Luminescent gold–thallium derivatives with a pyridine-containing 12-membered aza-thioether macrocycle
| Autor: | Anna Pintus, Francesco Caddeo, Antonio Laguna, M. Concepción Gimeno, Vanesa Fernández-Moreira, Massimiliano Arca, Vito Lippolis |
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| Přispěvatelé: | Ministerio de Ciencia, Innovación y Universidades (España), Agencia Estatal de Investigación (España), Gobierno de Aragón, European Commission, Fondazione di Sardegna, Regione Autonoma della Sardegna |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Zaguán. Repositorio Digital de la Universidad de Zaragoza |
| Popis: | The coordination modes of the ligand 2,5,8-trithia[9](2,6)pyridinophane (L) to thallium(I), gold(III) and gold(I) have been studied. Thallium(I) is coordinated by the macrocyclic ligand in [Tl(L)](PF6) (1) through all the sulfur and nitrogen atoms, in a distorted square-pyramidal geometry with the thallium(I) ion in the apical position and with the presence of an inert lone pair. Gold(III) is bonded by the ligand only through the nitrogen of the pyridine group in [AuCl3(L)] (2), whereas two AuI–C6F5 fragments coordinate the sulfur atoms next to the pyridine moiety of the ligand in [{Au(C6F5)}2(μ-L)] (3), which form a linear polymer through intermolecular aurophilic contacts. The heterometallic TlI/AuI complex {[Au(C6F5)2Tl]2(L)}n (4) features a polymeric structural nature with a metallic pseudo-rhombic Au2Tl2 core, which repeats itself forming a zig-zag polymer. In each Au2Tl2 unit only one thallium atom is bonded by the NS3 donor set of the macrocyclic ligand and also forms two unsupported Au–Tl bonds with two [Au(C6F5)2]− units in an overall pseudo-octahedral geometry. The other thallium atom similarly bridges the same [Au(C6F5)2]− units and links a neighbouring Au2Tl2 moiety, thus exhibiting a distorted trigonal planar geometry being bonded only to three gold atoms with unsupported Au–Tl interactions. This complex displays an interesting thermochromic behaviour showing emissions mainly resulting from MM′CT transitions at room temperature. At 77 K a dual emission appears, probably arising from the two different thallium environments. DFT calculations have been carried out in the attempt to investigate the origin of the emissions of complex 4. Authors thank the Agencia Estatal de Investigación (projects PID2019-104379RB-C21, RTI2018-097836-J100 and RYC2018-025872), Gobierno de Aragón–Fondo Social Europeo (Research Group E07_20R) and the Fondazione di Sardegna (FdS) and Regione Autonoma della Sardegna (RAS) (Progetti Biennali di Ateneo FdS/RAS annualità 2018) for financial support of our research. A. P. acknowledges RAS for the funding in the context of the POR FSE 2014–2020 (CUP F24J17000190009). |
| Databáze: | OpenAIRE |
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