TY - JOUR
T1 - Crystal Field in Rare-Earth Complexes
T2 - From Electrostatics to Bonding
AU - Alessandri, Riccardo
AU - Zulfikri, Habiburrahman
AU - Autschbach, Jochen
AU - Bolvin, Hélène
N1 - Publisher Copyright:
© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2018/4/11
Y1 - 2018/4/11
N2 - The flexibility of first-principles (ab initio) calculations with the SO-CASSCF (complete active space self-consistent field theory with a treatment of the spin-orbit (SO) coupling by state interaction) method is used to quantify the electrostatic and covalent contributions to crystal field parameters. Two types of systems are chosen for illustration: 1) The ionic and experimentally well-characterized PrCl3 crystal; this study permits a revisitation of the partition of contributions proposed in the early days of crystal field theory; and 2) a series of sandwich molecules [Ln(ηn-CnHn)2]q, with Ln=Dy, Ho, Er, and Tm and n=5, 6, and 8, in which the interaction between LnIII and the aromatic ligands is more difficult to describe within an electrostatic approach. It is shown that a model with three layers of charges reproduces the electrostatic field generated by the ligands and that the covalency plays a qualitative role. The one-electron character of crystal field theory is discussed and shown to be valuable, although it is not completely quantitative. This permits a reduction of the many-electron problem to a discussion of the energy of the seven 4f orbitals.
AB - The flexibility of first-principles (ab initio) calculations with the SO-CASSCF (complete active space self-consistent field theory with a treatment of the spin-orbit (SO) coupling by state interaction) method is used to quantify the electrostatic and covalent contributions to crystal field parameters. Two types of systems are chosen for illustration: 1) The ionic and experimentally well-characterized PrCl3 crystal; this study permits a revisitation of the partition of contributions proposed in the early days of crystal field theory; and 2) a series of sandwich molecules [Ln(ηn-CnHn)2]q, with Ln=Dy, Ho, Er, and Tm and n=5, 6, and 8, in which the interaction between LnIII and the aromatic ligands is more difficult to describe within an electrostatic approach. It is shown that a model with three layers of charges reproduces the electrostatic field generated by the ligands and that the covalency plays a qualitative role. The one-electron character of crystal field theory is discussed and shown to be valuable, although it is not completely quantitative. This permits a reduction of the many-electron problem to a discussion of the energy of the seven 4f orbitals.
KW - ab initio calculations
KW - bond theory
KW - crystal field effects
KW - lanthanides
KW - ligand effects
UR - http://www.scopus.com/inward/record.url?scp=85043353486&partnerID=8YFLogxK
U2 - 10.1002/chem.201705748
DO - 10.1002/chem.201705748
M3 - Article
C2 - 29356203
AN - SCOPUS:85043353486
SN - 0947-6539
VL - 24
SP - 5538
EP - 5550
JO - Chemistry - A European Journal
JF - Chemistry - A European Journal
IS - 21
ER -