Protonated amidopyridyl ligands show high selectivity for the extraction of [CoCl(4)](2-) or [ZnC... more Protonated amidopyridyl ligands show high selectivity for the extraction of [CoCl(4)](2-) or [ZnCl(4)](2-) over chloride ion into organic media via the formation of N-H and C-H hydrogen-bond donors to the outer coordination spheres of the chlorometallates.
Journal of The Chemical Society-dalton Transactions, 1998
J. Chem. Soc., Dalton Trans., 1998, 39533960 3953 ... Synthesis, structures and magnetochemistry... more J. Chem. Soc., Dalton Trans., 1998, 39533960 3953 ... Synthesis, structures and magnetochemistry of binuclear cobalt(II), ... Daniel Black,a Alexander J. Blake,a Keith P. Dancey,b Andrew Harrison,c Mary McPartlin,b Simon Parsons,c Peter A. Tasker,*c,d Gavin Whittakerc and ...
A series of tripodal receptors designed to recognise the outer coordination sphere of the hexachl... more A series of tripodal receptors designed to recognise the outer coordination sphere of the hexachlorometallate anion [PtCl(6)](2-), and thus show selectivity for ion-pair formation over chloride binding, has been synthesised and characterised. The tripodal ligands contain urea, amido or sulfonamido hydrogen-bond donors, which are aligned to bind to the regions of greatest electron density along the faces and edges of the octahedral anion. The ligand structure incorporates a protonatable bridgehead nitrogen centre that provides a positive charge to ensure the solubility of a neutral 2:1 [LH](+)/[PtCl(6)](2-) complex in water-immiscible solvents. The extraction of [PtCl(6)](2-) from acidic chloride solutions was evaluated by using a pH-swing mechanism to control the loading and stripping of the metallate anion. The ligands L(1)-L(3), L(5)-L(9), L(11)-L(13) and L(15) showed extremely high loading (up to 95% in some cases) and high selectivity for [PtCl(6)](2-) over chloride ions (present in a 60-fold excess) compared with trioctylamine, a model Alamine reagent, which, under identical conditions, only extracted 10% of the Pt(IV) anions. Generally, extraction was observed to be greater for urea-containing ligands than their amido analogues, and a quantitative recovery of platinum from feed solutions was achieved. The formation of neutral ([LH](+))(2)[PtCl(6)](2-) packages in organic media is supported by single-crystal X-ray structure determinations of [(L(2)H)(2)PtCl(6)] x 2 CH(3)CN, [(L(8)H)(2)PtCl(6)(MeOH)(2)], [(L(12)H)(2)PtCl(6)] x 2 CH(3)CN and [(L(14)H)(2)PtCl(6)], which confirm the presence of significant hydrogen bonding between the anion and urea or amido moieties of the protonated ligand and the anion. The structure of [(L(1)H)(H(3)O)PtCl(6)] x C(6)H(6) x CH(3)CN shows hydrogen bonding of a H(3)O(+) cation to the receptor and confirms that other stoichiometries are also possible, indicating that speciation in solution may be more complex.
Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in co... more Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in commercial solvent extraction processes can be doubly deprotonated and generate polynuclear Cu complexes with lower extractant:Cu molar ratios than those found in commercial operations. Electrospray mass spectrometry has provided an insight into the solution speciation in extraction experiments and has identified conditions to allow isolation and characterization of polynuclear Cu-complexes. Elevation of pH is effective in enhancing the formation of trinuclear complexes containing planar {Cu3-μ3-O}4+ or {Cu3-μ3-OH}5+ units. DFT calculations suggest that such trinuclear complexes are more stable than other polynuclear species. Solid structures of complexes formed by a salicylaldoxime with a piperidino substituent ortho to the phenolic OH group (L9H2) contain two trinuclear units in a supramolecular assembly, {[Cu3OH(L9H)3(ClO4)](ClO4)} 2, formed by H-bonding between the central {Cu3-μ3-OH}5...
Durch Kondensation des Triamins (I) mit dem Aldehyd (II) in siedendem Methanol in Gegenwart der M... more Durch Kondensation des Triamins (I) mit dem Aldehyd (II) in siedendem Methanol in Gegenwart der Metallperchlorate werden die Komplexe (III) erhalten.
Die Komplexe (I) wurden durch Zugabe der Hexaaquometallperchlorate zu einer Lösung aus 1,1,l‐Tris... more Die Komplexe (I) wurden durch Zugabe der Hexaaquometallperchlorate zu einer Lösung aus 1,1,l‐Tris‐[aminomethyl]‐äthan und PyridinQ‐carbaldehyd wasserfreiem Methanol dargestellt.
Ditopic receptors containing a macrocyclic cyclen unit and a urea moiety provide selective recogn... more Ditopic receptors containing a macrocyclic cyclen unit and a urea moiety provide selective recognition of first-row divalent metal salts.
