Zhan-Lin Xu

Syntheses, structures and photoluminescence of a series of metal-organic complexes with 1,3,5-benzenetricarboxylate and pyrazino[2,3-f][1,10]-phenanthroline ligands

A series of new metal-organic coordination complexes, [Co2(HBTC)2(Pyphen)2(H2O)4]·4H2O (1), [Mn(HBTC)(Pyphen)(H2O)] (2), [Cd2(OH)(BTC)(Pyphen)2]·H2O (3), [Cu2(OH)(BTC)(Pyphen)] (4), and [Zn2(OH)(BTC)(Pyphen)] (5) were prepared through hydrothermal reactions of pyrazino[2,3-f][1,10]-phenanthroline (Pyphen) and 1,3,5-benzenetricarboxylic acid (H3BTC) with different metal salts. All these compounds were structurally determined by X-ray single-crystal diffraction. In the dinuclear Co(II) compound (1) π–π interactions exist between Pyphen and HBTC2− ligands, resulting in interesting 2D supramolecular layers. For complex (2), the Mn(II) centers are linked by HBTC2− ligands to form a 2D (4,4) coordination layer, and these layers are interdigitated in pairs. Polymer (3) also possesses a 2D network structure composed of the tetrametallic clusters [Cd4(µ2-OH)2], which is extended to 3D arrays through the π–π interactions between Pyphen ligands. The isostructural coordination polymers (4) and (5) show the same 3D framework structure. Solid-state luminescent spectra of the Cd(II) and Zn(II) complexes indicate intense fluorescent emissions.

Syntheses and characterization of four coordination compounds derived from 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene and benzene-dicarboxylic acids

[Co2(TTBT)4(1,2-BDC)2] n  · 4nH2O (1), [Pb2(TTBT)2(1,3-BDC)2] n  · nTTBT · 2nH2O (2), [Fe(TTBT)(1,4-BDC)(H2O)] n (3), and [Zn(TTBT)(1,4-BDC)(H2O)] n (4) have been hydrothermally synthesized by self-assembly of TTBT (TTBT = 10,11,12,13-tetrahydro-4,5,9,14-tetraaza-benzo[b]triphenylene), benzene-dicarboxylic acid ligands 1,2-H2BDC, 1,3-H2BDC or 1,4-H2BDC (1,2-H2BDC = 1,2-benzenedicarboxylic acid, 1,3-H2BDC = 1,3-benzenedicarboxylic acid, 1,4-H2BDC = 1,4-benzenedicarboxylic acid), and various metal salts. Compound 1 has dinuclear cluster units, four dimeric Co2 units connected to form a 32-membered ring via weak offset π–π interactions, which are further stacked via strong π–π interactions to form a 3-D supramolecular framework. Complex 2 contains 2-D layers with rhombohedral grids, which are connected to a 3-D structure by π–π interactions. 3 and 4 feature 1-D infinite chains, which are further extended by strong π–π interactions and O–H···O hydrogen bonds resulting in 3-D supramolecular architectures. The photoluminescent properties of 2 and 4 have also been investigated.

catena-Poly[[aqua­(dipyrido[3,2-a:2′,3′-c]phenazine-κ2N4,N5)iron(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3N1,O2:O3]

In the title compound, [Fe(C6H2N2O4)(C18H10N4)(H2O)]n, the FeII ion adopts a slightly distorted octahedral mer-FeN3O3 geometry, arising from one N,N′-bidentate dipyrido[3,2-a:2′,3′-c]phenazine ligand, one N,O-chelating pyrazine-2,3-dicarboxylate dianion and one water molecule. An O-bonded symmetry-related dianion completes the coordination of the metal. The bridging dianion results in a one-dimensional polymeric chain. Aromatic π–π stacking interactions between ligands [centroid–centroid separations = 3.528 (2) and 3.741 (2) Å] and O—H⋯O and O—H⋯N hydrogen bonds link the chains together, leading to a three-dimensional supramolecular network.

