Layered structures coordination polymer networks

For example, numerous materials such as coordination networks [21] and inorganic crystals consist of layered structures [22], wherein each layer-when considered separately - fulfills the above criteria to be classified as a 2-D (supramolecular) polymer. There are, however, strong forces between layers, so that in most cases these equilibrium 2-D networks are unlikely to be separable (in intact form) one from another. In this chapter, however, attention is focused on the preparation of individual 2-D structures and not on 3-D layered systems the latter would need to be taken apart in a separation step in similar fashion to graphite (i.e., layered graphene) and some other inorganic laminar crystals (see Section 28.5.1) [23]. In a sense, these layered 3-D bulk materials went a step too far, unless isolation of the individual 2-D layers was feasible. 

In the presence of TMEDA, a 3-D brickwall coordination polymer of TMEDA-supported dimeric, less bulky 2,3-dialkyl-l,4-dilithio-1,3-butadiene If was formed, which has been confirmed by X-ray analysis (Type IV, Scheme 3) [32]. The expected TMEDA-chelated monomeric structure IF as a deaggregation product was not formed. As shown in Fig. 2 and Scheme 3, in monolayer of 3-D brickwall polymeric structure of If, six Li4 cores and six TMEDA bridges composed a chairlike macrocyclic unit. The macrocyclic unit extends to form 2-D brickwall mono-layer via N-Li coordination. The brickwall monolayers are linked by TMEDA molecules to form the 3-D network, also forming chair-Uke Li4-TMEDA... 

---