Chiral Cyclodimeric Zinc(II) Complexes: Enantio-recognition via Differential Pulse Voltammetry

Abstract

Self-assembly of a series of ZnX2 (X– = Cl–, Br–, and I–) with (S)-(1-isonicotinoylpyrrolidin-2-yl)­methyl isonicotinate (L) as a new chiral hemicircular bidentate ligand yields a system comprising 30-membered metallacyclodimeric species [ZnX2L]2 with two chiral centers. In the solid state, the metallacyclodimers’ packing arrays differ according to the anions and nestled solvate molecules. In the present study, the differential pulse voltammetry (DPV) technique was employed for chiral discrimination of amino acid enantiomers with S-chiral [ZnX2L]2 and was found to be an effective tool for enantio-recognition of amino acids.

Homochiral Metallacycle Used as a Stationary Phase for Capillary Gas Chromatographic Separation of Chiral and Achiral Compounds

“…(Figure ). Briefly, the ligand L (62.3 mg, 0.2 mmol) was dissolved in tetrahydrofuran (20 mL), and then a solution of ZnCl 2 (27 mg, 0.2 mmol) in acetone (20 mL) was added carefully to form an upper layer. The mixture was covered and stored at 25 °C without stirring.…”

“…The ligand L was synthesized according to the following procedure (Figure ). ( S )-(+)-2-Pyrrolidinemethanol (1.0 g, 9.9 mmol) was dissolved in CH 2 Cl 2 (25 mL) at 0 °C under a N 2 atmosphere, and N , N -diisopropylethylamine (8.6 mL, 49.4 mmol) was added. After stirring for 5 min, a solution of isonicotinoyl chloride hydrochloride (5.28 g, 29.65 mmol) in CH 2 Cl 2 (30 mL) was added over 10 min through a pressure equalizing dropping funnel.…”

“…Herein, we report the first example of using a homochiral metallacycle as a stationary phase for GC. The homochiral metallacycle, [ZnCl 2 L] 2 , was synthesized by self-assembly of ( S )-(1-isonicotinoylpyrrolidin-2-yl)­methyl-isonicotinate (L) with ZnCl 2 and coated onto the inner wall of a capillary to prepare a GC column using a static coating method. The separation capability of the fabricated column was assessed with various analytes, including racemates, organic isomers (positional, structural, and cis / trans -isomers) and organic mixtures ( n -alkanes, alkylbenzenes, n -alcohols, and a Grob mixture).…”

Pair of chiral 2D silver(i) enantiomers: chiral recognition of l- and d-histidine via differential pulse voltammetry

“…[19][20][21][22][23][24][25][26][27][28] Great efforts have been made to develop an effective chiral electrode surface by utilizing various chiral coordination networks for enantio-recognition of chiral amino acids. [29][30][31][32][33][34] Among the various amino acids, histidine is an essential constituent for humans, animals, microorganisms, and plants. The imidazole side-chain of histidine residue commonly serves as an important ligand in metalloproteins.…”

Construction of a chiral zinc–camphorate framework for enantioselective separation

“…Chiral metal-organic frameworks (CMOFs), composed of organic linkers and metal ions, have been considered to be a suitable platform for enantiomer separation in recent years because of their tunable chiral environment, accommodative guest space, and substrate size/shape selectivity. [7][8][9][10][11][12][13][14][15][16][17] Many representative CMOF-based adsorbents were constructed using well-designed enantiopure organic ligands and they demonstrated quite promising application potential in enantioseparation. For instance, the Cui group has presented a porous CMOF constructed from an enantiopure carboxylate ligand of 1,1′-biphenol, which enables separating a variety of aromatic alcohols and sulfoxides with high enantioselectivity.…”