Synthesis and structure of nonacoordinated tris-chelate lanthanide (III) complexes with tridentate 2,4,6,8-tetrakis(tert-butyl)-9-hydroxyphenoxazin-1-one ligands

Ivakhnenko, E. P.; Романенко, Г. В.; Simakov, V. I.; Knyazev, Pavel A.; Bogomyakov, A. S.

doi:10.1016/j.ica.2017.01.001

Cited by 7 publications

(4 citation statements)

References 23 publications

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“…To further support the ground state electronic structures in Ln(DOPO q ) 3 (Ln = Ce, Nd, and Gd), variable temperature magnetization and field-dependent magnetic measurements were performed (Figure ). At room temperature, the μ eff values of Ce(DOPO q ) 3 , Nd(DOPO q ) 3 , and Gd(DOPO q ) 3 were 2.49, 3.61, and 7.90 μ B , respectively, in good agreement with the expected magnetic moments, 2.53, 3.62, and 7.94 μ B for Ce 3+ , Nd 3+ , and Gd 3+ cations. ,− Upon cooling, the μ eff values decreased to 1.23, 1.97, and 6.49 μ B , respectively, at 2 K. Such decreases in moments at lower temperatures for Ce(DOPO q ) 3 and Nd(DOPO q ) 3 results from the depopulation of Stark energy levels created by crystal field perturbations of the J = 5/2 and J = 9/2 manifold for the respective Ce 3+ and Nd 3+ cations. The behavior of Gd(DOPO q ) 3 was consistent with that previously reported .…”

Section: Resultssupporting

confidence: 60%

“…Slow evaporation over 24 h caused blue crystals to reliably and reproducibly precipitate from these concentrated solutions. Analysis of the crystals by X-ray diffraction confirmed the identities as Ce(DOPO q ) 3 , Nd-(DOPO q ) 3 , Sm(DOPO q ) 3 , and Gd(DOPO q ) 3 , 17,18 and the molecular structures of Ce, Nd, and Gd are presented in Figure 1 (metrical parameters displayed in Table 1). In all cases, three statistically indistinguishable DOPO ligands were observed.…”

Section: Journal Of the American Chemical Societymentioning

confidence: 72%

“…Such a class of ligands have been shown to produce highly covalent transition-metal compounds . The dioxophenoxazine (DOPO) ligand (DOPO = 2,4,6,8-tetra- tert -butyl-1-oxo-1 H -phenoxazin-9-olate) is an appropriate choice, given its widespread use on d - , and f -block − metals. This ligand’s planar coordination mode, its ability to form robust metal–oxygen bonds, and its analogy to dipicolinate make it attractive for this study.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis and Characterization of Tris-chelate Complexes for Understanding f-Orbital Bonding in Later Actinides

et al. 2019

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An isostructural family of f-element compounds (Ce, Nd, Sm, Gd; Am, Bk, Cf) of the redox-active dioxophenoxazine ligand (DOPO q ; DOPO = 2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazin-9-olate) was prepared. This family, of the form M(DOPO q ) 3 , represents the first nonaqueous isostructural series, including the later actinides berkelium and californium. The lanthanide derivatives were fully characterized using 1 H NMR spectroscopy and SQUID magnetometry, while all species were structurally characterized by X-ray crystallography and electronic absorption spectroscopy. In order to probe the electronic structure of this new family, CASSCF calculations were performed and revealed these systems to be largely ionic in contrast to previous studies, where berkelium and californium typically have a small degree of covalent character. To validate the zeroth order regular approximation (ZORA) method, the same CASSCF analysis using experimental structures versus UDFT-ZORA optimized structures does not exhibit sizable changes in bonding patterns. This shows that UDFT-ZORA combined with CASSCF could be a useful first approximation to predict and investigate the structure and electronic properties of actinides and lanthanides that are difficult to synthesize or characterize.

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Section: Resultssupporting

confidence: 60%

Section: Journal Of the American Chemical Societymentioning

confidence: 72%

Section: Introductionmentioning

confidence: 99%

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Synthesis and Characterization of Tris-chelate Complexes for Understanding f-Orbital Bonding in Later Actinides

et al. 2019

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“…These ligands are known for covalent bonding with transition metals, making them of interest for exploring actinide covalency as well. Of particular interest is the dioxophenoxazine (DOPO) (DOPO = 2,4,6,8-tetrta- tert -butyl-1-oxo-1 H -phenoxazin-9-olate) ligand, which has been studied with first-row transition metals, main group metals, and lanthanides. , This ligand is attractive as it can exist in three different oxidation states, namely, the monoanionic quinone (DOPO q ) state, the dianionic semiquinone (DOPO sq ) state, and the trianionic catecholate, (DOPO cat ) state (Figure ). This redox flexibility allows the metals to be in their thermodynamically preferred oxidation state while potentially offering the ability to engage in covalent bonding.…”

Section: Introductionmentioning

confidence: 99%

Using Redox-Active Ligands to Generate Actinide Ligand Radical Species

et al. 2021

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Using a redox-active dioxophenoxazine ligand, DOPO (DOPO = 2,4,6,8-tetra-tert-butyl-1-oxo-1H-phenoxazine-9-olate), a family of actinide (U, Th, Np, and Pu) and Hf tris(ligand) coordination compounds was synthesized. The full characterization of these species using 1H NMR spectroscopy, electronic absorption spectroscopy, SQUID magnetometry, and X-ray crystallography showed that these compounds are analogous and exist in the form M(DOPOq)2(DOPOsq), where two ligands are of the oxidized quinone form (DOPOq) and the third is of the reduced semiquinone (DOPOsq) form. The electronic structures of these complexes were further investigated using CASSCF calculations, which revealed electronic structures consistent with metals in the +4 formal oxidation state and one unpaired electron localized on one ligand in each complex. Furthermore, f orbitals of the early actinides show a sizable bonding overlap with the ligand 2p orbitals. Notably, this is the first example of a plutonium–ligand radical species and a rare example of magnetic data being recorded for a homogeneous plutonium coordination complex.

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Reaction of 3,5-di-(tert-butyl)-o-benzoquinone with arylamines developing to the formation of a pentaheterocyclic 12Н-quinoxaline[2,3-b]phenoxazine system. A deeper insight into the reaction mechanism

et al. 2018

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Synthesis and structure of nonacoordinated tris-chelate lanthanide (III) complexes with tridentate 2,4,6,8-tetrakis(tert-butyl)-9-hydroxyphenoxazin-1-one ligands

Cited by 7 publications

References 23 publications

Synthesis and Characterization of Tris-chelate Complexes for Understanding f-Orbital Bonding in Later Actinides

Synthesis and Characterization of Tris-chelate Complexes for Understanding f-Orbital Bonding in Later Actinides

Using Redox-Active Ligands to Generate Actinide Ligand Radical Species

Reaction of 3,5-di-(tert-butyl)-o-benzoquinone with arylamines developing to the formation of a pentaheterocyclic 12Н-quinoxaline[2,3-b]phenoxazine system. A deeper insight into the reaction mechanism

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