Chapter 2 - Why bother with nets?

Abstract

This chapter describes the formation of nets as an organizing principle followed by nature when there are strong directional intermolecular forces in play and how “net-identification” helps. The analysis of a crystal structure is a fruitful way of looking at molecular crystals with strong, directed intermolecular bonding, as it reproduces many experimental data that are used in the design of new solid phases of ionic compounds. The analysis of molecular crystal structures of 3D nets has provided a useful way of looking at many compounds. There are also deliberate and successful designs of 3D-systems forming the desired predefined crystal structures. There are three different reasons for doing the structure analysis in terms of nets. Firstly, the pragmatic objective to get a mental picture of the particular structure to understand the molecular arrangement in three-dimensions. Secondly, use of the 3D-nets to understand the reason behind the formation of particular structure in certain molecules. The final level has to do with a more active understanding that helps in preparative labors in the laboratory. The three basic intrinsic properties of nets are they have strong interactions in three dimensions, have potentially large voids and channels as they are not closed pack, and has exact positioning of the molecules and coordination complexes used as building blocks. These are applicable in molecule based magnetic materials, spin crossover or spin transition materials, non-linear optical materials, and porous materials. Hence, the organizing principle can make useful compounds for the future science and industry.