title: Selective turn-off phosphorescent and colorimetric detection of mercury(II) in water by half-lantern platinum(II) complexes.
abstract: The platinum(ii) half-lantern dinuclear complexes [{Pt(bzq)(μ-C7H4NS2-κN,S)}2] () and [{Pt(bzq)(μ-C7H4NOS-κN,S)}2] () [bzq = benzo[h]quinolinate, C7H4NS2 = 2-mercaptobenzothiazolate, C7H4NOS = 2-mercaptobenzoxazolate] in solution of DMSO-H2O undergo a dramatic color change from yellowish-orange to purple and turn-off phosphorescence in the presence of a small amount of Hg(2+), being discernible by the naked-eye and by spectroscopic methods. Other metal ions as Ag(+), Li(+), Na(+), K(+), Ca(2+), Mg(2+), Ba(2+), Pb(2+), Cd(2+), Zn(2+) and Tl(+) were tested and, even in a big excess, showed no interference in the selective detection of Hg(2+) in water. Job's plot analysis indicated a 1 : 1 stoichiometry in the complexation mode of Hg(2+) by /. The phosphorescence quenching attributed to the formation of [/ : Hg(2+)] complexes showed binding constants of K = 1.13 × 10(5) M(-1) () and K = 1.99 × 10(4) M(-1) (). The limit of detection has been also evaluated. In addition, dried paper test strips impregnated in DMSO solutions of and can detect concentration of Hg(2+) in water as low as 1 × 10(-5) M for and 5 × 10(-5) M for , making these complexes good candidates to be used as real-time Hg(2+) detectors. The nature of the interaction of the Pt2 half-lantern complex with the Hg(2+) cation, has been investigated by theoretical calculations.
authors.affiliation: Instituto de Síntesis Química y Catálisis Homogénea (ISQCH), CSIC - Universidad de Zaragoza, Departamento de Química Inorgánica, Escuela de Ingeniería y Arquitectura de Zaragoza, Campus Río Ebro, Edificio Torres Quevedo, 50018, Zaragoza, Spain. sicilia@unizar.es.
authors.forename: Violeta
authors.initials: V
authors.lastname: Sicilia
authors.forename: Pilar
authors.initials: P
authors.lastname: Borja
authors.forename: Miguel
authors.initials: M
authors.lastname: Baya
authors.forename: José M
authors.initials: JM
authors.lastname: Casas
mesh_terms: D003124:Colorimetry; D056831:Coordination Complexes / Q000737:chemistry*; D004121:Dimethyl Sulfoxide / Q000737:chemistry; D049449:Luminescence; D008628:Mercury / Q000032:analysis* / Q000737:chemistry; D010984:Platinum / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000737:chemistry
chemical_list: D056831:Coordination Complexes; D014874:Water Pollutants, Chemical; D010984:Platinum; D008628:Mercury; D004121:Dimethyl Sulfoxide