title: The evaluation of the association constant between R-SN and Hg(2+).
abstract: The effective determination of heavy metals from environmental media is among the most important issues for many industrialized countries. The interaction between RS-N, as novel heavy metal probe, and metal ions was studied. RS-N shows selective color change from colorless to pink in the presence of Hg(2+) in methanol/water solvent and the UV-Vis study shows peak at 560 nm. Fluorescence data revealed that the fluorescence enhance of RS-N by Hg(2+) dramatically was the result of the formation of [Hg(2+)]RS-N complex. The effective association constants (K a ) were 3.97 × 10(5) and 0.204 × 10(5) M(-1) for Hg(2+) and Cu(2+) to RS-N, respectively. The thermodynamic parameters, enthalpy change (ΔH (0)) and entropy change (ΔS (0)), were calculated to be -6.431 ± 0.226 kJ/mol and -0.129 ± 0.008 J/K/mol, respectively, according to van't Hoff equation on the basis of Gibbs free energy (ΔG (0)) ranged from -33.8326 to -28.5389 kJ/mol.
authors.affiliation: School of Environment and Energy Engineering, Anhui Jianzhu University, 292 Ziyun Road, Hefei, 230601, People's Republic of China, tjs28@126.com.
authors.forename: Jian-She
authors.initials: JS
authors.lastname: Tang
authors.forename: Li
authors.initials: L
authors.lastname: Xiang
authors.forename: Hai-Zhou
authors.initials: HZ
authors.lastname: Fan
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D004785:Environmental Pollutants / Q000032:analysis / Q000737:chemistry*; D005453:Fluorescence; D008628:Mercury / Q000032:analysis / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013816:Thermodynamics
chemical_list: D004785:Environmental Pollutants; D008628:Mercury