Synthesis and characterization of three new solid polyoxometalates based on Wells-Dawson-derived sandwich-type polyanions [Co_(4)(H_(2)O)_(2)(P_(2)W_(15)O_(56))_(2)]^(16-)

Three polyoxometalate-based hybrid coordination materials,[Co_(8)(H_(2)O)_(34)(pz)_(2){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·16H_(2)O(compound 1),[H_(3)O]_(4)[Co_(6)(H_(2)O)_(22)(pz)_(2){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·21H_(2)(compound 2),and[H_(3)O]_(4)[Co_(6)(H_(2)O)_(22){Co_(4)(H_(2)O)_(2)P_(4)W_(30)O_(112)}]·29H_(2)O(compound 3)(pz-pyrazine),were built from the linkage of[Co_(4)(H_(2)O)_(2)(P_(2)W_(15)O_(56)_(2)]^(16-)-(abbreviated as{Co_(4)P_(4)W_(30})polyanions and pz and/or cobalt(II)cations.Although compounds 1 and 2 consisted of the same components,their lamellar networks were quite different.The inorganic lamellar network in compound 3 was constructed by connecting{Co_(4)P_(4)W_(30)}units with cobalt(I)cations.This work demonstrates that the coordination modes of{Co_(4)P_(4)W_(30)}are very sensitive to synthesis conditions,while the ring-belt tetrametals are easily substituted by different transition metal cations under mild reaction conditions.

Development of photoluminescence metal-organic framework sensors consisting of dual-emission centers

Incorporation of luminescent moieties into metal-organic frameworks（MOFs） has resulted in numerous photoluminescence（PL） sensors based on chromophore-analyte interactions. However, most of them are only highly sensitive to few analytes limited by the single luminescent centers in MOFs. To improve the application scopes, dual-emission MOFs were therefore emerged, which can significantly improve the sensitivity by monitoring the relative emission intensity of two luminescent centers. This short review will highlight the recent progress on dual-emission MOFs as highly sensitive sensors for probing of volatile organic molecules（VOMs）, picric acid and peroxynitrite, and as self-calibration PL thermometer.