Molecular structure of monomeric scandium trichloride by gas electron diffraction and density functional theory calculations on ScCl3 and Sc2Cl6 †

Haaland, Arne; Martinsen, Kjell-Gunnar; Shorokhov, Dmitry; Girichev, G. V.; Соколов, В. И.

doi:10.1039/a803339k

Cited by 18 publications

(9 citation statements)

References 23 publications

(21 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Scandium Trihalides. Our DFT calculations suggest the equilibrium structures of scandium trihalides to be planar and belong to D 3h symmetry, supporting the earlier gas-phase electron diffraction 9,11,102 and theoretical studies. 9,11,102−104 Table 1 collects the theoretical gas-phase thermochemical data of scandium trihalides along with their experimental counterparts.…”

Section: Resultssupporting

confidence: 85%

“…Our PBE0 DFT calculations support the D 2h equilibrium structures of the Sc 2 X 6 molecules, with the double halogen bridges and the other four halogen atoms lying in the perpendicular plane in line with the previous gas-phase electron diffraction studies. 9,11,102 Table 3 lists the gas-phase thermodynamic functions of scandium trihalide dimers. In addition to eq 5 heterolytic dissociation involving Sc + in its triplet ground state, we also considered the same reaction (denoted as eq 5* in Table 1) with a Sc + singlet excited state in the 4s 2 configuration.…”

Section: Resultsmentioning

confidence: 99%

“…Our PBE0 DFT calculations support the D2h equilibrium structures of the Sc2X6 molecules with the double halogen bridges and the other four halogen atoms lying in the perpendicular plane in line with the previous gas-phase electron diffraction studies. 9,11,102 Table 3 lists the gas phase thermodynamic functions of Sc trihalide dimers. In addition to Eq.…”

Section: Scandium Trihalide Dimersmentioning

confidence: 99%

See 2 more Smart Citations

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

et al. 2020

View full text Add to dashboard Cite

Domain-based local pair natural orbital coupled cluster approach with single, double and improved linear scaling perturbative triples correction via an iterative algorithm, DLPNO−CCSD(T1), was applied within a framework of the Feller-Peterson-Dixon approach to derive gas-phase heats of formation of scandium and yttrium trihalides and their dimers via a set of homolytic and heterolytic dissociation reactions. All predicted heats of formation moderately depend on reaction type with the most and the least negative values obtained for homolytic and heterolytic dissociation, respectively. The basis set size dependence, as well as the influence of static correlation effects not covered by the standard (DLPNO-)CCSD(T) approach, suggest that exploitation of the heterolytic dissociation reactions with formation of M +3 and Xions leads to the most robust heats of formation. The gas-phase formation enthalpies ΔH f °(0 K)/ ΔH f °(298.15 K) and absolute entropies S°(298.15 K) were obtained for the first time for the Sc2F6, Sc2Br6, and Sc2I6 species. For ScBr3, ScI3, Sc2Cl6, Y2Cl6 we suggest a re-examination of available in the literature experimental heats of formation. For other compounds the predicted values were found to be in good agreement with the experimental estimates. Extracted MX3 (M = Sc, Y, and X = F, Cl, Br, and I) 0K atomization enthalpies indicate the weaker bonding when moving from F to I and from Y to Sc. Likewise, the stability of yttrium trihalide dimers degrades when going from F to I. Respective scandium trihalide dimers are less stable, with 0 K dimer dissociation energy decreasing in row F -Cl -Br  I. Correlation of the (n-1)s 2 p 6 electrons on Br and I, inclusion of zero-point energy, relativistic effects, and the effective core-potential correction as well as amelioration of the DLPNO localization inaccuracy was shown to be of similar magnitude and is critical if accurate heats of formation are a goal.

show abstract

Section: Resultssupporting

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Section: Scandium Trihalide Dimersmentioning

confidence: 99%

See 1 more Smart Citation

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The conditions for the pyramidalization of tricoordinate complexes are therefore already significantly more restrictive than those for the bending of dicoordinate species. Thus, Group 3 or lanthanide trihalides tend to be planar13, 19, 32, 42, 43 (ref. 10 provides extensive further literature) or only very slightly pyramidalized, with shallow potential wells (“quasiplanar”).…”

