Network chains exchange reactions

There are also carboxylates15 (Section 17-E-10), phosphates, catecholates, and oxalates. Most of the divalent iron oxalato compounds have a chain structure but the product of photoreduction of mononuclear [bipyH] [Feni(ojc)2(H20)2] gives a three-dimensional anionic polymeric network of [Fe2I(ox)3]2 1 and [Fen(bipy)3]2+ ions.16 Magnetic exchange typically occurs through the oxalate bridges.17 Six-coordinate iron(II) a-amino acid complexes are readily obtained from the reaction of the 4-coordinate Fe(mes)2(phen) and the protic amino add, AH, in THF 18... 

Under certain reaction conditions so-called macroreticular or macro-porous networks are produced. In such cross-linked networks, the cross-linked chains of the polymeric substance are not completely randomly distributed over the whole of the volume occupied by the substance. They give a structure that is more or less porous (Figure 2-7). With equal branch densities, macroreticular networks are much more permeable to solute and solvent molecules, which leads to their use as ion-exchange and gel-... 

The insertion of PEO into mica-like sheet silicates in the reactions of a melt of the polymer with the host Na - or NH4 -exchanged lattice is one of tiie few examples of direct polymer intercalation. Poly(ethylene oxide) is also inserted into the lamellar networks of V205-nH20, MoOs," " - MnPSj, CdPSj, " etc. Thus an aqueous solution of PEO (M = 10 ) reacts with an aqueous gel of V2O5 nH20 to form a composite after removal of water. In this case, the interlayer distance increases from 1.155 to 1.32nm. Alkali metal ions react with PEO to form inclusion compounds. These can also be inserted into layers of ionic silicates, for example, into MMN. The distance between the layers of the PEO-Li salt complexes intercalated into MMN is 0.8 nm, the PEO chain adopts a slightly strained helicoid conformation in these locations. 

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