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1.
Phys Chem Chem Phys ; 22(19): 11012-11024, 2020 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-32367089

RESUMO

The solvent extraction of gold, palladium, technetium, indium and rhenium from both mixtures of a deep eutectic solvent with aqueous salt solutions and of two different aqueous salt solutions has been performed. Initially using gold and then the other metals the solvent extraction results were interpreted using an activity coefficient/function equation (specific ion interaction theory). The most important presented result is the addition of a new term to the specific ion interaction theory equation. Using the new model it will be possible to make predictions of the behaviour of a solvent extraction system where one of the liquid phases is a mixture of aqueous salts and the deep eutectic solvent.

2.
J Pediatr Orthop ; 40(9): 487-491, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32931690

RESUMO

BACKGROUND: The vast majority of pediatric distal-third tibial shaft fractures can be treated with closed reduction and casting. If conservative measures fail, then these fractures are usually treated with 2 antegrade flexible intramedullary nails. A postoperative cast is usually applied because of the tenuous fixation of the 2 nails. Recent studies have described the use of 4 nails to increase the stability of the fixation, a technique that may preclude the need for postoperative casting. The purpose of this biomechanical study is to quantify the relative increase in stiffness and load to failure when using 4 versus 2 nails to surgically stabilize these fractures. METHODS: Short, oblique osteotomies were created in the distal third of small fourth-generation tibial sawbones and stabilized with 2 (double) or 4 (quadruple) flexible intramedullary nails. After pilot testing, 5 models per fixation method were tested cyclically in axial compression, torsion, and 4-point bending in valgus and recurvatum. At the end of the study, each model was loaded to failure in valgus. Stiffness values were calculated, and yield points were recorded. The data were compared using Student's t tests. Results are presented as mean±SD. The level of significance was set at P≤0.05. RESULTS: Stiffness in valgus 4-point bending was 624±231 and 336±162 N/mm in the quadruple-nail and double-nail groups, respectively (P=0.04). There were no statistically significant differences in any other mode of testing. CONCLUSIONS: The quadruple-nail construct was almost 2 times as stiff as the double-nail construct in resisting valgus deformation. This provides biomechanical support for a previously published study describing the clinical success of this fixation construct.


Assuntos
Pinos Ortopédicos , Fixação Intramedular de Fraturas/instrumentação , Tíbia/lesões , Fraturas da Tíbia/cirurgia , Fenômenos Biomecânicos , Criança , Diáfises/lesões , Diáfises/cirurgia , Fixação Intramedular de Fraturas/métodos , Humanos , Masculino , Desenho de Prótese , Tíbia/cirurgia , Fraturas da Tíbia/fisiopatologia
3.
J Foot Ankle Surg ; 53(6): 768-73, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25135103

RESUMO

Tibiotalar dislocations without associated fractures are very uncommon in adults, and only a few studies have been published regarding this injury. More than 50% of these dislocations will be posteromedial, with a high incidence of open injuries, and 25% are pure posterior dislocations. In the present report, we discuss our experience and management of a medial tibiotalar dislocation with no associated fracture. In the present case, the patient was brought to the operating room on presentation to our facility and underwent irrigation and debridement with primary closure of his wound. He was immobilized postoperatively. The patient tolerated the operation well and did not sustain any postoperative complications. He was able to regain function of the injured extremity until he was lost to follow-up. Regarding treatment, the surgery should be speedy, gentle to the soft tissue, and with as little implanted material as possible. Although we do not advocate that our management and treatment of this injury become the standard, the present case provides a good example of some of the challenges often encountered when treating these injuries.


Assuntos
Traumatismos do Tornozelo/cirurgia , Articulação do Tornozelo , Luxações Articulares/cirurgia , Ferimentos e Lesões/cirurgia , Traumatismos do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/diagnóstico por imagem , Articulação do Tornozelo/cirurgia , Desbridamento , Humanos , Imobilização , Cápsula Articular/lesões , Cápsula Articular/cirurgia , Luxações Articulares/diagnóstico por imagem , Ligamentos Laterais do Tornozelo/lesões , Ligamentos Laterais do Tornozelo/cirurgia , Masculino , Radiografia , Tálus/diagnóstico por imagem , Traumatismos dos Tendões/cirurgia , Irrigação Terapêutica , Tíbia/diagnóstico por imagem , Adulto Jovem
4.
Acta Crystallogr Sect E Struct Rep Online ; 70(Pt 8): 80-3, 2014 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-25249860

