# US 5,345,032 A · Use of metal chelate complexes in dehalogenation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,345,032 A - Document ID: US5345032A - Status: Granted - Kind: A - Application number: 08/047,837 - Filed: 1993-04-19 - Granted: 1994-09-06 - Earliest claimed: 1988-05-09 - Assignees: Public Health Laboratory Service Board - Inventors: Trevor S. Marks; Andrew Maule - Web page: https://patentgrep.com/patent/US5345032A ## CPC - A62D 3/37: by reduction, e.g. hydrogenation - C07C 17/23: by dehalogenation - C07D 487/22: in which the condensed system contains four or more hetero rings - A62D 2101/04: Pesticides, e.g. insecticides, herbicides, fungicides or nematocides - A62D 2101/22: containing halogen - C02F 2101/36: containing halogen - A62D: CHEMICAL MEANS FOR EXTINGUISHING FIRES OR FOR COMBATING OR PROTECTING AGAINST HARMFUL CHEMICAL AGENTS; CHEMICAL MATERIALS FOR USE IN BREATHING APPARATUS - C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS - C07D: HETEROCYCLIC COMPOUNDS (macromolecular compounds C08) - C02F: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes) ## Abstract A method for dehalogenation of organohalogen compounds, e.g. environmental pollutants in industrial waste. The organohalogen is reacted with a reducing agent in the presence of a selected metal-centered corrin, porphyrin or phthalocyanine complex. Preferred complexes are hydrolysis products of cyanocobalamin, of formula (I), in which R.sup.1 is NH.sub.2 or OH, R.sup.2 is H, CH.sub.2 CH.sub.2 COOH or CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.3 is H, CH.sub.2 CH.sub.2 COOH or CH.sub.2 CH.sub.2 CONH.sub.2, and R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, OH or NH.sub.2. The complex is preferably immobilized on a substrate. Some novel metal-centered porphyrin complexes are also described. A dehalogenation apparatus using the method of the invention is also described. ##STR1## ## Claims ### Claim 1 A method for dehalogenation of a halogenated organic compound suspended, dispersed or dissolved in an aqueous medium, said method comprising the step of causing the halogenated compound to react with a reducing agent in the presence of a complex of a corrin containing a metal centered ring system of the formula: ##STR18## where M is cobalt, nickel, molybdenum, iron or magnesium; A and B are coordinating ligands which may be the same or different; a and b are each 0 or 1; R.sup.1 is selected from the group consisting of NH.sub.2 and OH; R.sup.2 is selected from the group consisting of H, CH.sub.2 CH.sub.2 COOH and CH.sub.2 CH.sub.2 CONH.sub.2 ; R.sup.3 is selected from the group consisting of H, CH.sub.2 CH.sub.2 COOH and CH.sub.2 CH.sub.2 CONH.sub.2 ; and R.sup.4 is selected from the group consisting of NHCH.sub.2 CH(OH)CH.sub.3, OH and NH.sub.2, wherein the halogenated compound suspended, dispersed or dissolved in the aqueous medium is an environmental pollutant or industrial waste and the dehalogenated reaction is carried out between ambient temperature and 80.degree. C. ### Claim 2 (depends on 1) The method according to claim 1 wherein the dehalogenation reaction is carried out at between 20.degree. C. and 80.degree. C. ### Claim 3 (depends on 1) The method according to claim 1 herein the dehalogenation step is carried out at about pH 9. ### Claim 4 (depends on 1) The method according to claim 1 wherein the dehalogenation step is carried out in the absence of light. ### Claim 5 (depends on 1) The method according to claim 1 wherein A and B are both CN.sup.-. ### Claim 6 (depends on 1) The method according to claim 1 wherein a and b are both 0. ### Claim 7 (depends on 1) The method according to claim 1 wherein M is cobalt. ### Claim 8 (depends on 1) The method according to claim 1 wherein R.sup.1 is NH.sub.2, R.sup.2 is H, R.sup.3 is CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, M is cobalt, A and B are both CN.sup.