2025/04/14 by Bethany R. Hood, Yovan de Coene, Claire F. Jones +8 · 1 voice · 1 citation
Chemistry · Materials Science · #Chemical Synthesis and Reactions #Metal-Organic Frameworks: Synthesis and Applications #Polyoxometalates: Synthesis and Applications
paper · pdf · doi:10.1021/acs.inorgchem.5c00915
openalex publication_date 2025/04/14 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
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.