5 research outputs found
Structures of 1,1′,3,3′-Tetra(2-methyl-2-nonyl)ferrocenium(1+) Oxoanion(1−) Salts. Layered Materials with Alternating Ionic and Low-Dielectric Paraffin-Like Domains Through Which Anion Diffusion is Rapid
The unprecedented interdigitated and layered structures
of 1,1′,3,3′-tetraÂ(2-methyl-2-nonyl)Âferrocene
(DEC) and the oxoanion ferrocenium salts DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup> were determined
by single-crystal X-ray diffraction. The four structures are similar
except that the three DEC<sup>+</sup> salts have layers of XO<sub><i>n</i></sub><sup>–</sup> oxoanions stuffed between
the layers of interdigitated ferrocenium ions. The perpendicular distances
between layers of Fe atoms are 8.530, 9.108, 9.009, and 9.158 Ã…
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The structures also contain
layers of rigorously coplanar Fe and X atoms that are tilted 65.4,
75.9, 61.9, and 61.1° from the aforementioned layers of Fe atoms
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The local environments
of the XO<sub><i>n</i></sub><sup>–</sup> oxoanions
consist of networks of C–H···O hydrogen bonds,
and the structures exhibit channels through which these anions could
diffuse. Facile diffusion of these anions in thin films of DEC<sup>+</sup>XO<sub><i>n</i></sub><sup>–</sup>, with structures
that appear to resemble the crystal structures, has been demonstrated
Structures of 1,1′,3,3′-Tetra(2-methyl-2-nonyl)ferrocenium(1+) Oxoanion(1−) Salts. Layered Materials with Alternating Ionic and Low-Dielectric Paraffin-Like Domains Through Which Anion Diffusion is Rapid
The unprecedented interdigitated and layered structures
of 1,1′,3,3′-tetraÂ(2-methyl-2-nonyl)Âferrocene
(DEC) and the oxoanion ferrocenium salts DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup> were determined
by single-crystal X-ray diffraction. The four structures are similar
except that the three DEC<sup>+</sup> salts have layers of XO<sub><i>n</i></sub><sup>–</sup> oxoanions stuffed between
the layers of interdigitated ferrocenium ions. The perpendicular distances
between layers of Fe atoms are 8.530, 9.108, 9.009, and 9.158 Ã…
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The structures also contain
layers of rigorously coplanar Fe and X atoms that are tilted 65.4,
75.9, 61.9, and 61.1° from the aforementioned layers of Fe atoms
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The local environments
of the XO<sub><i>n</i></sub><sup>–</sup> oxoanions
consist of networks of C–H···O hydrogen bonds,
and the structures exhibit channels through which these anions could
diffuse. Facile diffusion of these anions in thin films of DEC<sup>+</sup>XO<sub><i>n</i></sub><sup>–</sup>, with structures
that appear to resemble the crystal structures, has been demonstrated
Structures of 1,1′,3,3′-Tetra(2-methyl-2-nonyl)ferrocenium(1+) Oxoanion(1−) Salts. Layered Materials with Alternating Ionic and Low-Dielectric Paraffin-Like Domains Through Which Anion Diffusion is Rapid
The unprecedented interdigitated and layered structures
of 1,1′,3,3′-tetraÂ(2-methyl-2-nonyl)Âferrocene
(DEC) and the oxoanion ferrocenium salts DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup> were determined
by single-crystal X-ray diffraction. The four structures are similar
except that the three DEC<sup>+</sup> salts have layers of XO<sub><i>n</i></sub><sup>–</sup> oxoanions stuffed between
the layers of interdigitated ferrocenium ions. The perpendicular distances
between layers of Fe atoms are 8.530, 9.108, 9.009, and 9.158 Ã…
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The structures also contain
layers of rigorously coplanar Fe and X atoms that are tilted 65.4,
75.9, 61.9, and 61.1° from the aforementioned layers of Fe atoms
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The local environments
of the XO<sub><i>n</i></sub><sup>–</sup> oxoanions
consist of networks of C–H···O hydrogen bonds,
and the structures exhibit channels through which these anions could
