Chun-Sen Liu

Zinc(II) coordination architectures with two bulky anthracene-based carboxylic ligands: crystal structures and luminescent properties

To systematically investigate the influence of ligands with a large conjugated π-system on the structures and properties of their complexes, we synthesized seven ZnII complexes with two anthracene-based carboxylic ligands, anthracene-9-carboxylic acid (HL1) and anthracene-9,10-dicarboxylic acid (H2L2), and sometimes incorporating different auxiliary ligands, {[Zn(L1)2(H2O)2](H2O)}∞ (1), [Zn5(μ3-OH)2(L1)8(2,2′-bipy)2] (2), Zn2(L1)4(phen)2(μ-H2O) (3), {[Zn(L1)2(4,4′-bipy)(CH3OH)2]}∞ (4), {[Zn(L2)2](Hdmpy)2(H2O)2}∞ (5), {[Zn2(L2)(2,2′-bipy)4](HL2)2}∞ (6) and {[Zn2(L2)(pypz)2(Hpypz)2]}∞ (7) (2,2′-bipy = 2,2′-bipyridine, phen = 1,10′-phenanthroline, Hpypz = 3-(2-pyridyl)pyrazole, 4,4′-bipy = 4,4′-bipyridine and Hdmpy = protonated 2,6-dimethylpyridine), which were characterized by elemental analyses, IR spectroscopy, and X-ray crystallography. 1 has a one-dimensional (1-D) chain structure, whereas 2 exhibits a new pentanuclear cluster structure because of the introduction of a chelating 2,2′-bipy ligand. 3 and 4 take dinuclear and 1-D structures, respectively, by incorporating the auxiliary ligands phen and 4,4′-bipy. 5 is a three-dimensional (3-D) twofold interpenetrating diamondoid framework showing an open channel. 6 and 7 possess the corresponding chain structures containing Zn2 units as nodes by introducing Hpypz and 4,4′-bipy auxiliary ligands, respectively. These results indicate that the nature of ligands and auxiliary ligands has an important effect on the structural topologies of such complexes. Moreover, the luminescent properties of the corresponding complexes and ligands have been briefly investigated.

New d10 metal–organic coordination polymers with 9,10-bis(triazol-1-ylmethyl)anthracene (L): Syntheses, crystal structures, and luminescent properties

In our continuous efforts to explore the effects of metal ions, ligand structures, counter-anions on the structure and properties of metal–organic complexes, six new d10 metal coordination polymers with an anthracene-triazole ligand, 9,10-bis(triazol-1-ylmethyl)anthracene (L), {[Cu(L)I]}∞ (1), {[Ag(L)(BF4)]}∞ (2), {[Zn(L)(NO3)2]}∞ (3), {[Zn(L)(CH3OH)2(ClO4)2(H2O)]}∞ (4), {[Cd(L)(CH3OH)2(ClO4)2(H2O)]}∞ (5) and {[Hg(L)(Br2)]}∞ (6), were synthesized and structurally characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. 1–3 and 6 have similar one-dimensional (1-D) chain structures in which 1, 3 and 6 were further linked into infinite two-dimensional (2-D) sheets by inter-chain C–H⋯I, π⋯π or C–H⋯Br weak interactions, respectively, while 2 was extended into three-dimensional (3-D) supramolecular network by Ag⋯F and Ag⋯N weak interactions. 4 and 5 possess similar (4,4) 2-D sheet structure containing only one type of rhombic grid, and the Zn/Cd atoms are regarded as the four-connected nodes and the ligand as bridges. Obviously, the structural differences among them are attributable to the different metal ions and counter anions. In 1–6, L adopts a trans-gauche conformation with the shortest N⋯N distance between the two N donors. Furthermore, the fluorescent properties of 1–6 and ligand L have been investigated.

Cadmium(II) coordination polymers based on a bulky anthracene-based dicarboxylate ligand: crystal structures and luminescent properties

In our efforts to continuously explore the influence of ligands with larger conjugated π-systems on the related structures and properties of their complexes, four CdII complexes with anthracene-9,10-dicarboxylate (L) and relevant auxiliary ligands were synthesized and characterized: {[Cd2(L)2(bipy)(H2O)2](C2H5OH)0.5(H2O)2.25}∞ (1), Cd2(L)(HL)2(phen)4 (2), {[Cd2(L)1.5(Hpypz)4](L)0.5}∞ (3), and {[Cd(L)2](H2daco)(C2H5OH)2(H2O)}∞ (4) (bipy = 2,2′-bipyridine, phen = 1,10-phenanthroline, Hpypz = 3-(2-pyridyl)pyrazole, and daco = 1,5-diazacyclooctane). Structural analyses show that complex 1 has a three-dimensional (3D) structure with a Schlafli symbol of (6·82)2(6·85). Complexes 2 and 3 take dinuclear and two-dimensional (2D) structures, respectively, due to the introduction of different 2,2′-bipyridyl-like chelating ligands, phen for 2 and Hpypz for 3. Complex 4 possesses another three-dimensional (3D) two-fold interpenetrating diamondoid network by introducing daco as an auxiliary co-ligand. The present results indicate that the natures of the auxiliary ligands have important effects on the formation of the final structures of such complexes. Moreover, the luminescent properties of complexes 1–4 and the corresponding ligands have also been investigated in detail.

