Ligands hydrogen bond networks

Condensation of the carbonyl function with an amine from a second 1,2-diaminoethane molecule coupled with a repeat of the initial reaction sequence will lead to the cyclic product. It is of interest that this is one case in which the synthesis will also proceed in the absence of a metal ion. Starting from a mono-protonated salt of 1,2-diaminoethane in acetone, the metal-free condensation may proceed via a reaction such as [2.7], Once again, a hydrogen-bonding network may act as a template for the reaction and also serve to stabilize the product once it is formed. A revised synthesis of the metal-free ligand (61) has been published (Hay,... 

The relatively low cooperativity of this ID system has been attributed to the flexibility of the btzp bridging ligand, which may act as a shock absorber against the elastic interactions between active SCO sites, as well as to the absence of a hydrogen bonding network. This compound undergoes the... 

Similarly, analogous Rh(III) hydrolytic cations can be isolated by crystallisation with the super-anion, however these complexes show quite different hydrogen bonding networks. A second type of Russian Doll super-anion is found in the complex [Rh4(OH)6(H2O)12](20.21+8H). 33H2O [46]. The dehydrated Russian Doll Na([18]crown-6)(19)2 7 21 is skewed by comparison with the capsule structure of 20. The two trans aquo ligands are not present in the dehydrated super-anion, and the axial Na coordination positions are occupied by oxygens... 

Much of the impetus for the study of hydrogen bonded network structures of 24 and bipy or other linear N-donor ligands has come from the desire to perform time-resolved crystallographic studies of photoactive guest species embedded within the network as a guest [58,62,63]. Embedding a photoactive species within a network structure effectively dilutes it in the solid state. The advantages of this include improved uniformity of illumination of the crystal, less photons are... 

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