Polyoxometalate-based functional nanostructured films: Current progress and future prospects

Redox behaviour, electrochromic properties and photoluminescence of potassium lanthano phosphomolybdate sandwich-type compounds

“…Photo-luminescent studies were performed for Eu(PMo 11 ) 2 and Tb(PMo 11 ) 2 . Both emission spectra display emission in the visible spectral region (tentatively ascribed to d-d transition transitions) that, in the case of the Eu(PMo 11 ) 2 , are overlapped by a series of intra-4f 6 lines, whose main excitation path is mediated by O A Eu III and O A Mo VI LMCT transitions.…”

“…The excitation spectrum acquired at 12 K is similar to that measured at 300 K, but it is observed a red-shift of the band to ca. 278 nm and an increase in the relative intensity of the intra-4f 6 transitions. The low-relative intensity of the broad band points out that, at 12 K, the Eu 3+ excited states are mainly populated via direct intra-4f 6 excitation, rather than by the LMCT states, contrarily to that found at 300 K. Under UV/Vis excitation, the emission spectra of the Eu(PMo 11 ) 2 are formed of the typical Eu 3+ emission in the visible spectral range (Fig.…”

“…40u. The angle between the normal vectors of the oxygen-based square planes is 3.1(2)u and the distance between the two square planes (interplanar distance) is 2.537 (6) 2.420(9) Gd1 O48 2.400 (6) and bending vibrations of the crystallization water molecules present in the lanthano polyoxomolybdates structures. The electronic spectra of all compounds are very similar and present two intense bands in the region 300-200 nm assigned to transitions involving electronic states from the oxide cluster, also obtained using more concentrated solutions in order to visualize the f-f bands associated with the lanthanide ions, but only very low intense bands were observed (spectra not shown).…”

“…[1][2][3][4][5][6] One of the most promising properties of these metal oxide clusters is the rich redox chemistry as they can accept electrons to become mixed-valence colored species namely ''heteropoly blue''. This outstanding property makes them good candidates for photochromic and electrochromic materials.…”

Oxo‐Metalate Building Blocks: Conceptual Competitors for Tetravalent Carbon?

“…[22] Furthermore, combining POMs as building blocks [23] with cationic surfactants leads to the construction of interesting materials, like liquid crystals-this refers not only to the above-mentioned giant molybdenum-oxide based clusters (see, for instance, refs. [5], [23][24][25][26]). Three further topics of interest related to POM chemistry are: molecular magnetism, [27] nucleation processes in protein cavities, [28] and the fascinating aesthetic aspects.…”