Jia-Cheng Liu

Structurally diverse copper(II) complexes with pyridazine-integrated with pyrazine–Schiff base ligand featuring an easily lost proton in the hydrazone backbone

To probe the coordination approach of pyridazine and pyrazine ligands, five new complexes of [CuII2L2Cl2] (1), [CuII(L-H)(NO3)(H2O)2](NO3)(H2O) (2), {[CuII(L-H)(H2O)](ClO4)2(H2O)}n (3), [CuII2L2(OH)](NO3)(H2O)2 (4), [CuII2L2(OH)](ClO4) (5) based on Schiff base ligand (E)-3-chloro-6-[2-(pyrazin-2-ylmethylene)hydrazinyl]pyridazine (HL) bearing pyridazinyl and pyrazinyl groups have been synthesized and characterized by IR spectra, elemental analyses, the bond valence sum (BVS) analyses, powder X-ray diffraction (PXRD) analyses, X-ray single crystal diffraction and density function theory calculations. The structures of 1, 2 and 3 suggest that the second nitrogen donors of the pyrazinyl unit can link with other metal ions to construct a higher dimensional architecture by the reaction of HL with Cu(ClO4)2 [CuCl2 for 1, Cu(NO3)2 for 2 and Cu(ClO4)2 for 3]. The structures of 4 and 5 indicate that additional donor units of the pyridazinyl chromophore can bind multiple metal ions to form a multi-metallic cluster, when the protons of the hydrazone backbones are abstracted in the presence of triethylamine to strengthen the coordination behavior of the second nitrogen atom. However, for 1, the protons of the hydrazone backbone are lost with or without triethylamine and the additional nitrogen atoms of the pyrazinyl and pyridazinyl groups are not found to connect to other metal ions, which can probably be assigned to the strong coupling effect of chlorine ions. Magnetic measurements display weak antiferromagnetic coupling between the copper(II) ions in 1 and 5, and ferromagnetic coupling in 3. In addition, the antioxidant activities of HL and 1–5 were also studied.

A dye-sensitized solar cell containing an anchoring porphyrin

Abstract We have designed a self-assembly ZnP-ZnPA, based on a porphyrin ZnP bearing 1,3,5-triazine-2,4-diamine unit, and anchoring porphyrin ZnPA. The assembly with ZnP-ZnPA was immobilized on nanostructured TiO2 electrode surfaces. The assembled structures were characterized by transmission electron microscopy. The optical, photovoltaic, electrochemical impedance spectroscopy, and incident photon-to-current conversion efficiency were measured. The results revealed that the ZnP-ZnPA device had better photovoltaic performance than ZnPA and possessed a higher shortcircuit photocurrent density (JSC = 6.04) but a lower open-circuit photovoltage (VOC = 0.51) than anchoring ZnPA. Moreover, our previously reported assembly (ZnP-A1) as reference, the assembly device ZnP-ZnPA had better η (2.24%) and FF (72.7%).

Two self-assembled supramolecular solar cells sensitized via axial coordination with zinc porphyrin

Abstract In this work, two new self-assemblies based on zinc porphyrins substituted at the meso-positions with different donor units (denoted as ZnP1 and ZnP2) and anchor porphyrin (ZnPA) dyads formed by the coordination bonds of Zn-to-ligand have been prepared. Further, the assemblies were absorbed on semiconducting TiO2 electrode surfaces by the carboxylic groups of anchor porphyrin (ZnPA), and their photovoltaic performances in solar cells were performed under 100 mW cm−2 AM 1.5G sunlight. Photoelectrochemical studies reveal a significantly improved photovoltaic behavior for the dyad of triphenylamine-based zinc porphyrin (ZnP1) compared to the dyad with trimethylamine-based zinc porphyrin. The results were verified by electrochemical impedance spectroscopy, calculations, and optical performance. In addition, the modes of the assemblies immobilized on TiO2 electrode surfaces were also verified by transmission electron microscopy.

Two Zn(II) coordination polymers constructed by a new tricarboxylate and different N-containing ligands: synthesis, crystal structures, and selective luminescence sensing for Fe3+ in aqueous solution

Abstract Two Zn(II) coordination polymers, {[Zn3(L)2(bipy)2(H2O)4}n (1) and {[Zn(HL)(4,4′-bibp)}n (2), were obtained from Zn(II) nitrate, a tricarboxylate ligand (H3L) and different N-containing ligands with hydrothermal conditions, where H3L = 4-((6-carboxynaphthalen-2-yl)oxy)phthalic acid, bipy = 4,4′-bipyridine, and 4,4′-bibp = 4,4′-di(1H-imidazol-1-yl)-1,1′-biphenyl. Single-crystal X-ray analysis reveals that 1 has a 2-D layer framework formed by L3− and bipy and 2 has an infinite 1-D structure with Zn2 units built by 4,4′-bibp ligands. The phase purity, IR spectra, thermal stabilities, and fluorescence properties in the solid state of 1 and 2 were investigated. Moreover, 1 and 2 were chosen as fluorescent probes to sense different metal ions, showing selective response to Fe3+ ion through luminescence quenching. The possible sensing mechanism to Fe3+ ion is also discussed.

Bilayer structured supramolecular light harvesting arrays based on zinc porphyrin coordination polymers for enhanced photocurrent generation in dye sensitized solar cells.