RESUMO

The title compound, poly[[di-aqua-bis-[1,5-bis-(pyridin-4-yl)pentane-κ(2) N:N']cadmium] bis-(perchlorate) 1,5-bis-(pyridin-4-yl)pentane ethanol mono-solvate], [Cd(C15H18N2)2(H2O)2](ClO4)2·C15H18N2·C2H6O, is a layered coordination polymer built up from highly squashed 4(4) nets in which the octa-hedral trans-CdO2N4 nodes (Cd site symmetry -1) are linked by the bifunctional ligands, forming infinite (110) sheets. The cationic sheets are charge-balanced by inter-layer perchlorate ions. A free 1,5-bis-(pyridin-4-yl)pentane mol-ecule and an ethanol mol-ecule of crystallization are also found in the inter-sheet region. A number of O-H⋯O, O-H⋯N and C-H⋯O hydrogen bonds help to consolidate the layered structure.

5.
Microbiol Spectr ; 10(6): e0262322, 2022 12 21.
Artigo em Inglês | MEDLINE | ID: mdl-36321891

RESUMO

Mycobacterium abscessus is an emerging pathogen that critically depends on iron for growth and pathogenesis. The acquisition of iron in Mycobacterium tuberculosis is governed by siderophores called mycobactins, synthesized by the mbt gene cluster, but the role of this gene cluster in the adaption of M. abscessus to iron limitation is not characterized. We identified an M. abscessus Tn_mutant with interruption of the mbtE gene (MAB_2248c), a central component of mycobactin biosynthesis. We tested this isolate growth characteristic, dependency on supplements, and transcriptomic response, comparing it to the response of wild-type (WT) bacteria in iron-limiting conditions. We also compare the structure of the mbt gene cluster across several mycobacteria. The Tn_mbtE mutant had a substantial, but not absolute, growth defect, which was more substantial in iron-limited media. Supplementation with mycobactin-J, hemin, blood, and surprisingly, albumin, salvaged the poor growth. Similarly, secreted mature (carboxy)-mycobactins from WT bacteria rescued the Tn_mbtE mutant during iron deprivation. The transcriptomic response of the Tn_mbtE mutant involved the upregulation of genes known to be implicated in iron homeostasis and was comparable to that of WT bacteria grown in iron-limiting conditions. Interestingly, the response was not identical to the response of M. tuberculosis to iron limitation. The mbt gene cluster and mycobactins play important roles in the physiology of M. abscessus. (Carboxy)-mycobactin is secreted from WT bacteria and can serve as "public good." The role of several iron-homeostasis related genes (like ideR) may differ between M. abscessus and Mtb. IMPORTANCE Mycobacterium abscessus is an emerging human pathogen belonging to the nontuberculous mycobacteria (NTM) family, causing severe pulmonary disease in compromised individuals. How this bacterium acquires iron is poorly understood. Here, we provide the first characterization of the role(s) the mbtE gene required for the biosynthesis of siderophore mycobactin in M. abscessus. We show that the gene mbtE is required for growth during iron deprivation and can be compensated by several supplements, including, surprisingly, albumin. We also show the transcriptomic response of the mbtE-mutant is comparable to the response of the parental strain to iron starvation and seems different from the response of M. tuberculosis. These results indicate the importance of studying mycobactin in M. abscessus and NTM strains. Understanding this pathway is central to understanding the acquisition of iron within hosts and its role in pathogenesis, which in turn may facilitate the development of antimycobacterial therapeutics.


Assuntos
Mycobacterium abscessus , Mycobacterium tuberculosis , Tuberculose , Humanos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Ferro/metabolismo , Sideróforos/metabolismo
6.
BMJ Case Rep ; 15(9)2022 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-36123006

RESUMO

We present the unique case of a gastropericardial fistula with a rare, delayed presentation in a man in his 70s. Relevant surgeries include Watchman Left Atrial Appendage Closure device placement 1 year prior to arrival and gastric bypass surgery 20 years prior to arrival. The patient presented to the emergency department with weakness, diarrhoea and left knee pain. He was admitted for cellulitis of the left lower extremity, prosthetic septic arthritis of the left knee and group G streptococcus bacteraemia. His hospital course was complicated by acute chest pain and dyspnoea. Imaging revealed pneumopericardium. Oesophagogastroduodenoscopy visualisation confirmed the diagnosis of gastropericardial fistula. The patient could not be transferred to a tertiary centre for definitive management because of the effect of the COVID-19 pandemic on tertiary hospital volumes. After pericardial drainage and administration of antimicrobials without improvement, the patient was discharged to hospice care at his request and died 1 day after discharge.


