To further understand this behavior, we performed a titration study between the ligand and the corresponding Bi salt (Figure , S35). The concentration of ligand was kept at 10 M while the amount of inorganic Bi part was increased from 1 to 20 M in ACN. Initially the emission spectra of only the ligand and inorganic salt at 10 M concentration were recorded, using an excitation wavelength of 392 nm. As shown (Figure Photophysical studies in aggregates. In order to understand the effect of aggregation on the photophysical properties of the complexes, absorption, emission and lifetime measurements were performed at 10 M concentration in the mixture of DMF and water (Figure , S37 and S38).