Homochiral Coordination Polymers Research Articles

Homochiral coordination polymers constructed from V-shaped oxybisbenzoyl-based amino acid derivatives: structures, magnetic and photoluminescence properties.

Five novel homochiral coordination polymers (HCPs) [Cu2(ODBALa)2(bpa)2H2O]·7H2O (1), [M(ODBALa)H2O]·H2O (M = Mn for 2; Co for 3), [Cu(ODBPRo)(bpe)]·7H2O (4) and [Cd2.5(ODBPRo)(HODBPRo)3(bpe)2.5]·13H2O (5) have been successfully synthesized by using designed chiral 4,4'-oxybisbenzoyl alanine/proline derivatives in the absence/presence of N-donor ancillary ligands, where H2ODBALa = 4,4'-oxybisbenzoyl-bis(l-alanine), H2ODBPRo = 4,4'-oxybisbenzoyl-bis(l-proline), bpa = 1,2-bis(4-pyridyl)ethane, and bpe = 1,2-bis(4-pyridyl)ethene. Interestingly, the combination of the chiral derivatives and metal ions gives various chiral metal-organic fragments, which are connected by N-donor ancillary ligands to construct the intriguing homochiral structures. In 1, 40-membered [Cu2(ODBALa)2] metallacycles as beads are strung by bpa ligands, yielding a one-dimension (1D) tortuous chain. Compounds 2 and 3 are isomorphous and possess a 3D metal-organic framework, embedding the unique (μ2-COO)(μ2-Ocarboxylate)(μ2-H2O) triple-bridges and twisted (-Mn4(ODBALa)4-)n left-handed helical chains. In 4, the [Cu(ODBPRo)]n left-handed helical chains are linked by bpe ligands to constitute a high undulated 2D layer. In 5, the crab-like [(Cd1)2(Cd2)(Cd3)2(HODBPRo)6(ODBPRo)2] fragments are joined together to form a 1D left-handed helical chain, which is further connected by bpe ligands to build a remarkable layered network. Magnetic susceptibility measurements of 2 and 3 indicate typical antiferromagnetic behaviour between the triple-bridging Mn(ii) ions in 2, whereas ferromagnetic coupling between the triple-bridging Co(ii) ions exists in 3. Moreover, the photoluminescent spectrum of 5 exhibits a strong solid-state emission at 414 nm.

Synthesis and Structure Characterization of Homochiral Helical Coordination Polymers with 4-Connected Net Based on Lactic Acid Derivatives†

Synthesis and Structure Characterization of Homochiral Helical Coordination Polymers with 4-Connected Net Based on Lactic Acid Derivatives†

Homochiral coordination polymers with helixes and metal clusters based on lactate derivatives

Utilizing the lactic acid derivatives (R)-4-(1-carboxyethoxy)benzoic acid (denoted: (R)-H2CBA) and (S)-4-(1-carboxyethoxy)benzoic acid (denoted: (S)-H2CBA)as chiral linkers to self-assemble with 4, 4′-bipyridine (denoted: BIP) and Cd(II) ions, a couple of three-dimensional homochiral coordination polymers, namely [Cd3((R)-CBA)3 (BIP)2(H2O)]·xGuest (1-D) and [Cd3((S)-CBA)3(BIP)2(H2O)]·xGuest (1-L), have been synthesized under solvothermal reaction condition. Single crystal X-ray diffraction analysis reveals the two complexes contain single helical chains based on enantiopure ligands and cadmium clusters. Moreover, some physical characteristics such as PXRD, thermal stability, solid-state circular dichroism (CD) and luminescent were also investigated.

