There is no dramatic change in the peak at 1030 cm -1 attributed to C6-O stretching (Table ). These changes indicate that N2 and O3 groups interact strongly with Cd 2+ ions, while hydroxyl groups at C6 exhibit little contribution in these interactions. Based on these observations, we may infer that the possible spatial sites of Cd and CdS QDs are located near the C2 and C3 of the CTS units. FT-IR spectra revealed the formation of strong hydrogen bonding between the CdS QDs and CTS via N2 and O3 groups .