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The structures, semiconductor and photocurrent response properties of three 1,4-diazabicyclo[2.2.2]octane derivative-templated iodobismuthates, (Et2DABCO)3(BiI6)2 (1), (i-Pr2DABCO)2(Bi2I10) (2), [(Me2DABCO)2(Bi2I10)2]n (3) (Et2DABCO2+ = N,N′-diethyl-1,4-diazabicyclo[2.2.2] octane, i-Pr2DABCO2+ = N,N′-diisoproyl-1,4-diazabicyclo[2.2.2] octane, Me2DABCO2+ = N,N′-dimethyl-1,4-diazabicyclo[2.2.2] octane), are reported. Based on the templates with different substitutents on 1,4-diazabicyclo[2.2.2]octane, mono-nuclear ((BiI6)3− for 1), dimer ((Bi2I10)4− for 2) and 1-D chain ((BiI5)n2n− for 3) can be obtained. C-H···I hydrogen bonds contribute to the structural extension to 2-D layer (for 2) and 3-D network (for 3). Their absorption spectra were investigated, and energy band gaps of 2.24/1.73/1.44 eV indicate their narrow-gap semiconductor natures. Their photocurrent response properties were also discussed. Finally, theoretical calculation was executed to give structure-properties correlation. [ABSTRACT FROM AUTHOR]

A new iodobismuthate-based hybrid (Me2DABCO)7(BiI6)2(Bi2I9)2.2I3 (1) (Me2DABCO2+ = N,N′-dimethyl-1,4- diazabicyclo[2.2.2] octane) has been structurally determined. The highly interesting feature of 1 lies in its presence of mixed types of iodobismuthate clusters, i.e. mononuclear (BiI6)3− and (Bi2I9)3− dimer in one crystal lattice templated by Me2DABCO2+ cation, which is the first example of mixed iodobismuthate clusters in one lattice. Its absorption zone can be broadened compared with other single iodobismuthate cluster-containing analogy compounds. And due to the strong I···I interactions, an optical gap of 1.61 eV can be observed. The photocurrent response properties before and after heating were discussed, which suggests that the device can be potentially used as temperature-response switch. [ABSTRACT FROM AUTHOR]