Photoluminescence, magnetic and photocatalytic properties of three overlapping layered homochiral coordination polymers based on semi-rigid alanine ligands

Three homochiral coordination polymers based on semi-rigid alanine ligands and varied auxiliary N-donor ligands, [Cd(TMAla)(bpipa-4)]·2H2O (1), [Co2(TMAla)2(bipy)2]·2.5H2O (2), [Co(TBAla)(bpee)(H2O)2]·3H2O (3), (H2TMAla=terephthaloyl-mono(l-alanine), H2TBAla=terephthaloyl-bis(l-alanine), bpipa-4=N,N′-bis(pyridin-4-yl)isophthalamide, bipy=4,4′-bipyridine and bpee=1,2-bis(4-pyridyl)ethylene), have been synthesized and structurally characterized. In these structures, the different metal ions are connected into two types of chains by the semi-rigid alanine ligands and various N-donor ligands in different direction, respectively, to generate diverse 2D layered coordination networks, which are further stacked into 3D supramolecular frameworks in an ABAB overlapping mode through interlayered hydrogen bonds. Complex 1 exhibits the 2D squamous sheet constructed by zigzag chains. Complex 2 shows a thick 2D layer motif formed through the looped and ladder-shaped chains. Complex 3 features a (4,4) grid 2D coordination network built via the zigzag and linear chains. Complex 1 displays a strong fluorescent emission at 402nm in solid state at room temperature. Magnetic susceptibility measurement indicates weak antiferromagnetic interactions between the Co(II) ions in complex 2. Meanwhile, complex 2 shows good photocatalytic activity for the degradation of methylene blue (MB) and methyl orange (MO) dyes under UV light.

Two Pairs of Homochiral Coordination Polymers with Helices Based on Semi‐rigid Lactic Acid Ligands

Utilizing semirigid lactic acid derivatives (R)‐H2CBA and (S)‐H2CBA as chiral ligands, two pair of homochiral coordination polymers formulated as [Zn((R)‐CBA)(1,4‐DIB)]·H2O (1‐D), [Zn((S)‐CBA)(1,4‐DIB)]·H2O (1‐L), [Co((R)‐CBA)(1,4‐DIB)]·H2O (2‐D) and [Co((S)‐CBA)(1,4‐DIB)]·H2O (2‐L) were prepared under solvothermal reaction condition. Single X‐ray diffraction study reveals that all the complexes are comprised of three kinds of helical chains, which are constructed by corresponding metal ions, CBA2– ligands, and/or 1,4‐DIB ligands. Moreover, some physical characteristics, such as PXRD, thermal stabilities, solid‐state circular dichroism (CD), luminescent and magnetic properties are also investigated.

A robust metallomacrocyclic motif for the formation interpenetrated coordination polymers

The reproducibility of an M2L2 metallomacrocyclic synthon containing L-alanine substituted naphthalene diimide ligands (AlaNDI), and its ability to form both catenane and rotaxane motifs, has been demonstrated in a series of nine homochiral coordination polymers. The planes of the NDIs that comprise the metallomacrocycle are ∼7 A apart, an ideal distance for an aromatic group to reside within the ring with multiple parallel π-interactions. The tendency for these systems to be dominated by π-interactions appears to be a driving force for interpenetration of these coordination polymers by either the formation of catenanes between two {M2(AlaNDI)2} metallomacrocycles or the formation of rotaxanes by dipyridyl coligands passing through metallomacrocycles (4,4′-bipyridine, dipyridylethene and dipyridylnaphthalenediimide). Due to both of these interpenetration motifs being facilitated by parallel π-interactions, the interpenetration of the individual networks does not typically lead to increased dimensionality in the structures, with the exception of one material in which a 1D chain interpenetrates in a 1D → 2D manner. Two of the reported coordination polymers, both containing dipyridylnaphthalenediimide (4PyNDI), are not interpenetrated with π-interactions present between the 4PyNDI ligands themselves rather than engaging with the macrocycles. Overall the reproducibility of the metallomacrocycle, and the relatively common occurrence of catenane and rotaxane motifs, suggests that this is a promising synthon for further crystal engineering applications.

