Indium phosphide (InP) magic-size clusters (MSCs) are atomically-precise molecules that can be used as precursors to quantum dots (QDs). In a reaction to form InP MSCs, QDs are the thermodynamic product, whereas MSCs are a kinetic product, so there is a critical temperature below which a reaction will form MSCs but above which a reaction will form QDs. The goal of this project is to explore the effect of ligand identity on the formation and stabilization of InP MSCs and their subsequent conversion to QDs. For carboxylates, which bind weakly to InP surfaces, the critical temperature is about 120 ËšC. For phosphonic acids, which bind strongly to InP surfaces this temperature is so high that cannot be reached via a heating mantle – above about 400 ËšC. I am working to investigate the effects of native thiols/thiolate ligands on the synthesis of InP MSCs. Thiols are intermediate in their binding strength to and are commonly used with InP surfaces. I will probe the concentrations and temperatures at which thiolate-capped InP MSCs form. I hypothesize that the critical temperature for the synthesis of MSCs versus QDs reflects the ligand binding strength. If this is true, thiolate-capped InP MSCs should form readily at temperatures above 120 ËšC, but the temperature at which QDs are formed should be achievable via a heating mantle, opening up new parameter space for QD and cluster synthesis and study.