Tuning the topologies of MnII complexes with 3-(2-pyridyl)pyrazole and carboxylate ligands by intramolecular hydrogen bonds and the geometries of pendant ligands: crystal structures and magnetic properties

In our efforts to investigate the influence of intramolecular hydrogen bonding interactions and the geometries of pendant ligands on the structures of low-dimensional coordination architectures, two kinds of ligands have been selected: a) a chelating ligand, 3-(2-pyridyl)pyrazole (L1), with a non-coordinated nitrogen atom as a good hydrogen bonding acceptor and b) three pendant monocarboxylato ligands with different aromatic backbones (L2, L3 and L4) , and their MnII complexes, [Mn(L1)2(L2)2] (1), [Mn(L1)2(L3)2] (2) and [Mn2(L1)2(L4)4] (3), have been prepared and structurally characterized by single crystal X-ray diffraction analysis. The results show clearly that the chelating 3-(2-pyridyl)pyrazole ligand plays the dominant role in the adjustment of the modes of the monocarboxylate ligands through strong intramolecular hydrogen bonding interactions and results in the formation of low-dimensional coordination complexes. The geometry of the anthracene ring also plays a vital role in determining the topology of 3, which further affects the magnetic interactions between the metal centers.

Manganese(ii) Complexes with a Bulky Anthracene-Based Dicarboxylic Ligand: Syntheses, Crystal Structures, and Magnetic Properties

To investigate the influence of the bulky aromatic ring skeleton with a large conjugated π-system on the structures and properties of its complexes, two MnII complexes with the anthracene-based dicarboxylic ligand anthracene-9,10-dicarboxylic acid (H2L) and different 2,2′-bipyridyl-like chelating ligands were synthesized and characterized: {[Mn2(L)2(bipy)2(H2O)2]}∞ (1) and {[Mn(L)(phen)2](H2O)2.5}∞ (2) (L = anthracene-9,10-dicarboxylate, bipy = 2,2′-bipyridine, and phen = 1,10-phenanthroline). Complex 1 has a (4,4) two-dimensional (2D) sheet structure that is further assembled to form a three-dimensional (3D) supramolecular network by the co-effects of C–H···π and O–H···O hydrogen-bonding interactions. Complex 2 adopts a one-dimensional (1D) polymeric chain structure by using the chelating phen instead of bipy in 1, which is further interlinked by interchain C–H···π interactions, which results in a higher-dimensional supramolecular network from the different crystallographic directions. The relevant results reveal that the steric bulk of the anthracene ring in H2L may play an important role in the formation of 1 and 2. Moreover, the magnetic properties of 1 and 2 show that the long Mn···Mn intermetallic separations result in weak magnetic coupling, along with the corresponding coupling constant J parameters related to their structural characteristics, –0.35 cm–1 for 1 and –3.0 cm–1 for 2.

Tetra­kis(μ-anthracene-9-carboxyl­ato)bis­[(anthracene-9-carboxyl­ato)(2,2′-bipyrid­yl)lanthanum(III)]

The title complex, [La2(C15H9O2)6(C10H8N2)2], has a centrosymmetric binuclear cage structure in which two LaIII atoms are both nine-coordinated and bridged by four anthracene-9-carboxylate ligands, with an La⋯La separation of 4.0880 (4) Å. The remaining coordination sites are occupied by two N atoms of a 2,2′-bipyridine (bipy) and two O atoms of an anthracene-9-carboxylate ligand. The six anthracene-9-carboxylate groups coordinate each LaIII atom in three different ways. Adjacent discrete dinuclear units are arranged into a one-dimensional chain along the [111] direction by intermolecular π–π stacking interactions, with a centroid–centroid separation of 3.704 (7) Å.

Dichlorido[1-(1-naphthyl­meth­yl)-3-(2-pyrid­yl)-1H-pyrazole-κ2N2,N3]palladium(II)

In the title compound, [PdCl2(C19H15N3)], the PdII centre is four-coordinated by two N-atom donors from one 1-[3-(2-pyridyl)pyrazol-1-ylmethyl]naphthalene (L) ligand and by two Cl atoms in a distorted square-planar coordination geometry. In the crystal structure, adjacent PdII mononuclear units form intermolecular C—H⋯π interactions involving the benzene and pyridine rings of different L ligands and π–π stacking interactions between the pyrazolyl-pyridine and naphthalene rings of neighbouring L ligands, with a centroid–centroid separation of 3.522 (1) Å.

CCDC 749746: Experimental Crystal Structure Determination

Related Article: Chun-Sen Liu, Jun-Jie Wang, Ze Chang, Li-Fen Yan, Xian-He Bu|2010|CrystEngComm|12|1833|doi:10.1039/b923516g

catena-Poly[[diazido­manganese(II)]bis­[μ-1-(4-pyridylmeth­yl)-1H-benzimidazole]]

In the title polymeric compound, [Mn(N3)2(C13H11N3)2]n, each MnII centre is six-coordinated in an octahedral geometry by six N atoms from four 1-(4-pyridylmethyl)-1H-benzimidazole (L) ligands and two azide anions (N3 −). Each of the MnII ions lies on an inversion centre. The L ligands and N3 − anions bridge adjacent MnII centres, generating a polymeric chain running along the [110] direction. Adjacent polymeric chains are arranged in a two-dimensional network parallel to the (001) plane, linked by C—H⋯N hydrogen bonds.

CCDC 609249: Experimental Crystal Structure Determination

Related Article: Chun-Sen Liu, Jian-Rong Li, Cai-Yun Li, Jun-Jie Wang, Xian-He Bu|2007|Inorg.Chim.Acta|360|2532|doi:10.1016/j.ica.2006.12.032