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1.
BioDrugs ; 37(3): 433-440, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36881323

RESUMO

BACKGROUND: The Phase 3 CT-P6 3.2 study demonstrated equivalent efficacy and comparable safety between CT-P6 and reference trastuzumab in patients with human epidermal growth factor receptor-2 (HER2)-positive early breast cancer after up to 3 years' follow-up. OBJECTIVE: To investigate long-term survival with CT-P6 and reference trastuzumab. METHODS: In the CT-P6 3.2 study, patients with HER2-positive early breast cancer were randomised to neoadjuvant chemotherapy with CT-P6 or reference trastuzumab, surgery, and adjuvant CT-P6 or reference trastuzumab before a 3-year post-treatment follow-up. Patients who completed the study could enter a 3-year extension (CT-P6 4.2 study). Data were collected every 6 months to assess overall survival (OS), disease-free survival (DFS), and progression-free survival (PFS). RESULTS: Of 549 patients enrolled in the CT-P6 3.2 study, 216 (39.3%) patients continued in the CT-P6 4.2 study (CT-P6, 107; reference trastuzumab, 109) (intention-to-treat extension set). Median follow-up was 76.4 months for both groups. Medians were not reached for time-to-event parameters; estimated hazard ratios (95% confidence intervals) for CT-P6 versus reference trastuzumab were 0.59 (0.17-2.02) for OS, 1.07 (0.50-2.32) for DFS, and 1.08 (0.50-2.34) for PFS. Corresponding 6-year survival rates in the CT-P6 and reference trastuzumab groups, respectively, were 0.96 (0.90-0.99) and 0.94 (0.87-0.97), 0.87 (0.78-0.92) and 0.89 (0.81-0.94), and 0.87 (0.78-0.92) and 0.89 (0.82-0.94). CONCLUSIONS: Data from this extended follow-up of the CT-P6 3.2 study demonstrate the comparable long-term efficacy of CT-P6 and reference trastuzumab up to 6 years. EUDRACT NUMBER: 2019-003518-15 (retrospectively registered 10 March 2020).


Assuntos
Medicamentos Biossimilares , Neoplasias da Mama , Humanos , Feminino , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Seguimentos , Trastuzumab , Receptor ErbB-2/metabolismo , Medicamentos Biossimilares/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico
2.
Expert Opin Biol Ther ; 23(8): 737-747, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36757373

RESUMO

BACKGROUND: CT-P10 was the first licensed rituximab biosimilar. This Korean post-marketing surveillance study evaluated CT-P10 safety and effectiveness in approved indications. RESEARCH DESIGN AND METHODS: This prospective, open-label, observational, phase 4 study collected routine clinical practice data across 27 centers in the Republic of Korea. Patients received their first CT-P10 treatment, per prescribing information, for non-Hodgkin's lymphoma (NHL), chronic lymphocytic leukemia (CLL), rheumatoid arthritis (RA), granulomatosis with polyangiitis (GPA), or microscopic polyangiitis (MPA) during the surveillance period (16 November 2016-15 November 2020). Safety (including adverse events [AEs] and adverse drug reactions [ADRs]) and disease-specific clinical response (by best overall response [NHL/CLL], Disease Activity Score in 28-joints [RA], or Birmingham Vasculitis Activity Score for Wegener's Granulomatosis [GPA/MPA]) were assessed for ≤1 year (NHL/CLL) or ≤24 weeks (RA/GPA/MPA). RESULTS: The safety population comprised 677 patients (604 NHL, 16 CLL, 42 RA, 7 GPA, 8 MPA). AEs/ADRs were reported for 68.4%/27.7% (NHL/CLL), 31.0%/14.3% (RA), and 86.7%/13.3% (GPA/MPA) of patients. Serious AEs and unexpected ADRs did not raise new safety signals. Pneumonia was the most frequent serious ADR overall. Positive effectiveness outcomes were observed. CONCLUSIONS: Findings were consistent with the known CT-P10/reference rituximab safety profile, with high effectiveness observed in NHL/CLL and RA.


