title: Hydrogen bonds and steric effects induced structural modulation of three layered iodoplumbate hybrids from nonperovskite to perovskite structure.
abstract: Directed by diprotonated organic diamines containing both primary and tertiary ammonium groups, three layered iodoplumbate hybrids, {[H2DMPDA][PbI4]}n (1), {[H2DEPDA]4[Pb5I18]}n (2) and {[H2TMEDA][Pb3I8]}n (3) (DMPDA = N,N-dimethyl-1,3-propanediamine, DEPDA = N,N-diethyl-1,3-propanediamine, TMEDA = N,N,N',N'-tetramethylethylenediamine), have been synthesized solvothermally. 1 presents a layered perovskite structure based on corner-sharing PbI6 octahedra, compound 2 consists of a Pb4I20 perovskite motif and a Pb2I10 dimeric motif and compound 3 comprises Pb3I13 units connected by face-sharing and edge-sharing modes. Structural modulations from nonperovskite to perovskite structure are strongly correlated to steric effects and hydrogen bonding interaction at the organic-inorganic interface. Band gaps for 1-3 , estimated as 2.21, 2.58 and 2.73 eV, respectively, also reveal an interesting correlation with structural modulation, and the red shift for 1 is attributed to large Pb-I(equatorial)-Pb bond angles.
authors.affiliation: School of Chemistry & Material Science, Shanxi Normal University, Linfen 041004, P. R. China. yunlongfu@dns.sxnu.edu.cn.
authors.forename: Tanlai
authors.initials: T
authors.lastname: Yu
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Junju
authors.initials: J
authors.lastname: Shen
authors.forename: Yangbo
authors.initials: Y
authors.lastname: Fu
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Fu