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Zinc sulfide (ZnS) is a promising anode material for lithium-ion batteries (LIBs) because of its high theoretical capacity, abundance, cost-effectiveness, and environmental friendliness. Herein, a hydrangea-like ZnS-carbon composite (ZnS-NC) is synthesized through the hydrothermal method and subsequent pyrolysis of a supramolecular precursor guanosine. The resulting composite comprises ultrafine ZnS nanoparticles firmly stabilized on a nitrogen-doped carbon matrix, featuring mesoporous channels and high surface areas. When utilized as an anode material for LIBs, the initial discharge specific capacity of the ZnS-NC electrode reaches an impressive value of 944 mA h g−1 at 1.0 A g−1, and even after 450 cycles, it maintains a reversible capacity of 597 mA h g−1. Compared with pure ZnS, the ZnS-NC composite exhibits significantly improved rate performance and cycling stability. This enhancement in Li-storage performance can be attributed to a synergistic effect within the ZnS-NC composite, which arises from the large exposed active site area, efficient ion/electron transfer, and strong interaction between the ZnS nanoparticles and the carbon framework. Overall, this work presents an eco-friendly approach for developing metal sulfide-carbon composites with exceptional potential for energy storage applications. [ABSTRACT FROM AUTHOR]

Photochemical reactions are vital synthetic means for the synthesis of natural products and highly strained molecules. However, it remains an immense challenge to control the chemo- and regioselectivity in the photoreactions of anthracene derivatives while maintaining high reactivity. Herein, we report the synthesis of two photoactive metallarectangles 1a and 1b by coordination-driven self-assembly of 2,6- and 2,7-bifunctionalized anthracenes with a half-sandwich rhodium template. By taking advantage of the rhodium template, the anthracene groups within the metallarectangles can be preorganized in a parallel fashion and exclusively undergo a photochemical [4 + 4] cycloaddition. As a result, the syn-photodimers were obtained in quantitative yields under irradiation at 365 nm. The photocycloaddition of metallarectangles 1a and 1b was found to be reversible via photo- and thermal cleavage reactions, even after repeating three times. Furthermore, pure organic photodimers 3a and 3b, which are difficult to synthesize by conventional organic methods, can be readily dissociated from the metalloassemblies in high yields. [ABSTRACT FROM AUTHOR]

Reactions of the seven-membered heterocyclic potassium diamidoalumanyl, [K{Al(SiNDipp)}]2 (SiNDipp = {CH2SiMe2NDipp}2; Dipp = 2,6-di-isopropylphenyl), with a variety of Cu(I), Ag(I) and Au(I) chloride N-heterocyclic carbene (NHC) adducts are described. The resultant group 11-Al bonded derivatives have been characterised in solution by NMR spectroscopy and, in the case of [{SiNDipp}Al–Au(NHCiPr)] (NHCiPr = N,N′-di-isopropyl-4,5-dimethyl-2-ylidene), by single crystal X-ray diffraction. Although similar reactions of LAgCl and LAuCl, where L is a more basic cyclic alkyl amino carbene (CAAC), generally resulted in reduction of the group 11 cations to the base metals, X-ray analysis of [(CyCAAC)AgAl(SiNDipp)] (CyCAAC = 2-[2,6-bis(1-methylethyl)phenyl]-3,3-dimethyl-2-azaspiro[4.5]dec-1-ylidene) provides the first solid-state authentication of an Ag–Al σ bond. The reactivity of the NHC-supported Cu, Ag and Au alumanyl derivatives was assayed with the isoelectronic unsaturated small molecules, N,N′-di-isopropylcarbodiimide and CO2. While these reactions generally provided products consistent with nucleophilic attack of the group 11 atom at the electrophilic heteroallene carbon centre, treatment of the NHC-supported copper and silver alumanyls with N,N′-di-isopropylcarbodiimide yielded less symmetric Cu–C and Ag–C-bonded isomers. In contrast to the previously described copper and silver alumanyl derivatives, [(NON)Al(O2C)M(Pt-Bu3)] (M = Cu or Ag; NON = 4,5-bis(2,6-di-isopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene), which were prone to facile CO extrusion and formation of carbonate derivatives, the NHC-supported dioxocarbene species, [(NHCiPr)M(CO2)Al(SiNDipp)] (M = Cu, Ag, Au), are all stable at room and moderately elevated temperatures. The stabilising role of the NHC co-ligand was, thus, assessed by preparation of the t-Bu3P adducted copper-alumanyl, [(t-Bu3P)CuAl(SiNDipp)]. Treatment of this latter compound, which was also structurally characterised by X-ray analysis, with both N,N′-di-isopropylcarbodiimide and CO2 again provided smooth heteroallene insertion and formation of the relevant Cu–C-bonded products. Although both compounds were quite stable at room temperature, heating of [(t-Bu3P)Cu(CO2)Al(SiNDipp)] at 60 °C induced elimination of CO and formation of the analogous carbonate, [(t-Bu3P)Cu(OCO2)Al(SiNDipp)], which was identified by 13C and 31P NMR spectroscopy. Reflective of the more reliable nucleophilic behaviour of the gold centres in these group 11 alumanyls, computational (QTAIM and NBO) analysis highlighted a lower level of covalency of the Al–Au linkage in comparison to the analogous Al–Cu and Al–Ag interactions. Although substitution of the co-ligand significantly perturbs the charge distribution across the Cu–Al bond of [LCuAl(SiNDipp)] (L = NHCiPr or t-Bu3P), only a negligible difference is observed between the phosphine-coordinated copper systems derived from either the [SiNDipp]- or (NON)-based alumanyl ligands. Computational mapping of the reaction profiles arising from treatment of the various group 11 alumanyls with N,N′-di-isopropylcarbodiimide indicates that the observed formation of the Cu–N and Ag–N bound isomers do not provide the thermodynamic reaction outcome. In contrast, examination of the CO2-derived reactions, and their potential toward CO extrusion and subsequent carbonate formation, implies that the identity of the co-ligand exerts a greater influence on this aspect of reactivity than the architecture of the diamidoalumanyl anion. [ABSTRACT FROM AUTHOR]