Dinuclear enantiopure Ln3+ complexes with (S-) and (R-) 2-phenylbutyrate ligands. Luminescence, CPL and magnetic properties.

The reaction of Ln(NO3)2·6H2O (Ln = Nd, Sm, Eu, Tb, Dy, Tm and Yb) with the respective enantiopure (R)-(-)-2-phenylbutyric or (S)-(+)-2-phenylbutyric acid (R/S-2-HPhBut) and 4,7-diphenyl-1,10-phenanthroline (Bphen) allows the isolation of chiral dinuclear compounds of the formula [Ln2(µ-R/S-2-PhBut)4(R/S-2PhBut)2(Bphen)2] where Ln = Nd3+ (R/S-Nd-a), Sm3+ (R/S-Sm-a), Eu3+ (R/S-Eu-a), Tb3+ (R/S-Tb-a and R/S-Tb-b), Dy3+ (R/S-Dy-a and R/S-Dy-b), Tm3+ (R/S-Tm-b) and Yb3+ (R/S-Yb-b). Single crystal X-ray diffraction was performed for compounds S-Eu-a and S-Tm-b. Powder crystal X-ray diffraction was performed for all complexes. From the crystallographic data two different structural motifs were found which are referred to as structure type a and structure type b. In structure type a, the Ln3+ atoms are bridged through four R or S-2-PhBut ligands with two different kinds of coordination modes whereas in structure type b the two Ln3+ atoms are bridged through four R or S-2-PhBut ligands showing only one kind of coordination mode. For those lanthanide ions exhibiting both structure types, Tb3+ and Dy3+, a difference in the luminescence and magnetism behavior is observed. All compounds (except R/S-Tm-b) exhibit sensitized luminescence, notably the Eu3+ and Tb3+ analogues. Circular Dichroism (CD) and Circular Polarized Luminescence (CPL) in the solid state and in 1 mM dichloromethane (DCM) solutions are reported, leading to improved chiroptical properties for the DCM solutions. The asymmetry factor (glum) in 1 mM DCM is ±0.02 (+ for R-Eu-a) for the magnetically allowed transition 5D0 → 7F1 and ±0.03 (+ for R-Tb-a and R-Tb-b) for the 5D4 → 7F5 transition. Magnetic properties of all compounds were studied and the Dy3+ compound with the structural motif b (R-Dy-b) shows Single Molecular Magnet (SMM) behavior under a 0 T magnetic field. However, R-Dy-a is a field-induced SMM.

New series of mononuclear ß-diketonate cerium(III) field induced single-molecule magnets.

Five new ß-diketonate Ce3+ mononuclear complexes, [Ce(Btfa)3(H2O)2] (1), [Ce(Btfa)3(phen)] (2), [Ce(Btfa)3(bipy)] (3), [Ce(Btfa)3(terpy)] (4) and [Ce(Btfa)3(bathophen)(DMF)] (5), where Btfa- = 4,4,4-trifluoro-1-phenyl-1,3-butanedionate, phen = 1,10-phenanthroline, bipy = 2,2'-bipyridyl, terpy = 2,2':6',2''-terpyridine and bathophen = 4,7-diphenyl-1,10-phenanthroline, have been synthesized and structurally characterized through X-ray diffraction of single crystals. The central Ce3+ atom displays a coordination number of 8 for 1, 2 and 3 and of 9 for 4 and 5. Under a 0 T external magnetic field, none of the given compounds exhibits single molecule magnet (SMM) behaviour. However, a small magnetic field, between 0.02 and 0.1 T, is enough for all the compounds to exhibit slow relaxation of the magnetization. A comprehensive magnetic analysis, with experimental magnetic data and ab initio calculations, was undertaken for all the complexes, and the study highlights the significance of the different spin relaxation mechanisms that must be considered for a Ce3+ lanthanide ion.

Luminescence, CPL and magnetic properties of 1D enantiopure Ln3+ complexes with (S-) and (R-) α-methoxyphenylacetate ligand.

