Physicochemical properties of near-linear Ln(II) bis-silylamide complexes (Ln = Sm, Eu, Tm, Yb)Citation formats

  • External authors:
  • Conrad Goodwin
  • Gianni F. Vettese
  • Eufemio Moreno Pineda
  • Joseph W. Ziller
  • William J. Evans

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Physicochemical properties of near-linear Ln(II) bis-silylamide complexes (Ln = Sm, Eu, Tm, Yb). / Goodwin, Conrad; Chilton, Nicholas; Vettese, Gianni F.; Moreno Pineda, Eufemio; Crowe, Iain; Ziller, Joseph W.; Evans, William J.; Mills, David.

In: Inorganic Chemistry, Vol. 55, No. 20, 2016.

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Goodwin, Conrad ; Chilton, Nicholas ; Vettese, Gianni F. ; Moreno Pineda, Eufemio ; Crowe, Iain ; Ziller, Joseph W. ; Evans, William J. ; Mills, David. / Physicochemical properties of near-linear Ln(II) bis-silylamide complexes (Ln = Sm, Eu, Tm, Yb). In: Inorganic Chemistry. 2016 ; Vol. 55, No. 20.

Bibtex

@article{fa52ef4a263d4b09b81dac57e5c1185c,
title = "Physicochemical properties of near-linear Ln(II) bis-silylamide complexes (Ln = Sm, Eu, Tm, Yb)",
abstract = "Following our report of the first near-linear lanthanide (Ln) complex, [Sm(N††)2] (1), herein we present the synthesis of [Ln(N††)2] [N†† = {N(SiiPr3)2}–; Ln = Eu (2), Tm (3) and Yb (4)], thus achieving approximate uniaxial geometries for a series of “traditional” Ln(II) ions. Experimental evidence, together with calculations performed on a model of 4, indicate that dispersion forces are important for the stabilization of the near-linear geometries of 1-4. The isolation of 3 under a dinitrogen atmosphere is noteworthy, given that “[Tm(N′′)(μ-N′′)]2” (N′′ = {N(SiMe3)2}–) has not previously been structurally authenticated and reacts rapidly with N2(g) to give [{Tm(N′′)¬2}2(μ-η2:η2-N2)]. Complexes 1-4 have been characterized as appropriate by single crystal XRD, magnetic measurements, electrochemistry, and multinuclear NMR, EPR, and electronic spectroscopy, along with computational methods for 3 and 4. The remarkable geometries of monomeric 1-4 lead to interesting physical properties, which complement and contrast with comparatively well understood dimeric [Ln(N′′)(μ-N′′)]2 complexes. EPR spectroscopy of 3 shows that the near-linear geometry stabilizes mJ states with oblate spheroid electron density distributions, validating our previous suggestions. Cyclic voltammetry experiments carried out on 1-4 did not yield Ln(II) reduction potentials, so a reactivity study of 1 was performed with selected substrates in order to benchmark the Sm(III)→Sm(II) couple. The separate reactions of 1 with TEMPO (2,2,6,6-tetramethyl-piperidinyl-1-oxy), azobenzene and benzophenone gave crystals of [Sm(N††)2(TEMPO)] (5), [Sm(N††)2(N2Ph2)] (6) and [Sm(N††){μ-OPhC(C6H5)CPh2O-κ-O,O′}]2 (7), respectively. The isolation of 5-7 shows that the Sm(II) center in 1 is still accessible despite having two bulky N†† moieties, and that the N-donor atoms are able to deviate further from linearity or ligand scrambling occurs in order to accommodate another ligand in the Sm(III) coordination spheres of the products.",
author = "Conrad Goodwin and Nicholas Chilton and Vettese, {Gianni F.} and {Moreno Pineda}, Eufemio and Iain Crowe and Ziller, {Joseph W.} and Evans, {William J.} and David Mills",
year = "2016",
doi = "10.1021/acs.inorgchem.6b00808",
language = "English",
volume = "55",
journal = "Inorganic Chemistry",
issn = "0020-1669",
publisher = "American Chemical Society",
number = "20",

}

RIS

TY - JOUR

T1 - Physicochemical properties of near-linear Ln(II) bis-silylamide complexes (Ln = Sm, Eu, Tm, Yb)

AU - Goodwin, Conrad

AU - Chilton, Nicholas

AU - Vettese, Gianni F.

AU - Moreno Pineda, Eufemio

AU - Crowe, Iain

AU - Ziller, Joseph W.

AU - Evans, William J.

