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New bipyridine derivatives were synthesized using 2-oxo-4-(pyridin-3-yl)-6-(thiophen-2- yl)-1,2-dihydropyridine-3-carbonitrile 1a. Terpyridine derivatives were synthesized using 2-oxo-4- (pyridin-3-yl)-6-(pyridin-4-yl)-1,2-dihydropyridine-3-carbonitrile 1b as the starting material. Alkylation of compounds 1a, b gave the alkyl derivatives 2a, b which converted into acetohydrazides 3a,b. Treating the acetohydrazides with ethyl cyanoacetate obtained 2'-[2-(3,5-dioxopyrazolidin-1-yl)-2-oxoethoxy]-6'- (thiophen-2-yl)-3,4'-bipyridine-3'-carbonitrile 4a and 6'-[2-(3,5-dioxopyrazolidin-1-yl)-2-oxoethoxy]- (3,4':2',4''-terpyridine)-5'-carbonitrile 4b. While treatment of 3a, b with ethyl benzoylacetate obtained the carbonitrile derivatives 2'-(2-oxo-2-(5-oxo-3-phenyl-4,5-dihydropyrazol-1-yl)ethoxy)-6'-(thiophen-2- yl)-3,4'-bipyridine-3'-carbonitrile 5a and 6'-[2-oxo-2-(5-oxo-3-phenyl-4,5-dihydropyrazol-1-yl)ethoxy]- (3,4':2',4''-terpyridine)-5' carbonitrile 5b. Treating compounds 3a, b with two aromatic aldehydes (3,4-dihydroxy benzaldehyde, 4-chlorobenzaldehyde) obtained Schiff bases 6a-d. Finally, the treatment of 3a, b with p-toluenesulfonyl chloride (Tosyl chloride) obtained the corresponding benzene sulfonohydrazide 7a, b. IR, 1HNMR, 13CNMR, MS, and elemental analysis confirmed the of the synthesized compounds. The anticancer activity of the compounds was investigated against breast cancer MCF-7 cell line. Compound 6b demonstrated the strongest cytotoxic activity among the tested compounds and was more active than the reference drug 5-fluorouracil (5-FU). Thus, it was subjected to further investigations, where its effect on the cell cycle distribution in the MCF-7 cell line, its ability to inhibit topoisomerase II, the level of caspase-3/7 green flow cytometry assay was investigated. Also, molecular operating environmental docking (MOE) was studied and found that the inhibition efficiency could be organized as follows (S, Kcal/mol) values: 5b > 6d > 3a > 3b > 6b; while compound 5a did not show any interaction data belonging to the shaped complex with 1cca. Hence, most of the synthesized compounds can be used as anticancer and anti-oxidant agents. [ABSTRACT FROM AUTHOR]

Bipyridine and related compounds are starting materials or precursors for a variety of valuable substances such as biologically active molecules, ligands for catalysts, photosensitizers, viologens, and supramolecular architectures. Thus, it is important to classify their synthesis methods and understand their characteristics. Representative examples include methods using homo and heterocoupling of pyridine derivatives in the presence of a catalyst. Because bipyridine compounds strongly coordinate with metal centers, a decrease in catalytic activity and yield is often observed in the reaction system. To address this issue, this review provides insights into advances over the last ~30 years in bipyridine synthesis using metal complexes under both homogeneous and heterogeneous conditions. Moreover, strategies for bipyridine synthesis involving sulfur and phosphorous compounds are examined. These alternative pathways offer promising avenues for overcoming the challenges associated with traditional catalysis methods, providing a more comprehensive understanding of the synthesis landscape. [ABSTRACT FROM AUTHOR]

Supramolecular self-assembly is an important strategy in nanotechnology and surface science, which has attracted extensive attention in the past decades. In this field, how to obtain more diverse two-dimensional structures and make them more stable has always been a huge challenge. Scanning Tunneling Microscopy (STM), with atomic resolution, is a unique technique for exploring supramolecular self-assembly. In this review, we present the latest progress in the development of two-dimensional (2D) nanostructures using bipyridine derivatives as ligands in our laboratory. Our focus is mainly on: (1) supramolecular coordination on the HOPG surfaces; (2) synergistic interactions of H-bonding; and (3) regulation of aromatic acid derivatives. It is worth noting that the addition of bipyridine provides a new idea and method for the construction of diverse two-dimensional self-assembly structures. [ABSTRACT FROM AUTHOR]

