Electronic structures and spectral properties of double- and triple-decker phthalocyanine complexes in a localized molecular orbital view

Ishikawa, Naoto

doi:10.1002/1099-1409(200101)5:1<87::aid-jpp304>3.0.co;2-q

Cited by 64 publications

(7 citation statements)

References 52 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The changes in absorption spectra of [2] are almost identical to those found in the non-substituted lutetium(III) double-decker complexes extensively studied by Ishikawa et al [30][31]33 A sharp and strong absorption at 15840 cm −1 and smaller peaks at 14740 cm −1 in [2] are HOMO to degenerated LUMO+1 orbitals and HOMO-1 to degenerated LUMO respectively. The weak absorption at 6330 cm −1 in [2] 0 is related to the -radical on the ligand, which has been observed at ~7100 cm −1 in unsubstituted complexes, 66 and it corresponds to the transition from the highest two-electron filled molecular orbital to a singly occupied molecular orbital (|LUMO ← HOMO> transition).…”

Section: Electrochemical Analysis Of Multiple-decker Complexessupporting

confidence: 74%

Terbium(III) Phthalocyaninato Multiple-Decker Complexes in High Oxidation States: Correlation Between Electronic, Structural and Magnetic Properties and Unexpected Triplet Biradical States

Horii¹,

Damjanović²,

Ajayakumar³

et al. 2019

Preprint

View full text Add to dashboard Cite

Herein we present a comprehensive study of the highly oxidized species of multiple-decker complexes composed of Tb(III) and Cd(II) ions and two to five phthalocyaninato ligands, which are stabilized by electron-donating n-butoxy chains. Paramagnetic 1H NMR measurements for the series of triple, quadruple and quintuple-decker complexes revealed that ligand oxidations lead to a decrease in magnetic anisotropy, as predicted from ab initio calculations. Unusual paramagnetic shifts were observed in +2e charged quadruple and quintuple-decker complexes, indicating that those two species are actually triplet biradicals. The X-ray structural analysis for the series of oxidized multiple-decker complexes revealed that all the species show an axial compression induced by the ligand oxidations, resulting in the bowl-shaped distortion of the ligands, in agreement with predictions from DFT calculations. Magnetic measurements revealed that the series of complexes show single-molecule magnet (SMM) properties, which are controlled by the multi-step redox induced structural changes.

show abstract

Section: Electrochemical Analysis Of Multiple-decker Complexessupporting

confidence: 74%

Terbium(III) Phthalocyaninato Multiple-Decker Complexes in High Oxidation States: Correlation Between Electronic, Structural and Magnetic Properties and Unexpected Triplet Biradical States

Horii¹,

Damjanović²,

Ajayakumar³

et al. 2019

Preprint

View full text Add to dashboard Cite

show abstract

“…10 The control over the rotational behavior of macrocycles in sandwich complexes can be used to tune their physical and chemical properties by precise control of the specific interligand π−π interactions, which strongly depend on ϕ. Such dependencies were deduced from theoretical modeling, and these results suggest the possibility of tuning the spectral properties, 11 reactivity, 12 nonlinear-optical behavior, 13 etc., by variation of the skew angle. Moreover, in the case of sandwich complexes formed by REE ions, this skew angle dictates the coordination polyhedron of the metal ion, which alters from a square-prismatic (SP; ϕ ≈ 0°) to a distorted and squareantiprismatic (SAP; ϕ ≈ 45°) surrounding in the range of 0°< ϕ < 45°.…”

Section: ■ Introductionmentioning

confidence: 99%

Heteroleptic Crown-Substituted Tris(phthalocyaninates) as Dynamic Supramolecular Scaffolds with Switchable Rotational States and Tunable Magnetic Properties

et al. 2021

View full text Add to dashboard Cite

Herein we report single-crystal X-ray diffraction characterization and complementary solution studies of supramolecular interaction between potassium salts and heteroleptic homo- and heteronuclear triple-decker crown phthalocyaninates [(15C5)4Pc]M*[(15C5)4Pc]M(Pc) or [M*,M], where M* and M = Y and/or Tb. Our results evidence that, in contrast to the previously studied crown-substituted phthalocyanines, the interaction of K+ cations with [M*,M] does not induce their intermolecular aggregation. Instead, the cations reversibly intercalate between the crown-substituted phthalocyanine ligands, resulting in switching of the coordination polyhedron of the metal center M* from square-antiprismatic to square-prismatic. In the case of terbium(III) complexes, such a switching alters their magnetic properties, which can be read-out by 1H NMR spectroscopy. For [Tb*,Y], such a switching causes an almost 25% increase in the axial component of the magnetic susceptibility tensor. Even though the polyhedron of the paramagnetic center in [Y*,Tb] is not switched, minor structural perturbations associated with the overall reorganization of the receptor also cause smaller, but nevertheless appreciable, growth of the axial anisotropy. The observed effects render the studied complexes as molecular switches with tunable magnetic properties.

show abstract

“…The CASSCF active space contains the seven 4f orbitals of the central lanthanide, which transform as b 2 + e 1 + e 2 + e 3 in the approximate D 4d point group, and the π-SOMO (having a 2 symmetry) [29] of the Pc 2 rings (see Figure 1, top). RASSCF calculations were performed on a simpli ed model structure in order to reduce computational cost.…”

Section: Computational Detailsmentioning

confidence: 99%

Lanthanide-Radical Magnetic Coupling in [LnPc2]0: Competing Exchange Mechanisms Captured via Ab Initio Multi-Reference Calculations

Huang¹,

Heuvel²,

Soncini³

2020

Quantum Mater Res

View full text Add to dashboard Cite

We present a computational investigation of the intramolecular exchange coupling in [LnPc 2 ] 0 (Ln = Tb, Dy, Ho, and Er) between the Ln 3+ 4f electrons and the spin-1/2 radical on the phthalocyanine ligands. A series of ab initio multi-con gurational/multi-reference Complete/Restricted Active Space Self-Consistent-Field calculations (CASSCF/RASSCF), including non-perturbative spin-orbit coupling, were performed on [LnPc 2 ] 0 and on the smaller model compound [LnPz 2 ] 0. We nd that the exchange coupling mechanisms are restricted by symmetry, but also dependent on the spin polarization e ect triggered by the Pc 2 ligands π-π * excitations. The calculated exchange splittings are small, amounting to at most a few cm-1 , in disagreement with previous literature reports of strong antiferromagnetic coupling, but in good agreement with recent EPR experiments on [TbPc 2 ] 0. Furthermore, the coupling strength is found to decrease from [TbPc 2 ] 0 to [ErPc 2 ] 0 , with decreasing number of unpaired electron spins in the lanthanide ground (Hund's rule) Russell-Saunders term.

show abstract

Electronic structures and spectral properties of double- and triple-decker phthalocyanine complexes in a localized molecular orbital view

Cited by 64 publications

References 52 publications

Terbium(III) Phthalocyaninato Multiple-Decker Complexes in High Oxidation States: Correlation Between Electronic, Structural and Magnetic Properties and Unexpected Triplet Biradical States

Terbium(III) Phthalocyaninato Multiple-Decker Complexes in High Oxidation States: Correlation Between Electronic, Structural and Magnetic Properties and Unexpected Triplet Biradical States

Heteroleptic Crown-Substituted Tris(phthalocyaninates) as Dynamic Supramolecular Scaffolds with Switchable Rotational States and Tunable Magnetic Properties

Lanthanide-Radical Magnetic Coupling in [LnPc2]0: Competing Exchange Mechanisms Captured via Ab Initio Multi-Reference Calculations

Contact Info

Product

Resources

About