Anion exchange in trimethyl- and triphenyltin complexes with chromogenic ligands: solution equilibria and colorimetric anion sensing

作者：Villamil Ramos Raul; Yatsimirsky Anatoly K^*

来源：Applied Organometallic Chemistry, 2011, 25(5): 356-365.

DOI：10.1002/aoc.1771

• organotin(IV) compounds
• anion exchange
• anion sensing

A series of organotin(IV) compounds R(3)Sn(A) where R = Me or Ph and A is a chromogenic nitrophenolate ligand were prepared and studied as possible colorimetric sensors for anions (F(-), Cl(-), Br(-), AcO(-), H(2)PO(4)(-)). Equilibrium constants for a complete set of reactions between R(3)Sn(A) with A = 2-amino-4-nitrophenolate (ANP) or 4-nitrophenolate and anions (X(-)) involving formation of complexes R(3)Sn(A)(X)(-) and substitution products R(3)Sn(X) and R(3)Sn(X)(2)(-) were determined by UV-vis and (1)H NMR titrations in MeCN and DMSO. The binding selectivity was AcO(-) > F(-) > H(2)PO(4)(-) > Cl(-) >> Br(-) in both solvents and both for R = Me and Ph with higher affinity for R = Ph. Compounds with A = ANP were found to have the optimum properties as anion sensors allowing optical detection of F(-), AcO(-) and H(2)PO(4)(-) anions in the 5-100 mu M range by appearance of an intense absorption band of free ANP resulting from its substitution with the analyte. Selectivity and affinity of anion interactions with R(3)Sn(ANP) are similar to those for thiourea receptors, but the organotin receptor produces a much larger naked eye detected optical signal, operates equally well in nonpolar and polar solvents and tolerates the presence of up to 20% vol. of water in DMSO.

• 出版日期2011-5