Single-molecule magnet behaviour and catalytic properties of tetrahedral Co(II) complexes bearing chloride and 1,2-disubstituted benzimidazole as ligands.

Five cobalt(II) complexes of formula [CoCl2(Ln)2] [1 with L1 = 1-benzyl-2-phenyl-1H-benzimidazole, 2 with L2 = 2-(furan-2-yl)-1-(furan-2-ylmethyl)-1H-benzimidazole, 3 with L3 = 1-(4-chlorobenzyl)-2-(4-chlorophenyl)-1H-benzimidazole, 4 with L4 = 1-(2-methoxybenzyl)-2-(2-methoxyphenyl)-1H-benzimidazole and 5 with L5 = 2-(thiophen-2-yl)-1-(thiophen-2-ylmethyl)-1H-benzimidazole] have been synthesised, spectroscopically characterised and cryomagnetically investigated. The crystal structures of 1, 3, 4 and 5 have been determined by X-ray diffraction on single crystals. Each cobalt(II) ion is four-coordinate in a distorted tetrahedral environment built by two chloride anions and two benzimidazole ligands. The neutral molecules are well separated from each other, shortest intermolecular cobalt⋯cobalt distances being greater than 9.0 Å. Static (dc) magnetic susceptibility measurements in the temperature range 2.0-300 K of 1-5 reveal the occurrence of a Curie law behaviour of magnetically non-interacting spin quadruplets in the high-temperature domain with a downturn at low temperatures due to magnetic anisotropy. The values of the D and E/D parameters for these compounds vary in the ranges -8.75 to +8.96 cm-1 and 0.00140 to 0.23, respectively. Dynamic (ac) magnetic susceptibility measurements of 1-5 show slow magnetic relaxation in the lack (1) or under the presence (1-5) of applied dc magnetic fields, a feature which is typical of single-molecule magnet behaviour (SMM). The analysis of the ac data shows that a thermally activated Orbach relaxation mechanism dominates this behaviour. Complexes 1-5 also act as efficient and highly selective eco-friendly catalysts in the coupling reaction between CO2 and epoxides to produce cyclic carbonates under solvent-free conditions. Under optimized reaction conditions, different epoxides were converted to the respective cyclic carbonate, with excellent conversions, using catalyst 4.

Trinuclear Cobalt(II) Triple Helicate with a Multidentate Bithiazolebis(oxamate) Ligand as a Supramolecular Nanomagnet.

The cobalt(II)-mediated self-assembly of the potentially tris(chelating) N,N'-2,2'-(4,4'-bithiazole)bis(oxamate) (dabtzox) ligand gives a new metal-organic supramolecular nanomagnet of formula K6Co3(dabtzox)3·8H2O·MeOH (1) featuring a unique linear triple-stranded trinuclear structure of the helicate type.

A giant hybrid organic-inorganic octahedron from a narrow rim carboxylate calixarene.

Here we discovered an unprecedented giant octahedral coordination compound bearing 16 Zn2+, 12 Na+, 8 O2-, 4 OH-, 13 H2O and 6 L4- ligands [L4- = fully deprotonated tetra(carboxymethoxy)calix[4]arene]. Its structure was elucidated by single-crystal X-ray diffraction, wavelength-dispersive X-ray spectroscopy and MALDI-TOF mass spectrometry. This compound, Zn8Na6L6⊃Zn8Na6O8(OH)4(H2O)13 (external⊃internal), has eight tetrahedral zinc ions forming the coordination vertices of an outermost cube where carboxylate groups from the sodium calixarenes are anchored. Its core consists of eight Zn2+, six Na+, eight O2-, and four OH- distributed over three layers, besides thirteen coordinated H2O molecules.

Intermolecular interaction energies and magnetic properties of spin-isolated multinuclear CuII complexes.

Dinuclear CuII complexes with 3,5-dinitrobenzoates and 2,2'-bipyridine (2) or 1,10-phenanthroline (3) were synthesized and characterized. A complete energy framework analysis using the HF/3-21G energy model was performed which found that dispersion forces and C-H...O interactions are responsible for the crystal structure features. The magnetic properties of the complexes show a weak magnetic exchange between spins, resulting in low exchange constants of -2.72 (1) cm-1 and -1.10 (1) cm-1 for complexes (2) and (3), respectively. This results from the low overlap between magnetic orbitals induced by 3,5-dinitrobenzoate bridges and the arrangement of the magnetic orbitals. Consequently, the dinuclear complexes (2) and (3) behave as spin-isolated multinuclear CuII species in contrast to the trinuclear complex with similar ligands.

