Copper(II) Complexes of Substituted Macrobicyclic Hexaamines: Combined Trigonal and Tetragonal Distortions

Bernhardt, Paul V.; Bramley, Richard; Engelhardt, Lutz M.; Harrowfield, Jack M.; Hockless, David C. R.; Korybut‐Daszkiewicz, Bohdan; Krausz, Elmars; Morgan, T.; Sargeson, Alan M.

doi:10.1021/ic00118a005

Cited by 67 publications

(71 citation statements)

References 1 publication

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The two weaker bands are characteristic of a tetragonally distorted Cu(II) cage complex, although the nature of the distortion (elongation or compression) cannot be deduced from these data. 11 On the basis of our EPR data, the CuN 6 chromophore is certainly tetragonally elongated. Thus, the NIR band is due to an electronic transition between the d z 2 and d At voltammetric sweep rates higher than 100 mV s −1 the peakto-peak separation DE p increases and the peaks broaden.…”

Section: Physical Methodsmentioning

confidence: 76%

An expanded cavity hexaamine cage for copper(ii)

et al. 2007

Self Cite

View full text Add to dashboard Cite

The crystal structure of the bicyclic hexaamine complex [Cu(fac-Me 5 -tricosane-N 6 )](ClO 4 ) 2 ·H 2 O (fac-Me 5 -tricosane-N 6 = facial-1, 5,9,13,20-pentamethyl-3,7,11,15,18,22-hexaazabicyclo[7.7.7]tricosane) at 100 K defines an apparently tetragonally compressed octahedral geometry, which is attributed to a combination of dynamic interconversion and static disorder between two tetragonally elongated structures sharing a common short axis. This structure is fluxional at 60 K and above as shown by EPR spectroscopy. Aqueous cyclic voltammetry reveals that a remarkably stable Cu I form of the complex is stabilised by the encapsulating nature of the expanded cage ligand.

show abstract

Section: Physical Methodsmentioning

confidence: 76%

An expanded cavity hexaamine cage for copper(ii)

et al. 2007

Self Cite

View full text Add to dashboard Cite

show abstract

“…There are a number of other cases in which low-symmetry hexaamine Cu II complexes crystallize on (impossibly) high symmetry sites (trigonal or hexagonal) [30,47] or, when appearing on general sites, exhibit anomalous coordination geometries such as pseudooctahedral [48] or tetragonally compressed. [31] Regardless of the "apparent" structure obtained in the solid state, they all have been found in solution to exhibit tetragonally elongated (4+2) coordination geometries.…”

Section: Resultsmentioning

confidence: 99%

“…[30] Upon addition of 100 mm bromide ions to [Cu(AMME-N 3 S 3 sar)]A C H T U N G T R E N N U N G (ClO 4 ) 2 in DMSO, two species are formed within the 2 min interval required to mix the reagents and freeze the solution for measurement ( Figure 3B). Upon standing at room temperature for 3 h the EPR spectrum of the same [Cu(AMME-N 3 S 3 sar)]A C H T U N G T R E N N U N G (ClO 4 ) 2 /100 mm bromide solution simplifies to that of a single species ( Figure 3C); g z = 2.154 (A z = 164 G), g y = g x = 2.040 (A y = A x = 25 G).…”

Section: Epr Spectroscopymentioning

confidence: 99%

“…Such a tetragonal distortion opposes the threefold symmetry of sar-type ligands, and indeed this lowering of symmetry has been observed and reported on a number of occasions with different cage ligands in complexes with Cu II . [11,30,31] Removal of labile divalent Cu [32] and Hg [33] from ligands that belong to the sar family is remarkably slow in comparison with the processes that occur on nonoctahedrally encapsulating polyamines, [34,35] but it is able to be observed and studied under less extreme conditions than those required for demetalation of Co cage complexes. The rate of demetalation is also dependent on the nature of the apical substituents.…”

