Three Bis‐BODIPY Analogous Diruthenium Redox Series: Characterization and Electronic Structure Analysis

The dianion derived from (2Z,6Z)‐3,7‐diphenyl‐N2,N6‐di(pyridin‐2‐yl)pyrrolo[2,3‐f]indole‐2,6(1H,5H)‐diimine (H₂BL), a modified BODIPY ligand precursor, is shown to be capable of bridging two metal complex fragments RuL₂, L=2,4‐pentanedionato (acac^?), 2,2’‐bipyridine (bpy) or 2‐phenylazopyridine (pap) in [Ru(acac)₂Ru(μ‐BL)Ru(acac)₂] ( 1 / 2 ), [Ru(bpy)₂Ru(μ‐BL)Ru(bpy)₂](ClO₄)₂ ([ 3 ](ClO₄)₂) and [Ru(pap)₂Ru(μ‐BL)Ru(pap)₂](ClO₄)₂ ([ 4 ](ClO₄)₂). The compounds, including a diastereoisomeric pair 1 (meso) and 2 (rac) were spectroscopically and structurally characterized. Reversible electron transfers as revealed by cyclic and differential pulse voltammetry allowed for an EPR and UV‐vis‐NIR spectroelectrochemical investigation of several neighboring charge states. Together with susceptibility measurements and TD‐DFT calculations the assignment of oxidation states reveals that 1 , 2 are diruthenium(III) species which can be oxidized or reduced by one electron whereas 3 ²⁺ and 4 ²⁺ contain ruthenium(II) and get reduced or oxidized mainly at the dianionic bridge ( 3 ²⁺) or are reduced at the ancillary ligands pap ( 4 ²⁺).     

Selenadiazolopyridine: a synthon for supramolecular assembly and complexes with metallophilic interactions

The synthesis and characterization of the complexes of Cu(I), Ag(I), Cu(II), and Co(II) ions with 1,2,5-selenadiazolopyridine (psd) is reported. The following complexes have been prepared: [Cu(2)(psd)(3)(CH(3)CN)(2)](2+)2(PF(6)(-)); [(CuCl)(2)(psd)(3)]; [Cu(2)(psd)(6)](2+)2(ClO(4))(-); [Ag(2)(psd)(2)](2+)2(NO(3))(-); [Ag(2)(psd)(2)](2+)2(CF(3)COO)(-); [Cu(psd)(2)(H(2)O)(3)](2+)2(ClO(4))(-)·(psd)(2); [Cu(psd)(4)(H(2)O)](2+)2(ClO(4))(-)·(CHCl(3)); [Cu(psd)(2)(H(2)O)(3)](2+)2(NO(3))(-)·(H(2)O)·(psd)(2), and [Co(psd)(2)(H(2)O)(4)](2+)2(ClO(4))(-)·(psd)(2). The electronic structure of ligand psd, in particular the bond order of Se-N bonds, has been probed by X-ray diffraction, (77)Se NMR, and computational studies. A detailed analysis of the crystal structures of the ligand and the complexes revealed interesting supramolecular assembly. The assembly was further facilitated by the presence of neutral ligands for some complexes (Cu(II) and Co(II)). The molecular structure of the ligand showed that it was present as a dimer in the solid state where the monomers were linked by strong secondary bonding Se···N interactions. The crystal structures of Cu(I) and Ag(I) complexes revealed the dinuclear nature with characteristic metallophilic interactions [M···M] (M = Cu, Ag), while the Cu(II) and Co(II) complexes were mononuclear. The presence of M···M interactions has been further probed by Atoms in Molecules (AIM) calculations. The paramagnetic Cu(II) and Co(II) complexes have been characterized by UV-vis, ESI spectroscopy, and room temperature magnetic measurements.     

Terahertz optical asymmetric demultiplexer based tree-net architecture for all-optical conversion scheme from binary to its other 2n radix based form

To exploit the parallelism of optics in data processing,a suitable number system and an efficient encoding/decoding scheme for handling the data are very essential.In the field of optical computing and parallel information processing,several number systems like binary,quaternary,octal,hexadecimal,etc.have been used for different arithmetic and algebraic operations.Here,we have proposed an all-optical conversion scheme from its binary to its other 2n radix based form with the help of terahertz optical asymmetric demultiplexer (TOAD) based tree-net architecture.     

Catecholato complexes of palladium(II)–naphthylazoimidazoles: synthesis,spectral characterization,electrochemistry and solvatochromic studies

[Pd(-NaiR)(O,O)] [-NaiR = 1-alkyl-2-(naphthyl--azo)imidazoles; R = Me (a), Et (b), CH₂Ph (c) and O,O = pyrocatecholato (cat) (3), 4-t-butylcatecholato (tbcat) (4), 3,5-di-t-butylcatecholato (dtbcat) (5), and tetracholorocatecholato (tccat) (6)] complexes were characterized by elemental analyses, i.r. and ¹H-n.m.r. spectral data. Studies by cyclic voltammetry suggest the existence of two redox couples, positive saturated calomel electrode (s.c.e.) that are due to catecholes to semiquinone, and semiquinone to quinone oxidations, respectively; two couples at negative to s.c.e. are associated with azo reductions. The complexes exhibit ligand-to-ligand charge-transfer transition in the near-i.r. region. The band position is largely dependent upon the substituent on the catechole frame and exhibits a negative solvatochromic effect. The transition is qualitatively assigned to the HOMO (cat) LUMO (-NaiR) transition.     

