Quantitative determination of activation energies in mechanochemical reactions.
نویسندگان
چکیده
Mechanochemical reactions often result in 100% yields of single products, making purifying procedures obsolete. Mechanochemistry is also a sustainable and eco-friendly method. The ever increasing interest in this method is contrasted by a lack in mechanistic understanding of the mechanochemical reactivity and selectivity. Recent in situ investigations provided direct insight into formation pathways. However, the currently available theories do not predict temperature T as an influential factor. Here, we report the first determination of an apparent activation energy for a mechanochemical reaction. In a temperature-dependent in situ study the cocrystallisation of ibuprofen and nicotinamide was investigated as a model system. These experiments provide a pivotal step towards a comprehensive understanding of milling reaction mechanisms.
منابع مشابه
Kinetic Study of Reactions between Nitrile Oxides with Simple Cycloalkynes with DFT Method
In this study, reactions of the simple cycloalkynes with substituted Nitrile Oxides, by DFT method will be discussed. The investigation of the structural properties, theoretical thermodynamic and kinetic data, i.e., the activation free energies(DG*), the free energies changes of reaction(DrG) and rate constants of the reactions (k) in 298 K and effects of Electron-withdrawing and...
متن کاملEFFECT OF Si ANTIOXIDANT ON THE RATE OF OXIDATION OF CARBON IN MgO- C REFRACTORY
Progressive conversion/shrinking core (PC-SC) models of constant-size cylinders were exploited to interpret the decarburization reactions of MgO-C-Si bricks heated up under blown air. Chemical adsorption/solid (or pore) diffusion mechanisms governed the reaction rate. With 5% silicon, chemical adsorption vanished at 1000 and 1100°C. The oxidation rate lowered then with temperature. This was due...
متن کاملSolvent-free copper-catalyzed azide-alkyne cycloaddition under mechanochemical activation.
The ball-mill-based mechanochemical activation of metallic copper powder facilitates solvent-free alkyne-azide click reactions (CuAAC). All parameters that affect reaction rate (i.e., milling time, revolutions/min, size and milling ball number) have been optimized. This new, efficient, facile and eco-friendly procedure has been tested on a number of different substrates and in all cases afforde...
متن کاملIs the equilibrium composition of mechanochemical reactions predictable using computational chemistry?
The ability of computational methods to predict the structures and energetics that determine the equilibrium of solid state mechanochemical reactions has been assessed. Two previously characterised base-catalysed metathesis reactions between aromatic disulfides are studied using crystal structure prediction methods and lattice energy calculations that combine molecular electronic structure meth...
متن کاملThe Effect of Rotation Speed and Time of Milling on Synthesis and Properties of Fluoridated Hydroxyapatite Biomaterial
Synthetic hydroxyapatite (HA) is the most helpful because of its similarity to natural bone in both crystalline structure and chemical composition. Recently, fluoridated hydroxyapatite (FHA) has been developed in dental and orthopedic application because it has lower solubility than pure HA, while maintaining the comparable bioactivity and biocompatibility. The aim of this study was to...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Physical chemistry chemical physics : PCCP
دوره 18 33 شماره
صفحات -
تاریخ انتشار 2016