Chemical Design of Heterometallic Coordination Polymers Based on {Cu(Me₂mal)₂} Fragment

Abstract

Topological methods of analysis of coordination networks have become an integral part of design of coordination polymers, MOFs, and zeolites. It helps to chemists to understand the novelty of findings, to reveal relations between different structures, to propose new design concepts, and to communicate effectively with each other. However, this is not the limit of the methods. Description of coordination environment of structural units (metal atoms, ligands, SBUs), network topology (topological type), and topology of entanglement (entanglement pattern) intrinsically leads to finding relations between the topological parameters. Further, the correlations can be grouped (systematized) in a hierarchical manner to produce a knowledge database for design and prediction of new materials (their structure and properties) [1, 2]. Thus, new structural characteristics, the so-called descriptors, have to be invented for prediction of particular structural features. For example, we have proposed to use topological type of Hopf ring net for analysis of topology entanglements in coordination networks. Now we put forward Extended ring net (ERN), which incorporates information about topology of entangled nets and topology of entanglements. ERN is able to distinguish patterns of entanglements up to isomorphism and polymorphism, that allowed us to describe new type of isomerism of coordination polymers, entanglement isomerism. MOF structures are usually considered as a result of assembly of secondary building units in an isoreticular manner. Usually SBU is considered as a topologically dense 0D polynuclear complex group, which coordination figure is predetermined by orientation of points of extension (functional groups of ligands connected by linkers). However, many practically important MOFs contain infinite SBUs; e.g. rod-shaped 1D {AlOH(CO2)2} groups are connected by benzene linkers in parallel fashion into framework MIL-53. We have produced a comprehensive systematics of infinite SBUs and ways for their connection with new algorithms of rod-MOFs description as 2D net of rods connections. Selection of correct structural groups is also important for design of self-catenated networks. We proposed a universal algorithm for selection of all reasonable subnets and determining the structure driving ones. To describe the geometry and topology of voids and channels in porous structures we combined topological methods and Voronoi partitioning. The improved Voronoi partitioning provides much more characteristics of porous structures, e.g. periodicity, topology and crystallographic orientation of channels, minimal cages of framework, open sights of metal atoms etc. These descriptors give us an opportunity to define metal-organic nanotube as a 1-periodic tiling of face-shared 3D tiles. To enhance the usability of the results of topological analysis we collected values of descriptors into a knowledge database [2]. The database was applied in finding relations between topological parameters for heterometallic coordination polymers based on {C...

Coordination Properties of Hydroxyisophthalic Acids: Topological Correlations, Synthesis, Structural Analysis, and Properties of New Complexes

“…Preparations and properties 4,5,6-Trihydroxyisophthalic acid (H 2 L • 2H 2 O) was obtained as previously described by using gallic acid as a precursor. [14] The purity and structure of the sample were confirmed by TLC, 1 H and 13 C NMR techniques, FTIR spectroscopy, and thermogravimetric analysis (TGA; Figures S1-S4, S16). The reaction of 4,5,6trihydroxyisophthalic acid with NH 4 HCO 3 and KOH in 1 : 2 molar ratio afforded crystalline compounds (NH 4 ) 2 L • 2H 2 O (6) and [K 2 L(H 2 O) 2 ] (1), respectively.…”

“…Indeed the higher content of terminal aqua ligands reduces the network connectivity. [13,23] The chain can be simplified to its 3-c underlying net that belongs to the topological type (4,4)(0,2) (Fischer's 1D packing of spheres, or a "ladder" motif, Figure 5). The strontium(II) complex has a chain structure with polymeric groups oriented along crystallographic direction [100] (Figure 5).…”

“…Further, topologies and design strategies of coordination networks of alkali and alkali-earth cations with multi-donor ligands are still poorly explored. [13] Summarizing we can say that the trihydroxyisophthalic acids are also capable to serve as a building block for the construction of novel coordination networks with many potential applications. We expect the higher number of hydroxy groups will lead to the appearance of proton-conducting properties, which have not been observed for hydroxyisophthalates and dihydroxyisophthalates.…”

Exploitation of knowledge databases in the synthesis of zinc(II) malonates with photo-sensitive and photo-insensitive N,N′-containing linkers

“…1). Thus, dimethylmalonate (Me 2 mal) and diethylmalonate (Et 2 mal) anions (An) were used, as these fix the Zn:An ratio to 1:1 (to decrease the number of symmetrically independent anions in the unit cell) and have less coordination modes than the malonate anion (Gogoleva et al, 2017 An algorithm for the estimation of the most abundant nets of coordination polymers has been described in recent papers (Mitina & Blatov, 2013;Alexandrov et al, 2015a,b;Shevchenko et al, 2017). It is based on the analysis of crystallographic databases to reveal possible coordination numbers and coordination polyhedra of a given metal atom, ratio of cations, anions and neutral ligands which depend on the coordination number, and possible coordination modes of all ligands.…”

Binding Features of {M(3d)(cbdc)2} Blocks (M(3d)=VIVO, CuII; cbdc2–=Dianion of Cyclobutane‐1,1‐Dicarboxylic Acid) in Formation of Heterometallic Structures with d‐Metal Cations

“…Malonic acid (H 2 mal) which follows oxalic acid in the homologous row is the shortest dicarboxylic acid having numerous substituted analogues (H 2 R 2 mal), which differ in the substituent groups at the central carbon atom. The variety of coordination modes of malonate ligands causes a wide structural diversity of the compounds formed . It is known that malonic acid anions in aqueous solutions form stable bis‐chelate anions [M(mal) 2 (H 2 O) x ] 2– (where x=0, 1 or 2) with the majority of divalent cations of transition metals, in which the metal center is chelated by two anions of dicarboxylic acid .…”