Dibromido(4,7-diazadecane-1,10-di­amine)­copper(II)

In the title compound, [CuBr2(C8H22N4)], the CuII atom is six-coordinate forming a distorted octa­hedral complex and is bonded to two axial bromide anions and four equatorial nitro­gen donors. The equatorial Cu—N bond distances range from 2.005 (8) to 2.046 (8) Å while the axial Cu—Br distances are 2.8616 (17) and 2.9402 (17) Å, thus the six-coordinate Cu complex shows the usual Jahn–Teller distortion. All amine hydrogen atoms participate in either inter- or intra­molecular hydrogen bonding to the Br anions

catena-Poly[[[{5,5′-dimeth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}manganese(III)]-μ-acetato] methanol monosolvate]

The title MnIII compound, {[Mn(C18H18N2O4)(CH3COO)]·CH3OH}n, was synthesized by a reaction between mangan­ese(II) acetate and ethyl­enebis(4-meth­oxy­salicylaldimine). The structure is made up of bis­(4-meth­oxy­salicyldene)ethyl­enediaminatomanganese(III) units bridged by acetate groups, with Mn—N = 1.9786 (9), Mn—O = 1.8784 (10) and Mn—Oacetate = 2.056 (9) and 2.2571 (9) Å, forming a one dimensional polymer (–Mn–acetate–Mn–acetate–) along [100]. The MnIII atom is in a Jahn–Teller-distorted octa­hedral environment with cis angles ranging from 81.87 (4) to 96.53 (4)° and trans angles ranging from 166.11 (3) to 173.93 (3)°. The methanol solvent mol­ecule is hydrogen bonded to the phenolate O atom. In addition to this classical hydrogen bond, there are weak C—H⋯O inter­actions. The structure was determined from a crystal twinned by pseudo-merohedry

Bis[μ-2-(2-pyridylmethyl­amino­meth­yl)phenolato]-κ4 N,N′,O:O;κ4 O:N,N′,O-bis­[(thio­cyanato-κN)copper(II)]

The centrosymmetric binuclear complex, [Cu2(C13H13N2O)2(NCS)2], formed via phenolate oxygen bridges, involves the CuII atoms in a distorted square-pyramidal coordination [τ = 0.197 (1)]. A Cu⋯Cu separation of 3.2281 (3) Å is observed. The in-plane Cu—Ophenolate distance [1.9342 (8) Å] is shorter than the axial distance [2.252 (8) Å]. The Cu—Namine and Cu—Npy distances are similar [2.0095 (10) and 2.0192 (10) Å, respectively]. The Cu—Nthio­cyanate distance [1.9678 (11) Å] is in the range found for Cu—N distances in previously determined structures containing coordinated thio­cyanate anions. There is an inter­molecular hydrogen bond between the amine H atom and the S atom of a coordinated thio­cyanate anion

Recoil Order Chiral Corrections to Baryon Octet Axial Currents and Large NcN_c QCD

We compute the chiral corrections to octet baryon axial currents through ${\cal O}(p^3)$ in heavy baryon chiral perturbation theory, including both octet and decuplet baryon intermediate states. We include the latter in a consistent way by using the small scale expansion. We find that, in contrast to the situation at ${\cal O}(p^2)$, there exist no cancellations between octet and decuplet contributions at ${\cal O}(p^3)$. Consequently, the ${\cal O}(p^3)$ corrections spoil the expected scaling behavior of the chiral expansion. We discuss this result in terms of the $1/N_c$ expansion. We also consider the implications for determination of the strange quark contribution to the nucleon spin from polarized deep inelastic scattering data.Comment: 7 page

Di-μ-perchlorato-bis­{μ-2-[(2-pyrid­yl)methyl­amino­meth­yl]phenolato)dicopper(II) acetonitrile disolvate

In the crystal of the dinuclear title compound, [Cu2(C13H13N2O)2(ClO4)2]·2CH3CN, the two bridging perchlorate ions chelate to the two CuII atoms in a μ-O:O′ fashion on opposite sides of the equatorial plane. The CuII ions display a distorted octa­hedral coordination geometry (in the usual 4 + 2 Jahn–Teller arrangement), each being coordinated by two O atoms from the two perchlorate ligands, and two N and O atoms from the reduced Schiff base ligand. The asymmetric unit contains two acetonitrile solvent mol­ecules. In the crystal structure, in addition to N—H⋯O hydrogen bonds, there are weak C—H⋯O inter­actions between the perchlorate O atoms and the reduced Schiff base ligand. C—H⋯N inter­actions are also present