The reaction of Ln(NO3)2·6H2O (Ln = Eu, Tb, Dy and Sm) with (R)-(-)-α-methoxyphenylacetic acid (R-HMPA) and 1,10-phenanthroline (phen) in EtOH/H2O allows the isolation of 1D chiral compounds of formula [Ln(µ-R-MPA)(R-MPA)2(phen)]n in which Ln = Eu (R-Eu), Tb (R-Tb), Dy (R-Dy) and Sm (R-Sm). The same synthesis by using (S)-(+)-α-methoxyphenylacetic acid (S-HMPA) instead of (R)-(-)-α-methoxyphenylacetic acid allows the isolation of the enantiomeric compounds with formula [Ln(µ-S-MPA)(S-MPA)2(phen)]n where Ln = Eu (S-Eu), Tb (S-Tb), Dy (S-Dy) and Sm (S-Sm). Single crystal X-Ray diffraction measurements were performed for compounds R/S-Eu, R/S-Tb, S-Dy and S-Sm. The luminescence and the circular dichroism measured in the solid state are reported. All compounds show sensitized luminescence, notably the Eu3+ and Tb3+ ones, whose emission color can be perceived by the naked eye. For the Eu3+ and Tb3+ derivatives the quantum yield and the circular polarized luminescence have been measured. For the magnetic allowed transition 5D0 → 7F1 of the Eu3+ compound, the anisotropy factor glum is ±0.013 (+for S-Eu). Also, magnetic properties of all compounds were studied with the Dy3+ analogue showing slow relaxation of the magnetization under a direct current magnetic field of 1000 Oe.

Insights into the Spin Dynamics of Mononuclear Cerium(III) Single-Molecule Magnets.

Four novel CeIII mononuclear complexes of formulas [Ce(ntfa)3(MeOH)2] (1), [Ce(ntfa)3(5,5'-Me2bipy)] (2), [Ce(ntfa)3(terpy)] (3), and [Ce(ntfa)3(bipy)2] (4), where ntfa = 4,4,4-trifluoro-1-(naphthalen-2-yl)butane-1,3-dionato, 5,5'-Me2bipy = 5,5'-dimethyl-2,2'-dipyridyl, terpy = 2,2':6',2″-terpyridine, and bipy = 2,2'-bipyridine, have been synthesized and structurally characterized with CeIII displaying coordination numbers of 8, 8, 9, and 10, respectively. Magnetic measurements indicate that all the complexes show a field-induced single-ion magnet behavior under a small applied dc field. The magnetic analysis shows the relevance of the different spin relaxation mechanisms in the magnetic relaxation of the CeIII compounds, with special emphasis on the local-mode process. Multiconfigurational calculations were also performed to get more information on the axiality of the compounds.

Magnetic and Luminescence Properties of 8-Coordinate Holmium(III) Complexes Containing 4,4,4-Trifluoro-1-Phenyl- and 1-(Naphthalen-2-yl)-1,3-Butanedionates.

A new series of mononuclear Ho3+ complexes derived from the ß-diketonate anions: 4,4,4-trifluoro-1-phenyl-1,3-butanedioneate (btfa-) and 4,4,4-trifuoro-1-(naphthalen-2-yl)-1,3-butanedionate (ntfa-) have been synthesized, [Ho(btfa)3(H2O)2] (1a), [Ho(ntfa)3(MeOH)2] (1b), (1), [Ho(btfa)3(phen)] (2), [Ho(btfa)3(bipy)] (3), [Ho(btfa)3(di-tbubipy)] (4), [Ho(ntfa)3(Me2bipy)] (5), and [Ho(ntfa)3(bipy)] (6), where phen is 1,10-phenantroline, bipy is 2,2'-bipyridyl, di-tbubipy is 4,4'-di-tert-butyl-2,2'-bipyridyl, and Me2bipy is 4,4'-dimethyl-2,2'-bipyridyl. These compounds have been characterized by elemental microanalysis and infrared spectroscopy as well as single-crystal X-ray difraction for 2-6. The central Ho3+ ions in these compounds display coordination number 8. The luminescence-emission properties of the pyridyl adducts 2-6 display a strong characteristic band in the visible region at 661 nm and a series of bands in the NIR region (excitation wavelengths (λex) of 367 nm for 2-4 and 380 nm for 5 and 6). The magnetic properties of the complexes revealed magnetically uncoupled Ho3+ compounds with no field-induced, single-molecule magnet (SMMs).

