment.