Photoswitching of the second-order nonlinearity of a tetrahedral octupolar multi DTE-based copper(i) complexElectronic supplementary information (ESI) available: Synthesis and characterisations of ligands and complexes; details of theoretical calculations, extra TD-DFT analysis and NLO measurements. See DOI: 10.1039/c2cc34999j

The modulation of the quadratic NLO response of an octupolar metal-based chromophore featuring four photochromic dithienylethene units is reported. Quantum mechanical simulations are consistent with a full switching of the DTE units and reproduce the strong enhancement of the NLO response. Efficient modulation of the quadratic NLO response of an octupolar metal-based chromophore featuring four photochromic dithienylethene units.