diffuse. Facile diffusion of these anions in thin films of DEC<sup>+</sup>XO<sub><i>n</i></sub><sup>–</sup>, with structures
that appear to resemble the crystal structures, has been demonstrated
Structures of 1,1′,3,3′-Tetra(2-methyl-2-nonyl)ferrocenium(1+) Oxoanion(1−) Salts. Layered Materials with Alternating Ionic and Low-Dielectric Paraffin-Like Domains Through Which Anion Diffusion is Rapid
The unprecedented interdigitated and layered structures
of 1,1′,3,3′-tetraÂ(2-methyl-2-nonyl)Âferrocene
(DEC) and the oxoanion ferrocenium salts DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup> were determined
by single-crystal X-ray diffraction. The four structures are similar
except that the three DEC<sup>+</sup> salts have layers of XO<sub><i>n</i></sub><sup>–</sup> oxoanions stuffed between
the layers of interdigitated ferrocenium ions. The perpendicular distances
between layers of Fe atoms are 8.530, 9.108, 9.009, and 9.158 Ã…
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The structures also contain
layers of rigorously coplanar Fe and X atoms that are tilted 65.4,
75.9, 61.9, and 61.1° from the aforementioned layers of Fe atoms
for DEC, DEC<sup>+</sup>NO<sub>3</sub><sup>–</sup>, DEC<sup>+</sup>ClO<sub>4</sub><sup>–</sup>, and DEC<sup>+</sup>ReO<sub>4</sub><sup>–</sup>, respectively. The local environments
of the XO<sub><i>n</i></sub><sup>–</sup> oxoanions
consist of networks of C–H···O hydrogen bonds,
and the structures exhibit channels through which these anions could
diffuse. Facile diffusion of these anions in thin films of DEC<sup>+</sup>XO<sub><i>n</i></sub><sup>–</sup>, with structures
that appear to resemble the crystal structures, has been demonstrated
Redox-Active Bis(phenolate) N‑Heterocyclic Carbene [OCO] Pincer Ligands Support Cobalt Electron Transfer Series Spanning Four Oxidation States
A new
family of low-coordinate Co complexes supported by three redox-noninnocent
tridentate [OCO] pincer-type bisÂ(phenolate) N-heterocyclic carbene
(NHC) ligands are described. Combined experimental and computational
data suggest that the charge-neutral four-coordinate complexes are
best formulated as CoÂ(II) centers bound to closed-shell [OCO]<sup>2–</sup> dianions, of the general formula [(OCO)ÂCo<sup>II</sup>L] (where L is a solvent-derived MeCN or THF). Cyclic voltammograms
of the [(OCO)ÂCo<sup>II</sup>L] complexes reveal three oxidations accessible
at potentials below 1.2 V vs Fc<sup>+</sup>/Fc, corresponding to generation
of formally CoÂ(V) species, but the true physical/spectroscopic oxidation
states are much lower. Chemical oxidations afford the mono- and dications
of the imidazoline NHC-derived complex, which were examined by computational
and magnetic and spectroscopic methods, including single-crystal X-ray
diffraction. The metal and ligand oxidation states of the monocationic
complex are ambiguous; data are consistent with formulation as either
[(<sup>S</sup>OCO)ÂCo<sup>III</sup>(THF)<sub>2</sub>]<sup>+</sup> containing
a closed-shell [<sup>S</sup>OCO]<sup>2–</sup> diphenolate ligand
bound to a <i>S</i> = 1 CoÂ(III) center, or [(<sup>S</sup>OCO<sup>•</sup>)ÂCo<sup>II</sup>(THF)<sub>2</sub>]<sup>+</sup> with a low-spin CoÂ(II) ion ferromagnetically coupled to monoanionic
[<sup>S</sup>OCO<sup>•</sup>]<sup>−</sup> containing
a single unpaired electron distributed across the [OCO] framework.
The dication is best described as [(<sup>S</sup>OCO<sup>0</sup>)ÂCo<sup>II</sup>(THF)<sub>3</sub>]<sup>2+</sup>, with a single unpaired electron
localized on the d<sup>7</sup> CoÂ(II) center and a doubly oxidized,
charge-neutral, closed-shell <sup>S</sup>OCO<sup>0</sup> ligand.
The combined data provide for the first time unequivocal and structural
evidence for [OCO] ligand redox activity. Notably, varying the degree
of unsaturation in the NHC backbone shifts the ligand-based oxidation
potentials by up to 400 mV. The possible chemical origins of this
unexpected shift, along with the potential utility of the [OCO] pincer
ligands for base-metal-mediated organometallic coupling catalysis,
are discussed