RESUMO
With the aim of obtaining light-responsive liquid-crystalline palladium complexes, six palladium complexes derived from an orthometalated imine, bearing one or two azocarboxylato bridges, have been synthesized: [Pd(2)(µ-SC(10)H(21))(µ-O(2)CAzo)(L(1,2))(2)] (7 and 8), [Pd(2)(µ-SC(10)H(21))(µ-O(2)CAzo3C(10))(L(1,2))(2)] (9 and 10), [Pd(µ-O(2)CAzo)L(1)](2) (11), and [Pd(µ-O(2)CAzo3C(10))L(1)](2) (12), in which L(1) = p-H(21)C(10)OC(6)H(3)CHâNC(6)H(4)OC(10)H(21)-p, L(2) = p-H(21)C(10)OC(6)H(3)CHâNC(14)H(29), AzoCO(2)(-) = p-(phenylazo)benzoate, and Azo3C(10)CO(2)(-) = p-(2',3',4'-tris-n-decyloxyphenylazo)benzoate. Three of them (7-9), as well as the precursor Azo3C(10)CO(2)H (3), are thermotropic liquid crystals displaying nematic and smectic A mesophases, while 10-12 have been identified by X-ray diffraction to give rise to "soft" crystal phases. Electronic spectroscopy and (1)H NMR show that all of them undergo a trans-cis isomerization of the azobenzene moiety at λ = 365 nm. The molecular structure determines the photoresponse in solution, which is faster and more stable when the trisubstituted azocarboxylate is present and the motion of the azo group is not hindered by the orthometalated imine. The photoresponse has also been observed in the condensed phases, which change from the ordered phase to the isotropic liquid upon irradiation, except for compound 10, a soft crystal in which a permanent photoalignment highly sensitive to light polarization is produced. The latter is a behavior with potential applications, rather unusual in low-molecular-weight compounds.
RESUMO
OBJECTIVE: To determine the characteristics in citations of articles published in Revista Española de Anestesiología y Reanimación (REDAR). METHOD: References cited in REDAR articles published from 1999 through 2003 were analyzed in terms of type of document, number of pages, language, country of publication, and visibility. Obsolescence was studied based on document age, Burton and Kebler's half-life index, and Price's index. Citation errors were also counted. RESULTS: A total of 14271 citations in 692 articles published in the aforementioned years were studied. Journal articles were the type of document cited most often (n=13113; 91.9%). The average length of documents cited in REDAR articles was 7.29 pages. The language of the cited articles was English in 80.7% of the cases and the majority (51.8%) were published in the United States of America. Journals with impact factors were the sources cited 76% (n=10 833) of the time. The average age of cited works was 9.81 years, the half-life was 6 years, and Price's index was 38.8%. A total of 1610 errors were detected; 609 of them interfered with access to the document. CONCLUSION: The bibliographic references in REDAR are similar to those of other Spanish medical journals and other anesthesiology journals.
Assuntos
Anestesiologia , Bibliometria , Publicações Periódicas como Assunto , Editoração/estatística & dados numéricos , EspanhaRESUMO
OBJETIVO: Determinar las características de las citas incluidas en la bibliografía de los artículos publicados en la Revista Española de Anestesiología y Reanimación(REDAR). MATERIAL Y MÉTODOS: Se consideraron las citas de la lista de referencias de los artículos de la REDAR publicados en el periodo 1999-2003. Se analizaron las citas bibliográficas considerando: tipo de documento, número de páginas, idioma, país de publicación y visibilidad del mismo. Se estudió la obsolescencia, valorando la antigüedad de los documentos, el semiperiodo de Burton y Kebler y el índice de Price. Asimismo, se contabilizaron los errores de redacción. RESULTADOS: Se estudiaron 14.271 citas incluidas en los 692 artículos publicados durante el periodo de estudio. Las publicaciones científicas periódicas fueron el tipo documental más utilizado (n = 13113; 91,9%). Los documentos citados en los artículos de la REDAR tuvieron una extensión media de 7,29 páginas. El inglés fue el idioma del 80,7% de los documentos y Estados Unidos el país en el que se editó el mayor porcentaje de trabajos citados (51,8%). El 76% (n = 10.833) de las citas pertenecían a revistas con factor de impacto. La antigüedad media de las citas fue de 9,81 años, el semiperiodo 6años, y el índice de Price 38,8%. Se detectaron 1.610errores, 609 de los cuales impedían acceder al documento original. CONCLUSIÓN: Las referencias bibliográficas de los artículos de la REDAR presentan características similares a otras revistas médicas españolas y de la especialidad en los parámetros analizados
OBJECTIVE: To determine the characteristics in citations of articles published in Revista Española de Anestesiología y Reanimación (REDAR). METHOD: References cited in REDAR articles published from 1999 through 2003 were analyzed in terms of type of document, number of pages, language, country of publication, and visibility. Obsolescence was studied based on document age, Burton and Kebler's half-life index, and Price's index. Citation errors were also counted. RESULTS: A total of 14271 citations in 692 articles published in the aforementioned years were studied. Journal articles were the type of document cited most often (n=13113; 91.9%). The average length of documents cited in REDAR articles was 7.29 pages. The language of the cited articles was English in 80.7% of the cases and the majority (51.8%) were published in the United States of America. Journals with impact factors were the sources cited 76% (n=10 833) of the time. The average age of cited works was 9.81 years, the half-life was 6 years, and Price's index was 38.8%. A total of 1610 errors were detected; 609 of them interfered with access to the document. CONCLUSION: The bibliographic references in REDAR are similar to those of other Spanish medical journals and other anesthesiology journals
