Synthesis, crystal structure and properties of the novel chiral 3D coordination polymer with S-carboxymethyl-l-cysteine

Reaction of fresh Mn(OH)2 precipitate and S-carboxymethyl-l-cysteine (H2SCMC) in aqueous solution afforded a novel chiral 3D coordination polymer Mn(H2O)(SCMC) 1, which crystallizes in the acentric polar space group P21 with cell constants a = 5.079(1) Å, b = 9.617(2) Å, c = 8.649(2) Å, β = 94.40(3)°, V = 421.2(1) Å3, Z = 2, and exhibit a SHG effect and ferroelectricity (a remnant polarization Pr = 0.0159 uC cm−2, coercive field Ec = 0.83 kV cm−2, saturation of the spontaneous polarization Ps = 0.234 uC cm−2). To the best of our knowledge, the present compound represents the first example of S-carboxymethyl-l-cysteine coordination polymers that exhibit possible ferroelectric behavior. The structural analysis revealed that the Mn2+ ions in 1 are each coordinated by one N atom and five O atoms of four S-carboxymethyl-l-cysteine ligand bridges four symmetry-related Mn2+ ions to form 3D MOF of 66 topology type with irregular chiral channels extending along [1 0 0]. The temperature-dependent magnetic susceptibilities shows that 1 obeys Curie–Weiss law χm = C/(T − Θ) with C = 4.23 cm3 mol−1 K and Θ = −5.86 K and the best fit gave a weak antiferromagnetic coupling (J = −0.282(5) cm−1) among Mn ions.

Graphical abstractA novel 3D chiral MOF Mn(H2O)(SCMC) 1 of 66 topology represents a first example of the S-carboxymethyl-l-cysteine (H2SCMC) coordination polymers that exhibit a SHG effect, ferroelectricity and weak antiferromagnetic interactions between metal ions (J = −0.282(5) cm−1). The results demonstrate that 1 is a good candidate of multifunctional materials combining nonlinear optical, ferroelectric and antiferromagnetic properties.Figure optionsDownload full-size imageDownload as PowerPoint slide