TY - JOUR

T1 - A Sterically Hindered Derivative of 2,1,3-Benzotelluradiazole: A Way to the First Structurally Characterised Monomeric Tellurium–Nitrogen Radical Anion

AU - Petrov, Pavel A.

AU - Kadilenko, Evgeny M.

AU - Sukhikh, Taisiya S.

AU - Eltsov, Ilia V.

AU - Gushchin, Artem L.

AU - Nadolinny, Vladimir A.

AU - Sokolov, Maxim N.

AU - Gritsan, Nina P.

N1 - This work was supported by Russian Academy of Sciences (budgetary program V55.1.1). E.M.K. and N.P.G. acknowledge Russian Science Foundation for a financial support of the computational part of this work (project 16-13-10155) and the Supercomputer Centre of Novosibirsk State University for computational resources.

PY - 2020/11/17

Y1 - 2020/11/17

N2 - Interaction of the tetradentate redox-active 6,6′-[1,2-phenylenebis(azanediyl)]bis(2,4-di-tert-butylphenol) (H4L) with TeCl4 leads to neutral diamagnetic compound TeL (1) in high yield. The molecule of 1 has a nearly planar TeN2O2 fragment, which suggests the formulation of 1 as TeIIL2−, in agreement with the results of DFT calculations and QTAIM and NBO analyses. Reduction of 1 with one equivalent of [CoCp2] leads to quantitative formation of the paramagnetic salt [CoCp2]+[1].−, which was characterised by single-crystal XRD. The solution EPR spectrum of [CoCp2]+[1].− at room temperature features a quintet due to splitting on two equivalent 14N nuclei. Below 150 K it turns into a broad singlet line with two weak satellites due to the splitting on the 125Te nucleus. Two-component relativistic DFT calculations perfectly reproduce the a(14N) HFI constants and A∥(125Te) value responsible for the low-temperature satellite splitting. Calculations predict that the additional electron in 1.− is localised mainly on L, while the spin density is delocalised over the whole molecule with significant localisation on the Te atom (≥30 %). All these data suggest that 1.− can be regarded as the first example of a structurally characterised monomeric tellurium–nitrogen radical anion.

AB - Interaction of the tetradentate redox-active 6,6′-[1,2-phenylenebis(azanediyl)]bis(2,4-di-tert-butylphenol) (H4L) with TeCl4 leads to neutral diamagnetic compound TeL (1) in high yield. The molecule of 1 has a nearly planar TeN2O2 fragment, which suggests the formulation of 1 as TeIIL2−, in agreement with the results of DFT calculations and QTAIM and NBO analyses. Reduction of 1 with one equivalent of [CoCp2] leads to quantitative formation of the paramagnetic salt [CoCp2]+[1].−, which was characterised by single-crystal XRD. The solution EPR spectrum of [CoCp2]+[1].− at room temperature features a quintet due to splitting on two equivalent 14N nuclei. Below 150 K it turns into a broad singlet line with two weak satellites due to the splitting on the 125Te nucleus. Two-component relativistic DFT calculations perfectly reproduce the a(14N) HFI constants and A∥(125Te) value responsible for the low-temperature satellite splitting. Calculations predict that the additional electron in 1.− is localised mainly on L, while the spin density is delocalised over the whole molecule with significant localisation on the Te atom (≥30 %). All these data suggest that 1.− can be regarded as the first example of a structurally characterised monomeric tellurium–nitrogen radical anion.

KW - chelates

KW - EPR spectroscopy

KW - radical ions

KW - relativistic density functional calculations

KW - tellurium

KW - CRYSTAL-STRUCTURE

KW - DENSITY-FUNCTIONAL CALCULATIONS

KW - X-RAY-STRUCTURE

KW - ORDER REGULAR APPROXIMATION

KW - VALENCE TAUTOMERISM

KW - MAGNETIC-PROPERTIES

KW - PHENYLENEDIAMINE BIS(PHENOLATE)

KW - GAUSSIAN-BASIS SETS

KW - METAL-COMPLEXES

KW - ELECTRONIC-STRUCTURE

UR - http://www.scopus.com/inward/record.url?scp=85092350817&partnerID=8YFLogxK

U2 - 10.1002/chem.202002799

DO - 10.1002/chem.202002799

M3 - Article

C2 - 32776633

AN - SCOPUS:85092350817

VL - 26

SP - 14688

EP - 14699

JO - Chemistry - A European Journal

JF - Chemistry - A European Journal

SN - 0947-6539

IS - 64

ER -