- and a and b are both 1. ### Claim 9 (depends on 1) The method according to claim 1 wherein R.sup.1 is NH.sub.2, R.sup.2 is H, R.sup.3 is CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, M is cobalt, and a and b are both 0. ### Claim 10 (depends on 1) The method according to claim 1 wherein R.sup.1 is NH.sub.2, R.sup.2 is H, R.sup.3 is CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is OH, M is cobalt, and a and b are both 0. ### Claim 11 A method for dehalogenation of a halogenated organic compound suspended, dispersed or dissolved in an aqueous medium, said method comprising the step of causing the halogenated compound to react with a reducing agent in the presence of a complex of a corrin containing a metal centered ring system of the formula: ##STR19## where M is cobalt, nickel, molybdenum, iron or magnesium; A and B are coordinating ligands which may be the same or different; a and b are each 0 or 1; R.sup.1 is selected from the group consisting of NH.sub.2 and OH; R.sup.2 is selected from the group consisting of H, CH.sub.2 CH.sub.2 COOH and CH.sub.2 CH.sub.2 CONH.sub.2 ; R.sup.3 is selected from the group consisting of H, CH.sub.2 CH.sub.2 COOH and CH.sub.2 CH.sub.2 CONH.sub.2 ; and R.sup.4 is selected from the group consisting of NHCH.sub.2 CH(OH)CH.sub.3, OH and NH.sub.2, wherein the halogenated compound suspended, dispersed or dissolved in the aqueous medium is an environmental pollutant or industrial waste and the dehalogenated reaction is carried out between 20.degree. C. and 80.degree. C., at a pH of about 9 and in the absence of light. ### Claim 12 (depends on 11) The method according to claim 11 wherein R.sup.11 is NH.sub.2, R.sup.2 is H, R.sup.3 is CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, M is cobalt, A and B are both CN.sup.- and a and b are both 1. ### Claim 13 (depends on 11) The method according to claim 11 wherein R.sup.1 is NH.sub.2, R.sup.2 is H, R.sup.3 is CH.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is NHCH.sub.2 CH(OH)CH.sub.3, M is cobalt, and a and b are both 0. ### Claim 14 (depends on 11) The method according to claim 11 wherein R.sup.1 is NH.sub.2, R.sup.2 is H, R.sup.3 is Ch.sub.2 CH.sub.2 CONH.sub.2, R.sup.4 is OH, M is cobalt, and a and b are both 0. ### Claim 15 (depends on 11) The method according to claim 11, wherein the complex is immobilized on a water insoluble substrate. ### Claim 16 (depends on 15) The method according to claim 15 wherein the substrate is a derivatized polysaccharide, polyacrylamide or polystyrene, a derivatized inorganic oxide or an ion-exchange resin. ### Claim 17 (depends on 15) The method according to claim 15 wherein the immobilized complex is situated in a bed and the halogenated compound suspended, dispersed or dissolved in the aqueous medium is passed through the bed in the presence of reducing agent. ### Claim 18 (depends on 15) The method according to claim 15 wherein the immobilized complex is in the form of a bed, wherein the immobilized compound suspended, dispersed or dissolved in the aqueous medium is passed through the bed in the presence of reducing agent, wherein the pH of the medium is about pH 9 and the residence time in the bed is from 5 to 20 minutes. ### Claim 19 (depends on 1) The method according to claim 1 wherein the halogenated compound has the halogen to be removed attached to an aliphatic carbon atom. ### Claim 20 (depends on 1) The method according to claim 1 wherein the halogenated compound is selected from the group consisting of DDT, lindane, dieldrin, hexachloro-butadiene, carbon tetrachloride, and dichloromethane. ### Claim 21 (depends on 15) The method according to claim 15 wherein the halogenated compound is selected from the group consisting of carbon tetrachloride, dichloromethane and lindane, wherein the concentration of compound in the aqueous medium is up to 100 ppm, the reaction time is 10 minutes or less and 99% or more of the compound is dehalogenated. ### Claim 22 (depends on 15) The method according to claim 15, wherein the substrate is a sepharose and the complex is immobilized on the sepharose through amide bonds formed by reacting one or more of the carboxylic acid or carboxylic acid amide groups on the complex with amine or carboxylic acid groups on the sepharose. ### Claim 23 (depends on 15) The method according to claim 15 wherein the substrate is an alkylamine-derivatized polystyrene and the complex is immobilized on the alkylamine-derivatized polystyrene through amide bonds formed by reacting one or more of the carboxylic acid groups on the complex with the alkylamine groups on the polystyrene.