Versatile binding properties of di-pyridyl ligands with Cu(II) complexes: The syntheses,structural characterization and thermal analysis of six new species

A novel series of 4,4′-bipyridine- and 1,2-bis(4-pyridyl)ethane-Cu(II) complexes were synthesized using a variety of amine ligands (DPA = di(2-pyridylmethyl)amine, Medpt = 3,3′-diamino-N-methyldipropylamine, Hbpca = bis(2-pyridylcarbonyl)amine, TPA = tris(2-pyridylmethyl)amine) and cyclen = 1,4,7,10-tetraazacyclododecane). Different complexes were obtained including mononuclear [Cu(cyclen)(4,4′-bipy)](ClO₄)₂ (1), dinuclear {[Cu(μ₂-bpca)(4,4′-bipy)(H₂O)]ClO₄}₂ (2), [Cu₂(DPA)₂(μ₂-4,4′-bipy)(ClO₄)₄)]·H₂O (3), [Cu₂(cyclen)₂(μ₂-bpe)](ClO₄)₄ (4) and [Cu₂(TPA)₂(μ₂-bpe)](ClO₄)₄ (5) and the 1-D polymer, {[Cu(Medpt)(μ₂-4,4′-bipy)](ClO₄)₂}_n (6). In the 1–6 samples, cooling up to 100 K produces only the expected, minor, changes in cell constants given no space group changes. Therefore, data for the 100 K structures are reported only. Single-crystal X-ray crystallography reveals the monodentate coordination of the 4,4′-bipy in 1 and 2, and the bridged nature of the di-pyridyl ligands in the dinuclear complexes 2–5 and in the polymeric complex 6. In this series, structures 3–6 consist of the 4,4′-bipy or bpe bridging the two Cu(II) centers, the coordination by the tri- or the tetra-N donors of the amine, and the ClO₄^? groups as counter ions in 4–6 complexes. In the complexes 3–6, the Cu···Cu distances across the bridged di-pyridyl ligands were found to be greater than 11 Å. The magnetic properties of complex 3 reveal no evidence for magnetic coupling between the two Cu(II) centers (J = ?0.58 cm^?1).     

Polyketanils. Polymers protonated with Bronsted acid

New luminescent materials—aromatic polyketanils (PKs) containing p‐phenylene and biphenylene linkages in the backbone and electron‐donating, side‐group substitutions—were synthesized via melt polycondensation with the goal of studying the interactions between the polymer chains (PKs), primary dopant [1,2‐(di‐2‐ethylhexyl)ester of 4‐sulfophthalic acid (PSA)], and secondary dopant [m‐cresol (MC)] with ¹H NMR, ¹³C NMR, Fourier transform infrared (FTIR), ultraviolet–visible, and photoluminescence measurements. Spectral changes were observed for the PKs after primary and secondary doping, and they supported ionic‐ and hydrogen‐bond formation between the PKs and the PSA and MC, respectively. This specific interaction of the dopant with the host polymer influenced the PK properties, and the following observations were made: (1) HOMO/LUMO energy gap of the protonated PKs; (2) bathochromic/hypsochromic photoluminescence shifts observed after protonation with PSA; (3) a downfield chemical shift of the labile proton in the protonating agent OH group in the ¹H NMR spectra of the protonated polymers; (4) a protonation decrease in the intensity of the C?N stretching band in the FTIR spectrum; and (5) a spherulite‐like morphology, detected by atomic force microscopy and polarized optical microscopy. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 5645–5660, 2006     

Filament sets and decompositions of homogeneous continua

This paper applies the concepts introduced in the article: Filament sets and homogeneous continua [J.R. Prajs, K. Whittington, Filament sets and homogeneous continua, Topology Appl. 154 (8) (2007) 1581-1591, doi:10.1016/j.topol.2006.12.005] to decompositions of homogeneous continua. Several new or strengthened results on aposyndesis are given. Newly defined decompositions are discussed. A proposed classification scheme for homogeneous continua is shown to be mostly invariant under Jones' aposyndetic decomposition.     

Synthesis and Determination of Alkali Metal Binding Selectivities of Chiral Macrocyclic Bisamides Derived from D-Mannitol and L-Threitol

Eight new chiral macrocyclic diamides derived from D-mannitol and L-threitol, possessing C₂ symmetry, are prepared. Their application for alkali metal binding processes is studied using the ESI-MS technique.     

Organoboron water,part I: Synthesis and multinuclear magnetic resonance studies on the structure of tetramethyldialuminoxane

The structure of tetramethyldialuminoxane was studied. The low‐temperature ¹H and ¹³C NMR spectra suggest that the methyl groups bridge the aluminum atoms in the dialuminoxane trimer. A new method of synthesis of methylaluminoxanes and tetramethyldialuminoxanes in the reaction of tetraethyldiboroxane (organoboron water) with trimethylaluminum (1:1 and 1:2 respectively) was applied to synthesize the investigated system. Copyright © 2004 John Wiley & Sons, Ltd.     

Local order and shape of a polymer chain in an external electric field

A solution of polymer chains in the presence of an external electric field is considered. Dipole-like interactions between polymer chain segment-vectors and the electric field are assumed to be proportional to the cosine of the angle between the segment-vector and the direction of the electric field. Parameters characterizing the shape of the chain (i.e., the chain end-to-end distance and cross-section per chain), and parameters describing the local order at the segmental and chain level (i.e., moments of the first and second Legendre polynomials 〈P₁〉 and 〈P₂〉 are calculated. The optical anisotropy and the molecular shape change induced by the external electric field are discussed.     

Method of characteristic for functional equations in polynomial form

Properties of continuous solutions of a second order polynomial-like iterated functional equation are given by considering its characteristic. A useful method to discuss the general case is described indeed in this procedure. Supported by NSF of China, Sichuan Provincial Youth Sci-Tech Foundation and Math. Grant of CAS     

Starlikeness of Hadamard product of certain analytic functions

An interesting criterion was given by Lashin (A.Y. Lashin, Some convolution properties of analytic functions, Appl. Math. Lett. 18 (2005) 135–138) to be starlike for convolution of analytic functions f, g such that Re[f^′(z)],Re[g^′(z)]β,,β<1 in the unit disc U. In this paper we shall improve this criterion.