• Heterogenization of ru through polydopamine and bipyridine on carbon black. • Functionalized carbon Ru-catalysts active in the oxidative cleavage of oleic acid. • Total conversion and 95% of yields after 7 h of stirring at room temperature. • High catalytic activity of carbon black-polydopamine-Ru up to 5 recycling tests. Macroporous oxidized carbon black (CBO) have been functionalized with 4,4′-diamino-2,2′-bipyridine (NH 2 -bpy) and polydopamine (PDA) allowing the complexation of Ru for the catalytic valorization of oleic acid through its oxidative cleavage. This reaction produces azelaic and pelargonic acids which are highly demanded in pharmacology. Conventional bpy is a well-known chelating agent for Ru and the aim of this work is directed to assess its suitability along with polydopamine in building a stable catalyst in the oxidative cleavage reaction. NH 2 -bpy was covalently bonded to COOH groups on CBO surface by amidation through an acylation and cross-linking(NHS/EDC). On its side, dopamine was self-polymerized in contact with CBO. The success of the deposition of NH 2 -bpy and PDA was confirmed by FTIR, TGA, and N 2 physisorption, while Ru complexation was determined by ICP and XPS analyses. Among the three catalysts, the catalyst based on PDA was the most promising one, reaching a complete conversion of oleic acid with yields of pelargonic and azelaic acids around 95%. Although hot-filtration tests confirmed the presence of Ru species in the reaction medium, the PDA catalyst remained active even after five runs. Actually, post-catalysis characterization of the solid revealed that catechol groups of PDA re-adsorb Ru species once the reaction ends thereby ensuring the reusability of the heterogeneous catalyst. [Display omitted] [ABSTRACT FROM AUTHOR]

Six series of novel 4-(2-fluorophenoxy)-3,3′-bipyridine derivatives conjugated with aza-aryl formamide/amine scaffords were designed and synthesized through a structure-based molecular hybridization approach. The target compounds were evaluated for c-Met kinase inhibitory activities and cytotoxicity against four cancer cell lines (HT-29, A549, MKN-45 and MDA-MB-231) in vitro . Most compounds exhibited moderate to excellent potency, and the most promising candidate 26c (c-Met kinase IC 50 = 8.2 nM) showed a 4.7-fold increase in cytotoxicity against c-Met-addicted MKN-45 cell line in vitro (IC 50 = 3 nM), superior to that of Foretinib (IC 50 = 23 nM). The preliminary structure–activity relationship indicated that a 1 H -benzo [e] [1,3,4]thiadiazine-3-carboxamide-4,4-dioxide moiety as linker contributed to the antitumor potency. [ABSTRACT FROM AUTHOR]

The regioselective polymerizations of isoprene and 3-methyl-pentadiene catalyzed by a cationic iron (II) complex bearing bipyridine ligand have been computationally studied. Having achieved an agreement between calculation and experiment, it is found that the open-shell unpaired 3d-electrons localize on Fe center rather than partially distribute on the redox-active bipyridine ligand. The steric effect plays a more important role in controlling the regioselectivity in comparison with electronic factors. The deformation energy is mainly contributed by monomer and Fe-alkyl moieties rather than the bipyridine ligands themselves, although noncyclopentadienyl ancillary ligands are often deformed in most insertion transition states for selective polymerization of olefin. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

A new tetrapyridine ligand, 5,5′-(3-pyridyl)-2,2′-bipyridine (2) was prepared from 5,5′-dibromo-2,2′-bipyridine (1) via Pd(0)-mediated Suzuki coupling. The reaction was performed either directly upon the free ligand, or upon its Ru(II) complex. The structures of [Ru(1)3](PF6)2and [Ru(2)3](PF6)2were studied in solution by NMR, and in the solid state by single crystal X-ray diffraction. Solution NMR data suggests distorted structures, consistent with the observed slow reactivity of the ligands towards Ru(II) ions, and their reluctance to coordinate to Fe(II) ions. However, solid-state X-ray data indicated little distortion from ideal geometries, suggesting the effect may be more electronic than steric in nature. [ABSTRACT FROM AUTHOR]

Novel acrylate copolymer with carbazole pendant groups and derivatives of bipyridine as side chains were synthesized, in which derivatives of bipyridine as electro-optic chromophores and carbazolyl as photoconductive moiety were covalently linked to the acrylate backbone. 2-(9-Carbazolyl)ethyl methacrylate (CEM) and 2-methylacrylic acid 2-{4,4'-dimethyl-5'-[2-(5-methyl-thiophen-2-yl)-vinyl]- [2,2']bipyridinyl-5-yl}-ethyl ester (BiPy) were synthesized and then copolymerized to give (99:1), (98:2), and (92:8 mol/mol) CEM/BiPy copolymers. Solutions of the copolymers in dioxane were examined for their photoluminescence properties. [ABSTRACT FROM AUTHOR]

A new bipyridyl derivative 1 bearing rhodamine B as visible fluorophore was designed, synthesized and characterized as a fluorescent and colorimetric sensor for metal ions. Interaction with Cu2+, Zn2+, Cd2+, Hg+, and Hg2+ ions was followed by UV/Vis and emission spectroscopy. Upon addition of these metal ions, different colorimetric and fluorescent responses were observed. 'Off-on-off' (Cu2+, Zn2+, and Hg2+) and 'off-on' (Hg+ and Cd2+) systems were obtained. Probe 1 was explored to mimic XOR and OR logic operations for the simultaneous detection of Hg+-Cu2+ and Hg+-Zn2+ pairs, respectively. DFT calculations were also performed to gain insight into the lowest-energy gas-phase conformation of free receptor 1 as well as the atomistic details of the coordination modes of the various metal ions. [ABSTRACT FROM AUTHOR]

