Photophysical and DFT Studies of Cationic Ag(I) Complexes with Thiosemicarbazides Derived from p-Toluenesulfohydrazide

Author(s)

Borges, Alice P. ^[1] ; Gaspari, Ana P. S. ^[2] ; Oliveira, Carolina G. ^[3] ; de Sousa, Sinval F. ^[4] ; da Silva, Roberto S. ^[2] ; Deflon, Victor M. ^[3] ; Machado, Antonio E. H. ^[4] ; Patrocinio, Antonio O. T. ^[4] ; Maia, Pedro I. S. ^[1]

Affiliation

^[1] Univ Fed Triangulo Mineiro, Dept Chem, Av Dr Randolfo Borges 1400, BR-38025440 Uberaba, MG - Brazil

^[2] Univ Sao Paulo, FFCLRP, Dept Chem, Ave Cafe S-N, BR-14040903 Ribeirao Preto, SP - Brazil

^[3] Univ Sao Paulo, Inst Quim Sao Carlos, Dept Mol Chem & Phys, Av Trabalhador Saocarlense, 400, BR-12345678 Sao Carlos, SP - Brazil

^[4] Univ Fed Uberlandia, Inst Quim, Lab Fotoquim & Cithornncia Mat, Av Joao Naves de Avila 2121, BR-38400902 Uberlandia, MG - Brazil

• Document type: Journal article
• Source: CHEMISTRYSELECT; v. 3, n. 7, p. 2108-2114, FEB 21 2018.
• Web of Science Citations: 2

Abstract

Reactions of p-toluenesulfohydrazide with R-isothiocyanates afford new ligands containing both the sulfonamide and thiosemicarbazide moieties (L-R: R=cyclohexyl (Cy) or phenyl (Ph)). L-R reacts with AgNO3 in EtOH in a 2:1M ratio leading to formation of colourless Ag(I) complexes of general formula {[}Ag(L-R)(2)]NO3. The crystal structure of a representative complex was determined by crystallographic studies and shows the Ag(I) coordinated by two thiosemicarbazide ligands in a S-monodentate coordination mode along with a significant interaction with a nitrate counter-ion in a bent geometry. Photophysical studies show that both the free ligands and complexes are essentially non-luminescent at room temperature. At 77K and glassy media, the silver complexes exhibit a luminescence band in the visible-light region. Besides, experimental and theoretical analyses suggest the population of the triplet state of these complexes after electronic excitation at around 250nm. Overall, it was verified that the observed emission of the Ag(I) complexes can be attributed to (MLCT)-M-3 radiative decay and that the silver complex with L-Ph shows a higher intensity emission than the complex with L-Cy. (AU)

• FAPESP's process: 09/54011-8 - Acquisition of a single-crystal X-ray diffractometer for the structural analysis of small molecules and proteins
• Grantee: Victor Marcelo Deflon
• Support Opportunities: Multi-user Equipment Program