Hydrothermal Syntheses and Crystal Structures of Three Zn(II) Coordination Compounds Constructed with 3,5-Pyrazoledicarboxylic Acid

Three novel metal–organic coordination compounds, [Zn(Hdcp)(H2O)4]·1.5H2O (1), [Zn(Hdcp)(H2O)2]∞ (2) and [Zn3(dcp)2(H2O)5]∞ (3) with the ligand 3,5-pyrazoledicarboxylic acid were prepared by the hydrothermal method. The complexes were structurally characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Compound 1 is a mononuclear molecule that is linked into a 3D supramolecular framework via N–H···O and O–H···O hydrogen bonds. In 2, two types of carboxylic bridges were found between ZnII ions to form a 1D double-chain. The 1D chains were further construct into a 3D structure by hydrogen bonds. Trinuclear 3 consists of 1D bi-infinite parallelogram chains of [Zn3(dcp)2(H2O)3] trimers. In the basic trinuclear unit a further bridging mode of the ligand is seen where two dcp3− ligands chelate three ZnII ions by utilizing five donors of the dcp3− ligand. The photoluminescent properties of 1, 2 and 3 were investigated.

Poly[[[pyrazino[2,3‐f][1,10]phenanthroline]copper(II)]‐μ4‐fumarato‐μ2‐fumarato]

In the title compound, [Cu(C4H2O4)(C14H8N4)] or [Cu(fum)(Pyphen)], where fum is the fumarate dianion and Pyphen is pyrazino[2,3-f][1,10]phenanthroline, the CuII atom is five-coordinate in a distorted trigonal–bipyramidal geometry. The chelated CuII atoms are further bridged by the fum ligands to form a two-dimensional structure with (4,4)-grids.

catena-Poly[[aqua­(pyrazino[2,3-f][1,10]phenanthroline-κ2N8,N9)cobalt(II)]-μ-pyrazine-2,3-dicarboxyl­ato-κ3N1O2:O3]

In the title compound, [Co(C6H2N2O4)(C14H8N4)(H2O)]n, the Co atom is bonded to one N,N′-bidentate pyrazino[2,3-f][1,10]phenanthroline (Pyphen) ligand, one N,O-bidentate pyrazine-2,3-dicarboxylate (PZDC) dianion and one water molecule in a distorted octahedral mer-CoN3O3 geometry. The CoII atoms are bridged by the PZDC dianions, forming an infinite one-dimensional chain running along the b axis. Adjacent chains pack together through π–π stacking interactions [centroid–centroid separations = 3.498 (4) and 3.528 (4) Å], and O—H⋯O and O—H⋯N hydrogen bonds involving the water molecule complete the structure.

Highly efficient organic ultraviolet photodetectors based on excellent Cu (I) complexes

We demonstrate high response organic ultraviolet photodetectors using 4,4′,4″-tris[3-methyl-pheny(phenyl)amino]tri-phenylamine (m-MTDATA) and two novel Cu(I) complexes, [Cu(DPEphos)(PyPhen)]BF4 (CuDP)(DPEphos = Bis [2-(diphenylphosphino)phenyl]ether, PyPhen = pyrazino[2,3-f][1,10]phenanthroline) and [Cu(DPEbenz)(PyPhen)]BF4 (CuBP) (DPEbenz = 1,2-bis(diphenylphosphino)benzene) to act as the electron donor and acceptor, respectively. Strong photoluminescence quenching of m-MTDATA by Cu(I) complexes is observed manifesting the efficient photoinduced charge transfer that occurs between m-MTDATA and Cu(I) complexes. The optimized photodetector based on CuBP exhibits a maximum response of 276 mA/W at −12 V under an illumination of 365 nm UV light irradiation with an intensity of 1.75 mW/cm2. The high response is attributed to feasible energy level match, efficient electron transfer from m-MTDATA to CuBP and skillful device design. More detailed working mechanism of harvesting high performance is also discussed.

Crystal structure of (.4-oxygen)tetra(2-(4'-chlorobenzoyl) benzoato)trilead(II), Pb3O(C14H8O3Cl)4

C112H64Cl8O26Pb6, monoclinic, P21/n (no. 14), a = 11.4546(9) Å, b = 15.414(1) Å, c = 30.348(2) Å, * = 92.271(1)°, V = 5353.9 Å, Z = 2, Rgt(F) = 0.030, wRref(F ) = 0.077, T = 292 K.