Reactions of [Et4N][TpMoS(S4)] with three equiv. of CuI in MeCN or in pyridine gave rise to one dicubane and one tetracubane anionic clusters, [Et4N]2[{TpMo(μ3-S)3Cu3I}2(μ-I){Cu(μ-I)2(μ4-I)2}] and [PyH][{TpMo(μ3-S)4Cu3}4(μ12-I)], and their third-order nonlinear optical (NLO) responses were greatly enhanced relative to that of the precursor.
![Graphical abstract: [PyH][{TpMo(μ3-S)4Cu3}4(μ12-I)]: a unique tetracubane cluster derived from the S–S bond cleavage and the iodide template effects and its enhanced NLO performances](http://hg.y866.cn/compound/lib/scimg/usr/1/C3CC41280F.jpg)
