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 (β0,zzz = 190 × 10–30 esu; β0,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.

Three linear, dipolar arylimido-polyoxometalate (POM) and one 2-dimensional bis-functionalized arylimido-polyoxometalate charge transfer chromophore, with diphenylacetylene bridges, have been synthesi...

A new dinuclear cobalt complex selectively catalyses 4e− reduction of O2 to water in methanol containing acetic acid. Its TOF of 0.031 s−1 and overpotential of 690 mV outperform the few previous Co N,...

Staff in Lancaster’s Chemistry Department have successfully secured funding from the Royal Society of Chemistry, AIChemy and EPSRC for six undergraduate internships this summer.

Dr John Fielden, Reader and Head of the Inorganic Chemistry Section in the LU chemistry, has started the project “Probing for i-Motif DNA with Ruthenium Complexes”, with the arrival of Senior Research...