2D and 3D mixed MII/CuII metal-organic frameworks (M = Ca and Sr) with N,N'-2,6-pyridinebis(oxamate) and oxalate: preparation and magneto-structural study.

Three heterobimetallic complexes of formula [Ca2Cu3(mpyba)2(2-apyma)(H2O)7]·8.3H2O (1), [Sr2Cu3(mpyba)2(2-apyma)(H2O)8]·11.6H2O (2) and [Sr4.5Cu4(mpyba)4(ox)(H2O)20]·8.5H2O (3) [H4mpyba = N,N'-2,6-pyridinebis(oxamic acid), 2-apyma = 2-(6-aminopyridinyl)oxamate and ox = oxalate] have been synthesized and structurally characterized. Complexes 1 and 2 are isostructural compounds, with tricopper(ii) units having mpyba and its hydrolytic product (2-apyma) as ligands. They are interlinked through strontium(ii) (1) and calcium(ii) (2) ions to afford neutral two-dimensional networks. Two of the copper(ii) ions are five-coordinate in distorted square pyramidal (Cu3) and trigonal bipyramidal (Cu1) surroundings, whereas the other (Cu2) is six-coordinate in an elongated octahedral environment. The main difference between their structures, apart from the number of water molecules, resides in the nature of the alkaline earth cation coordinated to the oxamate fragments, Sr2+ (1)/Ca2+ (2), which exhibit eight and seven coordination, respectively. The π-π interactions and an extensive network of hydrogen bonds in 1 and 2 lead to supramolecular 3D structures. The relatively small size of their cavities, in the micropore domain, hinders the inclusion of N2 but allows CO2 adsorption (0.45 and 0.52 mmol g-1 for 1 and 2, respectively). The structure of 3 is made up of [3,3] metallacyclophane-type motifs, having the formula [Cu2(mpyba)2(H2O)2]4-. These act as tetrakis(bidentate) ligands towards the strontium(ii) ions (Sr1, Sr2 and Sr3), leading to a sheet-like polymer growing in the bc plane, which extends further along the crystallographic a axis by a bis(chelating) oxalate between the Sr1 atoms. The investigation of the magnetic properties of 1-3 in the temperature range 1.9-300 K shows the occurrence of an overall antiferromagnetic behaviour for 1 and 2 [J12 = J23 = -9.71(2) (1) and -10.81(5) cm-1 (2), with the Hamiltonian being defined as H = -J12S1·S2 - J23S2·S3 + gßH[S1 + S2 + S3], and a ferromagnetic coupling within the dicopper(ii) metallacylophane unit of 3 [J = +1.86(1) cm-1 through the Hamiltonian H = -JS1·S2 + gßH(S1 + S2)]. Simple orbital symmetry considerations (1-3) and the spin polarization mechanism (3) account for the observed magnetic properties.

Há relação entre custos hospitalares e tempo porta-balão? / Is there an association between hospital costs and door-to-balloon time?

O tempo porta-balão (TPB) tornou-se uma medida de desempenho e é foco de iniciativas de melhoria da qualidade assistencial. Este estudo teve como objetivo avaliar a relação entre o TPB e seu impacto nos custos de internação hospitalar. Métodos: Pacientes tratados com intervenção coronária percutânea primária, entre 2008 e 2013, foram divididos de acordo com o TPB < ou ≥ 90 minutos. Todos os custos registrados na alta hospitalar foram ajustados por meio do Índice de Variação de Custos Médico-Hospitalares.Resultados: Foram incluídos 141 pacientes, agrupados em TPB < 90 minutos (n = 77) e TPB ≥ 90 minutos(n = 64). Os TPB foram 64,0 ± 14,1 minutos e 133,8 ± 35,2 minutos, respectivamente. Não foram observadasdiferenças nos desfechos clínicos entre os grupos. Os custos foram de R$ 34.883,24 ± 27.749,46, sendo ocusto médio para TPB < 90 minutos de R$ 33.194,24 ± 27.387,61, e para TPB ≥ 90 minutos, de R$ 36.947,58± 28.267,80 (p = 0,43). Os custos, segundo a artéria culpada, foram de R$ 29.588,53 ± 16.358,85 para acoronária direita; R$ 48.494,62 ± 44.015,04 para a circunflexa; e de R$ 34.016,96 ± 26.503,94 paraa descendente anterior. Houve diferença entre os custos dos procedimentos relativos à artéria circunflexacomparados aos da coronária direita ou da descendente anterior (p = 0,01), mas não houve diferença entre os custos relativos à coronária direita, comparados à descendente anterior (p = 0,68). Conclusões: Não houve diferença nos custos hospitalares, no âmbito da saúde suplementar, quando os grupos foram divididos de acordo com o TPB. Os desfechos clínicos foram semelhantes, e foi encontrada uma diferença de custos em pacientes com a artéria circunflexa culpada...

