New organically templated chained and layered iodoplumbates

Abstract

In acidic alcohol/aqueous solution, simple solvo(hydro)thermal self-assembly between Pb(II) salts, KI and pip/dabco (pip = piperazine; dabco = 1,4-diazabicyclo[2,2,2]octane) created three new organically templated iodoplumbates as the chained [H₂dppip][Pb₂I₆]·H₂O 1 and [H₂depip][Pb₂I₆]·H₂O 2 and the layered [H₂dabco][Pb₃I₈] 3 (dppip = N,N′-dipropylpiperazine; depip = N,N′-diethylpiperazine). Note that dppip/depip were derived respectively from the solvothermal in situ N-alkylation reactions of pip with ethanol/propanol in acidic KI solution. Ultraviolet-visible (UV-vis) spectrum analysis indicates that the three compounds are all potential semiconductor materials with energy gaps of 3.46 eV for 1, 3.02 eV for 2 and 3.31 eV for 3.