A diiminoplatinum(II) complex of 4-ethynylbenzo-15-crown-5 as a luminescent sensor for divalent metal ions

The binding of a diiminoplatinum(II) complex of 4-ethynyl-benzo-15-crown-5 to divalent metal ions such as Mg2+ or Zn2+ is accompanied by substantial enhancement of emission intensity (1035- and 870-fold increase, respectively, with 40 equivalents of metal salt) at lambda(max) approximate to 555 nm; H+, Cd2+ and alkali-metal ions cause minor enhancement of the photo-luminescence (less than or equal to 10-fold) under similar conditions. (C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.