Herein, we show the controlled generation of multi-component libraries based on the [MoS2O2]2+/MoVIO42-/SeIVO32-/C4O42- system leading to the formation of a whole new family of nanosized molecular chalcoxides, {Se8Mo36} 1, {Se8Mo40} 2, {Se8Mo56} 3, {Se20Mo56} 4 and {Se26Mo68} 5, of the general formula {(MoO2S2)a(OH)b(SeIVO3)c(C4O4)d(MoO7)e}n-, where a, b, c, d, e, n = [16, 20, 8, 6, 2, 20] for ...