Abstract: The invention disclosed relates to an agent capable of selectively binding lithium ions to form a lithium complex, employed in association with a biologically inert carrier or excipient. Typically, the agent is included in a novel graft polymer, such as a cross-linked polystyrene polymer. This invention may also be applied to sensing lithium ion concentrations in aqueous solution and to the selective removal of lithium ions from an aqueous solution, including biological fluids.

Abstract: Disclosed herein are organometallic ternary charge transfer complexes of the formula (I)a(RX).multidot.MX.multidot.b(Ar) (I)whereinRX is an inorganic chloride or fluoride which contains at least one oxygen and/or sulfur atom and is capable of forming a complex salt a(R).multidot.MX.sub.(a+m) with the Lewis acid MX.sub.m, such as NOCl or NOF,MX.sub.m is a Lewis acid metal chloride or fluoride, such as BCl.sub.3, BF.sub.3, AlCl.sub.3, GaCl.sub.3, TlCl.sub.3, AsCl.sub.3, AsF.sub.5, SbCl.sub.5, FeCl.sub.3, SnCl.sub.4, TiCl.sub.4, ZrCl.sub.4, NbCl.sub.5, TaCl.sub.5, MoCl.sub.5 and WCl.sub.6,Ar is an aromatic compound, such as napthalene, anthracene, thiophene, furan and benzene which is unsubstituted or substituted with lower alkyl, halogen, diloweralkylamino, oxo or lower alkoxy,m is an integer representing the valency of the metal M,a is an integer selected such that the sum of a and m does not exceed the coordination number of the metal M of the given valency,b is 0.