Multifunctional MOFs through CO₂fixation: a metamagnetic kagome lattice with uniaxial zero thermal expansion and reversible guest sorption

Abstract

The properties of atmospheric CO2 fixation, metamagnetism, reversible guest adsorption and zero thermal expansion have been combined in a single robust MOF, [Cu3(bpac)3(CO3)2](ClO4)2·H2O (·H2O). This compound is a ditopically-bridged copper carbonate kagome lattice where desolvation of the MOF allows subtle tuning of the metamagnetic and uniaxial ZTE behaviour.

Phase Control of Ferromagnetic Copper(II) Carbonate Coordination Polymers through Reagent Concentration

“…In 1 , there is no exchange pathway between copper atoms on neighbouring layers, thus a ferromagnetic interaction is more likely in agreement with Hund's rule, whereas in 4 , the Cu atoms in neighbouring layers are connected through the bis(4‐pyridyl)acetylene ligand, thus ensuring that the Cu atoms are part of the same molecular orbital and thus would couple antiferromagnetically. The intralayer coupling constant in 1 is consistent with the other [Cu 3 (CO 3 ) 2 ] n 2 n + kagomes fitted with our model and fits well with the angular dependence in [Cu 3 (CO 3 )] trimers presented by Felix et al…”

“…In our previous work on another Cu II kagome, [Cu 3 (4,4′‐bipyridylacetylene) 3 (CO 3 ) 2 ](ClO 4 ) 2 · H 2 O ( 4 ), a weak antiferromagnetic interlayer interaction was seen, leading to a metamagnetic transition at ca. 100 G. The lack of a metamagnetic transition in 1 can be rationalised by inspection of the interlayer superexchange pathways in the two compounds.…”

“…The Curie–Weiss plot gives C = 0.403(3) cm 3 K mol –1 and θ = +21.5(8) K, indicating again a ferromagnetic interaction. Previous work by our group and others, indicates that ferromagnetic interactions occur between Cu II centres chelated and bridged by carbonate, thus the χT ( T ) data were modelled using a ferromagnetic S = 1/2 kagome model [Equation and Equation ) to give g = 2.039(5) and J/k B = +28.1(2) K to describe the intralayer interaction. where K = J/k B T and a n values for n = 1–8 are given in the Supporting Information.…”

“…Our previous work has explored the ability of strongly basic ammonia solutions containing copper to complex atmospheric CO 2 in order to form magnetically‐active and multifunctional coordination polymers and MOFs. As well as the kagome lattices formed in the previous example and by others,, a common motif of copper and carbonate in the presence of an amine ligand is chain formation .…”

Investigating the Structure Directing Properties of Designer 1,8-Naphthalimide and Amphiphilic Sulfonate Anions and Their FeIII Thiosemicarbazone Complexes

“…[11][12][13][14][15][16][17][18][19][20] Typically, this is through inclusion of structure directing groups (SDGs) into the ligand used for coordination, however it is also possible to include such structure directing properties through the use of designer counter ions.…”