Zur Elektronenstruktur metallorganischer Komplexe der f-Elemente LIX. Spektrochemische und nephelauxetische Effekte sowie experimentorientierte MO-Schemata (im f-Bereich) pseudo-trigonal-planarer (substituierter) Tris(η5-cyclopentadienyl)neodym(III)-Komplexe und eines THF-Monoaddukts

Jank, Stefan; Reddmann, Hauke; Amberger, H.‐D.; Apostolidis, Christos

doi:10.1016/j.jorganchem.2004.06.049

Cited by 16 publications

(20 citation statements)

References 45 publications

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“…For k ¼ 0.96, an excellent agreement between the calculated values of 1 and the experimental ones of the likewise j-trigonal-planar compound Nd(C 5 H 4 t Bu) 3 [39] was obtained (see Fig. 4 …”

Section: Paramagnetic Susceptibilitysupporting

confidence: 58%

“…In case of 2 [5] and likewise j-trigonal-planar Nd(C 5 H 4 t Bu) 3 [39] the energetic sequence E(18G 7 ) < E(20G 9 ) < E(18G 8 ) was found for the multiplet 4 G 5/2 . If one accepts this sequence for 1, the selection rules of Table 1 do not hold for the above-mentioned hypersensitive transitions, as the symmetry-forbidden "cold" transition 1G 7 ( 4 I 9/2 ) / 18G 7 ( 4 G 5/2 ) is extremely strong (s. Fig.…”

Section: Excited Multipletsmentioning

confidence: 91%

“…Fitting the free parameters of the phenomenological Hamiltonian of the spin-free f 1 system to the calculated energies of f orbitals of Nd(h 5 -C 5 H 5 ) 3 one arrives at B 2 0 ¼ À3428 cm À1 , B 4 0 ¼ 2904 cm À1 , B 6 0 ¼ 1065 cm À1 and B 6 6 ¼ 5919 cm À1 [39]. Comparing these values with those of compound 1 (see Table 4), it becomes evident that first of all the CF parameters B 6 6 (which considers the interactions between orbitals f xðx 2 À3y 2 Þ and f yð3x 2 Ày 2 Þ within the framework of CF theory) but also B 4 0 are heavily overestimated by the model calculation.…”

Section: Simulation Of the Experimental Cf Splitting Patternmentioning

confidence: 99%

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Electronic structures of organometallic complexes of f elements LXXV

Amberger

Reddmann

Mueller

et al. 2011

Journal of Organometallic Chemistry

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Section: Paramagnetic Susceptibilitysupporting

confidence: 58%

Section: Excited Multipletsmentioning

confidence: 91%

Section: Simulation Of the Experimental Cf Splitting Patternmentioning

confidence: 99%

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Electronic structures of organometallic complexes of f elements LXXV

Amberger

Reddmann

Mueller

et al. 2011

Journal of Organometallic Chemistry

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“…14,16,17 In 4, the splitting of the f-orbitals is approximately twice as large as that in 1, which can be attributed to the greater radial extent of the 5f-orbitals. This result is consistent with previous crystal field studies, which show essentially the same splitting of the 4forbitals and a similar ordering (the relative order of the nearly degenerate f z 3 and (f xyz , f z(x 2 -y 2 ) )-orbitals varies).…”

Section: Please Do Not Adjust Marginsmentioning

confidence: 95%

“…10 Common approaches to studying bonding in actinides and lanthanides are comparing ions with either similar ionic radii, e.g., Ce(III) vs U(III), or similar electronic structures, e.g., Nd(III) vs U(III). 14,16,18,19 The role of this orbital in bonding may also be observed by photoelectron spectroscopy although the effect is more pronounced in the Cp 3 M + molecular cations. More recently, the relative energies of the ligand and metal-orbitals have received increased attention due to their roles in increasing covalency by "accidental degeneracy" (increased covalency due to the similar ligand and metal-orbital energies).…”

Section: Introductionmentioning

confidence: 92%

The roles of 4f- and 5f-orbitals in bonding: a magnetochemical, crystal field, density functional theory, and multi-reference wavefunction study

et al. 2016

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The electronic structures of 4f(3)/5f(3) Cp''3M and Cp''3M·alkylisocyanide complexes, where Cp'' is 1,3-bis-(trimethylsilyl)cyclopentadienyl, are explored with a focus on the splitting of the f-orbitals, which provides information about the strengths of the metal-ligand interactions. While the f-orbital splitting in many lanthanide complexes has been reported in detail, experimental determination of the f-orbital splitting in actinide complexes remains rare in systems other than halide and oxide compounds, since the experimental approach, crystal field analysis, is generally significantly more difficult for actinide complexes than for lanthanide complexes. In this study, a set of analogous neodymium(iii) and uranium(iii) tris-cyclopentadienyl complexes and their isocyanide adducts was characterized by electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility. The crystal field model was parameterized by combined fitting of EPR and susceptibility data, yielding an accurate description of f-orbital splitting. The isocyanide derivatives were also studied using density functional theory, resulting in f-orbital splitting that is consistent with crystal field fitting, and by multi-reference wavefunction calculations that support the electronic structure analysis derived from the crystal-field calculations. The results highlight that the 5f-orbitals, but not the 4f-orbitals, are significantly involved in bonding to the isocyanide ligands. The main interaction between isocyanide ligand and the metal center is a σ-bond, with additional 5f to π* donation for the uranium complexes. While interaction with the isocyanide π*-orbitals lowers the energies of the 5fxz(2) and 5fyz(2)-orbitals, spin-orbit coupling greatly reduces the population of 5fxz(2) and 5fyz(2) in the ground state.