Chiral dinuclear Ln(iii) complexes derived from S- and R-2-(6-methoxy-2-naphthyl)propionate. Optical and magnetic properties.

The reaction of LnCl3·6H2O with (S)-(+)-2-(6-methoxy-2-naphthyl)propionic acid (S-HL), best known as naproxen, and 1,10-phenanthroline (phen) in EtOH allows the isolation of dinuclear chiral compounds S-1-4 of the formula [Ln2(S-L)6(phen)2]·3DMF·H2O [Ln(iii) = Eu (1), Gd (2), Tb (3) and Dy (4)]. The use of the R-enantiomeric species of the HL ligand led to complexes R-1-4 with the formula [Ln2(R-L)6(phen)2]·3DMF·H2O. Compounds R- andS-1, 3 and 4 show strong sensitized metal-centred luminescence in the visible region. Moreover, Dy(iii) complexes R- andS-4 display field-induced single-molecule magnet (SMM) behaviour. For chiral and emissive compounds circularly polarized luminescence (CPL) measurements have also been performed.

Circularly polarized luminescence on dinuclear Tb(iii) and Eu(iii) complexes with (S-) and (R-) 2-phenylpropionate.

The reaction of Ln(NO3)2·6H2O (Ln = Tb and Eu) with (S)-(+)-2-phenylpropionic acid (S-HL) and 1,10-phenanthroline (phen) in EtOH/H2O allows the isolation of the dinuclear chiral compounds of the formula [Ln2(S-L)6(phen)2]·2.5·S-HL in which Ln = Tb (S-1), Ln = Eu (S-2). The same synthesis by using (R)-(-)-2-phenylpropionic acid (R-HL) instead of (S)-(+)-2-phenylpropionic acid allows the isolation of the enantiomeric compounds with the formula [Ln2(R-L)6(phen)2]·2.5·R-HL where Ln = Tb (R-1), Ln = Eu (R-2). All compounds show sensitized luminescence. The luminescence study, including the circularly polarized luminescence spectra of the four compounds, is reported. The magnetic behavior of S-1 and S-2 is also reported.

Predetermined Ferromagnetic Coupling via Strict Control of M-O-M Angles.

An imidazolidine-phenolate ligand HL yields quadruple-bridged (µ-NCNimidazolidine)2(µ-Ophenolate)2 ferromagnetic dinuclear nickel and cobalt complexes. Both kinds of bridges contribute to the ferromagnetic coupling, but the ferromagnetism of these samples is mainly ascribed to the double µ-Ophenolate links, on the basis of density functional theory calculations. These studies demonstrate not only that the short M-O-M angles of the M2O2 cores favors the parallel alignment of the electrons but also that these angles are the optimal ones for maximizing the ferromagnetic contribution in these complexes. And these acute angles, close to 90°, are predetermined by the geometrical constrictions imposed by the ligand itself. Thus, HL is an uncommon polydentate donor that induces ferromagnetism per se in its metal complexes by strict control of one geometric parameter, the M-O-M angle.

µ1,1-R-phenylcyanamido bridges as a new safe synthetic strategy for ferromagnetic molecular clusters.

The reaction of Ni(NO3)2·6H2O with di-2-pyridyl ketone, (py)2CO, and the R-phenylcyanamides 4Cl-3CF3-PhHNCN and 4F-3CF3-PhHNCN in CH3OH or CH3CH2OH allows the isolation of the tetranuclear compounds [(Ni4(µ-py2COOCH3)2(µ3-py2COOH)2(µ1,1-4Cl-3CF3-PhNCN)2(4Cl-3CF3-PhNCN)2]·CH3OH (1), [(Ni4(µ-py2COOCH2CH3)2(µ3-py2COOH)2(µ1,1-4Cl-3CF3-PhNCN)2(4Cl-3CF3-PhNCN)2]·2EtOH (2) and [(Ni4(µ-py2COOCH3)2(µ3-py2COOH)2(µ1,1-4F-3CF3-PhNCN)2(4F-3CF3-PhNCN)2]·4CH3OH (3). {(py)2C(OH)O}(-) and {(py)2C(OR)O}(-) are the monoanions of the gem-diol and hemiketal (R = CH3, CH2CH3) forms of (py)2CO. X-ray diffraction analysis reveals defective double-cubane tetrameric entities in which the Ni(II) atoms are linked by µ1,1-R-phenylcyanamido bridges and two kinds of O-bridges. The molar magnetic susceptibility measurements of 1-3 in the 2-300 K range indicate bulk ferromagnetic coupling.

