A temperature-sensitive luminescent Ag20 nanocluster templated by carbonate in situ generated from atmospheric CO2 fixationElectronic supplementary information (ESI) available: Additional figures and tables. CCDC 940871. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c3nj00645j

A drum-like Ag 20 nanocluster, [(CO 3 2− )@Ag 20 (SBu t ) 10 (DMF) 6 (NO 3 ) 8 ] ( 1 ), has been synthesized by the unexpected carbonate-templated self-assembly of AgNO 3 and AgSBu t precursor. Structural analysis reveals that 1 contains centrosymmetric drum-like Ag 20 S 10 clusters constructed from two Ag 5 S 5 pentagrams and a Ag 10 ring. The CO 3 2− in situ generated from fixation of atmospheric CO 2 lies on the center of the cluster and acts as an anion template to direct the formation of 1 . Interestingly, bright-green photoluminescence of 1 is switched on when cooled with liquid nitrogen. A drum-like Ag 20 nanocluster has been synthesized directed using the unexpected carbonate template. Its bright-green photoluminescence can be switched on when cooled with liquid nitrogen.