Soluble metal chelates, unusually

Unusually Volatile and Soluble Metal Chelates Lanthanide NMR Shift Reagents... 

Solutions of the alkali elements, in a range of polar solvents, have been shown to contain M , M ", e, and the unusual anion, M , in equilibrium. Early studies were hindered by solubility and decomposition problems. The addition of a macrocylic chelate to these solutions provided a means of increasing the solubility of the metal as well as controlling what species predominate in solution. A metal chelate mole ratio of 2 1 leads to formation of the alkalides [M -i- L] M while a ratio of 1 1 leads to the electrides (see 10.2.2.5), [M -t- L] e (where M and M = Li, Na, K, Rb, Cs (not always the same) and L = two crown ethers (combinations of 12-C-4, 15-C-5, 18-C-6) or one cryptand [2.2.2]). Furthermore, these unique compounds could be isolated as solids and fully characterized. A wider range of alkalides than electrides is known including those with other chelates such as ethylenediamne , and aza crown ethers . Some representative examples are [Na -t- crypt]Na"(the first to be structurally characterized) , and [Cs + 18-C-6)(15-C-5)]Na- . 

Cross-Linked Polymers. Apart from the soluble polymers, insoluble resins with unusual functional groups are of interest in areas such as metal-chelating resins. The most promising monomers of Table I were studied as potential resins. To obtain cross-linked polymers without adding new interfering groups, 1,6-diallylaminohexane (XVI) was used in 5-10 mol % quantities as the cross-linking monomer. 

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