Crystal engineering of metalloporphyrin assemblies. New supramolecular architectures mediated by bipyridyl ligands

Targeted synthesis of new supramolecular motifs of metalloporphyrins in crystals by a concerted mechanism of molecular recognition in three dimensions, aided by organic ligands, is presented; it involves induced assembly of [tetrakis(4-hydroxyphenyl)porphyrinato]zinc species by a combination of axial coordination through bridging bipyridyls and of lateral hydrogen bonding.     

Dialgebra cohomology as a G-algebra

It is well known that the Hochschild cohomology of an associative algebra admits a G-algebra structure. In this paper we show that the dialgebra cohomology of an associative dialgebra has a similar structure, which is induced from a homotopy G-algebra structure on the dialgebra cochain complex .

     

Synthesis,spectral characterization and redox studies of [1-alkyl-2-(naphthyl-β-azo)imidazole] palladium(II) catecholates

1-Alkyl-2-(naphthyl--azo)imidazoles [-NaiR; R = Me (a), Et (b), CH₂Ph (c)] react with Pd(MeCN)₂Cl₂ to yield Pd(-NaiR)Cl₂ (2), the i.r. spectra of which support the presence of a cis-PdCl₂ configuration. The complexes react with catechols in the presence of Et₃N to yield ternary complexes [Pd(-NaiR)(O,O)] [O,O = pyrocatecholato (cat) (3), 4-t-butylcatecholato (tbcat) (4), 3,5-di-t-butylcatecholato (dtbcat) (5), and tetrachlorocatecholato (tccat) (6)], which were characterized by elemental analysis, i.r. and ¹H-n.m.r. spectral data. Redox studies by cyclic voltammetry suggest the existence of four successive redox couples wherein two responses, positive to s.c.e. are due to catechol to semiquinone and semiquinone to quinone oxidation, respectively; the couples at negative to s.c.e. are referred to azo reductions. The complexes exhibit ligand-ligand charge-transfer transitions in the near-i.r. region. The band position is largely dependent upon the substitutent on the catechol frame and exhibits negative solvatochromic effects. The transition is qualitatively assigned as the HOMO (cat) LUMO (-NaiR) transition. This fact is also supported by theoretical calculations using the PM3 method.     

Erratum to: Solution behavior of aqueous mixtures of low and high molecular weight hydrophobic amphiphiles

Mixtures of a hydrophobic triblock copolymer (L121, PEO₅PPO₆₈PEO₅) and a hydrophobic anionic surfactant (AOT, Sodium bis(2-ethylhexyl)sulfosuccinate), each alone forming turbid vesicular solutions in water, aggregate to produce a thermodynamically stable, transparent and isotropic solution. Mixed AOT/L121 aggregates could be confirmed by fluorescence, surface tension, differential scanning calorimetry (DSC) and isothermal titration calorimetry (ITC). In an isotropic region, where mixed aggregates are formed, there is a synergistic interaction between monomers of AOT and L121 in the mixture. In addition, Small Angle Neutron Scattering (SANS) experiments provided evidence that mixed aggregates have the shape of either spheres (with a certain polydispersity) or very short ellipsoids (axial ratio below 2), confirming a transition from giant multilamellar vesicles to small aggregates upon mixing the two hydrophobic amphiphiles. Upon dilution, the morphology changes to disk-like. From an examination of the results of all the methods the peculiar behavior of the mixed AOT/L121 system is explained.     

Finite frames,P-frames and basically disconnected frames

Let \({\mathcal{P}}\) be an ideal of closed quotients of a completely regular frame L and \({\mathcal{R}_{\mathcal{P}}(L)}\) the collection of all functions in the ring \({\mathcal{R}(L)}\) whose support belong to \({\mathcal{P}}\) . We show that \({\mathcal{R}(L)}\) is a Noetherian ring if and only if \({\mathcal{R}(L)}\) is an Artinian ring if and only if L is a finite frame. Using this result, we next show that if \({\mathcal{P}}\) is the ideal of all compact closed quotients of L and L is \({\mathcal{P}}\) -continuous, then \({\mathcal{R}_{\mathcal{P}}(L)}\) is a Noetherian ring if and only if L is finite. Moreover, we show that L is a P-frame if and only if each ideal of \({\mathcal{R}(L)}\) is of the form \({\mathcal{R}_{\mathcal{P}}(L)}\) for some choice of \({\mathcal{P}}\) . We furnish equivalent conditions for \({\mathcal{R}_{\mathcal{P}}(L)}\) to be a prime ideal, a free ideal, and an essential ideal of \({\mathcal{R}(L)}\) separately in terms of the cozero elements of L. Finally, we show that L is basically disconnected if and only if \({\mathcal{R}(L)}\) is a coherent ring.     

Quantitative Characterization of Bovine Serum Albumin, α-Lactalbumin and β-Lactoglobulin in Commercial Whey Sample by RP-LC

A simple, sensitive and precise reverse phase liquid chromatographic method has been developed and validated for quantification of bovine serum albumin (BSA), α-lactalbumin (α-La) and β–lactoglobulin (β-Lg) that are removed from whey waste by foam fractionation method. The data is reproducible over a wide concentration range. This optimized method allowed analysis of BSA, α-La, β-Lg in a mixture within 5 min and could be applied to the analysis of a variety of commercial and laboratory whey products within a short time.