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

Abstract

Photoinitiated solid-state reactions are known to affect the physical properties of coordination polymers, such as fluorescence and sorption behaviour, and also afford extraordinary architectures (e.g. three-periodic structures with polyorganic ligands). However, the construction of novel photo-sensitive coordination polymers requires an understanding of the factors which govern the mutual disposition of reactive fragments. A series of zinc(II) malonate complexes with 1,2-bis(pyridin-4-yl)ethylene and its photo-insensitive analogues has been synthesized for the purpose of systematic analysis of their underlying nets and mutual disposition of N-donor ligands. The application of a big data-set analysis for the prediction of a variety of possible complex compositions, coordination environments and networks for a four-component system has been demonstrated for the first time. Seven of the nine compounds possess one of the highly probable topologies for their underlying nets; in addition, two novel closely related four-coordinated networks were obtained. Complexes containing 1,2-bis(pyridin-4-yl)ethylene and 1,2-bis(pyridin-4-yl)ethane form isoreticular compounds more readily than those with 4,4 0 -bipyridine and 1,2-bis(pyridin-4-yl)ethylene. The effects of the precursor, either zinc(II) nitrate or zinc(II) acetate, on the composition and dimensionality of the resulting architecture are discussed. For three of the four novel complexes containing 1,2-bis(pyridin-4-yl)ethylene, the single-crystal-to-single-crystal [2 + 2] cycloaddition reactions were carried out. UV irradiation of these crystals afforded either the 0D!1D or the 3D!3D transformations, with and without network changes. One of the two 3D!3D transformations was accompanied by solvent (H 2 O) cleavage.

Topological Databases: Why Do We Need Them for Design of Coordination Polymers?

“…The concept of crystal design came to crystal chemistry recently but immediately led to rapid development of structural chemistry of different classes of substances with extended architectures such as coordination polymers of different periodicities (chain one-dimensional, layered two-dimensional, or framework three-dimensional). − This concept gained its theoretical basis from “reticular” chemistry, which is in turn based on the topological (graph) approach . Thus, topological properties of crystal structures became important and resulted in successful synthesis of large families of isoreticular metal–organic frameworks (MOFs). , It is the topological methods that enabled one to reveal many correlations of “chemical composition – structure – property”, which were then used in crystal design. ,− The main route of reticular chemistry in obtaining new coordination polymers includes utilizing structural units with predetermined topology and geometry (secondary building units, SBUs) for decoration of a particular topological motif (periodic net). − Importantly, this approach can be readily algorithmized and implemented into computer tools for analysis of crystal structures, their topological classification, and design of new crystalline compounds. − However, complicated compounds consisting of SBUs with a high degree of freedom and extended connection possibilities are still a challenge for crystal design. − This promoted inventing new structural descriptors and models that could reliably discriminate different topological motifs at both local and overall level, such as coordination figure, ligand coordination type symbol, − Hopf ring net, , net topological indices and tilings . These were formalized, digitalized, and computed for thousands of crystal structures from crystallographic databases such as the Cambridge Structural Database (CSD), Inorganic Crystal Structure Database (ICSD), or Pearson’s Crystal Database .…”

Topological motifs in dicyanamides of transition metals

“…Based on data about the most frequent dca : M II ratios, the most typical coordination modes of ligands, and coordination numbers of metal atoms, the most expected coordination formulas of complexes can be estimated as was previously demonstrated, for example, for metal cyanides, 18,21 zinc malonates with N-donor linkers, 42 and Zr-MOF pore structures. 43 Let us consider only neutral [M II L x IJdca) 2 ] complexes based on 3d-metals with CN = 5, 6 or 7, bridge B 2 anions, and neutral L co-ligands.…”

Design and synthesis of copper(ii) malonates with N,N′-containing linkers

“…A few years ago, we evaluated the most probable compositions of complexes that could be obtained from Zn( ii ) : L : R 2 mal 2− : H 2 O mixtures (L is 4,4′-bipyridine or its' linear analog, and R 2 mal 2− is malonic acid or its' substituted analog), as well as the most probable nets. 9 The fact that zinc( ii ) atoms in this family were inclined to form tetrahedral ZnNO 3 or octahedral ZnN 2 O 4 coordination polyhedra resulted in a prevalence of 3D coordination polymers based on [Zn(R 2 mal)] chains connected by N,N′-containing linkers. In order to demonstrate the dramatic effect of the local coordination environment on the overall architecture of complexes, we carried out in this work similar calculations for their copper( ii )-containing analogs.…”

“…10–17. Also, some examples of expert systems to predict 2D and 3D coordination polymers for copper( i , ii ) heterocyclic N-oxides, 18 zinc( ii ) malonates, 8,9 metal 4,5,6-trihydroxyisophthalates, 19 cyanides, 20 and polycyanides 21 have been published. Besides, a topological approach for the synthesis of acentric solids based on hydroxyisophthalates for applications in non-linear optics to proton conductors and fluorescent materials was also recently tested.…”

“…[3][4][5] Besides the porosity, other applications of the reticular approach to the synthesis of functional materials are known, including the dispositions of olefin fragments suitable for photoinitiated solid-state reactions, and the synthesis of porous materials as prospective catalysts and luminescent materials. [6][7][8][9] However, topological approaches to the analysis of coordination compounds and metal-organic frameworks (MOFs) of any periodicity also present reticular chemistry an opportunity to be used to synthesize unprecedented architectures, to estimate a variety of underlying nets that can be found in a given chemical system, and to reveal the most likely to occur as well. Some examples of reticular chemistry approaches to the design of coordination polymers with novel topologies by using polytopic ligands with a controlled coordination mode and metal ions with a controlled coordination figure are described in ref.…”