Hexavalent chromium detector

A method for detoxification of Cr6+ in an aqueous or organic liquid media, comprising:

• (i) contacting said liquid media with a divalent osmium (Os2+)-, iron (Fe2+)- or ruthenium (Ru2+)-based pyridyl complex capable of changing its oxidation state to Os3+-, Fe3+- or Ru3+-based pyridyl complex, respectively, in response to a reduction of Cr6+, for a sufficient time period at the presence of H+, wherein said pyridyl complex is carried as a layered structure on a substrate;
• (ii) monitoring the presence of Cr6+ and determining its concentration in a sample taken from said liquid media;
• and
• when Cr6+ is detected in said sample, reducing said Os3+-, Fe3+- or Ru3+-based pyridyl complex and repeating steps (i) and (ii) wherein said pyridyl complex is a charged tris-bipyridyl Os2+, Fe2+ or Ru2+ complex of the general formula I:
• wherein M is Os, Fe or Ru;
• n is the formal oxidation state of the osmium, iron or ruthenium,
• wherein n is 2 or 3;
• m is the positive charge of the tris-bipyridyl ligand, wherein m is an integer from 0 to 24,
• X is a counter anion selected from Br−, Cl−, F−, I−, PF6−, BF4−, OH−, ClO4−, SO3−, CF3COO−, CN−, alkylCOO−, arylCOO− or a combination thereof;
• R5 to R28 is each independently hydrogen, halogen, hydroxyl, azido, nitro, cyano, amino, substituted amino, thiol, C1-C10 alkyl, cycloalkyl, heterocycloalkyl, haloalkyl, aryl, heteroaryl, alkoxy, alkenyl, alkenyl, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, sulfonyl, substituted aryl, substituted cycloalkyl or substituted heterocycloalkyl,
• wherein at least one of said R5 to R28 is a group A or B:
• wherein group A is
• wherein
• group A is linked to the ring structure of the compound of general formula I via R4;
• R4 is cis/trans C═C, C≡C, N═N, C═N, N═C, C—N, N—C, alkylene, arylene or a combination thereof;
• R3 is C or N;
• R2 is absent or is hydrogen, alkyl, alkylene, aryl, arylene, OH, O-alkyl, O-alkylene or a combination thereof;
• R1 is absent or is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• group B is —O(CH2)p—R29 linked to the ring structure of the compound of general formula I via the oxygen, wherein p is an integer from 9 to 12;
• R29 is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• and
• any two vicinal R5-R28 substituents, together with the carbon atoms to which they are attached, may form a fused ring system selected from cycloalkyl, heterocycloalkyl, heteroaryl or aryl, wherein said fused system may be substituted by one or more groups selected from C1-C10 alkyl, aryl, azido, cycloalkyl, halogen, heterocycloalkyl, alkoxy, hydroxyl, haloalkyl, heteroaryl, alkenyl, alkynyl, nitro, cyano, amino, substituted amino, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, thiol, sulfonyl or substituted aryl;
• and said fused ring system may also contain at least one heteroatom selected from the group consisting of N, O and S.

A method for detoxification of Cr6+ in an aqueous or organic liquid media, comprising contacting said liquid media with a divalent osmium (Os2+)-, iron (Fe2+)- or ruthenium (Ru2+)-based pyridyl complex capable of changing its oxidation state to Os3+-, Fe3+- or Ru3+-based pyridyl complex, respectively, in response to a reduction of Cr6+, for a sufficient time period at the presence of H+, wherein said pyridyl complex is carried as a layered structure on a substrate