Assuntos
Artrite Reumatoide , Medicamentos Biossimilares , Granulomatose com Poliangiite , Leucemia Linfocítica Crônica de Células B , Linfoma não Hodgkin , Humanos , Rituximab/efeitos adversos , Medicamentos Biossimilares/efeitos adversos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Estudos Prospectivos , Artrite Reumatoide/diagnóstico , Artrite Reumatoide/tratamento farmacológico , Linfoma não Hodgkin/tratamento farmacológico , Granulomatose com Poliangiite/tratamento farmacológico , República da Coreia , Vigilância de Produtos Comercializados , Resultado do Tratamento
3.
BioDrugs ; 36(6): 749-760, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36169807

RESUMO

BACKGROUND: CT-P16 is a candidate bevacizumab biosimilar. OBJECTIVE: This double-blind, multicenter, parallel-group, phase III study aimed to establish equivalent efficacy between CT-P16 and European Union-approved reference bevacizumab (EU-bevacizumab) in patients with metastatic or recurrent non-squamous non-small cell lung cancer (nsNSCLC). PATIENTS AND METHODS: Patients with stage IV or recurrent nsNSCLC were randomized (1:1) to receive CT-P16 or EU-bevacizumab (15 mg/kg every 3 weeks; ≤ 6 cycles) with paclitaxel (200 mg/m2) and carboplatin (area under the curve 6.0; both for 4-6 cycles), as induction therapy. Patients with controlled disease after induction therapy continued with CT-P16 or EU-bevacizumab maintenance therapy. The primary endpoint was objective response rate (ORR) during the induction period. Time-to-event analyses, pharmacokinetics, safety, and immunogenicity were also evaluated. Results obtained after 1 year of follow-up are presented. RESULTS: Overall, 689 patients were randomized (CT-P16, N = 342; EU-bevacizumab, N = 347). ORR was 42.40% (95% confidence interval [CI] 37.16-47.64) and 42.07% (95% CI 36.88-47.27) for CT-P16 and EU-bevacizumab, respectively. The risk difference (0.40 [95% CI - 7.02 to 7.83]) and risk ratio (1.0136 [90% CI 0.8767-1.1719]) for ORR fell within predefined equivalence margins (- 12.5 to + 12.5%, and 0.7368 to 1.3572, respectively), demonstrating equivalence between CT-P16 and EU-bevacizumab. Median response duration, time to progression, progression-free survival, and overall survival were comparable between treatment groups. Safety profiles were similar: 96.2% (CT-P16) and 93.0% (EU-bevacizumab) of patients experienced treatment-emergent adverse events. Pharmacokinetics and immunogenicity were comparable between groups. CONCLUSIONS: Equivalent efficacy and similar pharmacokinetics, safety, and immunogenicity support bioequivalence of CT-P16 and EU-bevacizumab in patients with nsNSCLC. TRIAL REGISTRATION NUMBER: NCT03676192.


Assuntos
Medicamentos Biossimilares , Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Bevacizumab/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Medicamentos Biossimilares/efeitos adversos , União Europeia , Neoplasias Pulmonares/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Método Duplo-Cego , Tomografia Computadorizada por Raios X , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos
4.
Water Res ; 222: 118864, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-35870393

RESUMO

Environmental damage from serious nuclear accidents should be urgently restored, which needs the removal of radioactive species. Radioactive iodine isotopes are particularly problematic for human health because they are released in large amounts and retain radioactivity for a substantial time. Herein, we prepare platinum-coated iron nanoparticles (Fe@Pt) as a highly selective and reusable adsorbent for iodine species, i.e., iodide (I-), iodine (I2), and methyl iodide (CH3I). Fe@Pt selectively separates iodine species from seawater and groundwater with a removal efficiency ≥ 99.8%. The maximum adsorption capacity for the iodine atom of all three iodine species was determined to be 25 mg/g. The magnetic properties of Fe@Pt allow for the facile recovery and reuse of Fe@Pt, which remains stable with high efficiency (97.5%) over 100 uses without structural and functional degradation in liquid media. Practical application to the removal of radioactive 129I and feasibility for scale-up using a 20 L system demonstrate that Fe@Pt can function as a reusable adsorbent for the selective removal of iodine species. This systematic procedure is a standard protocol for designing highly active adsorbents for the clean separation and removal of various chemical species dissolved in wastewater.