Door-to-balloon time (DBT) has become a measure of performance and is the focus in quality of care improvement initiatives. This study aimed to evaluate the association between DBT and its impacton hospital costs. Methods: Patients treated with primary percutaneous coronary intervention between 2008 and 2013 were divided according to the DBT < or ≥ 90 minutes. All costs recorded at hospital discharge were adjusted bythe Medical-Hospital Cost Variation Index. Results: A total of 141 patients were included, grouped as DBT < 90 minutes (n = 77) and DBT ≥ 90 minutes(n = 64). DBT was 64.0 ± 14.1 minutes and 133.8 ± 35.2 minutes, respectively. There were no diferences in clinical outcomes between the groups. The costs were R$ 34,883.24 ± 27,749.46, with the mean cost for DBT < 90 minutes being R$ 33,194.24 ± 27,387.61 and the cost for DBT ≥ 90 minutes R$ 36,947.58 ±28,267.80 (p = 0.43). The costs, according to the culprit artery, were R$ 29,588.53 ± 16,358.85 for the rightcoronary artery; R$ 48,494.62 ± 44,015.04 for the left circumflex artery; and R$ 34,016.96 ± 26,503.94 forthe left anterior descending artery. There was a difference between the costs of procedures related to theleft circumflex artery when compared to the right coronary or left anterior descending arteries (p = 0.01),but there was no difference between the costs related to the right coronary, when compared to the left anterior descending artery (p = 0.68). Conclusions: There was no difference in hospital costs regarding the private health insurance, when the groups were divided according to the DBT. Clinical outcomes were similar and a difference in costs wasfound for patients with the circumflex artery as the culprit vessel...

Estudo multicêntrico dos resultados das trocas valvares com o uso da bioprótese Biocar no Estado de Minas Gerais / Results with implanted bioprothesis in Biocor in the state of Minas Gerais, Brazil

No período de março de 1981 a março de 1988, foram implantadas 2324 biopróteses, em 2016 pacientes, em 5 Centros do Estado de Minas Gerais. Este estudo inclui somente a análise dos pacientes submetidos a troca valvar aórtica (n = 603) e mitral (n = 1110), isoladamente. Neste grupo ( = 1713) , a mortalidade hospitalar foi de 104 pacientes (6,1%). Dos 1609 pacientes que receberam alta hospitalar, conseguimos o seguimento de 1101 pacientes (64,3). Esta análise corresponde a um período de 1 a 84 meses, com média de 48 meses e com um seguimento cumulativo d; aórticas (n = 385) = 1230 pacientes/ano; mitrais (n = 716) = 3018 pacientes/ano. Foram registradas 102 complicaçöes tardias em 716 pacientes mitrais (14,24%) e 51 complicaçöes no grupo aórtico (13,2%). Com relaçäo à faixa etária, encontramos 220 pacientes menores de 20 anos (mitrais = 176/aórticos = 44) e, neste subgrupo, as disfunçöes valvares incidiram em 43% dos pacientes mitrais e em 29% dos pacientes aórticos. A endocardite protética foi mais encontrada nos aórticos (45%) do que nos mitrais (29,7%). Dos 1101 pacientes, 62 foram reoperados, com mortalidade hospitalar de 12,6%. A reoperaçäo por disfunçäo valvar foi mais freqüente no grupo mitral com idade inferior a 20 anos. A curva atuarial livre de mortalidade relacionada à bioprótese foi de 97,1% (32/1101 pacientes). No grupo aórtico, 96,9% estiveram livres de disfunçäo valvar ao final de 7 anos, enquanto que, no grupo mitral, este índice foi de 95,2%. Nos pacientes menores de 20 anos do grupo mitral, encontramos o maior índice de falência valvar (85,3% livre após 7 anos). Ao final deste estudo, a maior parte destes pacientes encontrava-se em classe funcional I e II. Embora a incidência de reoperaçäo seja expressiva, esta é aceitável, tendo em vista que as biopróteses oferecem uma alternativa mais segura do que as próteses mecânicas, durante este mesmo período do seguimento. A análise destes resultados sugere a continuaçäo de pesquisas que tornem possível a fabricaçäo de um substituto valvar ideal. Todavia, estes resultados comparam-se, de modo favorável, a resultados com biopróteses semelhantes da literatura mundial