Coordination modes polycarboxylates

All of the coordination modes shown in Figure 1 have been observed in the structures of rare earth polycarboxylates reported so far, although only limited number of rare earth polycarboxylates have been stracturally characterized compared to monocarboxylates. The carboxylate groups within the same ligand are found to display the same or distinctly different coordination modes. The four most frequently observed coordination modes are if, f i-... 

Another interesting example of Ag(I)-backbone organometallic polymers are those based on diallylmelamine and poly-carboxylates. Silver-vinyl bonding represents a versatile synthon for the construction of polymeric metallosupramolecular architectures. The particular structural motifs result from the introduction of different auxiliary polycarboxylates into the silver/diallylmelamine system and the diverse coordination modes and conformations of diallylmelamine (Fig. 29.3) [108]. Remarkably, apparent silver-vinyl interactions with a ri mode were commonly observed in the solid-state structures of these complexes (Ag-C = 2.311(4)-2.467(5)A). In addition, they display solid-state photoluminescence and moderate thermal stabilities at room temperature. 

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