An acylhydrazone zinc porphyrin P1 and its coordination polymers (CPs, denoted as P1M, M = Mn, Co, Ni, Cu, Zn) with different metal ions (Mn2+, Co2+, Ni2+, Cu2+ and Zn2+) were synthesized. Then these coordination polymers were assembled into bilayer structured supramolecular chromophores through axially coordinating with anchoring porphyrin AP, and their performance in dye sensitized solar cells was investigated. Our results reveal that the bilayer structured supramolecular chromophore based solar cells show significantly improved photocurrent conversion efficiency. Particularly, P1Mn and P1Zn based solar cells showed a relatively higher short circuit current density (JSC) due to their broad absorption bands and remarkable light harvesting abilities. Meanwhile, the VOC values of the cells fabricated with the bilayered chromophores slightly decreased. Electrochemical impedance spectroscopy (EIS) in combination with charge extraction (CE) and transient photovoltage decay (TPD) measurements indicates that the decreased VOC resulted from the vigorous electron recombination and the downward shifted conduction band edge (ECB) of titania.

Pb(II) and Bi(III) complexes involving a Schiff base ligand: syntheses, structures, physical, and antioxidant properties

Two new complexes, {[PbL(NO3)2H2O]H2O}n (1) and [BiL2(NO3)2]NO3 (2), based on (E)-3-chloro-6-[2-(pyrazin-2-ylmethylene)hydrazinyl]pyridazine (L) were synthesized and characterized by IR spectra, single-crystal X-ray diffraction, and elemental analyzes. X-ray single crystal diffraction experiments of 1 and 2 display that extensive hydrogen bonds and π…π stacking interactions construct the 1-D infinite chain {[PbL(NO3)2H2O]H2O}n and [BiL2(NO3)2]NO3 into two 3-D supramolecular frameworks. Interestingly, pure phase PbO nano-particles were synthesized by thermolysis of 1 and characterized by scanning electron microscopy and X-ray powder diffraction analyzes. Furthermore, antioxidant activities of L, 1, and 2 were also studied.

New self-assemblies with zinc meso-tetra[3-(1H-imidazol-1-yl)phenyl] porphyrin for use in supramolecular solar cells

In this work, a new zinc meso-tetra[3-(1H-imidazol-1-yl)phenyl]porphyrin (ZnP) was synthesized. Further, the porphyrin ZnP was immobilized by metal-ligand axial coordination (ZnP-A) and a metal-ligand edged binding approach (ZnP-Zn-A) on the nanostructured TiO2 electrode surface modified with coordinating ligand functionality, isonicotinic acid (A). The performances of the assemblies-sensitized solar cells were performed under irradiance of 100 mW cm−2 AM 1.5G sunlight. Photo-electrochemical studies reveal significantly improved performance of the assembly ZnP-A. These assemblies can afford a fertile base for further design and fabrication of new supramolecular solar cells in future.

Syntheses, Crystal Structures, and Photoluminescent Properties of Zn(II) and Ag(I) Coordination Polymers Based on 1H-1,2,4-triazole-1-methylene-1H-benzimidazole

The title ligand, 1H-1,2,4-triazole-1-methylene-1H-benzimida- zole (L), and its two new derivatives, [ZnL2Cl2]n (1) and [AgL(NO3)]n (2), were synthesized and characterized by X-ray single diffraction, IR and elemental analysis. Owing to the greater distribution of the electron density associated with the benzimidazoyl and triazoyl units of L, the supramolecular frameworks of L, 1, and 2 are dominated by hydrogen bonding or π…π interactions in the solid state. In additional, the photoluminescent properties of L, 1, and 2 were also described.

Two novel self-assemblies of supramolecular solar cells using N-heterocyclic-anchoring porphyrins

Two novel N-substituted anchoring porphyrins (ZnPAtz and ZnPAim) have been devised and synthesized. Moreover, these two anchoring porphyrins were linked to the TiO2 semiconductor through carboxyl groups and then a zinc porphyrin ZnP was bound to the anchoring porphyrin using a zinc-to-ligand axial coordination approach. The different performances of these assemblies were compared with single anchoring porphyrin devices ZnPAtz and ZnPAim. The photoelectric conversion efficiency of the new supramolecular solar cells sensitized by ZnP-ZnPAx (x=tz, im) has been improved. The ZnP-ZnPAtz-based DSSCs provided the highest photovoltaic efficiency (1.86%). Fundamental studies showed that incorporation of these assemblies promote light-harvesting efficiency.

Synthesis, Crystal Structure, and Antibacterial and Antioxidant Properties of a New Ag(I) Coordination Polymer Based on 3-Chloro-6-(1H-1,2,4-triazol-1-yl) Pyridazine

A new Ag(I) complex [AgL2(NO3)] (1) (L = 3-chloro-6-(1H-1,2,4-triazol-1-yl) pyridazine) was synthesized and characterized by IR spectra and X-ray single-crystal diffraction. The structure reveals that each nitrate ion adopts not only bidentate chelating coordination, but also the bridging mode to connect surrounding Ag(I) atoms. Each ligand L binds three Ag(I) ions and each Ag(I) ion links three L to form a 1D chain structure. All 1D chains further construct a 3D supramolecular framework by hydrogen bonds (C-H…O) and π…π interactions (offset stacking) in the solid state. The antibacterial activity and antioxidant activity of L and 1 were also studied.