Bathophenanthroline sulfate

In the mechanism of an interfacial catalysis, the structure and reactivity of the interfacial complex is very important, as well as those of the ligand itself. Recently, a powerful technique to measure the dynamic property of the interfacial complex was developed time resolved total reflection fluorometry. This technique was applied for the detection of the interfacial complex of Eu(lII), which was formed at the evanescent region of the interface when bathophenanthroline sulfate (bps) was added to the Eu(lII) with 2-thenoyl-trifuluoroacetone (Htta) extraction system [11]. The experimental observation of the double component luminescence decay profile showed the presence of dinuclear complex at the interface as illustrated in Scheme 5. The lifetime (31 /as) of the dinuclear complex was much shorter than the lifetime (98 /as) for an aqua-Eu(III) ion which has nine co-ordinating water molecules, because of a charge transfer deactivation. 

Recently, the formation of the dinuclear Eu(II) complex at the toluene-water interface was found out by a time-resolved total reflection fluorometry. When bathophenanthroline sulfate (bps) was added to the extraction system of Eu(III) with 2-thenoyltrifluoroacetone (Htta), a double component luminescence decay profile was observed and it showed the presence of dinuclear complex at the interface [27]. The observed life times x — 22 and 203 ps were attributed to the dinuclear complex Eu2(tta)2(bps)2 and the mononuclear complex Eu(tta)2bps. The shorter lifetime of the dinuclear complex than x = 98 ps for an aqua-Eu(III) ion suggested a charge transfer deactivation in the dinuclear complex. 

Non-specific visualization procedures (e.g., charring) for tocopherols/tocotrienols are based on spraying with sulfuric acid, perchloric acid, nitric acid, or copper (II) sulfate phosphoric acid (54). More specific though still subject to many interferences are reactions which take advantage of the reducing properties of vitamin E derivatives. In the Emmerie-Engel reaction and its later modifications, ferric ions are reduced to ferrous ions, which form a red-colored complex with a,a -dipyridine ot bathophenanthroline (50,51). A comparable sensitivity is achieved by spraying with phospho-molybdic acid. The color can be stabilized by subsequent exposure of the plates to ammoniacal 2,7-dichlorofluorescein (51). 

The copper-catalyzed azide-alkyne cycloaddition is particularly suitable for F-labehng of sensitive biomolecules. Three different radiolabeled alkyne precursors react with azido-functionalized peptides in radiochemical yields (RCYs) of 54-99% and an overall reaction time of 30 min. The reaction is catalyzed by copper sulfate in combination with ascorbic acid or sodium ascorbate. Addition of bathophenanthroline disulfonate (Cul stabilizing agent) accelerates the cycloaddition [90]. 

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