Crystal structure of two homochiral metal-organic polymers based on S-3,3-dimethyllactic acid

By heating of an aqueous solution of zinc(II) or cobalt(II) acetates, 4,4-bipyridyl (bpy), and S-3,3-dimethyl hydroxypropionic acid (H2dml) two homochiral coordination polymers [Zn(H2O)(bpy)(Hdml)](CH3COO)∙ ∙2H2O (1) and [Co(H2O)(bpy)(Hdml)2] (2) are obtained. The crystal structure is determined by single crystal X-ray diffraction. Compound 1 has a layered structure and compound 2 has a chain structure.

A pair of novel 4-connected homochiral coordination polymers based on proline-tetrazole ligand

A pair of novel 2D homochiral coordination polymers based on proline-tetrazole ligand, namely [Cd((S)-PTZ)2]n (1-L) and [Zn((S)-PTZ)2]n (2-L), were obtained and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, solid-state CD spectra, single-crystal X-ray crystallography and powder X-ray diffraction. The compounds 1-L and 2-L display 4-connected net and SHG response.

Enantiopure phosphonic acids as chiral inducers: homochiral crystallization of cobalt coordination polymers showing field-induced slow magnetization relaxation.

This Communication reports, for the first time, that enantiopure phosphonic acids can serve as chirality-inducing agents towards homochiral coordination polymers. Hence homochiral chain compounds (M)- or (P)-Co(SO4)(1,3-bbix)(H2O)3 (1M or 1P) are obtained successfully using an achiral precursor of 1,3-bis((1H-benzo[d]imidazol-1-yl)methyl)benzene (1,3-bbix) in the presence of a catalytic amount of (S)- or (R)-3-phenyl-2-((phosphonomethyl)amino)propanoic acid [(S)- or (R)-2-ppapH3]. Furthermore, compound 1M provides the first example of homochiral cobalt compounds showing field-induced single ion magnet behavior.

Molecular tectonics: homochiral coordination polymers based on pyridyl-substituted cyclic tetrapeptides

Upon combining enantiopure bis-4-pyridylphenyl-substituted cyclotetrapeptides with HgCl2 and CdCl2, homochiral 1D zigzag coordination polymers were obtained, while the use of a bis-4-pyridyl-substituted cyclotetrapeptide with HgCl2 led to the formation of a different type of 1D coordination network.

Homochiral coordination polymers from a chiral dicarboxylic acid and dipyridyl ligands: Structural diversity, photoluminescence and magnetic properties

Utilizing the mixed-ligand strategy, six new homochiral coordination polymers based on enantiopure (1R,2R)-1,2-cyclohexanedicarboxylic acid and varied auxiliary bipyridyl ligands, [Zn3(L)2(OH)2] (1), [Cu3(HL)2(L)2(bpy)3]·4H2O (2), [M(L)(bpe)2(H2O)2]·H2O (M=Co, 3; Ni, 4; Cd, 5), [Ni(L)(bpa)(H2O)3]·2H2O (6), [H2L=(1R,2R)-1,2-cyclohexanedicarboxylic acid, bpy=4,4′-bipyridine, bpe=1,2-bis(4-pyridyl)ethylene, bpa=1,2-bis(4-pyridyl)ethane] have been hydrothermally synthesized. Compound 1 shows a 2D 63-hcb network in the absence of any bipyridyl ligand. Compound 2 is a 2D (4,4)-connected grid network in the presence of bpy. Compounds 3–5 are isomorphous and feature 1D staggered-sculls chains by using bpe instead of bpy. Compound 6 possesses a 1D left-handed helical chain sustained by flexible bpa ligand. Each type of these coordination structures is further extended into 3D supramolecular frameworks through different intermolecular interactions. Solid-state circular dichroism (CD) spectra of compounds 1–6 exhibit strong CD signals. Magnetic susceptibility measurement indicates weak antiferromagnetic interactions between the Cu(II) ions in compound 2. Compound 5 displays a strong fluorescent emission at 413nm in solid state at room temperature.

