Blanco E, Atienzar P, Hernández P, Quintana C
Departamento de Química Analítica y Análisis Instrumental, Universidad Autónoma de Madrid, Cantoblanco, 28049 Madrid, Spain.
Instituto Universitario de Tecnología Química CSIC-UPV, Departamento de Química, Universidad Politécnica de Valencia, 46022 Valencia, Spain.
Phys Chem Chem Phys. 2017 Jul 26;19(29):18913-18923. doi: 10.1039/c7cp03534a.
In this work, gold nanoparticles protected by the macrocycle cucurbit[7]uril were used as a catalyst in the reduction of the hazardous antimicrobial nitrofurantoin. 4-Nitrophenol was also employed as the substrate of the reduction for comparative purposes. The kinetic data were modeled to the Langmuir-Hinshelwood equation to know the affinities of the reactants for the surface and the real kinetic constants, a comparison at the molecular level that is made for the first time. From the results, it was observed that the adsorption of nitrofurantoin was stronger than that of 4-nitrophenol whilst the kinetic constant on the surface was higher for 4-nitrophenol than for nitrofurantoin. Additionally, shifts in the nanoparticle surface plasmon band permitted insights to be obtained into the adsorption rate and strength. The reaction induction times were also investigated and were highly dependent on the borohydride concentration and, due to the higher surface affinity of nitrofurantoin compared with 4-nitrophenol, an increase in nitrofurantoin concentration increased the induction time, while a lag phase was not observed for 4-nitrophenol.
在这项工作中，由大环葫芦[7]脲保护的金纳米颗粒被用作还原有害抗菌剂呋喃妥因的催化剂。为了进行比较，还使用4-硝基苯酚作为还原反应的底物。将动力学数据按照朗缪尔-欣谢尔伍德方程进行建模，以了解反应物对表面的亲和力和实际动力学常数，这是首次在分子水平上进行的比较。从结果可以看出，呋喃妥因的吸附比4-硝基苯酚更强，而4-硝基苯酚在表面的动力学常数高于呋喃妥因。此外，纳米颗粒表面等离子体带的位移有助于深入了解吸附速率和强度。还研究了反应诱导时间，其高度依赖于硼氢化物的浓度，并且由于呋喃妥因与4-硝基苯酚相比具有更高的表面亲和力，呋喃妥因浓度的增加会增加诱导时间，而4-硝基苯酚未观察到滞后阶段。
