The chromoionophore 2 has been synthesised from the corresponding diaza 18-crown-6 in two steps in good overall yield, and the reagent 2 extracts calcium cations from aqueous solutions in the pH range 7–9 with moderately high selectivity as compared with sodium and with high selectivity as compared with other cations of biological interest; the series of apparently similar reagents 2, 3 and 4 shows very wide variation in Na+/Ca2+ selectivity.
试剂 2 从 pH 值为 7-9 的
水溶液中萃取
钙阳离子,与
钠离子相比具有中等程度的高选择性,与其他具有
生物学意义的阳离子相比具有高选择性;表面上相似的试剂 2、3 和 4 系列在 Na+/Ca2+ 选择性方面的差异非常大。