Different topologies in three manganese-µ-azido 1D compounds: magnetic behavior and DFT-quantum Monte Carlo calculations.

The syntheses and structural characterization of three new monodimensional azido-bridged manganese(ii) complexes with empirical formulae [Mn(N3)2(aminopyz)2]n (1), [Mn(N3)2(4-azpy)2]n (2) and [Mn(N3)2(4-Bzpy)2]n (3) (pyz = pyrazine (1,4-diazine)), 4-azpy = 4-azidopyridine and 4-Bzpy = 4-benzoylpyridine) are reported. 1 is a monodimensional compound with double EO azido bridges, 2 is an alternating monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EE and 3 is a monodimensional compound with double end-on and double end-to-end azido bridges in the sequence di-EO-di-EO-diEO-di-EO-di-EE. The magnetic properties of 1-3 are reported. Periodic DFT calculations were performed to estimate the J values and quantum Monte Carlo simulations were carried out using the calculated J values to check their accuracy in comparison with the experimental magnetic measurements. From this theoretical analysis, two appealing features of the di-EO Mn(ii) compounds can be extracted: first, the exchange coupling becomes more ferromagnetic when the Mn-N-Mn bridging angle becomes larger and the spin density of the bridging nitrogen atoms has an opposite sign to that of the Mn(II) centers.

Four new trinuclear {Cu3(µ3-OH)(oximate)3}²âº clusters: crystal structure and magnetic behaviour.

Four new triangular copper(II) complexes with the fragment {Cu3(µ3-OH)(oximate)3}(2+) and formulae [Cu3(µ3-OH)(µ-Cl)(Py2CNO)3((t)BuPO3H)]·4H2O (1), [Cu3(µ3-OH)(µ-Br)(Py2CNO)3((t)BuPO3H)]·3.5H2O (2), [Cu3(µ3-OH)(µ-Br)(PhPyCNO)3((t)BuPO3H)(MeOH)]·1.5 MeOH (3), [Cu3(µ3-OH)Cl2(PhPyCNO)3]·0.5H2O (4), (Py2CNO = di(2-pyridyl)ketoximate, PhPyCNO = phenyl(2-pyridyl)ketoximate, (t)BuPO3H2 = tert-butylphosphonic acid) are reported. The magnetic properties of compounds 1-4 were studied. The compounds were found to exhibit strong antiferromagnetic coupling and antisymmetric exchange interaction.

Anatomía de la vía aérea para el broncoscopista. Una aproximación a la anestesia / Airway anatomy for the bronchoscopist: An anesthesia approach

Introducción: El conocimiento y desarrollo de habilidades en el manejo de la vía aérea es una de las competencias importantes en la formación del anestesiólogo; el «saber¼ y el «saber hacer bien y rápido¼ son determinantes en algunas situaciones críticas a las que se puede enfrentar durante el manejo anestésico. La broncoscopia es un procedimiento útil tanto diagnóstico como terapéutico. El conocimiento de la técnica y de la anatomía de la vía aérea constituye el pilar de la broncoscopia, encontrando diferentes variaciones anatómicas y clasificaciones de la vía aérea. Objetivo: Describir la anatomía de la vía aérea a través de esquemas, evaluar variaciones anatómicas y conocer características propias del procedimiento. Metodología: Con las palabras clave «Bronchoscopy¼, «Anatomy¼, «Airway¼ y «Anesthesia¼ se realizó una revisión no sistemática en bases de datos (PUBMED/MEDLINE, Science Direct, OVID, SciELO). Resultados y conclusiones: La broncoscopia es un procedimiento útil en el plano quirúrgico y diagnóstico, siendo utilizado en distintos procedimientos. Las variaciones anatómicas de la vía aérea se presentan en un porcentaje pequeño de la población. Las clasificaciones anatómicas son diversas tanto anatómica como numéricamente; sin embargo, lo relevante es desarrollar una relación espacial. La broncoscopia es una técnica que va en desarrollo paralelo a otros avances de la tecnología biomédica, es un procedimiento del cual el anestesiólogo debe investigar más con el fin de generar mejores efectos en el campo de la anestesiología.