AU - Mills, David

PY - 2016

Y1 - 2016

N2 - Following our report of the first near-linear lanthanide (Ln) complex, [Sm(N††)2] (1), herein we present the synthesis of [Ln(N††)2] [N†† = {N(SiiPr3)2}–; Ln = Eu (2), Tm (3) and Yb (4)], thus achieving approximate uniaxial geometries for a series of “traditional” Ln(II) ions. Experimental evidence, together with calculations performed on a model of 4, indicate that dispersion forces are important for the stabilization of the near-linear geometries of 1-4. The isolation of 3 under a dinitrogen atmosphere is noteworthy, given that “[Tm(N′′)(μ-N′′)]2” (N′′ = {N(SiMe3)2}–) has not previously been structurally authenticated and reacts rapidly with N2(g) to give [{Tm(N′′)¬2}2(μ-η2:η2-N2)]. Complexes 1-4 have been characterized as appropriate by single crystal XRD, magnetic measurements, electrochemistry, and multinuclear NMR, EPR, and electronic spectroscopy, along with computational methods for 3 and 4. The remarkable geometries of monomeric 1-4 lead to interesting physical properties, which complement and contrast with comparatively well understood dimeric [Ln(N′′)(μ-N′′)]2 complexes. EPR spectroscopy of 3 shows that the near-linear geometry stabilizes mJ states with oblate spheroid electron density distributions, validating our previous suggestions. Cyclic voltammetry experiments carried out on 1-4 did not yield Ln(II) reduction potentials, so a reactivity study of 1 was performed with selected substrates in order to benchmark the Sm(III)→Sm(II) couple. The separate reactions of 1 with TEMPO (2,2,6,6-tetramethyl-piperidinyl-1-oxy), azobenzene and benzophenone gave crystals of [Sm(N††)2(TEMPO)] (5), [Sm(N††)2(N2Ph2)] (6) and [Sm(N††){μ-OPhC(C6H5)CPh2O-κ-O,O′}]2 (7), respectively. The isolation of 5-7 shows that the Sm(II) center in 1 is still accessible despite having two bulky N†† moieties, and that the N-donor atoms are able to deviate further from linearity or ligand scrambling occurs in order to accommodate another ligand in the Sm(III) coordination spheres of the products.

AB - Following our report of the first near-linear lanthanide (Ln) complex, [Sm(N††)2] (1), herein we present the synthesis of [Ln(N††)2] [N†† = {N(SiiPr3)2}–; Ln = Eu (2), Tm (3) and Yb (4)], thus achieving approximate uniaxial geometries for a series of “traditional” Ln(II) ions. Experimental evidence, together with calculations performed on a model of 4, indicate that dispersion forces are important for the stabilization of the near-linear geometries of 1-4. The isolation of 3 under a dinitrogen atmosphere is noteworthy, given that “[Tm(N′′)(μ-N′′)]2” (N′′ = {N(SiMe3)2}–) has not previously been structurally authenticated and reacts rapidly with N2(g) to give [{Tm(N′′)¬2}2(μ-η2:η2-N2)]. Complexes 1-4 have been characterized as appropriate by single crystal XRD, magnetic measurements, electrochemistry, and multinuclear NMR, EPR, and electronic spectroscopy, along with computational methods for 3 and 4. The remarkable geometries of monomeric 1-4 lead to interesting physical properties, which complement and contrast with comparatively well understood dimeric [Ln(N′′)(μ-N′′)]2 complexes. EPR spectroscopy of 3 shows that the near-linear geometry stabilizes mJ states with oblate spheroid electron density distributions, validating our previous suggestions. Cyclic voltammetry experiments carried out on 1-4 did not yield Ln(II) reduction potentials, so a reactivity study of 1 was performed with selected substrates in order to benchmark the Sm(III)→Sm(II) couple. The separate reactions of 1 with TEMPO (2,2,6,6-tetramethyl-piperidinyl-1-oxy), azobenzene and benzophenone gave crystals of [Sm(N††)2(TEMPO)] (5), [Sm(N††)2(N2Ph2)] (6) and [Sm(N††){μ-OPhC(C6H5)CPh2O-κ-O,O′}]2 (7), respectively. The isolation of 5-7 shows that the Sm(II) center in 1 is still accessible despite having two bulky N†† moieties, and that the N-donor atoms are able to deviate further from linearity or ligand scrambling occurs in order to accommodate another ligand in the Sm(III) coordination spheres of the products.

U2 - 10.1021/acs.inorgchem.6b00808

DO - 10.1021/acs.inorgchem.6b00808

M3 - Article

VL - 55

JO - Inorganic Chemistry

JF - Inorganic Chemistry

SN - 0020-1669

IS - 20

ER -