Hai-Yan Liu

A new type of entangled motif: from 2D polyrotaxane layers to a 3D polythreaded framework

A new type of 3D entangled motif constructed from 2D polyrotaxane layers has been synthesized and characterized, which represents the first example of a 2D → 3D polythreaded framework with both polyrotaxane and polypeseudo-rotaxane character.

Two unprecedented 3D metal–organic polyrotaxane frameworks based on a new flexible tri(imidazole) ligand

Two Cd(II)-containing coordination polymers based on a new tri(4-imidazolylphenyl)amine (Tipa) ligand and carboxylates, namely, [Cd(Tipa)(L1)]·2H2O (1) and [Cd3(Tipa)2(L2)2Cl2]·4H2O (2), where H2L1 = 5-OH-1,3-benzenedicarboxylic acid and H2L2 = 1,4-benzendicarboxylic acid, have been synthesized by varying the carboxylates under hydrothermal conditions. In 1, adjacent Cd(II) centers are linked by L1 anions to generate Cd-carboxylate chains, which are further extended by Tipa ligands to form a puckered double sheet. The most peculiar feature of 1 is the entangled fashion between the [Cd2(Tipa)2] loop and the L1 ligand rod. Every [Cd2(Tipa)2] loop of each layer is threaded by one L1 ligand rod of an adjacent layer. In this entangled mode, the 2D → 3D polyrotaxane framework was obtained, which represents an unusual 2D → 3D metal–organic polyrotaxane framework entangled in a highly rare parallel fashion. In 2, two identical 3D self-penetrating frameworks interpenetrate each other in a 2-fold mode. If we regard each Cd2(Tipa)2 window as a loop and each L2 ligand as a single rod, undoubtedly, the structure of 2 also can be described as a 3D metal–organic polyrotaxane framework. As far as we know, compound 2 is the first example of a 2-fold interpenetrating 3D framework with polyrotaxane features. The luminescent properties for the two compounds were also investigated.

Diverse topologies of six coordination polymers constructed from a tris(4-imidazolylphenyl)amine ligand and different carboxylates

In this article, six new coordination polymers, namely, [Zn(Tipa)(L1)]·H2O (1), [Zn2(Tipa)(L2)(μ2-O)]·2H2O (2), [Zn2(Tipa)(L3)]·3.5H2O (3), [Mn(Tipa)(L2)]·H2O (4), [Cu4(Tipa)4(L4)2(CH3OH)2(H2O)2]·2(L4)·3(CH3OH)·8(H2O) (5), and Co3(Tipa)2(L4)3 (6), where H2L1 = 1,3-benzenedicarboxylic acid, H3L2 = 1,3,5-benzenetricarboxylic acid, H4L3 = 1,2,4,5-benzenetetracarboxylic, H2L4 = 1,4-benzenedicarboxylic acid and Tipa = tris(4-imidazolylphenyl)amine, have been synthesized by varying the carboxylates and metals under hydrothermal conditions. Compound 1 shows a 2D → 3D framework with parallel polycatenation of undulated square layers (sql). Compound 2 displays a 3D 3,4-connected (5·62·82·9)(63·72·9)(73)(62·8) topology, while compound 3 reveals a 3D 3,4,6-connected (42·62·7·8)(4·6·83·10)(6·8·10)(44·52·67·7·8)(42·82·102) topology. Compound 4 shows a 2D undulate layer. Compound 5 exhibits an unprecedented 2D → 2D polyrotaxane network with (3,4)-connected (4·52)(4·53·72) topology. Interestingly, the neighboring 2D polyrotaxane sheets are sandwiched by the free L4 ligands. Compound 6 is an unusual example of a 3D 2-fold interpenetrating framework with polyrotaxane feature. The effects of the carboxylates and metals have been elucidated. The IR spectra, elemental analyses and luminescent properties for the compounds have also been investigated.

A series of Zn(II) and Cd(II) coordination polymers based on flexible bis-[(pyridyl)-benzimidazole] ligand and different carboxylates: syntheses, structures, and photoluminescent properties

Eight new coordination polymers, namely, [Zn(m-bdc)(L)] (1), [Zn(NH2–bdc)(L)] (2), [Zn3(p-bdc)3(L)]·2H2O (3), [Zn3(btc)2(L)(H2O)]·H2O (4), [Cd(o-bdc)(L)(H2O)] (5), [Cd(m-bdc)(L)] (6), [Cd(p-bdc)(L)(H2O)] (7) and [Cd2(btda)(L)]·H2O (8) (m-H2bdc = 1,3-benzenedicarboxylic acid, NH2–H2bdc = 5-NH2–1,3-benzenedicarboxylic acid, p-H2bdc = 1,4-benzenedicarboxylic acid, H3btc = 1,3,5-benzenetricarboxylic acid, o-H2bdc = 1,2-benzenedicarboxylic acid, btda = 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and L = 1,1′-(1,4-butanediyl)-bis[2-(3-pyridyl)benzimidazole]), have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compounds 1 and 2 display bilayer structures. The neighboring layers of 2 are further linked by hydrogen-bonding interactions to form a 3D supramolecular architecture. Compound 3 shows a 3D 8-connected (36·410·511·6) topology. Compound 4 exhibits a 3D (3,4)-connected (5·7·8)2(42·6·72·8)2(42·52·6·7)2(72·84) net. Compound 5 reveals a layer. The layers are further connected by π–π interactions to give rise to a 3D supramolecular architecture. Compound 6 shows a 3D framework with (3,5)-connected (42·6)(4·102)2(43·6·84·102) topology. The structure of compound 7 is a 3D (3,4)-connected framework with (4·82)(4·9·10)2(42·82·92·104) topology. Compound 8 displays a 3D (3,4)-connected (4·102)2(42·82·102)(42·84)2 topology. Their photoluminescent behaviours have been investigated in detail.

