Syntheses and Crystal Structures of a Series of Coordination Polymers Constructed From C 2 ‐Symmetric Ligand 1,3‐Adamantanedicarboxylic Acid

This article systematically investigates the influence of the properties of inhomogeneous N‐auxiliary ligands and pH value on the helical structures of complexes based on C 2 ‐symmetric ligand 1,3‐adamantanedicarboxylic acid (H 2 ADC). Five kinds of neutral ligands (phen=1,10‐phenanthroline, bipy=4,4′‐bipyridine, bpa=1,2‐bis(4‐pyridyl)ethane, bpe=1,2‐bis(4‐pyridyl)ethane, and bpp=1,3‐bis(4‐pyridyl)propane) were selected, and a series of new Zn II /Co II dicarboxylates have been synthesized by slow diffusion, namely, [Zn(phen)(ADC)(H 2 O)] 2 ⋅ CH 3 OH ( 1 ), {[Zn(ADC)(bpe)] ⋅ H 2 O} n ( 2 ), {[Zn(ADC)(bipy)] ⋅ 2 H 2 O} n ( 3 ), {[Zn(ADC)(bpa)] 2 ⋅ 5 H 2 O} n ( 4 ), {[Zn(ADC)(bpp)] 2 ⋅ CH 3 OH} n ( 5 ), {[Zn(ADC)(bpp)]} n ( 6 ), {[Co(ADC)(bpp)(CH 3 OH)(H 2 O)] ⋅ CH 3 OH ⋅ 2 H 2 O} n ( 7 ), and {[Co(ADC)(bpp)]} n ( 8 ). Single‐crystal X‐ray structural analysis shows that complex 1 forms a 0D dinuclear with closed‐loop unit. The complex 2 is a 2D layer framework. Compounds 3 and 4 are isomorphous with a small discrepancy and present one‐dimensional chainlike structures. It is interesting that the 2D organic–inorganic hybrid frameworks containing meso ‐helical chains have been observed. Compound 5 is a 2D interpenetrated network with (4,4) topology, in which homochiral left‐handed helical chains are arranged in an ABAB sequence parallel to the plane defined by ( a , c ), and right‐handed helical chains running along the a axis are also observed in the solid state, resulting in a meso ‐helical structure. Compounds 6 , 7 , and 8 crystallize in a chiral space group P 212121. Highly dimensional 6 and 8 are essentially isostructural and present a threefold interpenetrated 3D diamondoid network containing three helical chains, whereas 7 exhibits a 2D grid layer with a left‐handed helical chain. Furthermore, thermal stability , X‐ray powder diffraction , and the luminescent properties of 1 , 2 , 3 , 4 , 5 , 6 are also discussed.