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Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 38 [1] Kristall‐, Molekül‐ und Elektronenstruktur von Tris(hydrotris(1‐pyrazolyl)borato)‐samarium(III)

Reddmann

Apostolidis

Walter

et al. 2005

Zeitschrift anorg allge chemie

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Tris(hydrotris(1-pyrazolyl)borato)samarium(III) (SmTp 3 ) crystallizes in the space group P6 3 /m (No. 176) with two molecules in the unit cell. The Sm 3ϩ central ion is coordinated by nine N atoms in the shape of a tricapped trigonal prism, leading to an effective crystal field (CF) of D 3h symmetry. The underlying CF splitting pattern was extracted from the absorption and luminescence spectra run at room and low temperatures, and simulated by fitting the free parameters of a phenomenological Hamiltonian achieving an r.m.s. deviation of 9.4 cm Ϫ1 for 58 assignments. The EinleitungHydrotris(pyrazolyl)borato (Tp)-Verbindungen der Lanthaniden (Ln) [2Ϫ7] sowie insbesondere deren substituierte Derivate waren in den letzten beiden Jahrzehnten Gegenstand zahlreicher optischer [8Ϫ16] und photophysikalischer Untersuchungen [17Ϫ20], da man sich bevorzugt von den entsprechenden Ce-, Eu-und Tb-Komplexen erhebliches Lumineszenzpotential verspricht, das möglicherweise in der Displaytechnologie Verwendung finden könnte [20].Bis vor kurzem konnten die zahlreichen inzwischen akkumulierten optischen Daten aus den folgenden Gründen nicht auf der Grundlage des phänomenologischen Kristallfeld (KF)-Ansatzes rationalisiert werden:• Die leichter kristallisierbaren substituierten Tp-Komplexe [14Ϫ15, 17, 18] sowie die homoleptischen LnTp 3 -Verbindungen der höheren Ln-Elemente [10, 12, 21] haben gemäß röntgenographischen und schwingungsspektroskopischen Untersuchungen häufig niedrige Symmetrien des effektiven KF, so daß die optischen Spektren kaum interpretierbar sind. 1487 parameters used allow the estimation of the global ligand field strength experienced by the Sm 3ϩ central ion, the insertion of SmTp 3 into empirical nephelauxetic and relativistic nephelauxetic series, and the set-up of experimentally based nonrelativistic and relativistic molecular orbital schemes in the f range. Abbildung 1 Molekülstruktur von SmTp 3 im Kristall. tungsmuster von Tb III -Verbindungen experimentell zu erfassen und anschließend rechnerisch zu reproduzieren. Aus diesem Grunde befassen wir uns in der vorliegenden Arbeit vorerst mit der entsprechenden Sm III -Verbindung, da hier das KF-Aufspaltungsmuster sowohl absorptions-als auch lumineszenzspektroskopisch (im Bereich 4900-6700 cm Ϫ1 überlappend) experimentell leichter erfaßbar sein sollte. Außerdem dürfte bei SmTp 3 aufgrund der relativen "Nähe" zum Element Pr ein von PrTp 3 nicht gravierend unterschiedlicher Satz von KF-Parametern vorliegen [23 (Tabelle 8, S. 175)], so daß die Zuordnung der KF-Zustände und die rechnerische Simulation ihrer Energien vereinfacht wird. Ergebnisse Strukturelle BefundeÄhnlich wie die leichteren LnTp 3 -Verbindungen (Lnϭ LaϪNd, EuϪTb) [10,12] kristallisiert SmTp 3 hexagonal in der Raumgruppe P6 3 /m (Nr. 176) mit zwei Molekülen pro Elementarzelle. Die dreizähligen molekularen Hauptdrehachsen (s. u.) der beiden Moleküle pro Elementarzelle sind nicht nur untereinander, sondern auch zur Längsachse der prismatischen Kristalle ausgerichtet, wodurch optische Polarisationsmessun...

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Zur Elektronenstruktur metallorganischer Komplexe der f-Elemente LIX. Spektrochemische und nephelauxetische Effekte sowie experimentorientierte MO-Schemata (im f-Bereich) pseudo-trigonal-planarer (substituierter) Tris(η5-cyclopentadienyl)neodym(III)-Komplexe und eines THF-Monoaddukts

Cited by 16 publications

References 45 publications

Electronic structures of organometallic complexes of f elements LXXV

Electronic structures of organometallic complexes of f elements LXXV

The roles of 4f- and 5f-orbitals in bonding: a magnetochemical, crystal field, density functional theory, and multi-reference wavefunction study

Zur Elektronenstruktur hochsymmetrischer Verbindungen der f‐Elemente. 38 [1] Kristall‐, Molekül‐ und Elektronenstruktur von Tris(hydrotris(1‐pyrazolyl)borato)‐samarium(III)

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