Fig. 2. (A) In situ absorption at λ = 400 nm during nucleation onset in the synthesis of PbS (yellow) and PbSe (red) from N-3,5-bis(trifluoromethyl)phenyl-N′-dodecylthiourea and N,N-dimethyl-N′-cyclohexylselenourea, which have similar conversion reactivity (kr(S) = 1.7 × 10−3 s−1, kr(Se) = 1.6 × 10−3 s−1). (B) Comparison of tind and kr for several thio-and selenoureas at 80 °C showing that the induction delay is consistently longer when synthesizing PbS.