Introduction: Knowledge and development of skills in the management of the airway is one of important competencies in the training of the anesthesiologist, "knowledge" and "know how well and fast" are decisive in some critical situations during the anesthetic management. Bronchoscopy is a useful both diagnostic and therapeutic procedure. Knowledge of technique and the anatomy of the airway is the key of bronchoscopy, finding different anatomic variations and classifications of the airway. Objective: Describe the airway anatomy through diagrams, evaluate anatomic variations and characteristics of procedure. Methodology: With the keywords "Bronchoscopy" and "Anatomy", "Airway", "Anesthesia" held a non-systematic review databases (PUBMED/MEDLINE, OVID, Science Direct, SciELO). Results and conclusions: The bronchoscopy is a useful procedure in the surgical level and diagnosis, being used in various procedures. Airway anatomical variations occur in a small percentage of the population. Anatomical classifications are different both anatomic as numerically, but what is important is developing a spatial relation. Bronchoscopy is a technique that goes in parallel development of other advances in biomedical technology, is a procedure whereby the anesthesiologist should be investigated in order to generate better effects in the field of the anesthesiology.

Metal ions directing the geometry and nuclearity of azido-metal(II) complexes derived from bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)amine.

The reaction of a methanolic solution containing M(ClO(4))(2)·nH(2)O (M = Cu, Ni, Zn or Cd) or CoCl(2)·6H(2)O with bis(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)amine (bedmpza) in the presence of NaN(3) afforded the complexes [Cu(bedmpza)(µ(1,1)-N(3))](2)(ClO(4))(2) (1), [Ni(bedmpza)(N(3))(µ(1,1)-N(3))](2)·1.5H(2)O (2), [Co(bedmpza)(N(3))(2)] (3), [Zn(bedmpza)(N(3))]ClO(4) (4) and [Cd(bedmpza)(N(3))(µ(1,1)-N(3))](2)·1.5H(2)O (5). The five complexes were characterized by spectroscopic techniques and their molecular structures were determined by single crystal X-ray crystallography. The two mononuclear complexes 3 and 4 display distorted TBP and tetrahedral geometry, respectively with the azide ions acting as monodentate ligands. Doubly bridged end-on-azido dinuclear complexes were obtained in the remaining compounds. Compounds 2 and 5 are isomorphic with distorted octahedral geometry, whereas distorted square pyramidal geometry was determined in the Cu(II) complex 1. The magnetic properties for complexes 1 and 2 were investigated by measuring the magnetic susceptibilities at variable temperatures (300-2 K). The Ni(II) complex exhibits moderate ferromagnetic coupling, whereas [Cu(bedmpza)(µ(1,1)-N(3))](2)(ClO(4))(2) (1) which contains two crystallographic independent dinuclear subunits in the unit cell, with different Cu-N(N3)-Cu bond angles, reveals different signs in the magnetic coupling. The complex represents the first example in the literature that has simultaneously two moieties with ferro- (J = 15.4 cm(-1)) and antiferromagnetic (J = -18.9 cm(-1)) interactions.

Hexanuclear copper(II) cages built on a central {µ3-O···H···µ3-O} moiety, 1,3-bis(dimethylamino)-2-propanolato and capping R-phosphonates: crystal structures, magnetic behavior, and DFT studies.

