This could support the stepwise ligand exchange or methyl protonation mechanism. It is worthwhile to note that during the NH3 pulse, in the thermal process, random 'forked' peaks were observed, which we attribute to instrument artifacts . Instrumental factors such as detector saturation, electronic noise, or ion suppression can possibly affect the shape and resolution of peaks thereby introducing distortions in the mass spectrum, leading to the appearance of forked peaks. This 'forking' effect can be eliminated by reducing the NH3 pulse time.