Crystal structure of bis[bis(1,4,7-triazacyclononane)nickel(III)] dithionate heptahydrate and its single-crystal EPR spectrum

Wieghardt, Karl; Walz, Wolfgang; Nuber, Bernhard; Weiß, Johannes; Ozarowski, A.; Stratemeier, Horst; Reinen, D.

doi:10.1021/ic00230a025

Cited by 60 publications

(50 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In this complex the metal ion is constrained within an octahedral geometry by the facial tridentate macrocyclic ligand. It has been suggested that [Ni( [9]ane~,),]~+/'+ is an adiabatic electron transfer reagent (3 1) and the present calculations appear to support that assertion.…”

Section: Kinetics Studiessupporting

confidence: 74%

“…Such an effect would serve to lower the adiabaticity, An average value of 0.01 for K,], as determined for the present complexes, would be consistent with K,, found for other transition metal complexes (14-16) and would account for the discrepancy. It is of interest to note that the calculated and observed values for [Ni( [9]aneN3),]"+/'+ agree remarkably well. In this complex the metal ion is constrained within an octahedral geometry by the facial tridentate macrocyclic ligand.…”

Section: Kinetics Studiesmentioning

confidence: 63%

“…As may be seen from these tabulated rate constants, with the exception of [Ni( [9]ane~,)~]"+/'+, there is a significant discrepancy between the theoretical values and those obtained experimentally through a Marcus-type cross correlation. A feature is that the ratio of k,,, to k,~,,, is roughly constant not only for the postulated sq.pl./sq.pl.…”

Section: Kinetics Studiesmentioning

confidence: 77%

See 2 more Smart Citations

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

McAuley¹,

Palmer²,

Whitcombe³

1993

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

Section: Kinetics Studiessupporting

confidence: 74%

Section: Kinetics Studiesmentioning

confidence: 63%

Section: Kinetics Studiesmentioning

confidence: 77%

See 1 more Smart Citation

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

McAuley¹,

Palmer²,

Whitcombe³

1993

Can. J. Chem.

View full text Add to dashboard Cite

show abstract

“…leading to the isolation of rather stable trivalent nickel complexes. [5][6][7] The stabilization of Ni"' is attributed to the full octahedral coordination with a minimum steric demand afforded by these ligands.6b*8 One of these stable nickel(rr1) complexes was obtained after chemical oxidation of the nickel(1r) complex of 1,4,7-triazacyclononane-N,N',N"-triacetate (nota3 -). ' The isolated [Ni"'(nota)] reveals a crystal structur.e with a six-coordinate centre around nickel, resulting from a distorted octahedral geometry generated by a N303 donor set.…”

mentioning

confidence: 99%

Formation and decomposition study of electrochemically-generated nickel(III)–nota complexes in aqueous solution (nota^3–= 1,4,7-triazacyclononane-N,N′,N″-triacetate)

Castro¹,

Gomes²,

Marques³

et al. 1995

J. Chem. Soc., Dalton Trans.

View full text Add to dashboard Cite

Electrochemical oxidation of the nickel(ii) complex of the macrocyclic ligand 1.4,7-triazacyclononane-N,N',N"-triacetate (nota3-) in aqueous solution yields the nickel(rii) complex, which undergoes fast base-promoted chemical decomposition. This decomposition process was studied by cyclic voltammetry, ESR and electronic spectroscopy, and gave first-order kinetics relative to the nickel(l1r) complex. This is compatible with intramolecular reduction of the metal centre by the ligand, followed by rapid decomposition of the radical species formed. The ligand fragmentation process was analysed by proton NMR spectroscopy of the electrolysed solution of the complex.The chemistry of metal complexes in less common oxidation states has been the subject of increasing interest in inorganic chemistry, due to the important role that these compounds play in catalytic and biological processes. Specifically, nickel-(I) and -(III) complexes have received considerable attention since it was recognized that nickel in those oxidations states participates in the catalytic cycles of several enzymes.Previous work from our laboratory focused on factors that control the availability of nickel-(I) and -(III) oxidation states with pseudo-macrocyclic Schiff-base ligands2 Polyazacycloalkanes are part of another family of ligands that allow the formation of several metal complexes in various oxidation states, whose stability may be varied over a substantial range through structural modifications of the macrocyclic frame~o r k .~'~' In particular triazamacrocycles and N-functionalized derivatives have been extensively inve~tigated,~.' leading to the isolation of rather stable trivalent nickel complexes. 5-7 The stabilization of Ni"' is attributed to the full octahedral coordination with a minimum steric demand afforded by these ligands.6b*8 One of these stable nickel(rr1) complexes was obtained after chemical oxidation of the nickel(1r) complex of 1,4,7-triazacyclononane-N,N',N"-triacetate (nota3 -).' The isolated [Ni"'(nota)] reveals a crystal structur.e with a six-coordinate centre around nickel, resulting from a distorted octahedral geometry generated by a N303 donor set.Just before the isolation of this complex, the electrochemical behaviour of Na[Ni"(nota)] in aqueous 0.05 mol dm-3 KCl was studied by Wieghardt et al. ,9 showing a reversible one-electron transfer process, that was attributed to the oxidation of Ni" to Ni"'. Formation of [Ni"'(nota)] in 0.05 mol dm-3 KCI aqueous solution by oxidation of the corresponding nickel(r1) complex by pulse-radiolytic techniques was reported and it was claimed that these species are stable in deaerated solution for at least 24 h at 25 O C 9 However, since then, no further characterization of this new species formed in solution has been performed.More recently Fabbrizzi et aLBb have shown in their electrochemical studies, with N a~i " ( n o t a ) ] , that the ligand (with an electric charge of 3 -) favours access to this unusually high oxidation state due to a very favourable entropy term, that refle...