The syntheses, structural characterization, and magnetic behavior of two new hexanuclear copper(II) complexes derived from R-phosphonic acids and 1,3-bis(dimethylamino)-2-propanol (Hbdmap) with formulas [Cu(6)(µ-bdmap)(3)(µ(3)-Ph-PO(3))(2)(µ(3)-O···H···µ(3)-O)(ClO(4))(2)(H(2)O)]·5H(2)O (1) and [Cu(6)(µ-bdmap)(3)(µ(3)-t-Bu-PO(3))(2)(µ(3)-O···H···µ(3)-O)(µ(1,3)-dca)(dca)(H(2)O)]·6H(2)O (2) (Ph-H(2)PO(3) = phenylphosphonic acid, t-Bu-H(2)PO(3) = tert-butylphosphonic acid, dca = dicyanamide) are reported. Compounds 1 and 2 are hexanuclear 3.111 R-phosphonate(2-)/1,3-bis(dimethylamino)-2-propanolato(1-) cages including in the center the [µ(3)-O···H···µ(3)-O](3-) unit. The temperature dependence of the magnetic properties of 1 and 2 clearly indicates an overall strong antiferromagnetic coupling confirmed by DFT calculations.

[Effectiveness of the correct use of inhalation devices in patients with COPD: randomized clinical trial]. / Eficacia de la utilización correcta de los dispositivos de inhalación en pacientes con enfermedad pulmonar obstructiva crónica: ensayo clínico aleatorizado.

BACKGROUND AND OBJECTIVE: We aimed yo assess whether an educational intervention on the use of inhalational devices improve the functional status of patients with COPD. PATIENTS AND METHOD: Randomized controlled trial with parallel design and simple blind trial performed in a clinic with 94 patients diagnosed with COPD and who used inhaled devices. Participants were randomized into 2 groups: the intervention group held a training session on the use of inhalers at baseline and one month and strengthening the control group with routine monitoring. The main outcome measure was the change in the synthetic index BODE (Body-Mass Index, Airflow Obstruction, Dyspnea and Exercise Capacity). RESULTS: Patients in the intervention group (n=48) experienced an improvement in the sensation of breathlessness decreasing by 0.85 points (95% CI -1.14 to -0.56) on the MMRC dyspnea scale, while the control group (n=46) did not show any significant change p<0.0001. On the walking test the intervention group walked 6.19 meters (95% CI -4.02 to 16.40) while the control group walked 20.55 meters lower (95% CI -37.80 to -3.28), significant differences with p=0.009. The BODE index decreased (improved) -0.82 points in the intervention group (95% CI -1.16 to -0.46) and increased (worsened) 0.20 in control group (95% CI -0.16 to 0.56) p<0.0001. CONCLUSIONS: Patients with COPD who receive specific training on inhaler use as compared with those with regular monitoring experience improvement in their functional state.

Topologic ferrimagnetism in cobalt(II)-azido chains.

New monodimensional Co(II)/azido systems with unusual topological ferrimagnetic response have been characterised.

Polynuclear copper(II) complexes of di-2-pyridyl ketone derivatives and tert-butylphosphonic acid: crystal structures and magnetic behaviour.

The syntheses, structural characterization, and magnetic behavior of four new copper(II) complexes derived from tert-butylphosphonic acid and di-2-pyridyl ketone with formulae [Cu{(py)(2)C(OH)(2)}](C(4)H(9)PO(3)H)(2).(H(2)O)(2) (1), [Cu(2)(mu(2)-C(4)H(9)PO(3)H){(py)(2)C(OCH(2)CH(3))O}(mu(2)-NO(3))(NO(3))(H(2)O)](n).(H(2)O)(n) (2), [Cu(4)(mu(2)-C(4)H(9)PO(3)H)(2)(mu(4)-C(4)H(9)PO(3))(2){(py)(2)C(OCH(3))O}(2)].2H(2)O (3) and Na[Cu(6)(mu(3)-C(4)H(9)PO(3))(3){(py)(2)C(OCH(3))O}(3)(mu(6)-NO(3))(NO(3))(3)] (4) (C(4)H(9)PO(3)H(2) = tert-butylphosphonic acid, (py)(2)C(OH)(2) = bis(2-pyridyl)methanediol, {(py)(2)C(OCH(2)CH(3))O}(-) = bis(2-pyridyl)ethoxymethanolato {(py)(2)C(OCH(3))O}(-) = bis(2-pyridyl)methoxymethanolato, are reported. 1 is a mononuclear compound, with tert-butylhydrogenphosphonate in the anionic form. 2 is a nitrate bridged monodimensional compound with 2.110 tert-butylhydrogenphosphonate bridging ligands. 3 is a tetranuclear compound with 2.110 tert-butylhydrogenphosphonate and 3.111 tert-butylphosphonate bridging ligands and 4 is a hexanuclear compound with 3.111 tert-butylphosphonate bridging ligands. The magnetic properties of 2-4 are reported.

