In bioimaging, luminogenic probes that 'switch on' after binding are of great interest because due to the absence of luminescent background signal of non-conjugated probe, thereby eliminating the need for washing steps prior to imaging. While both complexes 3 and 4 showed strong luminogenic behaviour upon reaction with BCN, the shorter wavelength spectral profile of complex 3 rendered it largely unsuitable for bioimaging due to overlap with tissue autofluorescence and the limited availability of excitation sources in this region. Therefore, as the spectral profile of complex 4 demonstrated absorption at 488 nm, a commonly utilised wavelength for bioimaging, this complex was carried forward for further experimentation. To better understand changes in photophysical properties before and after the click reaction, complex 8 was isolated following the IEDDA reaction (Figure ) with BCN-C10. The triazine complex 4 is only very weakly emissive, so no emission quantum yield could be estimated (i.e. Φ < 0.01). In contrast, the product of the reaction, complex 8, is highly emissive in deaerated EtOH (Φ = 0.23) and CH2Cl2 (Φ = 0.65) with emission maxima at 563 nm and 559