Racemic and homochiral coordination polymers based on carboxylates of different lengths

Three coordination polymers, {[Ag2(R-PHBU)(S-PHBU)(bpp)2]·H2O}n (1, racemic), {[Ag2(R-PHSU)0.5(S-PHSU)0.5(bpp)2]·2H2O}n (2, racemic), and {[Ag2(CHDA)(bpp)2]·9H2O}n (3, homochiral) (HPHBU = 2-phenylbutyric acid, H2PHSU = 2-phenylsuccinic acid, H2CHDA = 1,1-cyclohexanediacetic acid, bpp = 1,3-bis(4-pyridyl)propane), have been synthesized by solution reactions of Ag(I) with bpp and rac-PHBU−, rac-PHSU2−, or CHDA2−. Single-crystal X-ray diffraction reveals that all three complexes feature “AgAg” subunits extended by bpp ligands in two-dimensional (2-D) cation layers, which are embedded by the PHBU−, PHSU2−, or CHDA2− ligands of different lengths. Adjacent 2-D layers with pillar-shaped fillers are mutually interdigitated to 3-D H-bonded supramolecular coordination polymers with 1-D pores. As the length of the pillar-shaped fillers increases from 5.6, 6.4 to 7.3 Å, the dimensions of the pores range from 5.0 × 3.7 Å (narrow slit), 8.7 × 5.6 Å (elliptical) to 13.4 × 6.8 Å (quadrangular), and the solvent-accessible void volumes range from 3.6, 31.8 to 36.4% of the crystal volumes. The 1-D pores are filled with guest water molecules. The guest water molecules in 1 are discrete. Centrosymmetric water tapes and chiral right-handed 21 helical water tapes are observed in 2 and 3, respectively. Thermal and photoluminescent properties, as well as lead(II) adsorption, are also discussed.

Hydrothermal synthesis, crystal structure and photoluminescence of two homochiral zinc(II) coordination polymers.

Metal-organic frameworks (MOFs) have potentially useful applications and an intriguing variety of architectures and topologies. Two homochiral coordination polymers have been synthesized by the hydrothermal method, namely poly[(μ-N-benzyl-L-phenylalaninato-κ(4)O,O':O,N)(μ-formato-κ(2)O:O')zinc(II)], [Zn(C16H16NO2)(HCOO)]n, (1), and poly[(μ-N-benzyl-L-leucinato-κ(4)O,O':O,N)(μ-formato-κ(2)O:O')zinc(II)], [Zn(C13H18NO2)(HCOO)]n, (2), and studied by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) each have a two-dimensional layer structure, with the benzyl or isobutyl groups of the ligands directed towards the interlayer interface. Photoluminescence investigations show that both (1) and (2) display a strong emission in the blue region.

From pair quadruple- to single-stranded helices to lines in a mixed ligand system via adjusting the N-substituent of L-Glu.

Utilizing the mixed-ligand strategy, a novel fourfold-interpenetrated 3D homochiral metal-organic framework (1) with rare pair quadruple-stranded helices was assembled from bpee (1,2-bis(4-pyridyl)ethylene) and NCG (N-carbamyl-l-glutamate). Changing the carbamyl substituent of NCG with benzoyl group (NBzG: N-benzoyl-l-glutamate), a non-interpenetrated 3D homochiral coordination polymer (2) composed of alternate right-handed and left-handed single helix was obtained. When p-tolylsulfonyl substituent was used instead, an interesting homochiral linear structure (3) was formed from mixed-ligand bpee and NTsG (N-p-tolylsulfonyl-l-glutamate), with all individual NTsG being lined up orderly. The steric hindrance of N-substituent of l-glu has a tremendous impact on the construction of these diverse frameworks. Complexes 1-3 display second harmonic generation (SHG) efficiencies, which are approximately 0.32, 0.45, and 0.55 times as much as that of KDP powder.

