Donor and Geometry Optimization: Fresh Perspectives for the Design of Polyoxometalate Charge Transfer Chromophores
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Three linear, dipolar arylimido-polyoxometalate (POM) and one 2-dimensional bis -functionalized arylimido-polyoxometalate charge transfer chromophore, with diphenylacetylene bridges, have been synthesized and studied by spectroelectrochemistry, hyper-Rayleigh scattering (HRS), and DFT/TD-DFT calculations. The linear systems show that with julolidinyl (Jd) and −NTol 2 donor groups, the alkyne bridge yields high second-order nonlinear optical (NLO) coefficients β (Jd, β 0, zzz = 318 × 10 –30 esu; −NTol 2, β 0, zzz = 222 × 10 –30 esu), indeed the Jd compound gives the highest NLO activity of any organoimido-POM to date with minimal decrease in transparency. The bis -functionalized 2D ( C 2v ) POM derivative showed increased activity over its monofunctionalized analogue with no decrease in transparency, although the NLO response was only minimally two dimensional. Spectroelectrochemistry and TD-DFT calculations showed switchable linear optical responses for the monofunctionalized derivatives due to the weakened charge transfer character of the electronic transitions in the reduced state, while TD-DFT also indicated potential for switched NLO responses. These have been demonstrated by electrochemistry-HRS for the Jd compound, but cyclability is limited by relatively poor stability in the reduced state. IR and CV studies for these sterically protected arylimido polyoxometalates indicate that decomposition proceeds via a breakdown of the {Mo 6 } cluster in the reduced state, rather than simple solvolysis of the Mo≡N bond.
Source: Inorganic Chemistry
Authors: Bethany R. Hood, Yovan de Coene, Claire F. Jones, Noah Deveaux, Jack M. Barber, Charlotte G. Marshall, Chloe A. Jordan, Nathan R. Halcovitch, Benoît Champagne, Koen Clays, John Fielden
Language: English
Subfield: Materials Chemistry
Field: Materials Science
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funders: Lancaster University, Waalse Gewest, Leverhulme Trust, University of East Anglia, Fonds De La Recherche Scientifique - FNRS, Fonds Wetenschappelijk Onderzoek, Engineering and Physical Sciences Research Council, Fonds pour la Formation à la Recherche dans l’Industrie et dans l’Agriculture, Université de Namur
Awards: G1056058792, Polyoxometalate-Based Sensitizers for p-Type Dye-Sensitized Solar Cells, G2667865600, G2864349948, G3107011372, G3349916830, G3795038844, G3911975860, G4327442905, G458245579, G4591173043, G5282950546, G5914028328, G5960014127, G6035372637, G6102480258, G620669678, G624725315, G7309761604, G7374947437, G7957863203, G8084923984, Pushing the boundaries of third harmonic generation, Application by the School of Chemistry and the School of Pharmacy, University of East Anglia, for enhanced single-crystal X-ray diffraction facilities, G8971775043
OpenAlex ID: W4409416204