Anion-driven tetrel bond-induced engineering of lead(II) architectures with N'-(1-(2-pyridyl) ethylidene) nicotinohydrazide: experimental and theoretical findings

作者：Mahmoudi Ghodrat^*; Safin Damir A^*; Mitoraj Mariusz P^*; Amini Mojtaba^*; Kubicki Maciej; Doert Thomas; Locherer Franziska; Fleck Michel

来源：Inorganic Chemistry Frontiers, 2017, 4(1): 171-182.

DOI：10.1039/c6qi00477f

The evaluation of N'-(1-(2-pyridyl)ethylidene)nicotinohydrazide (HL) as a linker for the Pb-II tagged extended structures is described. The reaction of Pb(ClO4)(2) or Pb(OAc)(2) with HL in MeOH at 60 degrees C and room temperature, respectively, leads to heteroleptic complexes {[PbL] ClO4}(n)center dot nH(2)O and [PbL(OAc)](2), while the same reaction of Pb(ClO4)(2) with HL at 60 degrees C in the presence of two equivalents of NaOAc or NaNO2 leads to heteroleptic complexes {[Pb(HL)(OAc)] ClO4}(n) and [PbL(NO2)](n), respectively. Using Pb(NO3)(2) as a source of PbII in the same reaction with HL and two equivalents of NaN3 or NaNCS at room temperature yields [PbLN3](n) and [Pb-2(HL)(2)(NO3)(2)(NCS)(2)], respectively. The room temperature reaction of Pb(NO3)(2) with HL in the presence of two equivalents of NaClO4 leads to the transformation of the parent ligand to its perchlorate salt [H2L] ClO4. In all the obtained Pb-II structures, HL or its deprotonated form L acts both as a chelating and a bridging ligand. The nature of the inorganic anion also influences the final structure. In all complexes the PbII center exhibits a hemidirected coordination geometry with all the covalent bonds being concentrated on one hemisphere of the coordination sphere with the closest approach of two atoms on the other side varying from 151 degrees to 232 degrees. The sterically available PbII ion participates in tetrel bonding as evidenced from the detailed structural analysis of the described complexes. As a result of tetrel bonding, the structures of all the six compounds can be extended to a higher dimensional framework, which is further stabilized by pi center dot center dot center dot pi stacking interactions between the aromatic rings. The DFT based charge and energy decomposition (ETS-NOCV) calculations are performed in order to shed light on the nature of non-covalent interactions that determine the stability of the obtained structures.

• 出版日期2017