Structure, adsorption and magnetic properties of chiral metal–organic frameworks bearing linear trinuclear secondary building blocks

Abstract

The reactions of new chiral organic ligands trimesoyltri(L-alanine) (L-TMTAH(3)) or trimesoyltri(D-alanine) (D-TMTAH(3)) with transition metal salts in the presence of an ancillary ligand of 4,4'-bipyridine gave two pairs of three dimensional frameworks [Co(3)(L-TMTA)(2)(4,4'-bpy)(4)]·28H(2)O (1), [Co(3)(D-TMTA)(2)(4,4'-bpy)(4)]·28H(2)O (2) [Ni(3)(L-TMTA)(2)(4,4'-bpy)(4)]·2C(2)H(5)OH·14H(2)O (3) and [Ni(3)(D-TMTA)(2)(4,4'-bpy)(4)]·2C(2)H(5)OH·14H(2)O (4). These compounds were characterized by elemental analysis, IR, and X-ray powder diffraction analysis and the structures of 1-3 were determined from X-ray single crystal diffraction analysis. Complexes 1-4 feature linear trinuclear secondary building blocks [M(3)(COO)(4)](2+) formed via the connection of three metal ions by four carboxylato groups from four TMTA(3-) ligands. Every adjacent two linear trinuclear secondary building blocks are linked by one and three 4,4'-bipyridine molecules along the a and c axis, respectively, to form two-dimensional sheets, which are further connected by TMTA(3-) ligands to construct a porous three dimensional framework with one-dimensional channels. Compound 3 was taken as an example to investigate the adsorption properties of compounds 1-4. It revealed a saturated hydrogen uptake of 216.6 cm(3) g(-1) (2.0 wt%) at 11.1 atm measured at 77 K, a maximum CO(2) uptake of 119.4 cm(3) g(-1) (23.5 wt%) at 19.5 atm measured at 298 K and a saturated CH(4) uptake of 77.8 cm(3) g(-1) (5.6 wt%) at 27.1 atm measured at 298 K. The magnetic studies of complexes 1 and 3 indicate the presence of antiferromagnetic interactions between the metal ions in the two compounds.

Modulator Induced Formation of a Neutral Framework Based on Trinuclear Cobalt(II) Clusters and Nitrilotribenzoic Acid: Synthesis, Magnetism, and Sorption Properties

“…All cobalt(II) ions are found in an octahedral coordination environment typical for such carboxylate systems. [45][46][47] These trinuclear clusters are connected through the ntb 3 À ligands resulting in the formation of the 3D framework structure depicted in Figure 2. The shortest intercluster Co ••• Co distances are found at 515 and 661 pm.…”

Crystal structures and hydrogen bond analysis of five amino acid conjugates of terephthalic and benzene-1,2,3-tricarboxylic acids

“…6,18,19 In addition, terephthalamides and benzene-1,3,5-tricarboxamides derivatives have been reported to form liquid columnar crystal phases (LC), preorganized surfactants and multi-component organic cages within dynamic combinatorial libraries. [20][21][22][23] Introduction of amino acids into terephthalamide and benzene-1,3,5-tricarboxamides offers the possibility of producing enantiopure chiral building blocks and structures 5,7,24 with potential applications in enantioselective synthesis, separation and detection. The amino acid part can also stabilise the assemblies via hydrogen bonding and moreover provide metal coordination sites.…”

“…The amino acid part can also stabilise the assemblies via hydrogen bonding and moreover provide metal coordination sites. 5,11,16,17,[24][25][26] The complexing abilities of amino acid substituted terephthalamide and benzene-1,3,5-tricarboxamides have been studied by preparing network structures with metals such as copper, cobalt, manganese, nickel, cadmium, zinc, lantanoids, and calcium. 7,11,17,[24][25][26][27][28][29][30][31] These studies have focused on non-chiral glycine (-H) substituted ligands, but alanine (-CH 3 ) and phenylalanine (-CH 2 (C 6 H 5 )) examples are also known, although reported X-ray structures of such network compounds are rare.…”

“…5,11,16,17,[24][25][26] The complexing abilities of amino acid substituted terephthalamide and benzene-1,3,5-tricarboxamides have been studied by preparing network structures with metals such as copper, cobalt, manganese, nickel, cadmium, zinc, lantanoids, and calcium. 7,11,17,[24][25][26][27][28][29][30][31] These studies have focused on non-chiral glycine (-H) substituted ligands, but alanine (-CH 3 ) and phenylalanine (-CH 2 (C 6 H 5 )) examples are also known, although reported X-ray structures of such network compounds are rare. 32,33 The choice of the ligand and metal is essential in producing such metal-organic frameworks (MOFs) 34 that can have application in gas sorption, catalysis and molecular recognition.…”

A porous cobalt-based MOF with high CO2 selectivity and uptake capacity

“…Likewise, a high CO 2 uptake of 13.1, 11.6 and 10.1 wt% is observed under 1 bar at 273 K, 298 K and 313 K, respectively. Although the amount of absorbed CO 2 is moderate compared with those of the best performing MOFs such such as HKUST-1 11 (6.6 wt% at 1 bar and 313 K), MIL-53(Cr) (8.9 wt% at 1 bar and 298 K) 12 . The zero-coverage adsorption enthalpy (Q st ) of CO 2 in NJFU-2a is 38.2 kJ mol -1 , as shown in Fig.…”