N-Coordinated tellurenium(II) and telluronium(IV) cations: synthesis, structure and hydrolysis

0578070 - ÚOCHB 2024 RIV GB eng J - Journal Article
Hejda, M. - Doležal, L. - Blahut, Jan - Hupf, E. - Tydlitát, J. - Jambor, R. - Růžička, A. - Beckmann, J. - Dostál, L.
N-Coordinated tellurenium(II) and telluronium(IV) cations: synthesis, structure and hydrolysis.
Dalton Transactions. Roč. 52, č. 44 (2023), s. 16235-16248. ISSN 1477-9226. E-ISSN 1477-9234
Institutional support: RVO:61388963
Keywords : consistent basis-sets * convergent basis-sets * crystal structure
OECD category: Inorganic and nuclear chemistry
Impact factor: 4, year: 2022
Method of publishing: Open access
https://doi.org/10.1039/D3DT02404K

A set of N-coordinated tellurium(II) compounds containing either C,N-chelating ligands CNR (where CN = 2-(RN[double bond, length as m-dash]CH)C6H4, R = tBu or Dipp, Dipp = 2,6-iPr2C6H3) or N,C,N pincer ligands NCNR (where NCN = 2,6-(RN[double bond, length as m-dash]CH)2C6H4, R = tBu or Dipp) were synthesized. In the case of C,N-chelated compounds, the reaction of CNDippLi with Te(dtc)2 (where dtc = Et2NCS2) in a 1 : 1 molar ratio smoothly provided the carbamate CNDippTe(dtc) which upon treatment with 2 eq. of HCl provided the chloride CNDippTeCl. In contrast, the analogous conversion of NCNRLi with Te(dtc)2 surprisingly furnished ionic bromides [NCNRTe]Br as a result of the exchange of dtc by Br coming from nBuBr present in the reaction mixture. Furthermore, the reaction of CNDippTeCl or [NCNRTe]Br with silver salts AgX (X = OTf or SbF6) provided the expected tellurenium cations [CNDippTe]SbF6 and [NCNRTe]X. To further increase the Lewis acidity of the central atom, the oxidation of selected compounds with 1 eq. of SO2Cl2 was examined yielding stable compounds [CNtBuTeCl2]X and [NCNtBuTeCl2]X. The oxidation of the Dipp substituted compounds proved to be more challenging and an excess of SO2Cl2 was necessary to obtain the oxidized products [CNDippTeCl2]SbF6 and [NCNDippTeCl2]SbF6, which could solely be characterized in solution. Compounds [CNtBuTeCl2]OTf and [NCNtBuTeCl2]OTf were shown to undergo a controlled hydrolysis to the corresponding telluroxanes. All compounds were studied by multinuclear NMR spectroscopy in solution and for selected compounds solid state 125Te NMR spectroscopy and single-crystal X-ray diffraction analysis were performed. The Lewis acidity of the studied cations was examined by the Gutmann–Beckett method using Et3PO as the probing agent. The Te–N chalcogen bonding situation of selected compounds has also been examined computationally by a set of real-space bonding indicators.
Permanent Link: https://hdl.handle.net/11104/0347099


Research data: CCDC