Assuntos
Iodo , Neoplasias da Glândula Tireoide , Poluentes Químicos da Água , Adsorção , Humanos , Iodetos , Radioisótopos do Iodo/química , Água/química , Poluentes Químicos da Água/química
5.
BioDrugs ; 33(2): 173-181, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30850957

RESUMO

BACKGROUND: CT-P16 is a candidate biosimilar of bevacizumab, a monoclonal antibody targeting vascular endothelial growth factor that is used in the treatment of a range of advanced solid cancers. OBJECTIVE: The objective of this study was to demonstrate the pharmacokinetic equivalence of CT-P16 and European Union (EU)-approved bevacizumab (EU-bevacizumab) and US-licensed bevacizumab (US-bevacizumab) reference products. METHODS: In this double-blind, parallel-group phase I trial (ClinicalTrials.gov identifier NCT03247673), healthy adult males were randomized (1:1:1) to receive a single dose of CT-P16 5 mg/kg, EU-bevacizumab 5 mg/kg, or US-bevacizumab 5 mg/kg. Primary study endpoints were area under the concentration-time curve (AUC) from time zero to infinity (AUC∞), AUC from time zero to the last quantifiable concentration (AUClast), and maximum serum concentration (Cmax). Pharmacokinetic equivalence was shown if the 90% confidence intervals (CIs) of the geometric mean (GM) ratios of the AUC∞, AUClast, and Cmax were within the predefined bioequivalence margin of 80-125%. Safety and immunogenicity were also evaluated. RESULTS: A total of 144 subjects were randomized: 47 to CT-P16, 49 to EU-bevacizumab, and 48 to US-bevacizumab. The 90% CIs for the GM ratios of AUC∞, AUClast, and Cmax for CT-P16/EU-bevacizumab, CT-P16/US-bevacizumab, and EU-bevacizumab/US-bevacizumab comparisons were all within the bioequivalence margin. Mean serum concentration-time profiles, secondary pharmacokinetic parameters, and safety and immunogenicity profiles were comparable across all three treatment groups. CONCLUSION: CT-P16 demonstrated pharmacokinetic equivalence to EU-bevacizumab and US-bevacizumab. Safety and immunogenicity profiles were similar for CT-P16, EU-bevacizumab, and US-bevacizumab. These data support the further clinical evaluation of CT-P16 as a bevacizumab biosimilar. CLINICAL TRIALS REGISTRATION: NCT03247673.


Assuntos
Bevacizumab/farmacocinética , Medicamentos Biossimilares/farmacocinética , Adulto , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/sangue , Anticorpos Monoclonais/farmacocinética , Bevacizumab/efeitos adversos , Bevacizumab/sangue , Medicamentos Biossimilares/efeitos adversos , Medicamentos Biossimilares/sangue , Método Duplo-Cego , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Equivalência Terapêutica , Adulto Jovem
6.
Inorg Chem ; 57(14): 8299-8306, 2018 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-29952559

RESUMO

The electrochemical reduction of trivalent samarium in a LiCl-KCl eutectic melt produced highly stable divalent samarium, whose electrochemical properties and electronic structure in the molten salt were investigated using cyclic voltammetry, UV-vis absorption spectroscopy, laser-induced emission spectroscopy, and density functional theory (DFT) calculations. Diffusion coefficients of Sm2+ and Sm3+ were electrochemically measured to be 0.92 × 10-5 and 1.10 × 10-5 cm2/s, respectively, and the standard apparent potential of the Sm2+/3+ couple was estimated to be -0.82 V vs Ag|Ag+ at 450 °C. The spectroelectrochemical study demonstrated that the redox behavior of the samarium cations obeys the Nernst equation ( E°' = -0.83 V, n = 1) and the trivalent samarium cation was successfully converted to the divalent cation having characteristic absorption bands at 380 and 530 nm with molar absorptivity values of 1470 and 810 M-1 cm-1, respectively. Density function theory calculations for the divalent samarium complex revealed that the absorption signals originated from the 4f6 to 4f55d1 transitions. Additionally, laser-induced emission measurements for the Sm cations in the LiCl-KCl matrix showed that the Sm3+ ion in the LiCl-KCl melt at 450 °C emitted an orange color of fluorescence, whereas a red colored emission was observed from the Sm2+ ion in the solidified LCl-KCl salt at room temperature.

