摘要
I feel deeply honored to be invited as the guest editor of this special issue on Polyoxometalates(POMs).POMs are a large family of early transition metal-oxo anionic clusters with atomically precise chemical composition and geometric structures formed by corner‐,edge‐and face‐sharing of the MO_(6)(M=Mo,W,V,Nb,and Ta in high oxidation states)octahedral building blocks,which fully fulfills the aims and scope of the Tungsten journal launched in early 2019.The history of POM chemistry has been almost 200 years since the first reported example of polyoxometalate as an ammonium phosphomolybdate with the formula of(NH4)3[PMo12O40]by Berzelius in 1826.After that,great efforts have been devoted to solving and determining its geometrical structure,Linus Pauling was one of the first scientists trying to describe its structure,in terms of ionic radii.However,such structure was not unambiguously determined until the tungstate analogue[PW12O40]3‾was reported in Nature 1933 by J.F.Keggin.Tremendously thanks to the advances in modern high-resolution,sophisticated instrumentation(e.g.single-crystal X-ray crystallography)as well as the diversity of synthetic and analytical methods,the POM research area has been extensively investigated.A serious of famous POM structures have been continuously reported,including the Anderson-Evans POM structure in 1948,the Wells–Dawson POM structure in 1953,the Lindqvist and Dexter–Silverton POM structures in 1968,the Strandberg-type POM structure in 1973,and the Müller big-molybdate-ball(Keplerate)structure in 1998,etc.In addition,the lacunary POM ligands generated by controllably removing one or several terminal[W=O]4+building blocks from the traditional plenary Keggin or Wells–Dawson POMs are very effective multidentate O-donor coordinating ligands to stabilize various mono-or multinuclear d-and f-block transition metals,resulting in the isolation and identification of numerous transition-metal-substituted POM structures since the mid twentieth century.The attractive physicochemical properties of POMs including rich redox chemistry,tunable compositions(size,charge density,acid strength,etc.),high thermal stability in the solid state,and solubility in polar/nonpolar solvents,have rendered POMs of great interest in various research fields such as catalysis,medicine,biology,photochemistry,magnetism,materials science,energy storage,and others.
