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4282838 
Journal Article 
Chemosensing of Chloride Based on a Luminescent Platinum(II) NCN Pincer Complex in Aqueous Media 
Dorazco-Gonzalez, A 
2014 
1 
Organometallics
ISSN: 0276-7333
EISSN: 1520-6041 
33 
4 
868-875 
WOS:000331991800007 
The new luminescent platinum(II) pincer complex [Pt(NCN)(S)]TfO (1; NCN = 1,3-bis(2-N-phenylbenzimidazolyl)benzene, S = solvent, and TfO- = triflate anion) was synthesized and studied as a chemosensor for chloride in aqueous media. In 50 vol % aqueous DMF or CH3CN chloride quenches the fluorescence with association constants of 1.2 x 10(3) and 81 M-1, respectively. On the other hand, in the micellar medium of cetyltrimethylammonium hydrogensulfate at pH 7.0 additions of inorganic anions to I enhance the fluorescence with a pronounced selectivity toward chloride, which shows also much tighter binding to the receptor with association constant 7.9 X 10(4) M-1 in comparison to that in mixed organic solvents. On basis of H-1 NMR titration experiments and the crystal structure of the neutral chloro complex of I the binding mode of chloride is proposed involving the coordination of chloride to the Pt(II) atom with simultaneous formation of intramolecular short C-H center dot center dot center dot Cl-Pt contacts. The combination of the cyclometalated platinum complex I with a cationic surfactant allows for the detection of chloride in the micromolar concentration range in samples of bottled mineral water.