Binuclear cluster complexes of molybdenum containing 2,2′-bipyridine and 1,10-phenanthroline: Synthesis and structure

By the interaction between (Et₄N)₂[Mo₂O₂S₈] and I₂ in DMF with a subsequent addition of 2,2′-bipyridine or 1,10-phenanthroline, new binuclear complexes [Mo₂O₂S₂I₂(bipy)₂] (1) and [Mo₂O₂S₂I₂(phen)₂] (2) are obtained. The structure of [Mo₂O₂S₂I₂(bipy)₂] is determined using single crystal X-ray diffraction. The compounds are characterized by elemental analysis and IR spectra. The [MoO(S₂)₂(bipy)] complex as a product of oxidative destruction of 1 is isolated and characterized.     

Dioxochromium(V) complexes with 1,10-phenanthroline and 2,2′-bipyridine ligands

cis-[Cr^III(phen)₂(H₂O)₂]³⁺ and cis-[Cr^III(bipy)₂(H₂O)₂]³⁺ (phen = 1,10-phenanthroline and bipy = 2,2-bipyridine) were readily oxidized by either PbO₂ or PhIO to form the chromium(V) complexes [Cr^V(phen)₂(O)₂]⁺ and [Cr^V(bipy)₂(O)₂]⁺ respectively, which were characterized by elemental analysis, i.r. and e.s.r. spectroscopy.     

PbII 4,4,4-trifluoro-1-naphthyl-1,3-butanedione complexes of 1,10-phenanthroline and 2,2′-bipyridine ligands

Lead(II) 4,4,4-trifluoro-1-naphthyl-1,3-butanedione (Htfnb) complexes of 1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy), [Pb₂(bpy)₂(tfnb)₂] (1) and [Pb₂(phen)₂(tfnb)₂] (2), have been synthesized and characterized by elemental analysis, IR, spectroscopy and X-ray crystallography. The self-assembly of 1 and 2 is likely to be caused by C–H ··· F–C, C–H ··· O and π–π stacking interactions.     

The electron-donating properties of 2,2′-bipyridine. Charge-transfer studies

Molecular charge-transfer complexes of 2,2′-bipyridine with iodine and tetracyanoethylene have been investigated. The formation constants of these complexes were determined at different temperatures and the thermodynamic functions, ΔH_f and ΔS_f were calculated. The spectra and stability of the complexes were discussed and interpreted.     

2,2′-Dipyridyl and 1,10-phenanthroline in the synergetic extraction of Eu3+

The thermodynamics of the extraction of Eu³⁺ by thenoyltrifluoroacetone (HTTA) and by mixtures of HTTA and bidentate amine bases such as 2,2-dipyridyl (Dipy) and 1,10-phenanthroline (Phen) in benzene from an aqueous phase fixed to 0.1M ionic strength (NaClO₄), pH 3.9, has been investigated. Phenanthroline forms both the Eu(TTA)₃·Phen and Eu(TTA)₃·2Phen species, which are much stronger than the dipyridyl complexes. The diluent effect on the extraction is also studied.     

Role of cyanide as a bridging ligand in cis-aquocyanoCo(III) complexes containing 2,2′-bipyridine and 1,10-phenanthroline

Cis-aquocyanobis(2,2′-bipyridine)Co(III) and cis-aquocyanobis(1,10-phenanthroline)Co(III) cations present in their IR spectra as cyano-group band in a Nujol mull at ν = 2200 cm⁻¹. To justify the shift in the frequency from 2140 to 2200 cm⁻¹ of cyanide in these compounds, we have hypothesized that the cyano group is a bridge between the metal atom and one hydrogen atom of the water molecule in the cis position on the Co(III) coordination sphere.     

Revealing the structural chemistry of the group 12 halide coordination compounds with 2,2′-bipyridine and 1,10-phenanthroline

The coordination compounds of group 12 halides with 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen), 2[CdF₂(bpy)₂]·7H₂O (1), [ZnI(bpy)₂]⁺·I₃^? (2), [CdI₂(bpy)₂] (3), [Cd(SiF₆)H₂O(phen)₂]·[Cd(H₂O)₂(phen)₂]²⁺·F^–·0.5(SiF₆)^2–·9H₂O (4), [Hg(phen)₃]²⁺·(SiF₆)^2–·5H₂O (5), [ZnBr₂(phen)₂] (6), 6[Zn(phen)₃]²⁺·12Br^–·26H₂O (7) and [ZnI(phen)₂]⁺·I^– (8), have been synthesized and characterized by X-ray crystallography, IR spectroscopy, elemental and thermal analysis. Structural investigations revealed that metal?:?ligand stoichiometry in the inner coordination sphere is 1?:?2 or 1?:?3. A diversity of intra- and intermolecular interactions exists in structures of 1–8, including the rare halogen?halogen and halogen?π interactions. The thermal and spectroscopic properties were correlated with the molecular structures of 1–8. Structural review of all currently known coordination compounds of group 12 halides with bpy and phen is presented.     