Section: Introductionmentioning

confidence: 99%

“…For instance, the complex [CuA C H T U N G T R E N N U N G (diAMsar)] 2 + (Scheme 1) is remarkably resistant to acid-promoted demetalation. [30,32] However, reduction to Cu I or zero-valent Cu leads to immediate complex dissociation. [36] Indeed, only the expandedcavity hexaamine cage complex [Cu(Me 5 -tricosane)] 2 + (Scheme 1) exhibits quasireversible Cu II/I electrochemistry and makes it unique among the copper cage complexes in this respect.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Copper(II) Complexes of a Hexadentate Mixed‐Donor N₃S₃ Macrobicyclic Cage: Facile Rearrangements and Interconversions

Bell

Bernhardt

Gahan

et al. 2010

Chemistry A European J

View full text Add to dashboard Cite

The potentially hexadentate mixed-donor cage ligand 1-methyl-8-amino-3,13,16-trithia-6,10,19-triazabicyclo[6.6.6]eicosane (AMME-N(3)S(3)sar; sar=sarcophagine) displays variable coordination modes in a complex with copper(II). In the absence of coordinating anions, the ligand adopts a conventional hexadentate N(3)S(3) binding mode in the complex [Cu(AMME-N(3)S(3)sar)](ClO(4))(2) that is typical of cage ligands. This structure was determined by X-ray crystallography and solution spectroscopy (EPR and NIR UV/Vis). However, in the presence of bromide ions in DMSO, clean conversion to a five-coordinate bromido complex [Cu(AMME-N(3)S(3)sar)Br](+) is observed that features a novel tetradentate (N(2)S(2))-coordinated form of the cage ligand. This copper(II) complex has also been characterized by X-ray crystallography and solution spectroscopy. The mechanism of the reversible interconversion between the six- and five-coordinated copper(II) complexes has been studied and the reaction has been resolved into two steps; the rate of the first is linearly dependent on bromide ion concentration and the second is bromide independent. Electrochemistry of both [Cu(AMME-N(3)S(3)sar)](2+) and [Cu(AMME-N(3)S(3)sar)Br](+) in DMSO shows that upon reduction to the monovalent state, they share a common five-coordinated form in which the ligand is bound to copper in a tetradentate form exclusively, regardless of whether a six- or five-coordinated copper(II) complex is the precursor.

show abstract

Functionalization of Cage Amines with Pendant Aromatic and Heteroaromatic Substituents

Burnet

Choi

Donnelly

et al. 2001

Eur. J. Inorg. Chem.

View full text Add to dashboard Cite

Structural studies have confirmed that it is possible to exploit the relatively low nucleophilicity of the “external” amino substituents on the CoIII complex of 1,8‐diaminosarcophagine (“sarcophagine” = sar = 3,6,10,13,16,19‐hexaazabicyclo[6.6.6]icosane) in acylation and alkylation reactions leading to a variety of functionalized cage amine complexes. With the appropriate choice of solvent, all these reactions can be conducted with high efficiency, and the new complexes display properties foreshadowing the application of cage systems in, for example, electroactive polymers.

show abstract

Copper(II) Complexes of Substituted Macrobicyclic Hexaamines: Combined Trigonal and Tetragonal Distortions

Cited by 67 publications

References 1 publication

An expanded cavity hexaamine cage for copper(ii)

An expanded cavity hexaamine cage for copper(ii)

Copper(II) Complexes of a Hexadentate Mixed‐Donor N₃S₃ Macrobicyclic Cage: Facile Rearrangements and Interconversions

Functionalization of Cage Amines with Pendant Aromatic and Heteroaromatic Substituents

Contact Info

Product

Resources

About

Copper(II) Complexes of Substituted Macrobicyclic Hexaamines: Combined Trigonal and Tetragonal Distortions

Cited by 67 publications

References 1 publication

An expanded cavity hexaamine cage for copper(ii)

An expanded cavity hexaamine cage for copper(ii)

Copper(II) Complexes of a Hexadentate Mixed‐Donor N3S3 Macrobicyclic Cage: Facile Rearrangements and Interconversions

Functionalization of Cage Amines with Pendant Aromatic and Heteroaromatic Substituents

Contact Info

Product

Resources

About

Copper(II) Complexes of a Hexadentate Mixed‐Donor N₃S₃ Macrobicyclic Cage: Facile Rearrangements and Interconversions