Structural diversity through ligand flexibility: two novel metal-organic nets via ligand-to-ligand cross-linking of 'paddlewheels'

摘要

Solvothermal reaction of a partially flexible ligand, H_4L, and Cu(NO_3)_2-2.5H_2O afforded two cross-linked Kagome lattices of formula [Cu_2(L)]_n: an acs net sustained by novel trigonal prismatic supermolecular building blocks (SBBs) and the first example of a partially pillared Kagome net. Whereas metal-organic materials (MOMs) have existed for several decades, it was not until the early 1990's that crystal engineering approaches were adapted for design and synthesis of MOMs with 2D or 3D network structures.Exquisite control over structure is exemplified by the use of rigid linear linkers (e.g. benzene-1,4-dicarboxylate or 4,4'-bipyridine) to connect square, tetrahedral, trigonal prismatic or octahedral nodes (also known as molecular building blocks,~(le) MBBs) and thereby generate square grids,diamondoid (did),trigonal prismatic (acs) or octahedral (pcu) networks, respectively.