7.
J Foot Ankle Surg ; 56(2): 252-254, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28231961

RESUMO

The Manchester-Oxford Foot Questionnaire (MOXFQ) is a practical, reliable, and valid questionnaire for hallux valgus surgery and has been translated into several languages. However, the MOXFQ has not been translated into Korean. In the present study, we aimed to translate and evaluate the validity and reliability of the Korean version of the MOXFQ for patients affected by hallux valgus. In accordance with the guidelines of cross-cultural adaptation, we translated the English version of MOXFQ into Korean and then backward translated it into English. We sent out letters that included the Korean version of the MOXFQ, a visual analog scale measure of pain, and a validated Korean version of the short-form 36-item Health Survey to 135 patients with hallux valgus. A retest was administered after 2 weeks. Of the 135 patients, 104 responded to the first questionnaire, and 82 of the first-time responders returned their second questionnaires. We evaluated the test-retest reliability, internal consistency, concurrent validity, and construct validity of the Korean version of the MOXFQ. The intraclass correlation coefficient for test-retest reliability was 0.82 for the total MOXFQ and ranged from 0.81 to 0.82 for the 3 subscales. Cronbach's alpha for the total MOXFQ was 0.85 and ranged from 0.8 to 0.92 for the 3 subscales. Concurrent and construct validity was supported by significant correlation with the visual analog scale and short-form 36-item Health Survey subscale scores. The Korean version of the MOXFQ was tested, and it was found to be a valid and reliable instrument for patients with hallux valgus.


Assuntos
Avaliação da Deficiência , Hallux Valgus/fisiopatologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Hallux Valgus/psicologia , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , República da Coreia , Inquéritos e Questionários , Tradução
8.
J Foot Ankle Surg ; 55(4): 759-61, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27067199

RESUMO

Although translated versions of the Foot Function Index (FFI) in several languages are available, the absence of a Korean version has precluded comparing the data from Korea with the data from other countries using the FFI. We, therefore, evaluated the reliability and validity of the adapted Korean version of the FFI. We translated the English version of the FFI into Korean and back into English. We mailed the Korean version of the visual analog scale, FFI, and the previously validated Medical Outcomes Study Short-Form 36-item questionnaire (SF-36) to 121 patients with treated foot complaints. To evaluate the test-retest reliability and internal consistency, we used the intraclass correlation coefficient and Cronbach's α, respectively. We also evaluated the concurrent and construct validity of Korean version of the FFI by comparing the visual analog scale and SF-36. Cronbach's α was 0.91 and 0.95 for the pain and disability subscales, respectively. The reproducibility was good, and a strong correlation between the FFI and the SF-36 and visual analog scale with related content was observed, indicating good construct validity.The Korean version of the FFI is a reliable and valid questionnaire for the self-assessment of pain and disability in Korean patients with foot complaints.


Assuntos
Avaliação da Deficiência , Pé/fisiopatologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , República da Coreia , Tradução , Escala Visual Analógica , Adulto Jovem
9.
Macromol Rapid Commun ; 37(1): 73-78, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26488433

RESUMO

Electrohydrodynamic cojetting has been employed to synthesize compartmentalized microfibers from thermally responsive hydrogels. The synthesis of the hydrogels as well as their transformation into compartmentalized microcylinders is discussed. After programmable shape-shifting, snail-like particles are obtained that undergo functional and structural reconfiguration in response to a change in temperature.