• wherein said pyridyl complex is a charged tris-bipyridyl Os2+, Fe2+ or Ru2+ complex of the general formula I:
• wherein M is Os, Fe or Ru;
• n is the formal oxidation state of the osmium, iron or ruthenium,
• wherein n is 2 or 3;
• m is the positive charge of the tris-bipyridyl ligand, wherein m is an integer from 0 to 24,
• X is a counter anion selected from Br−, Cl−, F−, I−, PF6−, BF4−, OH−, OH4−, SO3−, CF3COO−, CN−, alkylCOO−, arylCOO− or a combination thereof;
• R5 to R28 is each independently hydrogen, halogen, hydroxyl, azido, nitro, cyano, amino, substituted amino, thiol, C1-C10 alkyl, cycloalkyl, heterocycloalkyl, haloalkyl, aryl, heteroaryl, alkoxy, alkenyl, alkynyl, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, sulfonyl, substituted aryl, substituted cycloalkyl or substituted heterocycloalkyl,
• wherein at least one of said R5 to R28 is a group A or B:
• wherein group A is
• wherein
• group A is linked to the ring structure of the compound of general formula I via R4;
• R4 is cis/trans C═C, C≡C, N═N, C═N, N═C, C—N, N—C, alkylene, arylene or a combination thereof;
• R3 is C or N;
• R2 is absent or is hydrogen, alkyl, alkylene, aryl, arylene, OH, O-alkyl, O-alkylene or a combination thereof;
• R1 is absent or is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• group B is —O(CH2)p—R29 linked to the ring structure of the compound of general formula I via the oxygen, wherein p is an integer from 9 to 12;
• R29 is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• and
• any two vicinal R5-R28 substituents, together with the carbon atoms to which they are attached, may form a fused ring system selected from cycloalkyl, heterocycloalkyl, heteroaryl or aryl, wherein said fused system may be substituted by one or more groups selected from C1-C10 alkyl, aryl, azido, cycloalkyl, halogen, heterocycloalkyl, alkoxy, hydroxyl, haloalkyl, heteroaryl, alkenyl, alkynyl, nitro, cyano, amino, substituted amino, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, thiol, sulfonyl or substituted aryl;
• and said fused ring system may also contain at least one heteroatom selected from the group consisting of N, O and S.

A catalytic process for reduction of Cr6+, comprising reducing said Cr6+ with a divalent osmium (Os2+)-based pyridyl complex of the general formula I:

• wherein M is Os;
• n is the formal oxidation state of the osmium, iron or ruthenium, wherein n is 2 or 3;
• m is the positive charge of the tris-bipyridyl ligand, wherein m is an integer from 0 to 24, X is a counter anion selected from Br−, Cl−, F−, I−, PF6−, BF4−, OH−, ClO4−, SO3−, CF3COO−, CN−, alkylCOO−, arylCOO− or a combination thereof;
• and R5 to R28 is each independently hydrogen, halogen, hydroxyl, azido, nitro, cyano, amino, substituted amino, thiol, C1-C10 alkyl, cycloalkyl, heterocycloalkyl, haloalkyl, aryl, heteroaryl, alkoxy, alkenyl, alkynyl, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, sulfonyl, substituted aryl, substituted cycloalkyl or substituted heterocycloalkyl, wherein at least one of said R5 to R28 is a group A or B:
• wherein group A is
• and wherein
• group A is linked to the ring structure of the compound of general formula I via R4;
• R4 is cis/trans C═C, C≡C, N═N, C═N, N═C, C—N, N—C, alkylene, arylene or a combination thereof;
• R3 is C or N;
• R2 is absent or is hydrogen, alkyl, alkylene, aryl, arylene, OH, O-alkyl, O-alkylene or a combination thereof;
• R1 is absent or is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• group B is —O(CH2)p—R29 linked to the ring structure of the compound of general formula I via the oxygen, wherein p is an integer from 9 to 12;
• R29 is hydrogen, trialkoxysilane, trihalidesilane, thiol, COOH, COO−, Si(OH)3 or phosphonate;
• any two vicinal R5-R28 substituents, together with the carbon atoms to which they are attached, may form a fused ring system selected from cycloalkyl, heterocycloalkyl, heteroaryl or aryl, wherein said fused system may be substituted by one or more groups selected from C1-C10 alkyl, aryl, azido, cycloalkyl, halogen, heterocycloalkyl, alkoxy, hydroxyl, haloalkyl, heteroaryl, alkenyl, alkynyl, nitro, cyano, amino, substituted amino, carboxamido, substituted carboxamido, carboxyl, protected carboxyl, protected amino, thiol, sulfonyl or substituted aryl;
• and said fused ring system may also contain at least one heteroatom selected from the group consisting of N, O and S,
• to thereby oxidize the Os2+ to Os3+, and exposing the oxidized Os3+ to water for a sufficient time period to thereby regenerate the Os3+ to Os2+.