28020-73-7Relevant articles and documents
Synthesis and crystal structure of a 3-D netlike supramolecular cobalt picrate complex with 2, 6-bis(benzimidazol-2-yl)pyridine
Yan, Zhen-Zhong,Hou, Na,Liang, Hua-Ding
, p. 344 - 347 (2014)
A novel complex of cobalt picrate with 2, 6-bis(benzimidazol-2-yl)pyridine (L), has been prepared and characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. The complex crystallizes in the monoclinic system, space group c2/c with a = 21.8756(6) A, b = 12.2995(3) A, c = 27.4827(7) A, β = 95.6060(10)°, and Z = 4. The structure was refined to the final R1 = 0.0708. The complex units are linked by π-π interactions and hydrogen bonds to give infinite two-dimensional (2-D) supramolecular layers, which are further linked by the intermolecular hydrogen bonds to form a three-dimensional (3-D) netlike supramolecule. Copyright Taylor & Francis Group, LLC.
Synthesis, characterization and antimicrobial activity of Fe(II), Zn(II), Cd(II) and Hg(II) complexes with 2,6-bis(benzimidazol-2-yl) pyridine ligand
Aghatabay, Naz M.,Neshat,Karabiyik,Somer,Haciu,Duelger
, p. 205 - 213 (2007)
2,6-Bis(benzimidazol-2-yl)pyridine (L) ligand and complexes [M(L)Cl2] and [Fe(L)2](ClO4)2 (M = Zn, Cd, Hg) have been synthesized. The geometries of the [M(L)Cl2] complexes were derived from theoretical calculation in DGauss/DFT level (DZVP basis set) on CACHE. The central M(II) ion is penta-coordinated and surrounded by N3Cl2 environment, adopting a distorted trigonal bipyramidal geometry. The ligand is tridentate, via three nitrogen atoms to metal centre and two chloride ions lie on each side of the distorted benzimidazole ring. In the [Fe(L)2](ClO4)2 complex, the central Fe(II) ion is surrounded by two (3N) units, adopting a octahedral geometry. The elemental analysis, molecular conductivity, FT-Raman, FT-IR (mid-, far-IR), 1H, and 13C NMR were reported. The antimicrobial activities of the free ligand, its hydrochloride salt, and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide (DMSO) as well as the minimal inhibitory concentration (MIC) dilution method, against 10 bacteria and the results compared with that for gentamycin. Antifungal activities were reported for Candida albicans, Kluyveromyces fragilis, Rhodotorula rubra, Debaryomyces hansenii, Hanseniaspora guilliermondii, and the results were referenced against nystatin, ketaconazole, and clotrimazole antifungal agents. In most cases, the compounds tested showed broad-spectrum (Gram positive and Gram negative bacteria) activities that were either more effective than or as potent as the references. The binding of two most biologically effective compounds of zinc and mercury to calf thymus DNA has also been investigated by absorption spectra.
Probing the Effects of Ligand Field and Coordination Geometry on Magnetic Anisotropy of Pentacoordinate Cobalt(II) Single-Ion Magnets
Mondal, Amit Kumar,Goswami, Tamal,Misra, Anirban,Konar, Sanjit
, p. 6870 - 6878 (2017)
In this work, the effects of ligand field strength as well as the metal coordination geometry on magnetic anisotropy of pentacoordinated CoII complexes have been investigated using a combined experimental and theoretical approach. For that, a strategic design and synthesis of three pentacoordinate CoII complexes [Co(bbp)Cl2]·(MeOH) (1), [Co(bbp)Br2]·(MeOH) (2), and [Co(bbp)(NCS)2] (3) has been achieved by using the tridentate coordination environment of the ligand in conjunction with the accommodating terminal ligands (i.e., chloride, bromide, and thiocyanate). Detailed magnetic studies disclose the occurrence of slow magnetic relaxation behavior of CoII centers with an easy-plane magnetic anisotropy. A quantitative estimation of ZFS parameters has been successfully performed by density functional theory (DFT) calculations. Both the sign and magnitude of ZFS parameters are prophesied well by this DFT method. The theoretical results also reveal that the α → β (SOMO-SOMO) excitation contributes almost entirely to the total ZFS values for all complexes. It is worth noting that the excitation pertaining to the most positive contribution to the ZFS parameter is the dxy → dx2-y2 excitation for complexes 1 and 2, whereas for complex 3 it is the dz2 → dx2-y2 excitation.
