Achiral and Chiral Coordination Polymers Containing Helical Chains: The Chirality Transfer Between Helical Chains

Abstract

Four achiral two-dimensional (2D) coordination polymers of [M(HIDC)(H 2 O)(prz) 0.5 ] n (M ) Fe, 1; Mn, 2; Cd, 3) and [Co(HIDC)(H 2 O)(pyz) 0.5 ] n (4), one chiral 2D coordination polymer of [Mn(HIDC)(H 2 O)] n (5), and one 2D coordination polymer of [Fe(HIDC)(H 2 O)] n (6) (H 3 IDC ) imidazole-4,5-dicarboxylic acid, prz ) piperazine, pyz ) pyrazine) were hydrothermally synthesized and characterized by single-crystal X-ray diffraction. In 1-3, the HIDC 2anions alternately bridge the M(II) cations to form a one-dimensional (1D) infinite helical chain of [M(HIDC)] ∞ along the 2 1 axis. The chirality of the original formed helical chain is transferred oppositely to neighboring helical chains through the parallel coordination interactions of prz molecules between two adjacent chains, resulting in an achiral 2D sheet of [M(HIDC)(H 2 O)(prz) 0.5 ] n , in which the helical chains are packed in an alternating left-and right-handed chirality. A similar achiral 2D coordination polymer of 4 was obtained when pyz was used as a linker. Compound 5 crystallizes in a chiral space group P2 1 . In 5, the HIDC 2anions also alternately bridge the Mn(II) to form a 1D right-handed helical chain of [MnHIDC] ∞ along the 2 1 axis, and the right-handed chirality of [MnHIDC] ∞ is transferred to neighboring helical chains through the zigzag interchain coordination interactions, leading to the formation of a homochiral 2D sheet, in which all the helical chains are packed in right-handed chirality. In addition, the bulk crystallization of 5 is enantiomeric excess rather than racemic, as evidenced by the results of solid-state vibrational circular dichroism (VCD) and CD spectroscopy. In the 2D structure of 6, the HIDC 2anions alternately bridge the Fe(II) to form a 1D zigzag chain of [FeHIDC] ∞ instead of a 1D helical chain, in which all the HIDC 2anions locate on the same side within the chain. Compound 3 displays strong blue fluorescent emission at room temperature. Magnetic susceptibility measurements of 2 and 5 exhibit antiferromagnetic interactions between the nearest Mn(II) within the sheet, with J ) -0.48 cm -1 , g ) 2.10 for 2, and J ) -0.51 cm -1 , g ) 2.03 for 5.

Synthesis, Crystal Structure and Magnetic Properties of a Mn(II) Fluorenedicarboxylate Complex

“…In recent years, much interest has been focused on design and synthesis of metal-organic frameworks (MOFs) with novel structural motifs due to not only their fascinating topological diversities [1 -5], but also their potential applications for luminescence [6], magnetic effects [7], catalysis [8], and gas storage and separation [9]. It has been documented that π-conjugated systems containing carboxylate groups are versatile ligands for the fabrication of MOFs, in which the carboxylates can exhibit different coordination geometries [10 -12].…”

Synthesis, crystal structures, and magnetic properties of cobalt(II) and nickel(II) complexes of 2,2′-bipyridine-6,6′-dicarboxylate: three three-dimensional networks formed via hydrogen bonding interactions

“…In recent years, the design and synthesis of supramolecular coordination polymers have attracted great interest due to not only their versatile architectures [1][2][3] but also their desirable luminescent [4], magnetic [5], catalytic [6], and gas absorption and separation properties [7]. The self-assembly of a supramolecular coordination polymer is the result of a combination of various forces, including not only strong interactions (for example metal-ligand coordination bonds) [1][2][3][4][5][6][7] but also weaker interactions such as hydrogen bonds [5,[8][9][10] and p-p stacking interactions [11,12].…”

“…The self-assembly of a supramolecular coordination polymer is the result of a combination of various forces, including not only strong interactions (for example metal-ligand coordination bonds) [1][2][3][4][5][6][7] but also weaker interactions such as hydrogen bonds [5,[8][9][10] and p-p stacking interactions [11,12]. Although the latter interactions are relatively weak, they have been recognized to play critical roles in the construction of supramolecular structures.…”

“…Among these ligands, multifunctional ligands with several functional groups are often employed for investigating the roles of supramolecular interactions that control the network topologies [1][2][3][4][5][6]. Multifunctional organic ligands with several potential coordination sites have the ability to interact with their surroundings in addition to their usual function of binding to the metal.…”

Synthesis, Structure, and Solvent‐Induced Spontaneous Homochiral Assembly of Bidentate Bis(N,N′‐diaryl‐N‐heterocyclic carbene)‐Palladium Complexes

“…[3] Such spontaneously resolved crystals have been applied to absolute asymmetric synthesis [4] and the construction of chiral architecture, [5] and the phenomenon has been translated into the origin of homochirality of life. [6] Although the mechanism of the chiral amplification process on crystallization is still unknown, it is probable that a chiral cluster (kinetic process) or chiral crystal packing (thermodynamic process) [7] would be more stable than the achiral (racemic) counterpart.…”