Noncentrosymmetric and Homochiral Metal−Organic Frameworks of (S)-2-(1H-Imidazole1-yl) Propionic Acid

Abstract

Four noncentrosymmetric coordination polymers of [Mn((S)-imp)((R)-imp)] (1), [Cu((S)-imp) 2 ] ¥ (2), [Zn((S)imp) 2 ] ¥ (3), and [Co((S)-imp) 2 ] ¥ (4) [(S)-imp = (S)-2-(1H-imidazole1-yl) propionate] have been prepared and structurally characterized by X-ray single crystal diffraction, X-ray powder diffraction (XRPD), infrared (IR) spectroscopy, elemental analysis, and thermogravimetric analysis (TGA). Compound 1 crystallizes in the space group Pna2 1 , exhibiting a twodimensional structure; 2 crystallizes in the space group of P2 1 , showing a chiral layered structure of (4, 4)-net, whereas 3 and 4 are isostructural, and they crystallize in the space group P2 1 2 1 2 1 , exhibiting a 3-fold interpenetrating diamondoid net. Because the ligand used for the synthesis is an enantiopure chiral compound, the obtained metal-organic frameworks show the homochirality in bulk except for compound 1, in which the ligand configuration was racemized during the solvothermal reaction.

A Case Study of ZnII-bmb Meso-Helical Coordination Polymers upon the Spacer Angles and Lengths of Dicarboxylate Coligands

“…Helical structures, the foundation of the genetic code, have attracted intense interest in coordination chemistry not only for their ubiquitous appearance in nature, a typical example being the DNA molecule, but also for their practical implications in multidisciplinary areas, such as optical devices, biomimetic chemistry, asymmetric catalysis chemistry, and structural biology . Until now, many single-, double-, triple-, and even multiple-stranded helices as well as circular and cylindrical helices have been prepared and comprehensively discussed . In contrast, the meso-helices are extremely infrequent, although meso-helical motifs are common in nature, such as the tendrils of a variety of plants.…”

Chiral and Noncentrosymmetric Metal–Organic Frameworks Featuring a 2D → 3D Parallel/Parallel Inclined Subpolycatenation

“…Compared with NCS inorganic materials, little attention has been paid to NCS inorganic–organic hybrid frameworks even though they have the advantage of containing both organic ligands and inorganic metal ions. Although some NCS coordination polymers have been reported, they commonly display no or small signals of related properties such as SHG and ferroelectricity …”

Two Chiral Nonlinear Optical Coordination Networks Based on Interwoven Two-Dimensional Square Grids of Double Helices

“…[12][13][14][15][16][17][18][19][20][21] The incorporation of chiral organic linkers into the coordination networks can enforce the construction of noncentrosymmetric solid state materials and thus induce their nonlinear optical properties at witnessed in the growing number of nonlinear optical chiral coordination networks. [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40] Motivated by Bu with respect to the design and construction of homochiral coordination networks from D-camphoric acid, [41][42][43] we developed a new chiral and helical organic linker to have both D-camphor and pyridyl moieties for their coordination to metal ions and thus the construction of chiral coordination networks (Scheme 1). Herein, we report two new chiral twodimensional (2D) coordination networks, ZnL 2 (H 2 O) 2 (1) and CdL 2 (H 2 O) 2 (2) [L = 1,2,2-trimethyl-3-(pyridin-4-ylcarbamoyl)cyclopentanecarboxylic acid], of very unusual interwoven (4,4) square grids of double-helix structures exhibiting nonlinear optical, luminescent, and ferroelectrical properties.…”