Stimuli-Responsive Cycloaurated “OFF-ON” Switchable Anion Transporters
Fares, Mohamed,Gale, Philip A.,Howe, Ethan N. W.,Keller, Paul A.,Lewis, William,Pérez-Tomás, Ricardo,Ramesh, Deepthi,Wu, Xin
, p. 17614 - 17621 (2020)
Anion transporters have shown potential application as anti-cancer agents that function by disrupting homeostasis and triggering cell death. In this research article we report switchable anion transport by gold complexes of anion transporters that are “switched on” in situ in the presence of the reducing agent GSH by decomplexation of gold. GSH is found in higher concentrations in tumors than in healthy tissue and hence this approach offers a strategy to target these systems to tumors.
Rational design of ruthenium complexes containing 2,6-bis(benzimidazolyl)pyridine derivatives with radiosensitization activity by enhancing p53 activation
Deng, Zhiqin,Yu, Lianling,Cao, Wenqiang,Zheng, Wenjie,Chen, Tianfeng
, p. 991 - 998 (2015)
Abstract The rational design of metal-based complexes is an effective strategy for the discovery of potent sensitizers for use in cancer radiotherapy. In this study, we synthesized three ruthenium complexes containing bis-benzimidazole derivatives: Ru(bbp)Cl3 (1), [Ru(bbp)2]Cl2 (2 a) (in which bbp=2,6-bis(benzimidazol-1-yl)pyridine), and [Ru(bnbp)2]Cl2 (2 b) (where bnbp=2,6-bis-(6-nitrobenzimidazol-2-yl)pyridine). We evaluated their radiosensitization capacities in vitro and mechanisms of action. Complex 2 b was found to be particularly effective in sensitizing human melanoma A375 cells toward radiation, with a sensitivity enhancement ratio of 2.4. Along with this potency, complex 2 b exhibited a high degree of selectivity between human cancer and normal cells. Mechanistic studies revealed that 2 b promotes radiation-induced accumulation of intracellular reactive oxygen species (ROS) by reacting with cellular glutathione (GSH) and then causing DNA stand breaks. The subsequent DNA damage induces phosphorylation of p53 (p-p53) and upregulates the expression levels of p21, which inhibits the expression of cyclin-B, leading to G2M arrest. Moreover, p-p53 activates caspases-3 and -8, triggers cleavage of poly(ADP-ribose) polymerase (PARP), finally resulting in apoptosis. Taken together, the results of this study provide a strategy for the design of ruthenium-based radiosensitizers for use in cancer therapy.
A simple 2,6-bis(2-benzimidazole)pyridyl incorporated optical probe affording selective ratiometric targeting of biologically and environmentally significant Zn2+ under buffer condition
Mashraqui, Sabir H.,Chandiramani, Mukesh,Ghorpade, Sushil,Upathayay, Jyoti,Mestri, Rupesh,Chilekar, Aniket
, p. 129 - 135 (2016)
A new chemosensor, designated as Dibcid has been synthesized in two steps from readily accessible 2,6-bis(2-benzimidazole)pyridine. Our photophysical studies revealed that of the several metal ions examined, biologically and environmentally significant Zn2+ exhibited highly selective emission wavelength shifts under the buffer condition. In contrast to Zn2+, the coordinatively competing and toxic Cd2+ elicited less remarkable optical responses as evidenced by its two order of magnitude lower stability constant compared to that of Zn2+. Moreover, metal ions, viz. Li+, Na+, K+, Mg2+, Ca2+, Ba2+, Co2+, Ni2+, Cu2+, Hg2+ and Pb2+ exhibited insignificant optical perturbations even in concentrations far exceeding Zn2+. Clearly, the probe has the attributes to selectively target Zn2+ by ratiometric analysis under buffer conditions.
Toward equatorial planarity about uranyl: Synthesis and structure of tridentate nitrogen-donor {UO2}2+ complexes
Copping, Roy,Jeon, Byoungseon,Pemmaraju, C. Das,Wang, Shuao,Teat, Simon J.,Janousch, Markus,Tyliszczak, Tolek,Canning, Andrew,Gronbech-Jensen, Niels,Prendergast, David,Shuh, David K.
