Three novel heterometallic oxysulfide clusters with different coordination small organic molecules have been solvothermally synthesized and structurally characterized, i.e., [( n BuSn)3La(DTT)3(DETA)(L)] ( n BuSn = n-butyltin; DTT = 1,4-dithiothreitol; DETA = diethylenetriamine; L = N,N-dimethylformamide (DMF) (1), N-methyl pyrrolidone (NMP) (2), and N-methyl formanilide (MFA) (3)). These clusters are a bowl-shaped structure, composed of a central DETA-coordinated La3+ cation fixed in the triangle ring, [( n BuSn)3(DTT)3], and an amide molecule bonded to La3+ confined inside the bowl. The coordinated amides can be changed and served as a molecular regulator to optimize the microsteric interaction between the clusters and further the physicochemical property. Remarkably, the crystals of 1 exhibit strong blue-violet light emission with the photoluminescence quantum yield (PLQY) of 3.69%, which significantly exceeds than that of 2 and 3 and most of the other organotin oxysulfide clusters. Theoretical calculations and Hirshfeld surface analyses indicate that the weak amide-oriented intercluster interactions of the compounds can regulate their photoluminescence (PL) efficiency. This work provides a paradigm to reveal the relationships between its PL and structurally fine-tuned coordination species.