Assuntos
COVID-19 , Fístula Gástrica , Pneumopericárdio , Fístula Gástrica/diagnóstico , Fístula Gástrica/etiologia , Fístula Gástrica/cirurgia , Humanos , Masculino , Pandemias , Pericárdio/cirurgia , Pneumopericárdio/etiologia
7.
Microbiol Spectr ; 10(2): e0199021, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35311553

RESUMO

Mycobacterium abscessus is an emerging pathogen causing severe pulmonary infections. While environmental in origin, in the clinical setting M. abscessus often changes to a Rough phenotype associated with severe non-remitting infections. Clinical isolates baring mutations in glycopeptidolipid-synthesis genes, leading to the Rough phenotype, were suggested to have increase bacterial virulence while possibly showing reduced transmissibility on fomites. We set to determine whether an isolated glycopeptidolipid (GPL) defect affects transmissibility. We used transposon technology to create a fully isogenic Rough (GPL-defective) (Tn_4099c) and compare it to the isogenic parent strain (ATCC 19977). Survival on fomites was determined by spotting, drying, and retrieving the isolates at designated time points. This was repeated as a competition experiment using a mixture of differentially fluorescent M. abscessus 19977 (Smooth) and the Tn_4099c mutant (Rough). Survival ability in chlorhexidine solution (Septal Scrub Teva) was performed using a disinfectant killing-assay for mycobacteria. Despite significant bacterial killing in all assays, we found no survival advantage to either GPL-defected Rough or GPL-reserved Smooth morphotype-both on fomites and in chlorhexidine. Our findings suggest that while transmission fitness may be altered due to some within-host evolutionary changes, decreased transmissibility of clinical strains cannot be attributed to the GPL-synthesis defect alone. Further studies are needed to determine the effect of other mutations on the transmission potential of M. abscessus in the clinical setting. IMPORTANCE Mycobacterium abscessus is an emerging pathogen causing severe pulmonary infections. In the clinical setting, M. abscsssus undergoes molecular and genetic changes associated with increased virulence. Specifically, bacterial defects in glycopeptidolipid (GPL) synthesis, creating the "Rough" colony phenotype, have been associated with increased virulence, yet were also presumably observed to have decreased survival on fomites, leading to reduced transmissibility. We set to determine whether GPL-synthesis defects are indeed responsible for reduced transmissibility of clinical isolates. We compared fully isogenic GPL-disrupted versus GPL-preserved strains, and demonstrated no survival advantage for either strain on fomites. Additionally, neither isolate had a survival advantage in chlorhexidine, a widely used disinfectant in health care settings. Our findings suggest that reduced transmissibility of clinical isolates, should it be found, cannot be attributed to GPL-synthesis mutations. While clinical isolates may show changes in transmission potential, more studies are needed to investigate the mechanisms leading to these phenotypic changes.


Assuntos
Infecção Hospitalar , Desinfetantes , Infecções por Mycobacterium não Tuberculosas , Mycobacterium abscessus , Clorexidina , Humanos , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium abscessus/genética
8.
JBJS Case Connect ; 11(4)2021 10 06.
Artigo em Inglês | MEDLINE | ID: mdl-34613936

RESUMO

CASE: Tibial plateau fractures can be associated with arterial injuries or dysvascular limbs, particularly in settings of trauma. Dysvascular limb in the setting of fracture is commonly due to dissection of the artery. Entrapment of the artery within the fracture is rare. We report a 48-year-old man who presented with left popliteal entrapment within a left tibial plateau fracture status-post external fixation and stent placement in the popliteal artery. CONCLUSION: Findings from this case highlight entrapment of an artery as a mechanism of a dysvascular limb in the setting of high-energy lower-extremity fractures and specifically for tibial plateau fractures.


