Cluster Oxalate Complexes [M₃(μ₃-Q)(μ₂-Q₂)₃(C₂O₄)₃]^2- and [Mo₃(μ₃-Q)(μ₂-Q)₃(C₂O₄)₃(H₂O)₃]^2- (M = Mo, W; Q = S, Se): Mechanochemical Synthesis and Crystal Structure

Mechanochemical reaction of cluster coordination polymers 1∞[M3Q7Br4] (M = Mo, W; Q = S, Se) with solid K2C2O4 leads to cluster core excision with the formation of anionic complexes [M3Q7(C2O4)3]2-. Extraction of the reaction mixture with water followed by crystallization gives crystalline K2[M3Q7(C2O4)3]·0.5KBr·nH2O (M = Mo, Q = S, n = 3 (1); M = Mo, Q = Se, n = 4 (2); M = W, Q = S, n = 5 (3)). Cs2[Mo3S7(C2O4)3]·0.5CsCl·3.5H2O (4) and (Et4N)1.5H0.5K{[Mo3S7(C2O4)3]Br}·2H2O (5) were also prepared. Close Q···Br contacts result in the formation of ionic triples {[M3Q7(C2O4)3]2Br}5- in 1−4 and the 1:1 adduct {[Mo3S7(C2O4)3]Br}3- in 5. Treatment of 1 or 2 with PPh3 leads to chalcogen abstraction with the formation of [Mo3(μ3-Q)(μ2-Q)3(C2O4)3(H2O)3]2-, isolated as (Ph4P)2[Mo3(μ3-S)(μ2-S)3(C2O4)3(H2O)3]·11H2O (6) and (Ph4P)2[Mo3(μ3-Se)(μ2-Se)3(C2O4)3(H2O)3]·8.5H2O·0.5C2H5OH (7). All compounds were characterized by X-ray structure analysis. IR, Raman, electronic, and 77Se NMR spectra are also reported. Thermal decomposition of 1−3 was studied by thermogravimetry.簇配位聚合物1∞[M3Q7Br4]（M = Mo、W；Q = S、Se）与固态草酸钾（K2C2O4）发生机械化学反应，可实现簇核切除，生成阴离子配合物[M3Q7(C2O4)3]²⁻。将反应混合物经水萃取后结晶，可得到晶体产物K2[M3Q7(C2O4)3]·0.5KBr·nH2O，其中M=Mo、Q=S时n=3（化合物1）；M=Mo、Q=Se时n=4（化合物2）；M=W、Q=S时n=5（化合物3）。此外还制备了Cs2[Mo3S7(C2O4)3]·0.5CsCl·3.5H2O（化合物4）以及(Et4N)1.5H0.5K{[Mo3S7(C2O4)3]Br}·2H2O（化合物5）。化合物1~4中存在近距离Q···Br相互作用，形成离子三重体{[M3Q7(C2O4)3]2Br}5⁻；而化合物5中则形成1:1加合物{[Mo3S7(C2O4)3]Br}3⁻。将化合物1或2与三苯基膦（PPh3）反应，可发生硫族元素脱除，生成[Mo3(μ3-Q)(μ2-Q)3(C2O4)3(H2O)3]2⁻，该产物分别以(Ph4P)2[Mo3(μ3-S)(μ2-S)3(C2O4)3(H2O)3]·11H2O（化合物6）和(Ph4P)2[Mo3(μ3-Se)(μ2-Se)3(C2O4)3(H2O)3]·8.5H2O·0.5C2H5OH（化合物7）的形式分离得到。所有化合物均通过X射线晶体结构分析（X-ray structure analysis）进行了表征，同时还报道了其红外光谱（IR）、拉曼光谱（Raman）、电子光谱以及77Se核磁共振（77Se NMR）谱图。本研究还通过热重分析（thermogravimetry）对化合物1~3的热分解行为进行了探究。