Guest‐Induced Chirality in the Ferrimagnetic Nanoporous Diamond Framework Mn₃(HCOO)₆

Abstract

Chiral magnets are obtained by inclusion of chiral guest molecules into the channels of an achiral nanoporous ferrimagnet consisting of the Mn3(HCOO)6 (1) framework. Insertion of the R or the S enantiomer of 2‐chloropropan‐1‐ol (CH3C*HClCH2OH) in the chiral pores of the previously emptied framework (space group P21/c) results in the two corresponding chiral solids (1R and 1S, space group P21), while insertion of a racemic mixture of the two enantiomers retains the achirality of the host for the meso solid (1RS, space group P21/c). The R guest is ordered in the M channels while the S guest is ordered in the P channels. In contrast, the R guests in the P channels and the S guests in the M channels are disordered on two crystallographic orientations. For the racemic mixture of the two enantiomers in 1RS, random disorder of guests in both channels is observed. Thus, the localization of the guest molecule depends on the nature of the surface to recognize the guest of a particular chirality. The guest inclusion compounds are thermally stable. The 1R and 1S compounds are optically active. All the compounds adopt a ferrimagnetic ground state. Compared to the host framework of 1 without guest, the Curie temperature decreases for both 1R and 1S but increases for 1RS. The additional interactions between the framework and the inserted guest alcohols strengthen the lattice via hydrogen bonds and other electrostatic forces, and it might account for the significant lowering of the lattice contribution as well as the magnetic component to the specific heat capacity upon guest loading.

Magnetic functionalities in MOFs: from the framework to the pore

“…5). [20][21][22][23][24][25][26] The magnetic behaviour of these magnetic MOFs depends on the type of metal ion: the iron and manganese formates are ferromagnets, with critical temperatures T c of 16.1 and 8.0, whereas the cobalt compound is a spin-canted antiferromagnet below 1.8 K and the nickel derivative displays 3D long-range ferromagnetic ordering at 2.7 K (see Fig. 5b).…”

Recent advance in porous coordination polymers from the viewpoint of crystalline-state transformation

“…[110] Guest-induced chirality in the ferrimagnetic nanoporous diamond framework Mn 3 (HCOO) 6 . [120] [Zn 3 (HCOO) 6 ]: A porous diamond framework conformable to guest inclusion. [121] A 3D porous lanthanide-fumarate framework with water hexamer occupied cavities, exhibiting a reversible dehydration and rehydration procedure.…”

New double formates Na3M(HCOO)6 (M=Ga, In) with diamond-like metal framework: Synthesis, structure and coordination modes

“…In fact, double formates, such as MM 0 (HCOO) 4 [27][28][29][30][31][32], M 2 M 0 (HCOO) 6 [27,30,[33][34][35], MM'(HCOO) 4 (H 2 O) 2 (M = Ca, Sr, and Ba, M 0 = Cu) [36], Ba 2 M(H-COO) 6 (H 2 O) 4 (M = Fe, Co, Ni, Cu, Zn) [37][38][39][40][41] and M x M 0 1Àx (HCOO) 2 Á2H 2 O (M = Mn, Co, Ni, Zn, Cd, Mg, and M 0 = Cu) [42][43][44][45][46], were known for many years. In the structure of SrCu(H-COO) 4 (H 2 O) 2 , for example, four different connection modes, 2.20, 2.11, 3.21 and 4.22 coexist. However, the study of these compounds was mainly focused on thermal properties since they were widely used as the precursors for the preparation of complex oxides, such as high Tc materials.…”

“…As the smallest and simplest carboxylate, formate has less stereo effect that can coordinate to metal cations as mono-, bis-, tri-or higher chelate ligands with various connection modes. For example, in the structure of anhydrous bivalent metal formates M 3 (HCOO) 6 (M = Mn, Fe, Co, Mg, Ni) [3][4][5][6][7][8][9], the connection modes of formates are 3.21, in (syn, syn, anti-) or (syn, anti, anti-) bridging fashions, while in their dihydrate form [M(HCOO) 2 ]Á2H 2 O (M = Fe, Co, Mn, Ni, Mg, Cu) [10][11][12][13] where water molecules act as co-ligands, the formates are in 2.11, (syn, anti-), (syn, syn-) or (anti, anti-) modes. The connection modes of formates also depend on the cation size.…”

“…Metal formates have attracted considerable attention due to their novel structures and interesting properties such as magnetism, absorption and separation [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. As the smallest and simplest carboxylate, formate has less stereo effect that can coordinate to metal cations as mono-, bis-, tri-or higher chelate ligands with various connection modes.…”