Section: Examples Of Homoleptic Complexes With “Non‐vsepr Structures”mentioning

confidence: 99%

“Non‐VSEPR” Structures and Bonding in d⁰Systems

Kaupp

2001

Angewandte Chemie Intl Edit

172

View full text Add to dashboard Cite

Under certain circumstances, metal complexes with a formal d0 electronic configuration may exhibit structures that violate the traditional structure models, such as the VSEPR concept or simple ionic pictures. Some examples of such behavior, such as the bent gas‐phase structures of some alkaline earth dihalides, or the trigonal prismatic coordination of some early transition metal chalcogenides or pnictides, have been known for a long time. However, the number of molecular examples for “non‐VSEPR” structures has increased dramatically during the past decade, in particular in the realm of organometallic chemistry. At the same time, various theoretical models have been discussed, sometimes controversially, to explain the observed, unusual structures. Many d0 systems are important in homogeneous and heterogeneous catalysis, biocatalysis (e.g. molybdenum or tungsten enzymes), or materials science (e.g. ferroelectric perovskites or zirconia). Moreover, their electronic structure without formally nonbonding d orbitals makes them unique starting points for a general understanding of structure, bonding, and reactivity of transition metal compounds. Here we attempt to provide a comprehensive view, both of the types of deviations of d0 and related complexes from regular coordination arrangements, and of the theoretical framework that allows their rationalization. Many computational and experimental examples are provided, with an emphasis on homoleptic mononuclear complexes. Then the factors that control the structures are discussed in detail. They are a) metal d orbital participation in σ bonding, b) polarization of the outermost core shells, c) ligand repulsion, and d) π bonding. Suggestions are made as to which of the factors are the dominant ones in certain situations. In heteroleptic complexes, the competition of σ and π bonding of the various ligands controls the structures in a complicated fashion. Some guidelines are provided that should help to better understand the interrelations. Bent's rule is of only very limited use in these types of systems, because of the paramount influence of π bonding. Finally, computed and measured structures of multinuclear complexes are discussed, including possible consequences for the properties of bulk solids.

show abstract

“…Daher neigen Trihalogenide der Gruppe 3 sowie Lanthanoidtrihalogenide zu planaren [13,19,32,42,43] (weitere Zitate finden sich in Lit. Die Bedingungen für eine Pyramidalisierung dreifach koordinierter Komplexe sind daher deutlich restriktiver als für die Abwinkelung zweifach koordinierter Verbindungen.…”

Section: Pyramidale Dreifach Koordinierte Komplexeunclassified

Nicht-VSEPR-Strukturen und chemische Bindung in d0-Systemen

Kaupp

2001

Angew. Chem.