show abstract

“…The reaction of mononuclear [Co III L], [4] in which L 3À is the hexadentate macrocyclic trianion 1,4,7-tris(4-tert-butyl-2-sulfidobenzyl)-1,4,7-triazacyclononane, with Cu II (OAc) 2´H2 O (2:1) in methanol affords upon addition of NaPF 6 red crystals of the heterotrinuclear complex 1-(PF 6 [5] (tacn 1,4,7-triazacyclononane) and addition of NaClO 4 yields blue-black microcrystals of 2-(ClO 4 ) 3´2 Me 2 -CO. Complex 2 is stable in the solid state for weeks but decomposes rapidly within minutes in solution (reduction).…”

Section: Methodsmentioning

confidence: 99%

A Paramagnetic Copper(III) Complex Containing an Octahedral CuIIIS6 Coordination Polyhedron

Krebs

Glaser

Bill

et al. 1999

Angew. Chem. Int. Ed.

Self Cite

View full text Add to dashboard Cite

Only the second octahedral, paramagnetic copper(III) complex (S=1) has now been synthesized and characterized. Six thiolato bridging ligands in the heterotrinuclear species [LCo Cu Co L](ClO ) ⋅2 Me CO (L=1,4,7-tris(4-tert-butyl-2-sulfidobenzyl)-1,4,7-triazacyclononane) stabilize this rare electron configuration. A section of the structure of the reduced form (Cu , S=½) is shown. XAS, EXAFS, and EPR spectroscopy prove unambiguously that the one-electron oxidation to the copper(III) is metal- rather than ligand-centered.

show abstract

Crystal structure of bis[bis(1,4,7-triazacyclononane)nickel(III)] dithionate heptahydrate and its single-crystal EPR spectrum

Cited by 60 publications

References 0 publications

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

Formation and decomposition study of electrochemically-generated nickel(III)–nota complexes in aqueous solution (nota^3–= 1,4,7-triazacyclononane-N,N′,N″-triacetate)

A Paramagnetic Copper(III) Complex Containing an Octahedral CuIIIS6 Coordination Polyhedron

Contact Info

Product

Resources

About

Crystal structure of bis[bis(1,4,7-triazacyclononane)nickel(III)] dithionate heptahydrate and its single-crystal EPR spectrum

Cited by 60 publications

References 0 publications

X-ray crystal structure of [Ni(III)(cyclam)(NO3)2](ClO4) and electron transfer reactions of the Ni(III)/Ni(II) couple

X-ray crystal structure of [Ni(III)(cyclam)(NO3)2](ClO4) and electron transfer reactions of the Ni(III)/Ni(II) couple

Formation and decomposition study of electrochemically-generated nickel(III)–nota complexes in aqueous solution (nota3–= 1,4,7-triazacyclononane-N,N′,N″-triacetate)

A Paramagnetic Copper(III) Complex Containing an Octahedral CuIIIS6 Coordination Polyhedron

Contact Info

Product

Resources

About

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

X-ray crystal structure of [Ni(III)(cyclam)(NO₃)₂](ClO₄) and electron transfer reactions of the Ni(III)/Ni(II) couple

Formation and decomposition study of electrochemically-generated nickel(III)–nota complexes in aqueous solution (nota^3–= 1,4,7-triazacyclononane-N,N′,N″-triacetate)