Assuntos
Síndrome do Aprisionamento da Artéria Poplítea , Fraturas da Tíbia , Fixação de Fratura , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Poplítea/diagnóstico por imagem , Artéria Poplítea/lesões , Artéria Poplítea/cirurgia , Estudos Retrospectivos , Fraturas da Tíbia/complicações , Fraturas da Tíbia/diagnóstico por imagem , Fraturas da Tíbia/cirurgia
9.
mSystems ; 5(5)2020 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082279

RESUMO

We present a technically simple, easy-to-perform method for generating the genomic libraries for Himar-1 transposon site sequencing (Tn-seq). In addition to being simpler than present methods in the technical aspect, it also allows more robust and straightforward identification of the insertion site, by generating a longer sequence surrounding the insertion TA in the genome. The method makes Tn-seq more user-friendly and accessible to laboratories with more-limited bioinformatic resources. Finally, we created a saturated transposon-mutant library in Mycobacterium abscessus and demonstrated the usefulness of the method in analysis of genes involved in colony morphology, as well as in analysis of the whole Tn-mutant library, with identification of over 8,000 unique mutants.IMPORTANCE Transposon insertion sequencing is a powerful tool, but many researchers are discouraged by the apparent technical complexity of preparing the genomic library for deep sequencing and by the complicated computational analysis needed for insertion site identification. Our proposed method makes the preparation of the library easy and straightforward, relying on well-known molecular biology techniques. In addition, the results obtained from the deep sequencing are easily analyzed in terms of transposon insertion site identification, placing library preparation and analysis within the reach of more researchers in the microbiology community, including those with less computational and bioinformatic resources and experience. This is demonstrated by analysis of the most saturated Tn-mutant library created to date in the emerging pathogen Mycobacterium abscessus.

10.
J Hazard Mater ; 393: 122372, 2020 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-32208329

RESUMO

In several industrial Lithium-ion batteries recycling processes, a thermal treatment with oxidative atmosphere is used to separate the battery components and to remove the organic components. This method is often combined with hydrometallurgical processes with the aim to increase the metal recovery rate or to improve the efficiency of the existing processes. Despite such efforts, the effects of a thermal treatment in an oxidative atmosphere on the microstructure and composition on cathode and anode materials has not been explored. In this manuscript, spent batteries which cathode active material has the composition Li(NixMnyCoz)Oz, i.e. NMC-LiBs, were subjected to thermal treatment at 400˚, 500˚, 600˚, and 700 °C for 30, 60, and 90 min. The microstructure and the composition were studied using XRD and ICP-OES. Thermodynamic calculations were performed to forecast the trend of the carbothermic reduction of active materials. It was observed the formation of gas and organic oil by-products from the decomposition of the polypropylene separator and the polyvinylidene fluoride binder. The identification of the composition of these by-products has great importance since they have a corrosive and toxic behavior. It was observed the fluorine behavior during the thermal treatment and its presence in the oil by-products.

11.
Dalton Trans ; 49(3): 781-796, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31851199

RESUMO

The reactions of [M(η3-C3H5)Br(CO)2(NCMe)2] (M = Mo, W) or [Mo(η3-C3H5)Br(CO)2(PMe2Ph)2] with Na[H2B(mt)2] (mt = methimazolyl) affords the complexes [M(η3-C3H5)(CO)2{κ3-H,S,S'-H2B(mt)2}], the 3-centre, 2-electron B-H-M interaction of which was found to be inert with respect to opening under mild conditions, while more forcing conditions (heating with PMe2Ph) resulted in cleavage of the entire allyl and borate ligands to form [Mo(CO)3(PMe2Ph)3]. In contrast, the reaction of [Mo(η3-C3H5)Br(CO)2(NCMe)2] with Na[H2B(pz)2] affords either [Mo(η3-C3H5)(CO)2{κ3-H,N,N'-H2B(pz)2}] or (more likely) [Mo(η3-C3H5)(CO)2(NCMe){κ2-N,N'-H2B(pz)2}] which in turn reacts with phosphines to provide [[Mo(η3-C3H5)(CO)2(PPhR2){κ2-N,N'-H2B(pz)2}] (R = Me, Ph). The reactions discussed indicate the propensity for 3-centre, 2-electron B-H-Mo interactions increases in the order H2B(pz)2 < H2B(pz*)2 < H2B(mt)2 (pz* = 3,5-dimethypyrazolyl).