Alerta bibliográfica y formación continuada: el Boletín Bibliográfico CESCA

The objective of this work is to analyze the quantity and quality of the comments included in CESCA Bibliography Bulletin and to study the usefulness of the Bulletin to its subscribers. We review the 1991 Bulletin and develop a postal survey to its suscribers. Papers from journals are 92 % of the total; they come from 90 different journals; 13 % of the journals give 55 % of the corhments. The clinical topics are the more frequent (29 %), being the health services research the second topic (29 %). There were 5 % of errors. Subscribers used the Bulletin as a source of information about new publications and as a tool for continuous medical education. CESCA Bibliography Bulletin is a useful publication which helps in following new publications and continuous medical education.El objetivo de este trabajo es analizar el contenido y calidad de los comentarios incluidos en el Boletín Bibliográfico CESCA, así como su utilidad para los suscriptores del mismo. Se realiza un estudio descriptivo de lo publicado en 1991 y se analizan las respuestas a una encuesta remitida a los suscriptores. Los artículos de revistas constituyeron el 92 % de todos los comentarios; se utilizaron 90 revistas distintas; 13 revistas concentran el 55 % del total de los comentarios. La temática más frecuente de los documentos comentados fue la clínica (39 %), seguida de la investigación de servicios sanitarios (29 %). Se ha encontrado un 5 % de errores. Los suscriptores emplearon el Boletín como alerta bibliográfica y como soporte de formación continuada. Así pues, el Boletín Bibliográfico CESCA, que comenta y califica los documentos, es una ayuda para los lectores, tanto en alerta bibliográfica como en formación continuada

{3,3′,5,5′-Tetra­meth­oxy-2,2′-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}nickel(II)

The title square-planar nickel complex, [Ni(C20H22N2O6)], has Ni—N and Ni—O bond lengths of 1.8448 (14)/1.8478 (14) and 1.8536 (12)/1.8520 (12) Å. There is a slight twist in the two benzene rings at each end of the complex [dihedral angle = 11.11 (5)°]. All the atoms of the meth­oxy substitutents are in the plane of the ring to which they are attached except for one which deviates slightly [0.365 (3) Å]. In the crystal, weak C—H⋯O inter­molecular inter­actions connect the mol­ecules

Di-μ2-acetato-diacetato-bis­{μ2-3,3′,5,5′-tetra­meth­oxy-2,2-[ethane-1,2-diylbis(nitrilo­methyl­idyne)]diphenolato}tricobalt(II,III) dichloro­methane disolvate

The trinuclear title compound, [Co3(CH3COO)4(C20H22N2O6)2]·2CH2Cl2, contains mixed-valence cobalt ions in the following order CoIII–CoII–CoIII where all the three cobalt ions are hexa­coordinated. The central cobalt ion is situated on an inversion centre and is in an all-oxygen environment, coordinated by four phenolate O atoms and two O atoms from bridging acetate groups, while the terminal cobalt ion is hexa­coordinated by two phenolate O atoms, two acetate O atoms and two imine N atoms. This complex contains a high-spin central CoII and two terminal low-spin CoIII i.e. CoIII(S = 0)–CoII(S = 3/2)-CoIII(S = 0). There are weak inter­molecular C—H⋯O inter­actions involving the meth­oxy groups, as well as inter­molecular C—H⋯O inter­actions involving the acetate anions. In addition, the dichoromethane solvate mol­ecules are held in place by weak C—H⋯Cl inter­actions

μ-Bromido-bis{μ-2,2′-[4,7-diaza­decane-1,10-diylbis(nitrilo­methanylyl­idene)]diphenolato}tricopper(II) bromide dimethyl­formamide disolvate

The complex mol­ecule of the title compound, [Cu3Br(C22H28N4O2)2]Br·2C3H7NO, contains three copper atoms, two of which are five-coordinate within a square-pyramidal environment and linked by a bridging Br atom occupying the apical position in each square pyramid. The remaining Cu atom is four-coordinate but with considerable tetra­hedral disortion [the dihedral angle between the two chelate planes is 69.21 (7)°]. There are two mol­ecules of dimethyl­formamide (DMF) present as solvent mol­ecules, one of which is disordered over two equivalent conformations with occupancies of 0.603 (5) and 0.397 (5). The amine H atoms are involved in both inter- and intra­molecular hydrogen-bonding inter­actions with the Br and O atoms of the cation, as well as with the O atom of the ordered DMF mol­ecule