Syntheses, structures and photoluminescent properties of Zn(II) and Cd(II) coordination polymers with flexible tripodal triazole-containing ligands

Seven new coordination polymers, namely, [Zn2(o-bdc)2(L)2]·H2O (1), [Cd2(o-bdc)2(L)2]·6H2O (2), [Zn2(m-bdc)2(L)(H2O)] (3), [Cd2(m-bdc)2(L)]·2H2O (4), [Zn3(p-bdc)3(L)2]·H2O (5), [Zn2(btec)(L)2]·H2O (6) and [Cd2(btec)(L)2]·H2O (7) (o-H2bdc = 1,2-benzenedicarboxylic acid, m-H2bdc = 1,3-benzenedicarboxylic acid, p-H2bdc = 1,4-benzenedicarboxylic acid, H4btec = 1,2,4,5-benzenetetracarboxylic acid and L = 1,3,5-tris(1H-1,2,4-triazol-1-ylmethyl)-2,4,6-trimethylbenzene) have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 displays a 1D ladder structure. The neighboring ladders are further linked by π–π interactions to form a 2D supramolecular layer. Compound 2 shows a 3D (3,5)-connected framework with (63)(66·84) topology. Compound 3 exhibits a 2D layer structure. The layers are further connected by hydrogen-bonds to give rise to a 3D supramolecular architecture. Compound 4 shows a 3D (4,5)-connected (4·85)(44·62·84)2 net. Compound 5 displays a 2D layer with self-penetrating characters. Hydrogen bonds among the water molecules and the p-bdc anions further link the layers into a 3D supramolecular architecture. Compound 6 displays a 2D sheet with dangling arms. Each sheet is threaded by the dangling arms of two others, leading to an unusual 3D polythreading framework. Compound 7 shows a 3D (3,4,5)-connected framework with (62·8)2(65·8)(65·84·10)2 topology. The photoluminescent properties of compounds 1–7 have been investigated in detail.

Three resorcin[4]arene-based complexes with Cu(II)-exchange characteristics and fluorescence sensing of polyoxometalates in aqueous solutions

Three new resorcin[4]arene-based coordination polymers, [Cd3L(H2L)(H2O)2]·2DMF·11.5H2O (1), [Zn4L2(H2O)4]·2DMF·10H2O (2) and [Mn9L4(HCOO)2(H2O)12·(DMF)2]·2DMF·10H2O (3) (H4L = tetrakis(ω-carboxybutyl)methylene resorcin[4]arene, DMF = N,N′-dimethylformamide), have been solvothermally synthesized. Compounds 1–3 are all bilayer structures constructed by secondary building units (SBUs), where trinuclear clusters are found in 1 and infinite rod-shaped chains are observed in 2 and 3. Strikingly, compounds 1–3 display partial Cu(II)-exchange characteristics. The solid-state emission spectra and fluorescence sensing abilities of 1 and 2 to detect polyoxometalates (POMs) in aqueous solutions were studied.

{5,5'-Bis(methoxy-carbonyl-meth-oxy)-2,2'-[ethane-1,2-diylbis(nitrilo-methyl-idyne)]-diphenolato}copper(II).

The title compound, [Cu(C22H22N2O8)], is a tetradentate Schiff base complex. The CuII ion has a nearly square-planar geometry, being coordinated by two N atoms and two O atoms. The two chemically equivalent halves of the molecule are crystallographically independent. One of the carboxylic acid methyl ester units is located in the main plane of the molecule and the other is rotated by 65.3 (5)° with respect to this unit. In the crystal structure, there are π–π stacking interactions between adjacent six-membered chelate rings, with centroid-to-centroid distances of 3.602 (2) Å.

catena-Poly[[[aquasilver(I)]-μ-2,3-dimethylpyrazine-κ2N:N′] 4-amino-2,5-dichlorobenzenesulfonate]

In the title compound, {[Ag(C6H8N2)(H2O)](C6H4Cl2NO3S)}n, the AgI ion is three-coordinated by two N atoms from two symmetry-related 2,3-dimethylpyrazine (dmp) ligands, and one water O atom in a distorted trigonal–planar geometry. The dmp ligands bridge AgI ions to form a one-dimensional chain structure with charge-balancing 4-amino-2,5-dichlorobenzenesulfonate anions. In the crystal structure, intermolecular O—H...O and N—H...O hydrogen bonds form a two-dimensional network.