Homochiral ZnII–Camphorate Frameworks With 4′-p-tolyl-2,2′:6′,2″-Terpyridine and 1,10-Phenanthroline as Accessorial Ligands: Syntheses, Crystal Structures, and Properties

The homochiral coordination polymers of zinc(II) with D-camphoric acid (D-H2Cam) as bridges and 4′-p-tolyl-2,2′:6′,2″-terpyridine (ttpy) and 1,10-phenanthroline (phen) as accessorial terminal ligands, namely [Zn2(D-Cam)2(ttpy)2]n (I1) and [Zn2(D-Cam)2(phen)2]n (I2), have been synthesized and characterized by elemental analysis, IR, PXRD, and X-ray diffraction analysis. Both complexes have 1D homochiral coordination chains bridged by D-Cam. Interestingly, the coordination numbers of ZnII ions, the coordination modes of D-Cam, and the crystal structures in I1 and I2 vary with the accessorial ligands ttpy and phen used. Additionally, compounds I1 and I2 have stronger fluorescence and higher thermostability, indicating their potential utility in photoluminescent materials.

A multi-functional coordination polymer coexisting spontaneous chirality resolution and weak ferromagnetism

A multifunctional homochiral coordination polymer, [Co(H2O)(BDC)(4,4′-BPY)]∙3H2O (1) (H2BDC=1,2-benzenedicarboxylate and 4,4′-BPY=4,4′-bipyridine), has been successfully isolated from Co(II) ions and mixed ligands (1,2-benzenedicarboxylate and 4,4′-bipyridine). Complex 1, which exhibits spontaneous chirality resolution and weak ferromagnetism, is built by chiral helices interconnected via end-to-end 4,4′-BPY bridges into a two-dimensional (2D) layer structure.

A homochiral Cu(II) coordination polymer built from helical motif based on two V-shaped ligands

By using a V-shaped N-containing ligand and a V-shaped carboxylate ligand, we have successfully synthesized a 3D novel copper homochiral coordination polymer, namely [Cu(OPY)(1,3-bdc)]n (complex 1), [1,3-H2bdc=isophthalic acid, OPY=4,4′-(oxybis(4,1-phenylene))dipyridine]. The compound has been solvothermally synthesized and characterized by IR, elemental analysis, single crystal X-ray diffraction, XRD, UV–vis, and TG analysis. The complex 1 crystallizes in the chiral space group P65 and possesses an unprecedented uninodal 3D 75∙8 topology. However, the complex was synthesized by achiral materials. The complex 1 displays a moderate SHG response and its SHG efficiency is about 0.3 times that of urea. In addition, the compound shows high thermal stability.

Synthesis, crystal structures and characterizations of two homochiral coordination polymers based on a chiral reduced Schiff base ligand

Two homochiral coordination polymers based on a chiral reduced Schiff base ligand, namely poly[(μ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)zinc(II)], [Zn(C17H15NO4)]n, (1), and poly[(μ5-4-{[(NR,1S)-(1-carboxylato-2-phenylethyl)amino]methyl}benzoato)cobalt(II)], [Co(C17H15NO4)]n, (2), have been obtained by hydrothermal methods and studied by single-crystal X-ray diffraction, elemental analyses, powder X-ray diffraction, thermogravimetric analysis, IR spectroscopy and fluorescence spectroscopy. Compounds (1) and (2) are isostructural and crystallize in the P2(1)2(1)2(1) space group. Both display a three-dimensional network structure with a one-dimensional channel, with the benzyl group of the ligand directed towards the channel. An investigation of photoluminescence properties shows that compound (1) displays a strong emission in the purple region.

Homochiral Silver-Based Coordination Polymers Exhibiting Temperature-Dependent Photoluminescence Behavior

Homochiral coordination polymers based on zigzag or helical polymers are assembled from a semiflexible fluorescent bipyridyl ligand and linear coordinated Ag(I) ions; they exhibit unusual temperature-dependent photoluminescence behavior, including multistep changes in energy and intensity upon cooling.

Hierarchical importance of coordination and hydrogen bonds in the formation of homochiral 2D coordination polymers and 2D supramolecular assemblies

2D homochiral coordination polymers and their conversion to the corresponding homochiral 2D supramolecular assemblies using 4,4’-bipyridine as a bifunctional linker are reported.