View full text Add to dashboard Cite

Martin Kaupp, geboren 1962 in Stuttgart, studierte dort sowie in Cincinnati Chemie. Nach der Diplomarbeit, die er 1989 in Stuttgart bei Hermann Stoll in theoretischer Chemie anfertigte, promovierte er 1992 in Erlangen mit einer quantenchemischen Arbeit bei Paul von RagueÂ Schleyer. Nach einem Aufenthalt am Max-Planck-Institut für Festkörperforschung in Stuttgart bei Hans-Georg von Schnering (1992Schnering ( /1993 setzte er seine Postdoc-Arbeiten 1993/1994 bei Dennis Salahub in MontreÂal fort. 1997 habilitierte er sich in theoretischer Chemie in Stuttgart, und seit 1999 ist er Professor an der Universität Würzburg. Seine Forschungsinteressen erstrecken sich über einen weiten Bereich der theoretischen Chemie und der Computerchemie. Das Thema der vorliegenden Arbeit spiegelt sein generelles Interesse an Strukturen und Bindungsverhältnissen von Verbindungen des gesamten Periodensystems wider. Ein weiteres, zentrales Forschungsthema ist die Entwicklung und Anwendung von Dichtefunktionalmethoden zur Berechnung und Interpretation von NMR-und EPR-Parametern, insbesondere die Erweiterung dieser Methoden auf Anwendungen mit schwereren Elementen. Diesbezüglich, aber auch hinsichtlich vieler anderer Bereiche der Chemie, ist er besonders am Einfluss relativistischer Effekte und an deren quantenchemischer Behandlung interessiert. AUFS¾TZE d 0 -Komplexe plexe, werden aber gelegentlich auch d 1 -oder d 2 -Beispiele erwähnen. AUFS¾TZE M. Kaupp Gasphasenelektronenbeugungs(GED)-Untersuchungen ergaben ebenfalls gewinkelte Strukturen. [26] Auf dem MP2-Niveau durchgeführten Ab-initio-Rechnungen an [MCp 2 ] [27] zufolge sind die energetisch günstigsten Isomere bei den Metallen Strontium, Barium, Samarium, Europium gewinkelt. Linear sind die Strukturen hingegen bei Calcium oder Ytterbium (für weitere Rechnungen siehe Lit. [26d, 28]). In allen Fällen war das Abwinkelungspotential extrem flach, sodass diese Komplexe am besten als quasilinear angesehen werden sollten. Infolgedessen werden verlässliche Strukturbestimmungen derartiger Verbindungen durch GED-Untersuchungen wegen des ¹Shrinkingª-Effektes schwierig. [10] Demgegenüber ergaben Rechnungen an den isoelektronischen, jedoch stärker kovalent gebundenen hypothetischen Kationen [MCp 2 ] (M Sc, La) [29] signifikant gewinkelte Strukturen mit groûen Linearisierungsbarrieren. Demnach nimmt die Tendenz zu gewinkelten Strukturen mit steigendem kovalentem Bindungsanteil zu (siehe auch Abschnitt 3.7). Gewinkelte Strukturen sind auch das Ergebnis von Rechnungen an den heteroleptischen Modellsystemen [CpM(NH)] (M Y, La), [30] und auch die Strukturen der Kationen [YH 2 ] , [31c] [ScF 2 ] [9f, 32] sowie [ScH 2 ] [32, 33] sind Rechnungen zufolge signifikant gewinkelt. Kleine Winkel und groûe Linearisierungsenergien wurden theoretisch und teilweise experimentell für [MO 2 ] (M Ti, Zr, Hf) gefunden. [34±36] Noch stärker gewinkelte Strukturen wurden für die Kationen [MO 2 ] (M Nb, Ta) [37] nachgewiesen sowie für die hypothetischen Ionen [MO 2 ] 2 (M Mo, W) vorausgesagt. [38] Auch für [CeO 2 ] lieferten...

show abstract

Molecular structure of monomeric scandium trichloride by gas electron diffraction and density functional theory calculations on ScCl3 and Sc2Cl6 †

Cited by 18 publications

References 23 publications

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

“Non‐VSEPR” Structures and Bonding in d⁰Systems

Nicht-VSEPR-Strukturen und chemische Bindung in d0-Systemen

Contact Info

Product

Resources

About

Molecular structure of monomeric scandium trichloride by gas electron diffraction and density functional theory calculations on ScCl3 and Sc2Cl6 †

Cited by 18 publications

References 23 publications

Gas-Phase Thermochemistry of MX3 and M2X6 (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

Gas-Phase Thermochemistry of MX3 and M2X6 (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

“Non‐VSEPR” Structures and Bonding in d0Systems

Nicht-VSEPR-Strukturen und chemische Bindung in d0-Systemen

Contact Info

Product

Resources

About

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

Gas-Phase Thermochemistry of MX₃ and M₂X₆ (M = Sc, Y; X = F, Cl, Br, I) from a Composite Reaction-Based Approach: Homolytic versus Heterolytic Cleavage

“Non‐VSEPR” Structures and Bonding in d⁰Systems