Recently, carbon nanostructures have attracted interest because of their unique properties and interesting applications. Here, CoC@SiO₂-850 (3) and CoC@SiO₂-600 (4) cobalt–carbon/silica nanocomposites were prepared by solid-state pyrolysis of anthracene with Co(tph)(2,2′-bipy)·4H₂O (1) complex in the presence of silica at 850 and 600 °C, respectively, where 2,2′-bipy is 2,2′-bipyridine and tph is the terephthalate dianion. Moreover, Co(μ-tph)(2,2′-bipy) (2) was isolated and its X-ray structure indicated that cobalt(II) has a distorted trigonal prismatic coordination geometry. 2 is a metal–organic framework consisting of one-dimensional zigzag chains within a porous grid network. 3 and 4 consist of cobalt(0)/cobalt oxide nanoparticles with a graphitic shell and carbon nanotubes embedded in the silica matrix. They were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). XPS revealed that the nanocomposites are functionalized with oxygen-containing groups, such as carboxylic acid groups. In addition, the presence of metallic cobalt nanoparticles embedded in graphitized carbon was verified by XRD and TEM. The efficiency of 3 for adsorption of crystal violet (CV) dye was investigated by batch and column experiments. At 25 °C, the Langmuir adsorption capacity of 3 for CV was 214.2 mg g⁻¹ and the fixed-bed column capacity was 36.3 mg g⁻¹. The adsorption data were well fitted by the Freundlich isotherm and pseudo-second-order kinetic model. The adsorption process was spontaneous and endothermic.

3D hierarchical graphitic carbon nanowalls encapsulating cobalt nanoparticles HPC-Co were prepared in high yield from solid-state pyrolysis of cobalt 2,2′-bipyridine chloride complex. Annealing of HPC-Co in air gave HPC-CoO, which consists of a mixture of crystallite Co₃O₄ nanospheres and nanorods bursting out of mesoporous carbon. Both nanocomposites were fully characterized using SEM, TEM, BET, and powder X-ray diffraction. The elemental composition of both nanocomposites examined using SEM elemental mapping and TEM elemental mapping supports the successful doping of nitrogen. The powder X-ray diffraction studies supported the formation of hexagonal cobalt in HPC-Co, and cubic crystalline Co₃O₄ with cubic cobalt in HPC-CoO. HPC-Co and HPC-CoO can be used as a modified carbon electrode in cyclic voltammetry experiments for the detection of fructose with limit of detection LOD 0.5 mM. However, the single-frequency impedimetric method has a wider dynamic range of 8.0–53.0 mM and a sensitivity of 24.87 Ω mM⁻¹ for the electrode modified with HPC-Co and 8.0–87.6 mM and a sensitivity of 1.988 Ω mM⁻¹ for the electrode modified with HPC-CoO. The LOD values are 3 and 4 mM, respectively. The effect of interference increases in the following order: ascorbic acid, ethanol, urea, and glucose. A simple method was used with negligible interference from glucose to measure the percentage of fructose in a corn syrup sample with an HPC-CoO electrode. A specific capacitance of 47.0 F/g with 76.6% retentivity was achieved for HPC-Co and 28.2 F/g with 87.9% for HPC-CoO for 3000 charge–discharge cycles. Thus, (1) has better sensitivity and specific capacitance than (2), because (1) has a higher surface area and less agglomerated cobalt nanoparticles than (2).

Recently, carbon nanostructures are of high importance due to their unique characteristics and interesting applications. Pyrolysis of anthracene with cobalt complex Co(2,2′-bipy)Cl₂(1), where (2,2′-bipy) is 2,2′-bipyridine, in the absence and presence of silica gave in high yield cobalt-carbon nanocomposite CoCNC (2) and CoCNC@SiO₂(3) at 600 °C and 850 °C, respectively. They were characterized using SEM, TEM, PXRD, Raman and XPS. (3) and (2) contain core–shell cobalt(0)/cobalt oxide-graphite with or without silica support. PXRD indicates that (2) contains crystalline hexagonal α-Co and cubic β-Co phases while (3) contains only cubic β-Co phase and silica. The structure of (2) is 3D hierarchical carbon architecture wrapping spherical and elliptical cobalt nanoparticles. (3) consists of graphitized structures around cobalt nanoparticles embedded in the silica matrix. XPS reveals that the nanocomposites contain oxygen functional groups that enhance uptake of cationic dyes. CoCNC@SiO₂(3) has higher capacity and thus is better adsorbent of Basic Violet 3 than CoCNC (2). The Langmuir adsorption capacity of (3) is 19.4 mg g⁻¹ while column capacity is 12.55 mg g⁻¹ at 25 °C. Freundlich isotherm and pseudo-second-order kinetic models fit well the adsorption data. Thermodynamics indicate that adsorption(3) is exothermic. Column regeneration was tested for three cycles and Yan et al. was found the best kinetic model.

The efficacy of boron-based catalysts has drawn considerable attention from the scientific community due to their relatively low toxicities and high selectivities. Formation of a new carbon–carbon or carbon–nitrogen bond to generate an amide/urea functionality using mild, catalytic reaction protocols has always been an important challenge, as functionalised amides and urea derivatives are important scaffolds in medicinal chemistry. Herein we report a facile and mild catalytic reaction protocol towards the amidation of N-methyl indoles/pyrroles (17 examples, yields up to 58%) using B(C₆F₅)₃ (30 mol%). Moreover, our investigation revealed that although catalytic amounts of B(C₆F₅)₃ (10 mol%) are efficient towards the N-carboxamidation of unprotected indoles, catalytic BCl₃ (5 mol%) is capable of producing near quantitative yields of the N-carboxamidation products (21 examples, yields up to 95%). In contrast with previous literature reports, the reaction between 2-(alkynyl)anilines and aryl isocyanates using catalytic BCl₃ (5 mol%) afforded N–H inserted products (9 examples, yields up to 71%) chemo-selectively as opposed to the intramolecular hydroamination product. Comprehensive DFT studies have been undertaken to understand the mechanistic details of the N–H functionalisation of indoles.

Precise control of selective alkene functionalization is a continuing challenge in the chemical community. In this study, we develop a substitution‐controlled regiodivergent thioetherification of di‐ or trisubstituted alkenes using 10 mol % tris(pentafluorophenyl)borane [B(C₆F₅)₃] as a catalyst and N‐thiosuccinimide as a sulfenylating reagent. This metal‐free borane catalyzed C−S bond forming method is utilized for a Csp²−H sulfenylation reaction to synthesize an array of diphenylvinylsulfide derivatives with good to excellent yields (25 examples, up to 91 % yield). Some of the products exhibit aggregation‐induced emission luminogen properties used in organic light‐emitting diodes (OLEDs), chemical sensors, and biological imaging units. Depending upon the starting alkene, Csp³−S sulfenylation products could also be generated regioselectively. A variety of allylic thioethers from α‐alkyl substituted styrenes were isolable in good yields and selectivities (14 examples, up to 67 % yield). The DFT‐supported mechanistic study confirms that the reaction proceeds via a thiiranium ion intermediate, where the regioselectivity and product formation is determined by the alkene substituents which influence the activation barriers and energy profiles. Diphenylvinylsulfide derivatives can also be efficiently transformed into a range of synthetically valuable compounds, including vinyl sulfoxides, vinyl sulfones, and vinyl sulfoximines.