Study On The Synthesis Of Linear Carbon By Two-steps Method Of Oxidative Coupling Of Copper Acetylide And The Application

The synthesis of linear carbon by two-steps method of oxidative coupling of copper acetylide and the transformation of β linear carbon to diamond is studied in this paper. In the experiment, the type, quality of reagent added and the time of reaction is studied profoundly. In the same time, the method of synthesizing linear carbon by the phase-transformation based on the reaction of oxidative coupling of copper acetylide is used in the experiment, when benzene is used, the product is more pure and whose carbon chain is longer than that in aqueous. At last, we success in transformation of β linear carbon to diamond under moderate conditions.The result shows that: when HC1 is added, the product is shown that the main constituent is β -form by FT-IR; when KCN is added, the main product will be α -form; and when HC1O4 is added, the product is a mixture of a -form and β -form .The quality of the product is affected by the quantity of HC1 added: when the quantity of HC1(1:1) is 145ml(pH=7.0), the conversion of product is about 54%,and the residual copper is 3.3%;but when the quantity of HC1 is creased to 160ml,the conversion of product is about 43%,and the residual copper is 0.70%. The quantity of KCN(HC1O4) added is affected the product too: the quantity of KCN(HC104) is more, the residual copper is few and the product is pure more. At last, we assess the synthetic conditions: 13-15drops/min of HC1, under 35℃ and bubbling O₂ whenthe pH=7, sloped the reaction(about 8 hours), a stable product is obtained by this method.It is supposed that"-C=C-" from CU2C2 will form the longer chain carbyne in some organic phase, so, in the experiment the two-steps method to prepare linear carbon is used and benzene is chosen as organic phase, the product of linear carbon is almost transformed into organic phase. The quantity of product obtained in organic phase is better than that in aqueous phase.The DSC of β linear carbon suggests that: the β -form can be transformed into α -form under 250℃; and the β -form will be turn to diamond under 350℃-400℃. Based on the result we choose the conditions of 350℃-400℃ and suction, normal pressure, 0.45MPa to prepare diamond, the result show that: the β linear carbon turn to diamond under 400℃ and 0.45 MPa for 8 hours.Based on the experiment, we optimized the conditions of prepare linear carbon by two-steps method of oxidative coupling of copper acetylide, it spend only several hours to get the product, and the quantity of product is stable. Benzene-ammonia is used in the synthesis of linear carbon by the phase- transformation. The conditions of prepare diamond by β -form linear carbon is more mild than others as reported, it dose not need "catalyst" and "diamond-crystal seeds", the cost is cut down sharply.