Co(II) coordination polymers exhibiting reversible structural transformation and color change: A comparative analysis with Ni(II) analogue.

By employing the flexible ligands, bis(3,5-dicarboxyphenyl)adipoamide, H 4 L 1 ; bis( N -pyrid-3-ylmethyl)adipoamide, L 2 ; and bis( N -pyrid-3-ylmethyl) suberoamide, L 3 , four coordination polymers of the types {[M( L 1 ) 0.5 ( L 2 )(H 2 O) 2 ]·H 2 O} n (M = Co, 1 ; Ni, 2 ) and {[M 2 ( L 1 )( L 3 ) 2 (H 2 O) 4 ]·3H 2 O} n (M = Co, 3 ; Ni, 4 ) have been hydrothermally synthesized and structurally characterized by single crystal X-ray diffraction. Complexes 1 – 4 are topologically identical coordination polymers having the 2-fold interpenetrating 3D net with the mog topology. Additionally, the Co(II) complexes exhibit the reversible structural transformation with color change on dehydration/rehydration but Ni(II) complexes are unable to show such a behavior. All four complexes display good photo-degradation performance and the Co(II) complexes show slightly higher efficiencies than the Ni(II) ones. [ABSTRACT FROM AUTHOR]