RESUMEN
In the title compound, C(7)H(5)FO(2)·C(7)H(7)NO, a moderate-strength hydrogen bond is formed between the carboxyl group of one mol-ecule and the pyridine N atom of the other. The benzoic acid mol-ecule is observed to be disordered over two positions with the second orientation only 4% occupied. This disorder is also reflected in the presence of diffuse scattering in the diffraction pattern.
RESUMEN
We present a new facet of isobenzofuran chemistry which allows for its efficient manipulation to generate biologically relevant entities. This methodology has been successfully applied toward the synthesis of ajudazol A.
Asunto(s)
Benzofuranos/química , Cumarinas/síntesis química , Ascomicetos/química , Ascomicetos/metabolismo , Productos Biológicos/química , Cumarinas/química , Cristalografía por Rayos X , Modelos Moleculares , Estructura Molecular , Oxidación-ReducciónRESUMEN
We describe the synthesis, structure, and magnetic properties of two new complexes, one decanuclear iron(III) cluster and one hexanuclear mixed-valence manganese(II/III) cluster, where the previously unexplored polydentate ligand Bis-tris propane {(CH2OH)3CNH(CH2)3NHC(CH2OH)3} is used to link small cluster fragments into high-nuclearity complexes.
RESUMEN
An investigation of the magnetic properties of the cobalt(II) citrate cubane [C(NH 2) 3] 8{Co 4(cit) 4}.4H 2O reveals that the cluster is a new cobalt(II) single-molecule magnet, with an energy barrier to reorientation of the magnetization, Delta E/ k B = 21 K, and tau 0 = 8 x 10 (-7) s. The compound displays distinct, frequency-dependent peaks in the out-of-phase (chi'') component of the ac magnetic susceptibility and magnetization versus field hysteresis loops that are temperature and sweep rate dependent. The hysteresis loops collapse at zero field due to very fast quantum tunneling of the magnetization (QTM).
RESUMEN
The synthesis and characterization of ruthenium(II) arene complexes [(eta(6)-arene)Ru(N,N)Cl](0/+), where N,N = 2,2'-bipyridine (bipy), 2,2'-bipyridine-3,3'-diol (bipy(OH)(2)) or deprotonated 2,2'-bipyridine-3,3'-diol (bipy(OH)O) as N,N-chelating ligand, arene = benzene (bz), indan (ind), biphenyl (bip), p-terphenyl (p-terp), tetrahydronaphthalene (thn), tetrahydroanthracene (tha) or dihydroanthracene (dha), are reported, including the X-ray crystal structures of [(eta(6)-tha)Ru(bipy)Cl][PF(6)] (1), [(eta(6)-tha)Ru(bipy(OH)O)Cl] (2) and [(eta(6)-ind)Ru(bipy(OH)(2))Cl][PF(6)] (8). Complexes 1 and 2 exibit CH (arene)/pi (bipy or bipy(OH)O) interactions. In the X-ray structure of protonated complex 8, the pyridine rings are twisted (by 17.31 degrees). In aqueous solution (pH = 2-10), only deprotonated (bipy(OH)O) forms are present. Hydrolysis of the complexes was relatively fast in aqueous solution (t(1/2) = 4-15 min, 310 K). When the arene is biphenyl, initial aquation of the complexes is followed by partial arene loss. Complexes with arene = tha, thn, dha, ind and p-terp, and deprotonated bipyridinediol (bipy(OH)O) as chelating ligands, exhibited significant cytotoxicity toward A2780 human ovarian and A549 human lung cancer cells. Complexes [(eta(6)-bip)Ru(bipy(OH)O)Cl] (7) and [(eta(6)-bz)Ru(bipy(OH)O)Cl] (5) exhibited moderate cytotoxicity toward A2780 cells, but were inactive toward A549 cells. These activity data can be contrasted with those of the parent bipyridine complex [(eta(6)-tha)Ru(bipy)Cl][PF(6)] (1) which is inactive toward both A2780 ovarian and A549 lung cell lines. DFT calculations suggested that hydroxylation and methylation of the bipy ligand have little effect on the charge on Ru. The active complex [(eta(6)-tha)Ru(bipy(OH)O)Cl] (2) binds strongly to 9-ethyl-guanine (9-EtG). The X-ray crystal structure of the adduct [(eta(6)-tha)Ru(bipy(OH)O)(9-EtG-N7)][PF(6)] shows intramolecular CH (arene)/pi (bipy(OH)O) interactions and DFT calculations suggested that these are more stable than arene/9-EtG pi-pi interactions. However [(eta(6)-ind)Ru(bipy(OH)(2))Cl][PF(6)] (8) and [(eta(6)-ind)Ru(bipy)Cl][PF(6)] (16) bind only weakly to DNA. DNA may therefore not be the major target for complexes studied here.