, p. 2506 - 2515 (2014)
The reaction of UO2Cl2·3THF with the tridentate nitrogen donor ligand 2,6-bis(2-benzimidazolyl)pyridine (H 2BBP) in pyridine leads to the formation of three different complexes: [(UO2)(H2BBP)Cl2] (1), [(UO) 2(HBBP)(Py)Cl] (2), and [(UO2)(BBP)(Py)2] (3) after successive deprotonation of H2BBP with a strong base. Crystallographic determination of 1-3 reveals that increased charge through ligand deprotonation and displacement of chloride leads to equatorial planarity about uranyl as well as a more compact overall coordination geometry. Near-Edge X-ray Absorption Fine Structure (NEXAFS) spectra of 1-3 at the U-4d edges have been recorded using a soft X-ray Scanning Transmission X-ray Microscope (STXM) and reveal the uranium 4d5/2 and 4d3/2 transitions at energies associated with uranium in the hexavalent oxidation state. First-principles Density Functional Theory (DFT) electronic structure calculations for the complexes have been performed to determine and validate the coordination characteristics, which correspond well to the experimental results.
Low spin Fe(II) complexes formed of monosubstitued 2,6-bis(2-benzimidazolyl)pyridine ligands
Rajnák, Cyril,Titi?, Ján,Fuhr, Olaf,Ruben, Mario,Bo?a, Roman
, p. 122 - 131 (2017)
Five ligands as monosubstituted derivatives of the basic skeleton of 2,6-bis(2-benzimidazyl)pyridine were synthesized, and characterized by NMR and IR spectra along with the X-ray structure analysis. Their complexation gave a set of hexacoordinate Fe(II) complexes showing predominantly the diamagnetism until ambient temperature. Some temperature-independent paramagnetism along with an onset of the spin transition is also detected.
Synthesis, structure, and supramolecular chemistry of three azide manganese complexes with 2, 6-Bis(benzimidazol-2-yl)pyridine
Wang, Chuan-Feng,Dai, Guo-Liang,Jin, Zheng-Neng,He, Zhi-Cai
, p. 1340 - 1344 (2012)
Three azide complexes with the tridentate ligand 2, 6-bis(benzimidazol-2- yl)pyridine (H2BBIP) were synthesized and their complicated supramolecular interactions were investigated with single-crystal X-ray diffraction. Interestingly, the complexes are assembled by bifurcated hydrogen bonding, double helical π-π stacking, or anion-π stacking interactions of the benzimidazole rings by tuning the reaction conditions (temperature, ratio, solvent). Complex 1 is a mononuclear compound, namely, Mn(H 2BBIP)N3(CH3O)·CH3OH. In its 3D supramolecular network, the nitrogen atom of the azide anion is acting as hydrogen bonding bifurcated acceptor. Complex 2 is a dinuclear compound, namely, Mn2(H2BBIP)2(N3) 2·(H2O)0.5. The dinuclear unit is connected by intramolecular π-π stacking interactions. Furthermore, double helical π-π stacking interactions in the benzimidazole rings are observed. Complex 3, Mn2(H2BBIP)2(N 3)2·CH3OH, can be formulated as a pseudopolymorph of complex 2, which exhibits intramolecular π-π stacking interactions as well as anion-π interactions in the dinuclear unit. Copyright
Concise design and synthesis of water-soluble fluorescence sensor for sequential detection of Zn(II) and picric acid via cascade mechanism
Jiang, Kai,Chen, Si-Hong,Luo, Shi-He,Pang, Chu-Ming,Wu, Xin-Yan,Wang, Zhao-Yang
, p. 164 - 173 (2019)
Under microwave assistance, 2,6-bis(benzimidazolyl)-pyridine has been concisely synthesized and further productively converted to the functional molecule BMBP via accessible N-alkylation reaction. For the introduction of alkoxyalkyl chain, this original substance BMBP with better solubility in water exhibits specific fluorescence response toward Zn2+ from colourless to blue in aqueous solution. A sequential detection for picric acid (PA) can be conducted in this following system, showing the high selectivity and sensitivity of quenching over other analogues. On the basis of the comparison with the control BMBB, a cascade sensing mechanism has been disclosed to accelerate the recognition of structure-property relationship, which is fully supported by LC-MS, 1H NMR, lifetime measurement and theoretical calculation. Noteworthily, BMBP is also readily available for practical application not only in quantitative determination of Zn2+ and PA in real water samples, but also in visible detection of two analytes in multiple forms on paper test strips, offering convenient process for low-cost, portable and versatile sensing device.
