Heterometallic Coordination Polymers Assembled from Trigonal Trinuclear Fe₂Ni-Pivalate Blocks and Polypyridine Spacers: Topological Diversity, Sorption, and Catalytic Properties

Abstract

Linkage of the trigonal complex [Fe2NiO(Piv)6] (where Piv(-) = pivalate) by a series of polypyridine ligands, namely, tris(4-pyridyl)triazine (L(2)), 2,6-bis(3-pyridyl)-4-(4-pyridyl)pyridine (L(3)), N-(bis-2,2-(4-pyridyloxymethyl)-3-(4-pyridyloxy)propyl))pyridone-4 (L(4)), and 4-(N,N-diethylamino)phenyl-bis-2,6-(4-pyridyl)pyridine (L(5)) resulted in the formation of novel coordination polymers [Fe2NiO(Piv)6(L(2))]n (2), [Fe2NiO(Piv)6(L(3))]n (3), [Fe2NiO(Piv)6(L(4))]n·nHPiv (4), and [{Fe2NiO(Piv)6}4{L(5)}6]n·3nDEF (5, where DEF is N,N-diethylformamide), which were crystallographically characterized. The topological analysis of 3, 4, and 5 disclosed the 3,3,4,4-connected 2D (3, 4) or 3,4,4-connected 1D (5) underlying networks which, upon further simplification, gave rise to the uninodal 3-connected nets with the respective fes (3, 4) or SP 1-periodic net (4,4)(0,2) (5) topologies, driven by the cluster [Fe2Ni(μ3-O)(μ-Piv)6] nodes and the polypyridine μ3-L(3,4) or μ2-L(5) blocks. The obtained topologies were compared with those identified in other closely related derivatives [Fe2NiO(Piv)6(L(1))]n (1) and {Fe2NiO(Piv)6}8{L(6)}12 (6), where L(1) and L(6) are tris(4-pyridyl)pyridine and 4-(N,N-dimethylamino)phenyl-bis-2,6-(4-pyridyl)pyridine, respectively. It was shown that a key structure-driven role in defining the dimensionality and topology of the resulting coordination network is played by the type of polypyridine spacer. Compounds 2 and 3 possess a porous structure, as confirmed by the N2 and H2 sorption data at 78 K. Methanol and ethanol sorption by 2 was also studied indicating that the pores filled by these substrates did not induce any structural rearrangement of this sorbent. Additionally, porous coordination polymer 2 was also applied as a heterogeneous catalyst for the condensation of salicylaldehyde or 9-anthracenecarbaldehyde with malononitrile. The best activity of 2 was observed in the case of salicylaldehyde substrate, resulting in up to 88% conversion into 2-imino-2H-chromen-3-carbonitrile.

Effective Photocatalytic Activity of Mixed Ni/Fe-Base Metal-Organic Framework under a Compact Fluorescent Daylight Lamp

“…However, there is a recombination of excessive electrons and holes, resulting in the restricted photocatalytic activity of this material. In our study, mixed a metal Fe/Ni-based framework that consists of a mixed-metal cluster Fe 2 NiO with electron transfer effect may enhance the photocatalytic performance [45,61,65].…”

“…However, there is a recombination of excessive electrons and holes, resulting in the restricted photocatalytic activity of this material. In our study, mixed a metal Fe/Nibased framework that consists of a mixed-metal cluster Fe2NiO with electron transfer effect may enhance the photocatalytic performance [45,61,65]. Besides, a mixed metal Fe/Ni-based framework that consists of the mixed-metal cluster Fe2NiO possesses large pores and a high surface area, as compared with a single metal Fe-based framework; therefore, Ni/Fe-MOF exhibited a high adsorption capacity of RhB and high photocatalytic activity in RhB degradation.…”

New Topologically Unique Metal-Organic Architectures Driven by a Pyridine-Tricarboxylate Building Block

“…The research on metal-organic frameworks (MOFs) has become a very hot topic in materials science, especially given their almost infinite structural diversity [1][2][3] and notable functional properties, with significance in the areas of luminescent materials [4][5][6], molecular magnetism [7][8][9][10], gas storage [11][12][13], sensing and separation [14][15][16], and catalysis [17][18][19][20]. A high diversity of factors can affect the metal-organic architectures and functional properties of MOFs, such as, for example, the nature and coordination preferences of metal nodes, types of organic spacers, and linkers, and various reaction conditions [21][22][23][24][25][26].…”

A Flexible Aromatic Tetracarboxylate as a New Linker for Coordination Polymers

“…Coordination polymers (CPs) and metal-organic frameworks (MOFs) have been extensively explored in different chemistry branches on account of their unique and diverse structures, remarkable functional properties, and important application in a wide variety of fields, which, among others, includes gas adsorption and storage [1][2][3][4], catalysis [5][6][7][8][9], molecular magnetism [10][11][12], and photochemistry [13][14][15][16]. In the synthesis of functional CPs and derived materials, various structural and experimental parameters, such as a metal-ion coordination environment and ligand type [17][18][19], pH value [20,21], solvent composition [22,23], and temperature [24][25][26], can play structure-guiding roles.…”