Asunto(s)
Supervivencia Celular/efectos de los fármacos , Rutenio/toxicidad , Células Tumorales Cultivadas/patología , 2,2'-Dipiridil/toxicidad , Cationes/química , Línea Celular Tumoral/efectos de los fármacos , Cristalografía por Rayos X/métodos , Femenino , Humanos , Enlace de Hidrógeno , Hidrólisis , Neoplasias Pulmonares/patología , Espectroscopía de Resonancia Magnética/métodos , Modelos Moleculares , Neoplasias Ováricas/patología , Espectrometría de Masa por Ionización de Electrospray/métodos , Células Tumorales Cultivadas/efectos de los fármacosRESUMEN
The synthesis, structure and magnetic properties of [Co(II)(4)Co(III)(3)(HL)(6)(NO(3))(3)(H(2)O)(3)](2+) [H(3)L = H(2)NC(CH(2)OH)(3)] are reported: the complex is an exchange-biased single molecule magnet.
RESUMEN
We report structure-activity relationships for organometallic RuII complexes of the type [(eta6-arene)Ru(XY)Cl]Z, where XY is an N,N- (diamine), N,O- (e.g., amino acidate), or O,O- (e.g., beta-diketonate) chelating ligand, the arene ranges from benzene derivatives to fused polycyclic hydrocarbons, and Z is usually PF6. The X-ray structures of 13 complexes are reported. All have the characteristic "piano-stool" geometry. The complexes most active toward A2780 human ovarian cancer cells contained XY=ethylenediamine (en) and extended polycyclic arenes. Complexes with polar substituents on the arene or XY=bipyridyl derivatives exhibited reduced activity. The activity of the O,O-chelated complexes depended strongly on the substituents and on the arene. For arene=p-cymene, XY=amino acidate complexes were inactive. Complexes were not cross-resistant with cisplatin, and cross-resistance to Adriamycin was circumvented by replacing XY=en with 1,2-phenylenediamine. Some complexes were also active against colon, pancreatic, and lung cancer cells.
Asunto(s)
Antineoplásicos/síntesis química , Compuestos Organometálicos/síntesis química , Rutenio , 2,2'-Dipiridil/química , Antineoplásicos/química , Antineoplásicos/farmacología , Derivados del Benceno/química , Carboplatino/farmacología , Línea Celular Tumoral , Quelantes/química , Cisplatino/farmacología , Cristalografía por Rayos X , Diaminas/química , Doxorrubicina/farmacología , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Ligandos , Estructura Molecular , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Compuestos Policíclicos/química , Relación Estructura-ActividadRESUMEN
Antiviral cyclam macrocycles block viral entry into cells by binding to the CXCR4 co-receptor. Cyclams bind transition metal ions strongly and can potentially form a range of trans (I-V) and cis configurations which may be recognised differently by co-receptor proteins. A survey of the CSD (crystallographic structural database) shows that the trans-III configuration is the most common in the solid state for complexes of cyclam itself. Other configurations can be induced by N-substitution or ternary complexation and by interaction with solvents in solution. We report X-ray structures for the square-planar trans-III complexes [Pd(cyclam)]Cl(2).2MeOH and the C-C linked dimer [Pd(2)(2,2'-bi-(1,4,8,11-tetraazacyclotetradecane))](ClO4)(4), in which the planes of the two cyclam rings are close to perpendicular (100.1 degrees ), and for tetra-N-benzyl-cyclam and its 5-coordinate Ni(II) complex [Ni(Bz(4)-cyclam)Cl]Cl which has the unusual trans-I configuration.