Octanuclear manganese(II,III) clusters stabilized with diamino-alcoxo ligands.

The employment of the 1,3-bis(dimethylamino)-2-propanolate (bdmap) ligand as a chelating/bridging ligand in manganese chemistry is described. The reaction of Mn(R-BzO)(2) and bdmap affords [Mn(8)(O)(4)(R-BzO)(12)(bdmap)(2)(H(2)O)(2)], R = H (1), R = 3-Cl (2) and R = 4-Cl (3), which are mixed-valence Mn(II)(2)Mn(III)(6) clusters. Structural characterization was achieved for 1 and 2, which can be described as a central double defective dicubane Mn(III)(4) subunit, capped by two oxo-bridged Mn(II)-mu(bdmap)-Mn(III) dinuclear units. DC variable-temperature magnetic susceptibility studies were carried out in the 2-300 K range, revealing an overall antiferromagnetic behaviour for 1-3. This work demonstrates for the first time the ability of this kind of polytopic ligands in high nuclearity manganese chemistry.

New topology in azide-bridged cobalt(II) complexes: the weak ferromagnet [Co(2)(N(3))(4)(Hexamethylenetetramine)(H(2)O)](n).

A new polynuclear azido-bridged Co(II) compound with formula [Co(2)(N(3))(4)(HMTA)(H(2)O)](n) (1) (HMTA = hexamethylenetetramine) has been structurally and magnetically characterized. The compound 1 crystallizes in the monoclinic system C2/m space group, and consist of a complex three-dimensional system in which end-to-end and end-on azido bridging ligands between the Co(II) atoms coexist. The HMTA ligand is also linking three different Co(II) atoms. The network analysis shows for 1 a three- and six-connected network topology not previously reported. The magnetic properties of 1 are also reported, and it was found that the magnetic interactions define another new three- and four-connected net assigned as a (6.8(2))(6(4).10(2))-tfo net. In the high temperature region the chi(M) versus T plot can be fitted by using the Curie-Weiss law, and the best fit theta value is -26.6 K. For 1 magnetic ordering and spontaneous magnetization is achieved below T(c) = 15.6 K.

Rational design of manganese-micro-azido 3D compounds by using diazines as co-ligands: synthesis, structure and magnetic behaviour.

The syntheses, structural characterization, and magnetic behaviour of three new 3D manganese(II) complexes with the empirical formulae [Mn(N3)2(5-Brpym)]n (1), [Mn(N3)2(Mepyz)]n (2) and [Mn(N3)2(2-acpy)]n (3), (5-Brpym=5-bromopyrimidine, Mepyz=methylpyrazine, 2-acpy=2-acetylpyridine), are reported. In 1, each manganese atom is linked to the four nearest neighbours by only end-to-end azido bridges, forming square layers. These layers are further connected to 3D networks by the N,N'-bridging ligand. In 2, Mn2(micro(1,1)-N3)2 subunits are connected to the four nearest neighbours by end-to-end azido bridges to form a 3D Mn-azido-sublattice. The Mn2(micro(1,1)-N3)2 subunits are further linked by pairs of N,N'-bridging Mepyz ligands to form 1D ribbons extended along the c-axis of the unit cell. The Mepyz pairs show pi-pi-interactions. In 3, the only end-to-end azido bridges form a diamondoid-like 3D Mn-azido-sublattice. The magnetic properties of 1-3 are reported. At high temperatures, the plots of chiM or chiMTvs.T for can be fitted as a homogeneous 2D system with J=-5.4 cm(-1), g=2.05. Also, at high temperatures the plots of chiM or chiMTvs.T for compound can be fitted with the simple cubic expansion series with J=-1.6 cm(-1), g=2.04. Compound 1 shows spontaneous magnetization below Tc=45 K, which corresponds to the presence of spin-canted antiferromagnetism, whereas 2 and 3 do not show spontaneous magnetization up to 2 K.