Abstract: Thorocene [Th(Cot)2] (Cot=η8-C8H8) readily reacts with 2,2′-bipyridine to give [Th(Cot)2(κ2-bipy)], which has an unusual bent geometry. This compound is rapidly reduced by KC8 into the anionic derivative [(Th(Cot)2(κ2-bipy)]−. X-ray diffraction studies suggest the latter to be a Th(IV) compound with the bipyridyl radical anion. These complexes are rare examples of bent actinocene [An(Cot)2(L)] q− (q =0, 1; An=actinide) and bipyridine-containing thorium species. [Copyright &y& Elsevier]

Abstract: Three classes of fused bipyridine heterocycles were designed, synthesized and evaluated for their antimycobacterial activities. The method for preparation of fused bipyridine derivatives is straight and efficient. The primary antimycobacterial screening reveals that mono-indolizine mono-salts are displaying potency superior to the second-line antitubercular drugs Cycloserine and Pyrimethamine and, equal as the first line anti-TB Ethambutol. The data from Cycle-2 screening assay (MIC, MBC, LORA, intracellular (macrophage) drug screening, and MTT cell proliferation) confirm the promising anti-TB results from Cycle-1 for mono-indolizine mono-salts. These data indicate that mono-indolizine mono-salt 6d is a potent compound against both replicating and non-replicating Mycobacterium tuberculosis, is active against both extracellular and intracellular organisms, has a bacteriostatic mechanism of action and has basically no toxicity. We see no influence concerning the anti-TB activity of the fused-pyridine substituents. [Copyright &y& Elsevier]

Metal-ligand axial coordination of zinc(II) phthalocyanines is an efficient strategy for regulation of structures and properties. In this work, we designed and prepared four unsubstituted zinc(II) phthalocyanine (ZnPc) dimer-based supramolecular complexes (1 – 4) via axtial coordination with bipyridine derivatives. Single crystal X-ray analysis revealed that the four novel complexes were dimeric (i.e. ZnPc-ligand-ZnPc), with H-shape for 1 , saddle-like for 2 , and Z-shapes for 3 and 4. It's interesting that a pair of saddle-like dimers of 2 crossed each other to form an interlocked tetramer structure. Furthermore, 3 and 4 were dense stacking because of their semirigid ligands, which significantly enhanced the intermolecular interactions. Intriguingly, in the crystal structure of 4 , the naphthalimide ring of the ligand embedded into two neighboring phthalocyanine macrocycles, resulting in a slipped sandwich structure of ZnPc-naphthalimide-ZnPc with double π···π interactions. More importantly, the strong intermolecular interactions led to very broad absorption spectra in vis-NIR region, quenched fluorescence, and highly efficient photothermal effect. Upon irradiation, 3 and 4 could reach up to 85.7 °C and 89.2 °C, respectively, enabling them to serve as outstanding photothermal conversion materials used for photothermal imaging and therapy. [Display omitted] • ZnPc coordinated with bipyridine derivatives to form four crystal complexes 1 – 4. • Two saddle-like dimers of 2 crossed each other to generate an interlocked tetramer. • The crystal of 4 showed a slipped sandwich structure of ZnPc-naphthalimide-ZnPc. • Stronger molecular interactions of 3 and 4 led to highly efficient photothermal activity. • The photothermal temperature of 3 and 4 reached 85.7 °C and 89.2 °C, respectively. [ABSTRACT FROM AUTHOR]

Nucleophilic substitutions involving [Ru(η2-bipy)2(η2-bipy–Cl2)]2+2PF6 − (bipy=2,2′-bipyridine; bipy–Cl2=4,4′-dichloro-2,2′-bipyridine) and NaSH or LiS(p-tol) (p-tol=4-CH3–C6H4), carried out in tetrahydrofuran at 115 °C, lead to [Ru(η2-bipy)2(η2-bipy–(SH)2)]2+2PF6 − or [Ru(η2-bipy)2{η2-bipy–(S(p-tol))2}]2+2PF6 −, respectively. Treatment of [Ru(η2-bipy)2(η2-bipy–Cl2)]2+2PF6 − with NaCN in methanol at 55 °C leads to [Ru(η2-bipy)2{η2-bipy–(OCH3)2}]2+2PF6 −. The complexes [Ru(η2-bipy)2(η2-bipy–X2)]2+2PF6 −, with X=Cl and OCH3, were structurally characterized by single crystal X-ray diffraction. Some spectroscopic features of the products are presented. [Copyright &y& Elsevier]