2024/12/06 by Bethany R. Hood, Yovan de Coene, Claire F. Jones +6 · 1 voice
Materials Science · #Magnetism in coordination complexes #Polyoxometalates: Synthesis and Applications #Porphyrin and Phthalocyanine Chemistry
paper · pdf · doi:10.1021/acs.inorgchem.4c04179
openalex publication_date 2024/12/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
High Resolution Image Download MS PowerPoint Slide We present the first study of arylimido-polyoxometalate nonlinear optical (NLO) chromophores with two-dimensional (2D) structures, and a comparison with one-dimensional analogues, through the synthesis of a family of arylimido-hexamolybdate derivatives where one or two polyoxometalate (POM) acceptors are connected to a tolyl-amino donor through phenyl bridges. Electronic absorption spectra and TD-DFT calculations reveal significant red-shifts in ligand-to-polyoxometalate charge transfer (LPCT) absorption bands for the 2D species compared to linear, dipolar analogues, consistent with the involvement of a larger conjugated (bridge + POM) system in the transitions. Electrochemical measurements indicate reversible, one-electron processes for the POM acceptors with class II mixed valence behavior observed where the POMs are connected to the same aryl ring and electronic isolation of the acceptors when they are on separate rings. Molecular first hyperpolarizabilities β have been determined using hyper-Rayleigh scattering at 1064 and 1200 nm: for the most active compound, the HRS measurements and depolarization studies reveal a strongly 2D, off-diagonal response (β 0,zzz = 190 × 10 –30 esu; β 0,zyy = −56.5 × 10 –30 esu), consistent with the wide A–D–A angle and TD-DFT computed electronic transitions, which show both phenyl bridges and POMs equally involved in the acceptor orbitals.