Crystal structure, magnetism, and luminescent properties of two isostructural pcu MOFs based on a triangular ligand.

Two isomorphous metal-organic frameworks, {[M(TIPA) (btec)½]H 2 O} n , [M = Co ( 1 ) or Zn ( 2 )] were synthesized hydrothermally based on a semi-rigid N-center triangular ligand TIPA, where TIPA = tris(4-(1H-imidazol-1-yl)-phenyl)amine, H 4 btec = 1,2,4,5-benzenetetracarboxylic acid. Single crystal structural analyses show that complexes 1 and 2 are isostructural and both feature a twofold interpenetrated pcu topology. In 1 and 2 , the btec 4− ligand adopting μ 2 -η 2 :η 1 and μ 1 -η 1 :η 0 coordination modes connect adjacent dinuclear Co/Zn units to form a 1D straight polymeric chain. Then these chains arranged in parallel/parallel fashion were further extended to a 3D network by exo-tridentate ligand TIPA with μ 2 -κ 2 N:N′ coordination mode. The magnetic property of 1 and the luminescent property of 2 were investigated. Furthermore, the structure and spectroscopic property of 2 were further investigated by DFT and TD-DFT calculations. [ABSTRACT FROM AUTHOR]