12.
Nurs Outlook ; 57(3): 166-71, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19447237

RESUMO

Nursing has a shortage of doctorally-prepared underrepresented minority (URM) scientists/faculty. We describe a five-year University of Illinois at Chicago (UIC) Bridges program for URM master's students' transition to doctoral study and factors in retention/graduation from the PhD program. Four master' students from two partner schools were recruited/appointed per year and assigned UIC faculty advisors. They completed 10 UIC credits during master's study and were mentored by Bridges faculty. Administrative and financial support was provided during transition and doctoral study. Partner schools' faculty formed research dyads with UIC faculty. Seventeen Bridges students were appointed to the Bridges program: 12 were admitted to the UIC PhD program since 2004 and one graduated in 2007. Eight Bridges faculty research dyads published 5 articles and submitted 1 NIH R03 application. Mentored transition from master's through doctoral program completion and administrative/financial support for students were key factors in program success. Faculty research dyads enhanced the research climate in partner schools.


Assuntos
Educação de Pós-Graduação em Enfermagem/organização & administração , Docentes de Enfermagem/organização & administração , Grupos Minoritários/educação , Pesquisa em Enfermagem , Preceptoria/organização & administração , Atitude do Pessoal de Saúde , Chicago , Comportamento Cooperativo , Diversidade Cultural , Currículo , Necessidades e Demandas de Serviços de Saúde , Humanos , Relações Interinstitucionais , Mentores/psicologia , Pesquisa em Educação em Enfermagem , Pesquisa em Enfermagem/educação , Pesquisa em Enfermagem/organização & administração , Avaliação de Programas e Projetos de Saúde , Critérios de Admissão Escolar , Escolas de Enfermagem/organização & administração , Evasão Escolar , Apoio ao Desenvolvimento de Recursos Humanos
13.
Pharmacol Biochem Behav ; 89(4): 523-34, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18377968

RESUMO

JZP-4 is a potent calcium and sodium channel blocker, which is currently being evaluated in patients as an anticonvulsant and mood stabilizer. In the current studies, JZP-4 was evaluated in a variety of animal models for anticonvulsant, antimania and antidepressant activity. In the mouse and rat maximal electroshock models, JZP-4 was slightly more potent than LTG. In the mouse pentylenetetrazole induced seizures model, JZP-4 was approximately twice as potent as lamotrigine in prolonging the time to clonus. In the mouse 6-Hz model for drug resistant or refractory epilepsy, JZP-4 had potent anticonvulsant activity at all current intensities, whereas LTG was active at only the lowest current intensity. In the mouse amphetamine-chlordiazepoxide model for antimanic effects, JZP-4, but not LTG, produced dose-related and significant effects at 3 and 10 mg/kg i.p. In the rat forced swim model of antidepressant activity, JZP-4 (30 mg/kg i.p.) produced a significant reduction in immobility and an increase in climbing behavior. LTG (30 mg/kg i.p.) produced similar effects but these effects did not achieve statistical significance. The specificity of this antidepressant response was confirmed in the rat locomotor test. In this test, JZP-4 produced dose-related and significant reductions in locomotor activity, indicating that it was not a CNS stimulant. LTG produced no significant effects in the rat locomotor test. The studies have demonstrated that JZP-4 has greater potency and efficacy than LTG in models of refractory epilepsy, antidepressant activity and antimania activity. The variance between the effects of LTG and JZP-4 may be related to the greater potency at sodium channels or the additional pharmacological actions of JZP-4 on calcium channels.


Assuntos
Anticonvulsivantes/farmacologia , Antidepressivos/farmacologia , Antimaníacos/farmacologia , Pirazinas/farmacologia , Animais , Anticonvulsivantes/química , Antidepressivos/química , Antimaníacos/química , Comportamento Animal/efeitos dos fármacos , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacologia , Sistema Nervoso Central/efeitos dos fármacos , Modelos Animais de Doenças , Epilepsia/tratamento farmacológico , Humanos , Excitação Neurológica/efeitos dos fármacos , Lamotrigina , Masculino , Camundongos , Estrutura Molecular , Atividade Motora/efeitos dos fármacos , Pirazinas/química , Ratos , Ratos Sprague-Dawley , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico , Bloqueadores dos Canais de Sódio/química , Bloqueadores dos Canais de Sódio/farmacologia , Triazinas/farmacologia
14.
JBJS Case Connect ; 8(3): e49, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29995663

RESUMO

CASE: We report a case of a chronic, irreducible carpometacarpal (CMC) dislocation of the thumb, which was managed with a trapeziometacarpal arthrodesis. CONCLUSION: This case demonstrates that arthrodesis is a suitable salvage procedure for chronic, irreducible CMC dislocations of the thumb.


