Design of Lead(II) Metal-Organic Frameworks Based on Covalent and Tetrel Bonding

作者：Gargari Masoumeh Servati; Stilinovic Vladimir^*; Bauza Antonio; Frontera Antonio; McArdle Patrick; Van Derveer Donald; Ng Seik Weng; Mahmoudi Ghodrat

来源：Chemistry - A European Journal, 2015, 21(49): 17951-17958.

DOI：10.1002/chem.201501916

• crystal engineering
• lead
• metal-organic frameworks
• noncovalent interactions
• supramolecular chemistry

Three solid materials, [Pb(HL)(SCN)(2)]center dot CH3OH (1), [Pb(HL)(SCN)(2)] (2), and [Pb(L)(SCN)](n) (3), were obtained from Pb(SCN)(2) and an unsymmetrical bis-pyridyl hydrazone ligand that can act both as a bridging and as a chelating ligand. In all three the lead center is hemidirectionally coordinated and is thus sterically optimal for participation in tetrel bonding. In the crystal structures of all three compounds, the lead atoms participate in short contacts with thiocyanate sulfur or nitrogen atoms. These contacts are shorter than the sums of the van der Waals radii (3.04-3.47 angstrom for Pb center dot center dot center dot S and 3.54 angstrom for Pb center dot center dot center dot N) and interconnect the covalently bonded units (monomers, dimers, and 2D polymers) into supramolecular assemblies (chains and 3D structures). DFT calculations showed these contacts to be tetrel bonds of considerable energy (6.5-10.5 kcalmol(-1) for Pb center dot center dot center dot S and 16.5 kcalmol(-1) for Pb center dot center dot center dot N). A survey of structures in the CSD showed that similar contacts often appear in crystals of Pb-II complexes with regular geometries, which leads to the conclusion that tetrel bonding plays a significant role in the supramolecular chemistry of Pb-II.

• 出版日期2015-12-1