The identification of two hydrides in the Cu18PTT NC through SCXRD measurement suggests the preferred Cu atoms position to stabilize the hydrides in the NC unit which is not visible in the other two NCs. We then quantified the hydrides in Cu18PTT NC through the ESI-MS measurements. In the positive mode ESI-MS spectra, all the three NCs exhibit single molecular ion peak which suggests their robust stability. The peak at m/z = 1690.63 correspond to the [Cu11(PTT)9(PPh3)6] 2+ (Figure ) and peak at m/z = 1695.61 correspond to the [Cu11(ABT)9(PPh3)6] 2+ (Figure ) matches well with their corresponding simulated spectra where the isotropic patterns confirm their divalent charge state.