Assuntos
Artrodese/métodos , Articulações Carpometacarpais/lesões , Traumatismos da Mão/cirurgia , Luxações Articulares/cirurgia , Polegar/lesões , Adulto , Articulações Carpometacarpais/diagnóstico por imagem , Traumatismos da Mão/diagnóstico por imagem , Humanos , Masculino , Traumatismos Ocupacionais/cirurgia , Polegar/diagnóstico por imagem
16.
J Radioanal Nucl Chem ; 317(1): 535-543, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29950750

RESUMO

As an emergency action during the Fukushima accident, seawater was used to maintain cooling. To evaluate the effect of the salt on fission-products, sodium chloride, and tellurium were heated together using different ratios in different atmospheres (inert or oxidizing) using thermogravimetric analysis. The experiment under inert conditions showed no indication of interaction. However, under oxidizing conditions an interaction for all samples was observed that prevented an otherwise observed mass increase of the tellurium reference. The change in the appearance of the samples at increasing temperatures was studied by heating them in a furnace.

17.
Dalton Trans ; 48(1): 209-219, 2018 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-30516190

RESUMO

A range of ruthenaboratranes of the form [Ru(CO)L{κ4-B,S,S',S''-B(mt)3}] (mt = N-methylmercaptoimidazolyl) have been prepared either by substitution of the PPh3 ligand in [Ru(CO)(PPh3){κ4-B,S,S',S''-B(mt)3}] by L (L = PMe2Ph, PMe3, P(OMe)3, P(OEt)3, P(OPh)3) or reactions of [RuCl(R)(CO)Ln] (R = Ph, CH[double bond, length as m-dash]CHPh; n = 2, L = PCy3; n = 3, L = P(OMe)3, PMe2Ph) with Na[HB(mt)3].

18.
Acta Crystallogr E Crystallogr Commun ; 73(Pt 10): 1576-1579, 2017 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29250385

RESUMO

The reaction of diethyl malonate with phthaloyl chloride in aceto-nitrile in the presence of tri-ethyl-amine and magnesium chloride results in the formation of the title compound, diethyl 2-(3-oxo-1,3-di-hydro-2-benzo-furan-1-yl-idene)propane-dioate, C15H14O6. One of the ester groups of the diethyl malonate fragment is almost coplanar with the isobenzo-furan unit, while the plane of the other group is perpendicular to it [dihedral angles = 5.45 (3) and 83.30 (3)°, respectively]. The C-C and C-O distances both in the heterocyclic furan ring and the diethyl malonate fragment are indicative of the dipolar delocalization occurring within the isobenzo-furan unit. This delocalization is likely to be responsible for the unusual inter-molecular O⋯O contact [2.756 (2) Å], established between the O atom of the furan ring and the carbonyl O atom of the diethyl malonate fragment. In the crystal, weak C-H⋯O inter-actions are observed, which link the mol-ecules into [100] chains.

19.
Dalton Trans ; 46(43): 14957-14972, 2017 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-29044261

RESUMO

The reaction of Na[H2B(mt)2] (mt = 2-mercapto, 3-methylimidazol-1-yl, methimazolyl) with [Ru(X)Cl(CO)(PPh3)n] (n = 3 X = H; n = 2 BO2C6H4, SiCl3, SiMe3) affords the complexes [Ru(X)(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}]. Evidence is presented to also support the transient formation of [Ru(X)(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}] (X = CH[double bond, length as m-dash]CHPh, Ph) via a similar strategy, although these are unstable. The osmium complex [OsH(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}] is similarly obtained from [OsHCl(CO)(PPh3)3] or [OsH(NCMe)2(CO)(PPh3)2]BF4. The reaction of [RuH(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}] with chloroform or diphenyldiselenide provides [Ru(X)(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}] (X = Cl, SePh), the latter reaction also providing traces of [Ru(SeH)(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}]. Spectroscopic and structural data for the series [Ru(X)(CO)(PPh3){κ2-H,S,S'-H2B(mt)2}] are discussed in terms of perturbations on the B-H-Ru interaction by the trans-ligand X.

20.
Chem Commun (Camb) ; (2): 221-3, 2005 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-15724192

RESUMO

The reaction of [Rh(C6H5)Cl2(PPh3)2] with Na[HB(mt)3](mt = methimazolyl) provides [RhCl(PPh3){B(mt)3}](Rh-->B) the first authentic example of a compound with a rhodium-boron dative bond.

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