From dicopper acetylide to carbyne

Freshly prepared dicopper acetylide, air-aged and Cu ²⁺ oxidized samples have been studied by FTIR and electronic spectroscopy. There is some evidence about the polymeric and semiconductive nature of dicopper acetylide, and it is proposed to represent this compound by the general formula (Cu₂ C₂ · nH₂O)_x in which n=0.5–1 and x is unknown but large. It has been found that upon oxidation, the acetylide ion C₂²⁺ in copper acetylide undergoes a coupling reaction with formation of a diacetylene derivative and/or its higher homologues. No definitive evidence about the presence of cumulenic isomers has been found. After hydrolysis of dicopper acetylide in HCl, acetylene (the main product) together with a mixture of polyynes having the general formula H (CC)_n H with n=1, 2, 3, 4, 5, 6 has been identified by electronic spectroscopy. The carbonaceous insoluble matter, obtained from aged/oxidized dicopper acetylide, hydrolyzed in HCl is carbyne as indicated by the FTIR band at 2200 cm⁻¹. It has been shown that carbyne is also formed by oxidizing dicopper acetylide with H₂O₂ in aqueous ammonia suspension (FTIR bands at 2203 and 2139 cm⁻¹), and is recovered as insoluble carbonaceous matter. Carbyne is also formed by thermal decomposition of dicopper acetylide in vacuo. Under these conditions, carbyne is a fluffy, very fine carbon powder having a high tint strength, whose FTIR spectrum shows bands at 2220 and 2200 cm⁻¹ due to triple bond stretching vibrations. Volatile compounds are sublimable from carbyne and have been studied by electronic spectroscopy. © 1999 Society of Chemical Industry     

Liquid/solid two‐phase carbonization of low‐molecular‐weight chloro‐/bromo‐hydrocarbons

A novel liquid/solid two‐phase reaction has been discovered that enables destruction of a series of low‐molecular‐weight chloro‐/bromo‐hydrocarbons to carbon‐based materials. The solid phase is anhydrous potassium hydroxide and the liquid phase is a benzene or tetrahydrofuran solution of halide and contains a certain amount of tetrabutyl ammonium bromide (TBAB) as phase transfer catalyst. The structure of the carbon‐based materials have been characterized by elemental analysis, Fourier transform infrared (FT‐IR), FT‐Raman, and X‐ray photoelectron spectroscopies, and their morphologies have been examined by wide‐angle X‐ray diffraction and transmission electron microscopy. The results indicate that the products are amorphous nanoparticles and contain mainly elemental carbon. They consist of sp, sp², and sp³ carbon atoms simultaneously and can be regarded as carbyne analogues. This work provides a convenient method for synthesizing new carbon‐based materials in relatively high yields. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 1510–1515, 2000     

共沸物混合气体中收集碳链C_8H_2

为了大批量制备高纯碳链样品并研究利用液相电弧放电法制备碳链的机理,提出了一种新的碳链收集方法.采用乙醇溶液收集电弧放电过程中产生的逸出气体并分析逸出气体的组成成分.利用高效液相色谱仪对逸出气体和乙醇溶液进行分离,并对逸出气体的吸收光谱进行了分析.结果表明,逸出气体中含有大量以C8H2为主的短碳链,且其组成成分和在甲醇溶液的碳链蒸馏过程中得到的共沸物成分一致,表明电弧放电过程中产生的逸出气体是一种含有碳链的共沸物,通过收集放电时产生的逸出气体可以大批量制备短碳链C_8H_2.     

炭素材料的定义及分类原则

赋于炭素材料新的定义，将碳的同素异形体石墨、金刚石、富勒烯、咔宾等统称为炭素材料，并对其多样性进行论述以及对特性和功能进行了比较。对以碳纳米材料为首的新型碳材料的应用前景做了前瞻性的预测。     

新型碳材料的研究现状

评述了讨论了卡宾,富勒烯和碳纳米管等新型碳材料的制备,结构,性质及潜在的应用前景。     

Poly(carbyne)s via reductive C1 polymerization

C1 polymerizations enable the synthesis of densely functionalized, persubstituted polymers that are challenging to access using conventional methods. One class of C1 polymers are the poly(carbyne)s, which are unique in that they can adopt branched or linear structures, or combinations thereof. Herein, we report the synthesis of new poly(carbyne)s, including those that feature side chains with carbonyl‐containing functional groups. The polymers were obtained by exposing solutions of monomers outfitted with trihalomethyl or trimethyl orthoformate groups to metallic lithium, and reaction performance was improved when electron transfer agents (e.g. naphthalene) were included. The mechanisms of the polymerizations were also deconvoluted and found to depend on the monomer employed.     

A New Wide Bandgap Semiconductor: Carbyne Nanocrystals

Deep ultraviolet (DUV) photodetectors (PDs) always and inevitably face a drastic working environment such as high temperature. However, DUV PDs based on the reported wide bandgap semiconductor materials cannot simultaneously possess high stability and high performance at high temperatures. Here, for the first time, a new wide bandgap semiconductor material, carbyne nanocrystals (CNCs), is reported. The constructed DUV PD made from CNCs demonstrates high-performance and high stability at the temperature of 300 °C, which is the highest working temperature reported to date for DUV PDs. Under 266 nm light at room temperature, the CNCs-based PD exhibits a low dark current of less than 10 pA and a high signal-to-noise ratio of greater than 10⁶ at a bias voltage of 2 V. It can work at the temperature up to 300 ° C, exhibiting a current on-off ratio of 2.1, and accompanied by a fast response/recovery speed of less than 0.06 s. The excellent transport properties of CNCs would be of great benefit to enhance the performance of devices. These findings open the door to the applications of CNCs as a new wide bandgap semiconductor material.     

二次锂电池用正极材料多硫化碳炔充放电机理探讨

二次锂电池用正极材料多硫化碳炔具有较高的充放电效率与良好的循环性能,200次循环容量保持率为60.21%,效率接近100%。应用循环伏安、XRD、RAMAN等方法对其充放电机理进行了研究。结果表明:充放电过程中,多硫化碳炔中无Li2S生成,有可逆的新相生成,碳基体也发生了可逆的变化,这些变化的高度可逆性是多硫化碳炔循环性能优良的根本原因。