Impact of N-donor auxiliary ligands on two new Co(ii)-based MOFs with N-heterocyclic ligands and a magnetism study. (31st May 2022) - Dong, Xiuyan
Abstract : These current results show that the use of Co(ii )-MOF chemistry, especially in the presence of various auxiliary linkers, is an efficient method to prepare multifunctional MOFs combining new outstanding structures and excellent properties. Abstract : Two new cobalt(ii ) MOFs, namely [Co2 (L)2 (4, 4′-bipy)] n (1 ) and {[Co(L)(dib)0.5 (H2 O)2 ]·H2 O} n (2 ), were obtained by the self-assembly of Co(NO3 )2 ·6H2 O with V-shaped 2, 4-[6-(4-carboxyphenyl)pyrazin-2-yl]benzoic acid (H2 L) in the presence of two bridging auxiliary N-donor linkers, 1, 4-di(1 H -imidazole-1-yl) benzene (dib) and 4, 4′-bipyridine (4, 4′-bipy). 1 is a 3D (3, 4)-connected framework containing 2-fold interpenetration, while 2 features an infinite 2D network structure with [Co2 (μ2 -O)2 ] 4+ subunits. The structural diversity of the two MOFs suggests that different auxiliary linkers can induce different conformations and coordination modes of H2 L and have an influence on the resulting networks. A computational study of Hirshfeld surface analysis was also conducted. In addition, the magnetic properties of 1 and 2 were investigated in detail, which revealed the ferromagnetic and antiferromagnetic interactions that occurred between Co(ii ) centers in 1 and 2, respectively.