11.
Nano Lett ; 14(10): 5493-9, 2014 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-25255444

RESUMO

Single molecule break junction experiments and nonequilibrium Green's function calculations using density functional theory (NEGF-DFT) of carbodithioate- and thiol-terminated [5,15-bis(phenylethynyl)-10,20-diarylporphinato]zinc(II) complexes reveal the impact of the electrode-linker coordination mode on charge transport at the single-molecule level. Replacement of thiolate (-S(-)) by the carbodithioate (-CS2(-)) anchoring motif leads to an order of magnitude increase of single molecule conductance. In contrast to thiolate-terminated structures, metal-molecule-metal junctions that exploit the carbodithioate linker manifest three distinct conductance values. We hypothesize that the magnitudes of these conductances depend upon carbodithoate linker hapticity with measured conductances across Au-[5,15-bis(4'-(dithiocarboxylate)phenylethynyl)-10,20-diarylporphinato]zinc(II)-Au junctions the greatest when both anchoring groups attach to the metal surface in a bidentate fashion. We support this hypothesis with NEGF-DFT calculations, which consider the electron transport properties for specific binding geometries. These results provide new insights into the origin of molecule-to-molecule conductance heterogeneity in molecular charge transport measurements and the factors that optimize electrode-molecule-electrode electronic coupling and maximize the conductance for charge transport.


Assuntos
Complexos de Coordenação/química , Condutividade Elétrica , Metaloporfirinas/química , Tiocarbamatos/química , Zinco/química , Eletrodos , Eletrônica/instrumentação , Desenho de Equipamento , Modelos Moleculares
12.
Adv Mater ; 26(18): 2883-8, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24677551

RESUMO

Selective growth of metal organic framework materials on the surface of compartmentalized polymer microparticles is achieved by electro-hydrodynamic co-jetting, selective surface modification, and anisotropic crystal growth.

13.
J Control Release ; 172(1): 239-245, 2013 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-23973814

RESUMO

In the last several decades, research in the field of drug delivery has been challenged with the fabrication of carrier systems engineered to deliver therapeutics to the target site with sustained and controlled release kinetics. Herein, we report the fabrication of microparticles composed of two distinct compartments: i) one compartment containing a pH responsive polymer, acetal-modified dextran, and PLGA (polylactide-co-glycolide), and ii) one compartment composed entirely of PLGA. We demonstrate the complete release of dextran from the microparticles during a 10-hour period in an acidic pH environment and the complete degradation of one compartment in less than 24h. This is in congruence with the stability of the same microparticles in neutral pH over the 24-hour period. Such microparticles can be used as pH responsive carrier systems for drug delivery applications where their cargo will only be released when the optimum pH window is reached. The feasibility of the microparticle system for such an application was confirmed by encapsulating a cancer therapeutic, irinotecan, in the compartment containing the acetal-modified dextran polymer and the pH dependent release over a 5-day period was studied. It was found that upon pH change to an acidic environment, over 50% of the drug was first released at a rapid rate for 10h, similar to that observed for the dextran release, before continuing at a more controlled rate for 4 days. As such, these microparticles can play an important role in the fabrication of novel drug delivery systems due to the selective, controlled, and pH responsive release of their encapsulated therapeutics.


Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Camptotecina/análogos & derivados , Preparações de Ação Retardada/química , Dextranos/química , Ácido Láctico/química , Ácido Poliglicólico/química , Camptotecina/administração & dosagem , Concentração de Íons de Hidrogênio , Irinotecano , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico
14.
Small ; 9(18): 3051-7, 2013 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-23606461

RESUMO

On-demand degradable polymer particles are fabricated via electrospraying of a solution of acetal-protected dextran that further includes 2-(4-methoxystyryl)-4,6-bis(trichloromethyl)-1,3,5-triazine as a photoacid generator. The illumination of UV light gives rise to photoacid and activates the catalytic deprotection of hydroxyl groups of dextran, leading to controlled dissolution of the microparticles in water.


Assuntos
Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Polímeros/química , Nanopartículas/química
15.
ACS Nano ; 7(5): 4479-86, 2013 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-23550717

RESUMO

Plasmonic nanostructures can induce a number of interesting responses in devices. Here we show that hot electrons can be extracted from plasmonic particles and directed into a molecular electronic device, which represents a new mechanism of transfer from light to electronic transport. To isolate this phenomenon from alternative and sometimes simultaneous mechanisms of plasmon-exciton interactions, we designed a family of hybrid nanostructure devices consisting of Au nanoparticles and optoelectronically functional porphyin molecules that enable precise control of electronic and optical properties. Temperature- and wavelength-dependent transport measurements are analyzed in the context of optical absorption spectra of the molecules, the Au particle arrays, and the devices. Enhanced photocurrent associated with exciton generation in the molecule is distinguished from enhancements due to plasmon interactions. Mechanisms of plasmon-induced current are examined, and it is found that hot electron generation can be distinguished from other possibilities.