Asunto(s)
Fármacos Anti-VIH/química , Fármacos Anti-VIH/farmacología , Lactamas Macrocíclicas/química , Lactamas Macrocíclicas/farmacología , Compuestos Organometálicos/química , Compuestos Organometálicos/farmacología , Fármacos Anti-VIH/síntesis química , Cristalografía por Rayos X , Humanos , Técnicas In Vitro , Lactamas Macrocíclicas/síntesis química , Ligandos , Espectroscopía de Resonancia Magnética , Conformación Molecular , Estructura Molecular , Compuestos Organometálicos/síntesis química , Receptores CXCR4/efectos de los fármacos , EstereoisomerismoRESUMEN
AIMS: To determine whether non-urgent referrals can be adequately assessed in a triage clinic, to determine the service outcome of these referrals, and whether triage was acceptable to families, referrers and CAMHS clinicians. METHOD: Families, CAMHS clinicians and GPs were surveyed to ascertain the acceptability of triage. Non-attendance and outcome of triage were recorded. RESULTS: Ninety-two cases were included and the DNA rate fell by one-third. CONCLUSIONS: Overall, clinicians and families reported high rates of satisfaction with triage (93.7% and 95.2%) and multidisciplinary working improved.
RESUMEN
Addition of a coligand in reactions of phosphonates with salts of late 3d metals can lead to more soluble and tractable materials, such as the {Co13 } cage shown (Co: green; P: purple). The structure contains two central PhPO32- ligands, surrounded by a hexanuclear cobalt helix, capped by seven further cobalt sites.
RESUMEN
BACKGROUND: Outcome measurement in child and adolescent mental health services in New Zealand became mandatory in 2005 and little is known about how this is perceived by service users. AIMS: This study aimed to ascertain what service users think about routine outcome measurement in child and adolescent mental health services. METHOD: Nine semi-structured focus groups of child and adolescent service users (n=34) and family members (n=21) were held in different sites in New Zealand to determine their views on outcome measures. RESULTS: Consumers supported outcome assessment with some provisos that have important implications for clinical services: the method of collecting information is critical to acceptance; assessment should be done in the context of an established relationship with the clinician; care is needed over the timing and context of assessment, access to information and feedback of results; and measures should be brief and holistic and their limitations recognised. CONCLUSION: Service users support outcome measures but their implementation requires care and consultation.
Asunto(s)
Servicios de Salud del Adolescente/organización & administración , Servicios de Salud del Niño/organización & administración , Trastornos Mentales/terapia , Servicios de Salud Mental/organización & administración , Evaluación de Resultado en la Atención de Salud , Adolescente , Niño , Necesidades y Demandas de Servicios de Salud , Humanos , Nueva ZelandaRESUMEN
A concise synthesis of the tricyclic core of the marine diterpene natural products labiatin A and australin A has been accomplished. The key ring-forming transformation is a cascade reaction comprising generation of a copper carbenoid from a diazo ketone, intramolecular reaction of the carbenoid with a cyclic ether, and rearrangement of the resulting free oxonium ylide or its metal-bound equivalent with ring expansion of the original cyclic ether.
