First Observation of Alkali Metal Ion Induced Trans–Cis Isomerization of Palladium(II) Phosphane Complexes Containing Crown Ether Moieties

Abstract

There has been growing interest in the design of allosteric host molecules that can efficiently transmit the information associated with the binding of an ion or molecule to another[*] Prof.

Synthesis, Characterization, Spectroscopic, and Electrochemiluminescence Properties of a Solvatochromic Azacrown‐Containing Cyanoruthenate(II): Potential Applications in Separation and Indirect Photometric Detection of Cations and Amino Acids in HPLC

“…Besides, most of these studies were focused on the synthesis and spectroscopic changes that occur upon cation binding, with relatively few studies involving application of anionic complexes with a pendant crown as both inorganic host and ion-pairing reagent to separate cations by high-performance liquid chromatography (HPLC). As an extension of our previous work on the utilization of transition-metal complexes containing crown ethers for spectrochemical and luminescence chemosensing, [13][14][15] herein we report the preparation of a new anionic solvatochromic cyanoruthenate(ii) complex bearing an azacrown pendant, (Et 4 N)[RuA C H T U N G T R E N N U N G (tpyA18C6)(CN) 3 ] (Figure 1), which exhibits both chromophoric properties and cation-binding ability. We believe that the incorporation of an additional cation-binding site, such as a crown ether, would give rise to allosteric effects that would provide the selectivity, specificity, and improved resolution for cation separation and detection in comparison to complexes with no binding site.…”

“…13 C NMR spectra, 1 H- 13 C HETCOR, and HMBC two-dimensional spectra were recorded on a Bruker DPX-600 Fourier Transform NMR spectrometer. Negativeion EI mass spectra were recorded on a Finnigan MAT95 mass spectrometer.…”

“…The characteristic photoluminescence and electrochemiluminescence (ECL) of the complex were also found to be progressively quenched as the proportion of water in a water/acetonitrile mixture increased. Large changes in the chemical shifts of the 1 H NMR and 13 …”

Al3+‐Ion‐Triggered Conformational Isomerization of a Rhodamine B Derivative Evidenced by a Fluorescence Signal – A Crystallographic Proof

“…[6][7][8][9] There are some reports on thermally induced and photoinduced cis-trans conformational isomerization, [10,11] but metal-ion-induced cis-trans conformational isomerization is scarce. [12] Herein, we describe the first observation of Al 3+ -ion-induced cistrans conformational isomerization, which was observed in a new rhodamine B derivative through detailed structural elucidations.…”