Kinetics and mechanism of substitution of bis(tptz)iron(II) by 2,2′-bipyridine and 1,10-phenanthroline

The kinetics of substitution of Fe(tptz)²+₂ by 2,2-bipyridine and 1,10-phenanthroline have been investigated in acetate buffers in the 3.6–5.6pH range employing stopped-flow spectrophotometry. These reactions are very fast and complete within 5s. The rate of substitution is linearly dependent on [phen] and [bpy]², and increases with the increase in pH. Suitable mechanisms have been proposed involving the unprotonated form of the entering ligand, viz. bipyridine/phenanthroline as the reactive species. The pK_a values of bipyridine and phenanthroline, determined from the kinetic data, are in agreement with the literature values. It is concluded that the substitutions of iron(II)-diimine complexes also occur by an associative mechanism.     

Synthesis,characterization, and cytotoxicity of Pt(IV) complexes containing 1,10-phenanthroline and 2,2′-bipyridine and diaminocyclohexane ligands

Four platinum(IV) complexes containing intercalating ligands [1,10-phenanthroline (phen) and 2,2′-bipyridine (bpy)] and ancillary ligands [(1S,2S)-diaminocyclohexane (SS-DACH) and (1R,2R)-diaminocyclohexane (RR-DACH)] were synthesized and characterized by ¹H nuclear magnetic resonance, electrospray ionization mass spectrometry, X-ray crystal structure analysis, elemental analysis, ultraviolet absorption spectroscopy, circular dichroism spectroscopy, and electrochemical analysis. The reactions between [Pt(phen)(SS-DACH)Cl₂]²⁺ and glutathione and Ac-CPFC-NH₂ were investigated by high-performance liquid chromatography. [Pt(phen)(SS-DACH)Cl₂]²⁺ was reduced to its corresponding Pt(II) complex [Pt(phen)(SS-DACH)]²⁺, while glutathione and Ac-CPFC-NH₂ were oxidized to glutathione-disulfide and a peptide containing an intramolecular disulfide bond, respectively. The cytotoxicities of the Pt(IV) complexes against a human non-small cell lung cancer cell line (A549) and the corresponding cisplatin-resistant cell line (A549cisR) were evaluated. These Pt(IV) complexes showed a higher activity toward A549 and A549cisR than did cisplatin. Also, the cytotoxicities of the Pt(IV) complexes were higher for A549cisR than for A549 cells. Moreover, the cytotoxicities of the (SS-DACH)-liganded platinum complexes were higher than those of the (RR-DACH)-liganded platinum complexes in either A549 or A549cisR cells. Phen-liganded platinum complexes were more cytotoxic than the bpy-liganded platinum complexes. The cytotoxicities of these Pt(IV) complexes had no correlation with reduction potentials.     

Syntheses and structures of copper benzene-1,4-dioxydiacetate complexes with 4,4′-bipyridine and 1,10-phenanthroline

Two new copper complexes, [Cu₂(BDOA)(4,4′-bpy)₂] ? 2H₂O (1) and [Cu(BDOA)(phen)] (2) (H₂BDOA = benzene-1,4-dioxydiacetic acid; 4,4′-bpy = 4,4′-bipyridine; phen = 1,10-phenanthroline), were synthesized and characterized by IR, elemental analysis, and single-crystal X-ray diffraction. Complex 1 exhibits a 2-D three-connected network structure with 6³ topology. Complex 2 displays a 1-D chain structure. Furthermore, the 3-D supramolecular networks of 1 and 2 are constructed via rich hydrogen bonds. Thermal stability of 1 is discussed in this article.     

