Al-Yasari A, El Moll H, Purdy R, Vincent KB, Spence P, Malval JP, Fielden J. Optical, third order non-linear optical and electrochemical properties of dipolar, centrosymmetric and C
2v organoimido polyoxometalate derivatives.
Phys Chem Chem Phys 2021;
23:11807-11817. [PMID:
33987634 DOI:
10.1039/d0cp06610a]
[Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A family comprising seven arylimido-polyoxometalate (POM) hybrid chromophores (three of which are new), with linear dipolar, C2v and linear centrosymmetric geometries have been synthesised and studied by electronic absorption spectroscopy, electrochemistry, Z-scans (two photon absorption, TPA) and computation (DFT/TD-DFT). These reveal that POM acceptor units are an effective basis for TPA materials: the centrosymmetric bis-POM chromophores produce significant cross sections (δ up to 82 GM) from a single aryl bridge, a similar performance to larger dipolar π-systems combining carbazole or diphenylamino donors with the imido-POM acceptor. DFT/TD-DFT calculations indicate strong communication between POM and organic components is responsible for the linear and non-linear optical behaviour of these compounds, while electrochemical measurements reveal class II mixed valence behaviour resulting from an interplay of through-bond and through-space effects.
Collapse