Protonated amidopyridyl ligands show high selectivity for the extraction of [CoCl(4)](2-) or [ZnC... more Protonated amidopyridyl ligands show high selectivity for the extraction of [CoCl(4)](2-) or [ZnCl(4)](2-) over chloride ion into organic media via the formation of N-H and C-H hydrogen-bond donors to the outer coordination spheres of the chlorometallates.
Journal of The Chemical Society-dalton Transactions, 1998
J. Chem. Soc., Dalton Trans., 1998, 39533960 3953 ... Synthesis, structures and magnetochemistry... more J. Chem. Soc., Dalton Trans., 1998, 39533960 3953 ... Synthesis, structures and magnetochemistry of binuclear cobalt(II), ... Daniel Black,a Alexander J. Blake,a Keith P. Dancey,b Andrew Harrison,c Mary McPartlin,b Simon Parsons,c Peter A. Tasker,*c,d Gavin Whittakerc and ...
A series of tripodal receptors designed to recognise the outer coordination sphere of the hexachl... more A series of tripodal receptors designed to recognise the outer coordination sphere of the hexachlorometallate anion [PtCl(6)](2-), and thus show selectivity for ion-pair formation over chloride binding, has been synthesised and characterised. The tripodal ligands contain urea, amido or sulfonamido hydrogen-bond donors, which are aligned to bind to the regions of greatest electron density along the faces and edges of the octahedral anion. The ligand structure incorporates a protonatable bridgehead nitrogen centre that provides a positive charge to ensure the solubility of a neutral 2:1 [LH](+)/[PtCl(6)](2-) complex in water-immiscible solvents. The extraction of [PtCl(6)](2-) from acidic chloride solutions was evaluated by using a pH-swing mechanism to control the loading and stripping of the metallate anion. The ligands L(1)-L(3), L(5)-L(9), L(11)-L(13) and L(15) showed extremely high loading (up to 95% in some cases) and high selectivity for [PtCl(6)](2-) over chloride ions (present in a 60-fold excess) compared with trioctylamine, a model Alamine reagent, which, under identical conditions, only extracted 10% of the Pt(IV) anions. Generally, extraction was observed to be greater for urea-containing ligands than their amido analogues, and a quantitative recovery of platinum from feed solutions was achieved. The formation of neutral ([LH](+))(2)[PtCl(6)](2-) packages in organic media is supported by single-crystal X-ray structure determinations of [(L(2)H)(2)PtCl(6)] x 2 CH(3)CN, [(L(8)H)(2)PtCl(6)(MeOH)(2)], [(L(12)H)(2)PtCl(6)] x 2 CH(3)CN and [(L(14)H)(2)PtCl(6)], which confirm the presence of significant hydrogen bonding between the anion and urea or amido moieties of the protonated ligand and the anion. The structure of [(L(1)H)(H(3)O)PtCl(6)] x C(6)H(6) x CH(3)CN shows hydrogen bonding of a H(3)O(+) cation to the receptor and confirms that other stoichiometries are also possible, indicating that speciation in solution may be more complex.
Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in co... more Conditions have been identified in which phenolic aldoximes and ketoximes of the types used in commercial solvent extraction processes can be doubly deprotonated and generate polynuclear Cu complexes with lower extractant:Cu molar ratios than those found in commercial operations. Electrospray mass spectrometry has provided an insight into the solution speciation in extraction experiments and has identified conditions to allow isolation and characterization of polynuclear Cu-complexes. Elevation of pH is effective in enhancing the formation of trinuclear complexes containing planar {Cu3-μ3-O}4+ or {Cu3-μ3-OH}5+ units. DFT calculations suggest that such trinuclear complexes are more stable than other polynuclear species. Solid structures of complexes formed by a salicylaldoxime with a piperidino substituent ortho to the phenolic OH group (L9H2) contain two trinuclear units in a supramolecular assembly, {[Cu3OH(L9H)3(ClO4)](ClO4)} 2, formed by H-bonding between the central {Cu3-μ3-OH}5...
Durch Kondensation des Triamins (I) mit dem Aldehyd (II) in siedendem Methanol in Gegenwart der M... more Durch Kondensation des Triamins (I) mit dem Aldehyd (II) in siedendem Methanol in Gegenwart der Metallperchlorate werden die Komplexe (III) erhalten.
Die Komplexe (I) wurden durch Zugabe der Hexaaquometallperchlorate zu einer Lösung aus 1,1,l‐Tris... more Die Komplexe (I) wurden durch Zugabe der Hexaaquometallperchlorate zu einer Lösung aus 1,1,l‐Tris‐[aminomethyl]‐äthan und PyridinQ‐carbaldehyd wasserfreiem Methanol dargestellt.
Ditopic receptors containing a macrocyclic cyclen unit and a urea moiety provide selective recogn... more Ditopic receptors containing a macrocyclic cyclen unit and a urea moiety provide selective recognition of first-row divalent metal salts.
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