Design and Synthesis of Luminescent Bis(isocyanoborato) Rhenate(I) Complexes as a Selective Sensor for Cyanide Anion

A series of luminescent bis(isocyanoborato) rhenate(I) phenanthroline complexes with the general formula of cis,trans[Re(CO)(2)(CNBR3)(2)(phen)]K (R = C6F5 and C6H5) have been designed and synthesized. The solutions of these complexes exhibit MLCT phosphorescence. Detailed anion titration study showed that the emission intensity of bis(isocyanotriphenylborato) complex in CH3CN/H2O solution would be significantly decreased in the presence of cyanide anion, while such a change would not be observed in the presence of other anions including F-, Cl-, Br-, I-, OH-, AcO-, N-3(-), ClO4-, H2PO4-, NO3-, NO2-, IO3-, and SCN-. This provides a new strategy for developing highly selective cyanide luminescent sensors based on isocyanoborato transition metal complexes.