Cadmium(II) diallyldithiocarbamato complexes with 2,2′-bipyridine and 1,10-phenanthroline: spectroscopic and crystal structure analysis

Complexes of Cd(II) with diallyldithiocarbamato (hereafter denoted aldtc) and 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) are discussed. Derivatives of general formula [Cd(aldtc)₂(NN)] [NN = bipy, 1 and phen, 2] have been obtained by direct reaction between Cd(NO₃)₂ and a 2 : 1 molar ratio of aldtc and NN. The new complexes have been characterized by IR, ¹H, and ¹³C NMR spectroscopy. Their single crystal structures were also determined. Compounds 1 and 2 have severely distorted octahedral coordination around cadmium, defined by an N₂S₄ donor set. The structure of 1 is isomorphous with the recently reported zinc analogue. The crystal packing of 1 shows different non-classical intermolecular interactions represented in both hydrophilic (π)C–H ··· S and hydrophobic (allyl)C–H ··· C(π) intermolecular interactions. Such interactions result in a chain arrangement of molecules along the crystallographic c-axis. These chains are further connected via π ··· π stacking along with (π)C–H ··· S parallel to b leading to an overall crystal packing that can be regarded as layers of complexes along the bc plane. Molecules in the crystal structure of 2 are arranged into infinite chains, down the b-axis, that are connected by aryl ··· aryl stacking. The chains are further connected to each other in a and c directions via (allyl)C–H ··· S interactions.     

CdII 4,4,4-trifluoro-1-phenyl-1,3-butandione complexes of 1,10-phenanthroline and 4,4′-bipyridine

Cadmium(II) 4,4,4-trifluoro-1-phenyl-1,3-butandione (HTFPB) complexes of 1,10-phenanthroline (phen) and 4,4′-bipyridine (4,4′-bipy), Cd(L)(TFPB)₂, have been synthesized and characterized by elemental analysis, IR-, ¹H NMR spectroscopy and X-ray crystallography. The self-assembly of Cd(L)(TFPB)₂ complexes, (L?=?phen or 4,4′-bipy) is caused by C–H?···?F–C, and π–π stacking interactions.     

Investigations of ternary complexes of Co(II) and Ni(II) with oxydiacetate anion and 1,10-phenanthroline or 2,2′-bipyridine in solutions

Potentiometric (PT) and conductometric (CT) titration methods have been used to determine the stoichiometry and formation constants in water for a series of ternary complexes of Co(II) and Ni(II) involving the oxydiacetate anion (ODA) and 1,10-phenanthroline (phen) or 2,2′-bipyridine (bipy) ligands, namely [Co(ODA)(phen)(H₂O)], [Co(ODA)(bpy)(H₂O)], [Ni(ODA)(phen)(H₂O)] and [Ni(ODA)(bpy)(H₂O)]. The ternary complex formation process was found to take place in a stepwise manner in which the oxydiacetate ligand acts as a primary ligand and the phen or bipy ligands act as auxiliary ones. The stability of the ternary complexes formed is discussed in the relation to the corresponding binary ones. Furthermore, the kinetics of the substitution reactions of the aqua ligands in the coordination sphere of the Ni-ODA and Co-ODA complexes to phen or bipy were studied by the stopped-flow method. The kinetic measurements were performed in the 288–303 K temperature range, at a constant concentration of phen or bipy and at seven different concentrations of the binary complexes (4–7 mM). The influence of experimental conditions and the kind of the auxiliary ligands (phen/bipy) on the substitution rate was discussed.      

Di- and trinuclear Ru(II) complexes of 1,10-phenanthroline and 2,2′-bipyridine derivatives; synthesis,photophysical and electrochemical properties

Three heterotopic ligands L¹, L², and L³ based on 1,10-phenanthroline and 2,2′-bipyridine moieties have been synthesized and characterized. The Ru(II) complexes [{Ru(bpy)₂}₃(µ₃-L¹)](PF₆)₆, [{Ru(bpy)₂}₃(µ₃-L²)](PF₆)₆, and [{Ru(bpy)₂}₂(µ₂-L³)](PF₆)₄ (bpy = 2,2′-bipyridine) have been prepared by refluxing Ru(bpy)₂Cl₂·2H₂O with each ligand in ethanol. All three complexes display MLCT absorptions at around 455 nm and emissions at around 618 nm. Electrochemical studies of the complexes reveal one Ru(II)-centered quasi-reversible oxidation at around 1.32 V and three ligand-centered reductions in each case.     

A DFT study of transition metal complexes with 1,10-phenanthroline,C-C-dimeric 2,2′-bi-1,10-phenanthroline,and its tetraaza chromophore anion

Quantum-chemical calculations of the 1,10-phenanthroline complexes [M(en)(1,10-phen)]²⁺ (M = Pt, Pd, Ni; en = NH₂C₂H₄NH₂) were performed by the DFT B3LYP method in the 6-31G** basis set using the GAMESS-2006 program package. The calculations were also performed for the nickel complexes with 2,2′-bi-1,10-phenanthroline, [Ni(2,2′-bi-1,10-phen)]²⁺, and with its electron-excessive analog, [Ni(2,2′-bi-1,10-phen)]⁰, and also for the octahedral complex cation [Ni(2,2′-bi-1,10-phen)Cl(H₂O)]⁺ characterized by single crystal X-ray diffraction. For the Ni(II) complexes, the stabilities of their high-and low-spin isomers were evaluated, and the structural features were revealed. The barriers to mutual transformations of the low-and high-spin Ni(II) complexes are low.     