16.
Langmuir ; 29(20): 6181-6, 2013 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-23617390

RESUMO

Janus microcylinders composed of different polymers were prepared through coaxial co-jetting with dual-core flows, followed by cross-linking, microsectioning, and shell removal. Uniquely shaped building blocks can be fabricated by photo-patterning of one hemisphere of the microcylinders.


Assuntos
Técnicas Analíticas Microfluídicas , Poliglactina 910/química , Hidrodinâmica , Técnicas Analíticas Microfluídicas/instrumentação
18.
Nano Lett ; 12(5): 2414-9, 2012 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-22545580

RESUMO

Temperature-dependent transport of hybrid structures consisting of gold nanoparticle arrays functionalized by conjugated organic molecules [(4'-thiophenyl)ethynyl-terminated meso-to-meso ethyne-bridged (porphinato)zinc(II) complexes] that possess exceptional optical and electronic properties was characterized. Differential conductance analysis distinguished the functional forms of the temperature and voltage dependences for a range of sample particles and molecular attachments. Thermally assisted tunneling describes transport for all cases and the associated mechanistic parameters can be used to determine the relative roles of activation energy, work function, and so forth. These results provide the basis on which to examine plasmon-influenced conduction in hybrid systems.

19.
Nano Lett ; 12(6): 2722-7, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22500812

RESUMO

Understanding and controlling electron transport through functional molecules are of primary importance to the development of molecular scale devices. In this work, the single molecule resistances of meso-to-meso ethyne-bridged (porphinato)zinc(II) structures (PZn(n) compounds), connected to gold electrodes via (4'-thiophenyl)ethynyl termini, are determined using scanning tunneling microscopy-based break junction methods. These experiments show that each α,ω-di[(4'-thiophenyl)ethynyl]-terminated PZn(n) compound (dithiol-PZn(n)) manifests a dual molecular conductance. In both the high and low conductance regimes, the measured resistance across these metal-dithiol-PZn(n)-metal junctions increases in a near linear fashion with molecule length. These results signal that meso-to-meso ethyne-bridged porphyrin wires afford the lowest ß value (ß = 0.034 Å(-1)) yet determined for thiol-terminated single molecules that manifest a quasi-ohmic resistance dependence across metal-dithiol-PZn(n)-metal junctions.


Assuntos
Nanoestruturas/química , Nanoestruturas/ultraestrutura , Porfirinas/química , Condutividade Elétrica , Transporte de Elétrons , Teste de Materiais , Tamanho da Partícula
20.
J Am Chem Soc ; 133(50): 20138-41, 2011 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-22122560

RESUMO

High reversibility during crystallization leads to relatively defect-free crystals through repair of nonperiodic inclusions, including those derived from impurities. Microporous coordination polymers (MCPs) can achieve a high level of crystallinity through a related mechanism whereby coordination defects are repaired, leading to single crystals. In this work, we discovered and exploited the fact that this process is far from perfect for MCPs and that a minority ligand that is coordinatively identical to but distinct in shape from the majority linker can be inserted into the framework, resulting in defects. The reaction of Zn(II) with 1,4-benzenedicarboxylic acid (H(2)BDC) in the presence of small amounts of 1,3,5-tris(4-carboxyphenyl)benzene (H(3)BTB) leads to a new crystalline material, MOF-5(O(h)), that is nearly identical to MOF-5 but has an octahedral morphology and a number of defect sites that are uniquely functionalized with dangling carboxylates. The reaction with Pd(OAc)(2) impregnates the metal ions, creating a heterogeneous catalyst with ultrahigh surface area. The Pd(II)-catalyzed phenylation of naphthalene within Pd-impregnated MOF-5(O(h)) demonstrates the potential utility of an MCP framework for modulating the reactivity and selectivity of such transformations. Furthermore, this novel synthetic approach can be applied to different MCPs and will provide scaffolds functionalized with catalytically active metal species.


Assuntos
Compostos Orgânicos/química , Paládio/química , Cristalização , Difração de Pó
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