Functionalized Rhenium(I) Complexes with Crown Ether Pendants Derived from 1,10-Phenanthroline:  Selective Sensing for Metal Ions

Abstract

A series of rhenium(I) tricarbonyl diimine complexes with crown ether pendants has been synthesized and characterized. The complexes showed selective and specific binding properties for various metal ions of different sizes and degrees of hardness and softness by variation of the cavity size and donor atoms of the crown ether. Upon binding of metal ions, obvious spectral changes were observed in the UV-vis spectra of the complexes and the emission intensity was found to be strongly enhanced. The X-ray crystal structure of one of the complexes has also been determined.

Syntheses, characterization and properties of rhenium(I) tricarbonyl complexes based on tetrathiafulvalene substituted naphthyridine ligands

“…The rhenium atoms are also coordinated by three carbonyl ligands in a fac arrangement, as well as one halogen atom. The average Re\N bond length is 2.338 and 2.182 Å for 1 and 2, respectively, which are consistent with other similar complexes [33][34][35]. The bite angles of N\Re\N (average 59.1°for 1 and 59.71°for 2) are significantly deviating from the ideal value of 90°, imposed by satiric requirement of chelating geometry of the naphthyridine ring.…”

Luminescent sensor for copper(II) ion based on imine functionalized monometallic rhenium(I) complexes

“…The red shift of the emission maxima could be explained by the fact that the binding of the cations to imine ligand would decrease σ-donating ability and stabilize the π* orbital of the bipyridine ligand and hence decreased the emission energy [63]. Recently Wang et al and others [22,23,6466] pointed out that the weak luminescence of coumarin derivative containing imine group can be explained by C=N isomerization mechanism which facilitates the decay of the excited state via nonradiative process.…”

Chromo- and Fluorogenic Organometallic Sensors

“…The incorporation of soft donor atoms such as S or Se in the pendant groups allows for specific binding of soft metal cations. For example, Yam et al [8] have achieved highly selective sensing of Pb 2+ and Hg 2 using complexes 1c and 1d, respectively (Fig. 1).…”