Asunto(s)
Diterpenos/síntesis química , Compuestos Heterocíclicos con 3 Anillos/síntesis química , Ciclización , Modelos Moleculares , Estructura Molecular , EstereoisomerismoAsunto(s)
Azidas/química , Reactivos de Enlaces Cruzados/química , Fosfatos de Dinucleósidos/química , Guanosina Monofosfato/química , Compuestos Organoplatinos/química , Antineoplásicos/farmacología , Reactivos de Enlaces Cruzados/farmacología , Estabilidad de Medicamentos , Humanos , Concentración de Iones de Hidrógeno , Espectroscopía de Resonancia Magnética/métodos , Modelos Moleculares , Isótopos de Nitrógeno , Compuestos Organoplatinos/farmacología , FotoquímicaRESUMEN
We describe the synthesis, structure and magnetic properties of two decanuclear Fe(III) complexes with novel core topologies, assembled using the tetra-deprotonated form of Bis-tris {2-[bis(2-hydroxyethyl)amino]-2-(hydroxymethyl)propane-1,3-diol, H5L}.
RESUMEN
Understanding the conformations adopted by the sulfonamide group is essential to the understanding of the way that sulfa drugs act upon the body. The relative energies of these conformations in the solid state are estimated from the Cambridge Structural Database (CSD) using cluster analysis, and are used to confirm earlier findings that many high-level ab initio calculations do not reproduce the observed solid-state structure. These conformational studies have been extended to the adjacent torsion angles, and it has been shown that the sulfonamide group significantly affects the form adopted. The relative energies of the observed forms in the solid state have been estimated using data available in the CSD.
RESUMEN
[Ni4Cl4(HL)4] () {H2L=HN(CH2CH2OH)2} has S4 symmetry and crystallises in the tetragonal space group I4(1)/a. Two exchange couplings are observed between the four Ni(II) centres, with J1=7.29 cm(-1) and J2=-2.08 cm(-1), leading to an S=4 ground state. The Ni4 complex shows the onset of frequency dependent signals in the out-of-phase ac susceptibility below 3 K. In single-crystal measurements carried out using a micro-SQUID, hysteresis loops are observed below 0.5 K, confirming that shows slow relaxation of magnetisation. The loops are temperature dependent but only weakly sweep rate dependent due to the presence of small intermolecular interactions, which hinder quantum tunnelling. This exchange bias between Ni4 molecules is also seen in high-frequency high-field EPR measurements, which give the parameters D=-0.75 cm(-1), B4 degrees=-6.7x10(-5) cm(-1) and gz=2.275.
RESUMEN
A new polymorph of 2,4-dihydroxybenzoic acid is reported. The structure was characterized by multiple-temperature X-ray diffraction and solid-state DFT computations. The material shows a geometric pattern of hydrogen bonding consistent with cooperativity between the intermolecular carboxylic acid dimer and intramolecular hydrogen bonds. The presence of proton disorder within this hydrogen-bond system, which would support such a cooperative model, was not fully ruled out by the initial X-ray studies. However, solid-state calculations on the three possible end-point tautomers indicate that the dominant crystallographically observed configuration is substantially lower in energy than the other tautomers (by at least 9 kJ mol(-1)), indicating that no disorder should be expected. It is therefore concluded that no disorder is observed either in the intra- or intermolecular hydrogen bonds of the title compound and that the cooperativity between the hydrogen bonds is not present within the temperature range studied.
RESUMEN
The synthesis, structure and magnetic properties of [Mn(13)O(8)(OEt)6(O(2)CC(6)H(4)OPh)12] are reported as the first example of a high nuclearity manganese complex with 2-phenoxybenzoate: the complex possesses S6 symmetry and an S = 11/2 ground state.
RESUMEN
Cluster analysis can be an effective tool for analysing large quantities of data. Here it has been applied to the conformational analysis of enones and enimines in the crystalline solid state, using structural information mined from the Cambridge Structural Database. The forms that are common in the gaseous state and in solution are already known from spectroscopic studies. These forms are also found to be the most common conformations observed in the solid state; however, the clustering method highlights those structures that do not conform to the expected geometries. The study is supported by ab initio gas phase calculations on simple enone and enimine fragments.