Metal-radical coordination complexes of thiazyl and selenazyl ligands

Preuss, Kathryn E.

doi:10.1016/j.ccr.2014.09.016

Cited by 65 publications

(38 citation statements)

References 112 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…quently part of an important class of highly conductive materials. [56][57][58] Representative dimers in this class are shown in Figure 8; further examples have been recently reviewed by Preuss. [57] Many of these dimeric structures have been interpreted as being pancake bonded.…”

Section: Chalcogen-containing Pancake-bonded Systemsmentioning

confidence: 99%

“…[56][57][58] Representative dimers in this class are shown in Figure 8; further examples have been recently reviewed by Preuss. [57] Many of these dimeric structures have been interpreted as being pancake bonded. [59] The CSD lists about 50 dimeric DTDA derivatives with heteroaromatic five membered rings and about 20 selenium analogues.…”

Section: Chalcogen-containing Pancake-bonded Systemsmentioning

confidence: 99%

“…A number of heterocyclic conjugated radicals form strongly bonded dimers and larger π‐stacking aggregates which are frequently part of an important class of highly conductive materials . Representative dimers in this class are shown in Figure ; further examples have been recently reviewed by Preuss . Many of these dimeric structures have been interpreted as being pancake bonded .…”

Section: Chalcogen‐containing Pancake‐bonded Systemsmentioning

confidence: 99%

See 2 more Smart Citations

Pancake Bonding: An Unusual Pi‐Stacking Interaction

Kertész

2018

Chemistry A European J

211

227

View full text Add to dashboard Cite

A category of parallel π-stacking interaction, termed pancake bonding, is surveyed. The main characteristics are: the interaction occurs among radicals with highly delocalized π-electrons in their singly occupied molecular orbitals (SOMOs), the contact distances in the π-stacking direction are shorter than the typical van der Waals distances, and the stabilization obtained by the bonding combination of the SOMO orbitals leads to direct atom-to-atom overlap with strong orientational preferences. These atypical intermolecular interactions contain a component of electron sharing between the radicals that can be viewed as covalent-like. Pancake bonded dimers characteristically have low-lying singlet and triplet states and show characteristic interlayer vibrational modes. Pancake bonded aggregates serve as molecular components in many conducting and other functional organic materials. The role of van der Waals (vdW) interactions in pancake bonded dimers, chains, and other aggregates is different from closed shell vdW aggregates: here the Pauli repulsions reduce the attractive dispersion interaction significantly. Fluxionality between π- and σ-bonded aggregates often occur in the context of pancake bonding. Both experimental and computational aspects are reviewed.

show abstract

Section: Chalcogen-containing Pancake-bonded Systemsmentioning

confidence: 99%

Section: Chalcogen-containing Pancake-bonded Systemsmentioning

confidence: 99%

Section: Chalcogen‐containing Pancake‐bonded Systemsmentioning

confidence: 99%

See 1 more Smart Citation

Pancake Bonding: An Unusual Pi‐Stacking Interaction

Kertész

2018

Chemistry A European J

211

227

View full text Add to dashboard Cite

show abstract

“…The synthetic strategies developed for making metal-radical complexes are strongly based on transition metal cation affinities for specific heteroatom coordination, including direct coordination of radical ligand (L) sites with high spin density, as in aminoxyl [1,5,6], verdazyls [7][8], thiazyls [9], triazinyl [10][11], nindigo [12], TCNE [13] and semiquinone radicals [14][15]. We have been interested in the additional role played by size-exclusion and steric effects on both primary structure of metal-radical materials, and on intermolecular packing effects that are so crucial to bulk magnetic behavior in molecule-based systems.…”

Section: Introductionmentioning

confidence: 99%

Copper(II) coordination compounds with sterically constraining pyrenyl nitronyl nitroxide and imino nitroxide

2016

View full text Add to dashboard Cite

2-(1'-Pyrenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (PyrNN) and 2-(1'-pyrenyl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl (PyrIN) form pentacoordinate metal-radical complexes with Cu(hfac) 2 : [Cu(hfac) 2 PyrNN] and [Cu(hfac) 2 PyrIN], 1 and 2, respectively. In 1, one aminoxyl unit of PyrNN coordinates to Cu(II) in a distorted square pyramidal environment. In 2, an unusual example of monodentate Cu-N coordination of the imino nitroxide, PyrIN, gives an environment intermediate between square pyramidal and trigonal bipyramid. Both complexes show novel close contacts of the pyrene π-electron cloud with the Cu(II) ion. Compound 1 has a particularly short Cu-O(N) bond of 1.948 Å, giving strong intramolecular antiferromagnetic (AFM) spin-pairing and an absence of significant paramagnetic susceptibility response. The magnetic behavior of compound 2 indicates copper-radical intramolecular ferromagnetic exchange of 2J = 151 cm-1 , and intermolecular AFM spin pairing of 2J =-220 cm-1 due to close antiparallel contacts between non-coordinated NO units. EPR spectra for both complexes are silent at 293 and 77 K. UB97D/6-31G(d) computations find strong antiferromagnetic (2J =-213 cm-1) and ferromagnetic (2J = 610 cm-1) intramolecular metalradical exchange in 1 and 2, respectively in agreement with experimental results.

show abstract

“…For the later p-block elements the redox active nature of many electron-rich S/N and Se/N-based heterocycles have led to the discovery of some of the highest magnetic ordering temperatures for organic magnets, 5 as well as molecule-based conductors 6 and as redox active paramagnetic ligands inter alia. 7 Alongside this, the ability to tune the Lewis acidity of early p-block elements has attracted attention in main group promoted or catalysed organic transformations 8,9 while frustrated Lewis pair (FLP) combinations continue to activate a diverse range of small gas molecules including CO 2 and dihydrogen. 10 Among the many aspects of main group chemistry, there has been increasing use of heterocyclic phosphorus compounds as catalysts for organic transformations, exemplified by work by Zhang et al on the nucleophilicity of diazaphospholene hydrides.…”

Section: Introductionmentioning

confidence: 99%