Study Of Reaction Mechanisms Of Several By Solid State Reaction

The studies of low-heat solid-state reaction (solid state reaction ofintermolecular-crystallines) mainly in the synthesis of compounds. Theknowledge of mechanism of reaction, especially in The microscopic level,is deficient and not enough. At present, the existing theories that explainthe regulations and mechanisms of solid state reaction ofintermolecular-crystallines basically is cited from traditionally theoreticalthe soul of high temperature solid-state reaction, and neglect the inherentor distinguishing characteristics in the condition of which producingreactions at or near room temperature. Toward how to overcome theobstacle of diffuse to come across to react and what principles thereactions should adheres to in the condition of which producing reactionsat or near room temperature, we have came up with the theorty ofcold-melting mechanism and the cold-dissolving-melting mechanism.This text based on the theorty of cold-melting mechanism and thecold-dissolving-melting mechanism, which were further studied byDR-UVS, IR, 1HNMR, DTA, TG, DSC, XRD and in suitmicro-photograph techniques with the mixture of dimethylglyoxime andNi(Ac)₂, hexamethylene tetramine and COCl₂, 2-Aminobenzoic and4-Hydroxybenzaldehyde as the modeled reactive examples.The results of TG/DTA or TG/DSC showed that endothermic effectand TG curves revealed the formation of process of cold-melting layerand the cold-dissolving-melting layer, and speculated the reactions howto take place. Moreover, cold-melting state and thecold-dissolving-melting state were observed by the in-suit micrographs,and analysed the direction of diffuse. These results provided the directevidences for the theories of cold-melting mechanism and thecold-dissoving-melting mechanism. The results of tracks of XRD showedthe change of content and lattic of reactants, which help to understandreaction mechanism. The method of UV-visible reflection specture(UVmethod) was theoretically and experimentally proposed to investigate theinitial kinetic characters of the solid-state reaction under differenttemperature with the mixture of above mentioned modeled reactiveexamples, analysed the process of "non-solid state" in low-heat solid-state reaction, discovered that reaction velocity is the result ofmutual competion of which form cold-melting layer or thecold-dissolving-melting to accelerate reaction and form product layer atthe surface reactants, validated cold-melting mechanism and thecold-dissoving-melting mechanism. In addition, the product synthesizedby organic low-heat solid-state reaction was analysed by element analysis,IR, ¹HNMR, and utilized state diagram to illustrate reaction mechanismand to speculate reaction phenomenon.