Belousov-Zhabotinskii oscillatory chemical reactions involving complexes of transition metals with 1,10-phenanthroline and 2,2′-bipyridyl

An analysis is given of features of the catalytic effect of complexes of manganese, iron and ruthenium with 1,10-phenanthroline and with 2,2-bipyridyl on the oscillatory Belousov-Zhabotinskii chemical reaction. On the basis of the experimental results, the redox properties of the various complexes and the composition of their coordination spheres consideration is given to the possibility (not previously taken into account) of the conversion of the catalyst during the formation and consumption of key substances [bromide ion, bromous acid HBrO₂, the bromyl and malonyl radicalsBrO₂ andCO(COOH)₂], the concentrations of which govern the oscillatory regime of the reaction. A scheme is proposed for the action of the complexes of transition metals with 1,10-phenanthroline and 2,2-bipyridyl which removes the discrepancies between the usually accepted mechanism for the Belousov-Zhabotinskii reaction and the experimental results.Sonar Scientific Research Center for the Automation of Biotechnical Systems, Cybernetics Institute of the Ukrainian SSR, Kiev. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 3, pp. 346–353, June, 1991. Original article submitted March 14, 1991.     

&“RuNO&”6 and &“RhNO&”6 compexes with 2,2′-bipyridine and 1,10-phenanthroline

The reactions of nitrosyl halides NOX (X = Cl, Br or Br₃) and N₂O₃ with RuCl₃(H₂O)₃ and RhCl₃(H₂O)₃ in the presence of 2,2′-bipyridine and 1,10-phenanthroline results in the formation of neutral nitrosyl complexes of types Ru(NO)X₃(L-L) and Rh(NO)X₂(L-L) (L-L = 2,2′-bipyridine or 1,10-phenanthroline).     

Ruthenium(II) complexes containing 2,9-dimethyl-1,10-phenanthroline and 4,4′-dimethyl-2,2′-bipyridine as ancillary ligands: synthesis,characterization and DNA-binding

Two new Ruthenium (II) polypyridyl complexes [Ru(dmp)₂(ipbp)](ClO₄)₂ (1) (dmp = 2,9-dimethyl-1,10-phenanthroline, ipbp = 3-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-4H-1-banzopyran-2-one) and [Ru(dmb)₂(ipbp)](ClO₄)₂ (2) (dmb = 4,4′-dimethyl-2,2′-bipyridine) have been synthesized and characterized by elemental analysis, FAB-MS, ES-MS and ¹H NMR and cyclic voltammetric methods. The DNA-binding behaviors of these complexes were investigated by spectroscopic titration, viscosity measurements, and thermal denaturation. Absorption titration and thermal denaturation studies reveal that these complexes are moderately strong binders of calf thymus DNA (CT-DNA). Viscosity measurements show that the complexes 1 and 2 interact with CT-DNA by intercalative mode. The DNA-binding affinity of the complex 2 is larger than that of complex 1.     

Synthesis and Characterization of Tris(2,2′-bipyridine) and tris(1,10-phenanthroline) Copper(II) Hexafluorophosphate. Crystal Structure of the Phenanthroline Complex

The tris-(bidentate)chelate complexes [Cu(NN)₃](PF₆)₂ where NN=2,2'-bipyridine or 1,10-phenanthroline have been isolated as secondary products in the reaction between the dimers [{Cu(NN)}₂(μ-OH)₂](PF₆)₂·2H₂O and di-2-pyridylketone. the X-ray crystal structure of [Cu(phen)₃](PF₆)₂ showed a distorted octahedral C ₂ geometry around teh metal atom, with two Cu-N distances being much longer than the other four. Magnetic susceptibility measurements (in the 4.4-290K range) correspond, in both cases, to a d⁹ configuration without significant magnetic interaction. A signal (g=2.102) was observed in the EPR spectrum of the bipy complex and the two axial components were resolved for the phen complex, with g_||=2.249, g_⊥=2.083 and A_||=137 x 10^-4cm^-1. In this case also a signal at g=2.128 is observed.