Tuning Photophysical Properties by p-Functional Groups in Zn(II) and Cd(II) Complexes with Piperonylic Acid
Sánchez Férez, Francisco (Universitat Autònoma de Barcelona. Departament de Química)
Rius-Bartra, Joaquim Mª (Universitat Autònoma de Barcelona. Departament de Química)
Ayllon, Jose Antonio (Universitat Autònoma de Barcelona. Departament de Química)
Calvet, Teresa (Universitat de Barcelona. Departament de Mineralogia, Petrologia i Geologia Aplicada)
Font-Bardia, Mercè (Universitat de Barcelona. Unitat de Difracció de Raig-X)
Pons Picart, Josefina (Universitat Autònoma de Barcelona. Departament de Química)

Date:	2022
Abstract:	Aggregation between discrete molecules is an essential factor to prevent aggregationcaused quenching (ACQ). Indeed, functional groups capable of generating strong hydrogen bonds are likely to assemble and cause ACQ and photoinduced electron transfer processes. Thus, it is possible to compare absorption and emission properties by incorporating two ligands with a different bias toward intra-and intermolecular interactions that can induce a specific structural arrangement. In parallel, the π electron-donor or electron-withdrawing character of the functional groups could modify the Highest Ocuppied Molecular Orbital (HOMO)-Lowest Unocuppied Molecular Orbital (LUMO) energy gap. Reactions of M(OAc)2·2H2O (M = Zn(II) and Cd(II); OAc = acetate) with 1,3benzodioxole-5-carboxylic acid (Piperonylic acid, HPip) and 4-acetylpyridine (4-Acpy) or isonicotinamide (Isn) resulted in the formation of four complexes. The elucidation of their crystal structure showed the formation of one paddle-wheel [Zn(μ-Pip)2(4-Acpy)]2 (1); a mixture of one dimer and two monomers [Zn(µ-Pip)(Pip)(Isn)2]2·2[Zn(Pip)2(HPip)(Isn)]·2MeOH (2); and two dimers [Cd(μPip)(Pip)(4-Acpy)2]2 (3) and [Cd(μ-Pip)(Pip)(Isn)2]2·MeOH (4). They exhibit bridged (1, µ2-η:η), bridged, chelated and monodentated (2, µ2-η:η, µ1-η:η and µ1-η), or simultaneously bridged and chelated (3 and 4, µ2-η:η) coordination modes. Zn(II) centers accommodate coordination numbers 5 and 6, whereas Cd(II) presents coordination number 7. We have related their photophysical properties and fluorescence quantum yields with their geometric variations and interactions supported by TD-DFT calculations.
Grants:	Agència de Gestió d'Ajuts Universitaris i de Recerca 2017/SGR-1687
Note:	Altres ajuts: Fundació La Caixa: projectes CB615921 i CB616406
Rights:	Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l'obra i la creació d'obres derivades, fins i tot amb finalitats comercials, sempre i quan es reconegui l'autoria de l'obra original.
Language:	Anglès
Document:	Article ; recerca ; Versió publicada
Subject:	Zn(II) and Cd(II) ; 4-Acetylpyridine ; Isonicotinamide ; Piperonylic acid ; Photoluminescence
Published in:	Molecules, Vol. 27, Issue 4 (February 2022) , art. 1365, ISSN 1420-3049

DOI: 10.3390/molecules27041365
PMID: 35209159

29 p, 6.8 MB

The record appears in these collections:
Articles > Research articles
Articles > Published articles