New Approaches to the Analysis of High Connectivity Materials:  Design Frameworks Based upon 4⁴- and 6³-Subnet Tectons

Abstract

Coordination framework polymers derived from lanthanide metal ions with N,N'-dioxide ligands (4,4'-bipyridine-N,N'-dioxide, pyrazine-N,N'-dioxide, 1,2-bis(pyridin-4-yl)ethane-N,N'-dioxide, trans-1,2-bis(pyridin-4-yl)ethene-N,N'-dioxide) exhibit such intricate architectures that a new strategy is required to appreciate and understand their structures. Rather than analyzing the overall structure in terms of the connectivity of individual metal nodes, which can lead in some cases to extremely complex topological treatments, our new strategy is based on the visualization of the structures as combinations of interconnected layered 2-D sheets or subnet tectons. Despite the diversity and relative complexities of many of the structures discussed here, they can all be described by the interconnection of just two types of 2-D subnet tectons, 4(4) square grids or 6(3) hexagonal grids. The interconnection of these layered sheets with bridging N,N'-dioxide molecules gives rise to both 2-D bilayer and 3-D network extended structures depending upon the relative dispositions of the interconnecting N,N'-dioxide ligands. Thus, 2-D bilayers result when the N,N'-dioxide ligands that bridge two subnet tectons are located on the same side of the sheet, while 3-D networks are formed when the bridging N,N'-dioxide ligands are located on both sides of the sheet. This analysis allows ready identification and interpretation of some of the most highly connected and complex architectures yet observed in materials chemistry.

Crystal structure of diaquabis(benzoato-κO)(1,10-phenanthroline- κ2N,N')- manganese(II) 1.5 hydrate, C26H25MnN2O7.5

“…The study of coordination polymers has gained great recognition as an importantinterface betweensynthetic chemistryand materialss cience andp rovidesas olid foundationf or understanding howm olecules can be organized and how functions can be achieved.I nt he recent years, the supramolecular chemistry of transition metal-organic polymers based on coordination bonds and/or weaker intermolecular forces (such as hydrogen bonding and p-p stacking interaction) has been widely investigated due to their variety of intriguing architectures and topologies [1][2][3][4] and their potential applications in magnetism,electric conductivity, molecular adsorption, heterogeneous catalysis, and fluorescent materials [5][6][7][8][9]. Ag reat research effort was made to obtain designed andp redictable frameworks and properties by using an versatileo rganic ligand and functional metal ionsi nsitu solvothermal synthesis.…”

“…Hatoms bonded to Nand Oatoms were located in adifference electron density map and refined with distance restraints of O-H =0.84 (2) and N-H =0.87(2) Å, and with U iso (H) =1.2U eq (N, O). Other Hatoms werepositioned geometrically and refined using a riding model, with C-H =0 .95-0.99 Åa nd with U iso (H) =1 .2 times U eq (C).…”

Crystal structure of poly[bis(1,4-di(1H-imidazol-1-yl)butane-κ2N:N′) zinc(II)]bis(hexafluoridophosphate), C20H28F12N8P2Zn

“…Metal-organicframeworks (MOFs) are of contemporary interest becauseoftheir structural topologies andpotential applications in theareas of catalysis, adsorption,luminescence, nonlinearoptics, magnetism,and ion exchange [1][2][3][4][5][6][7][8][9]. The ligands and metal centers both are the keys to the design and construction of MOFs with fascinating topology and physicochemical properties [10,11].…”

Crystal structure of pentaaqua-tris[(1,3,4-thiadiazole-2,5- diyldithio)diacetato]diyttrium(III), Y2(H2O)5(C6H12N04S3)3

“…In past decades, the design and synthesis of metal-organic frameworks has been a field of rapid growth in supramolecular and material chemistry due to their fascinating topologies and useful properties [1][2][3][4][5]. An effective approach in building such materials is to employ suitable organic bridging ligands [6,7].…”