Helicenes as Molecular Tweezers in the Formation of Cation- Complexes. Bonding and Circular Dichroism Properties from Relativistic DFT Calculations

Autor(es)

Ortolan, Alexandre O. ^[1] ; Caramori, Giovanni F. ^[1] ; Parreira, Renato L. T. ^[2] ; Munoz-Castro, Alvaro ^[3]

Afiliação do(s) autor(es)

^[1] Univ Fed Santa Catarina, Dept Quim, Campus Univ Trindade, CP 476, BR-88040900 Florianopolis, SC - Brazil

^[2] Univ Franca, Nucleo Pesquisa Ciencias Exatas & Tecnol, BR-14404600 Franca, SP - Brazil

^[3] Univ Autonoma Chile, Grp Quim Inorgan & Mat Mol, Fac Ingn, Santiago - Chile

• Tipo de documento: Artigo Científico
• Fonte: ChemPhysChem; v. 19, n. 18, p. 2321-2330, SEP 18 2018.
• Citações Web of Science: 3

Resumo

Helicene ligands possess a unique helicoidal -conjugated framework providing high optical rotation values. This has stimulated a growing interest in helicene derivatives as building blocks, which has triggered the development of simple strategies to tune their properties. In this context, we evaluated the formation of cation- complexes derived from {[}6]- and {[}7]helicene, involving Sn2+, Cd2+, and In+ in addition of Ag+, which appears as a plausible modification of such helicoidal structure. The nature of the cation- interaction in the studied helicene complexes exhibits a covalent character, accounting for ligand -donation to 5s and 5p empty orbitals of the involved cations. Furthermore, the evaluation of their optical activity exhibits notorious modification patterns in the circular dichroism spectrum, suggesting that the modifications of the optical activity are dependent on the nature of the cation and its related charge state. Thus, the plausible formation of new cation- complexes derived from helicene ligands, as discussed here, may lead to the characterization of novel species expanding the chemistry of helicene metal complexes to even to larger helicene units. We believe that the present study may open new avenues in the formation of cation- helicene complexes. (AU)

• Processo FAPESP: 11/07623-8 - Utilização de métodos mecânicos-quânticos para estudo das ligações e interações químicas em sistemas auto-organizados com aplicação em catálise, química medicinal, eletrocromismo, armazenamento e conversão de energia
• Beneficiário: Renato Luis Tame Parreira
• Modalidade de apoio: Auxílio à Pesquisa - Jovens Pesquisadores