A p-orbital honeycomb-Kagome lattice realized in a two-dimensional metal-organic framework.

The experimental realization of p-orbital systems is desirable because p-orbital lattices have been proposed theoretically to host strongly correlated electrons that exhibit exotic quantum phases. Here, we synthesize a two-dimensional Fe-coordinated bimolecular metal-organic framework which constitutes a honeycomb lattice of 1,4,5,8,9,12-hexaazatriphenylene molecules and a Kagome lattice of 5,15-di(4-pyridyl)-10,20-diphenylporphyrin molecules on a Au(111) substrate. Density-functional theory calculations show that the framework features multiple well-separated spin-polarized Kagome bands, namely Dirac cone bands and Chern flat bands, near the Fermi level.

Highly Efficient and -Selective C-H Functionalization of Polystyrene Providing a Versatile Platform for Diverse Applications.

Postpolymerization modification of polystyrene (PS) can afford numerous value-added materials with different functions and applications, but it has been hampered by the lack of efficient methods. We report herein a highly efficient and -selective conversion of the C-H bonds of the aromatic ring of PS into diverse functional groups using a combination of thianthrenation and thio-Suzuki-Miyaura coupling reaction. Notably, the thianthrenation efficiency of PS is as high as 99% and the degree of thianthrenation can be conveniently controlled using stoichiometric tuning of the amount of thianthrene--oxide added, resulting in 24-99 mol % thianthrenation.

Synthesis of Single-Layer Two-Dimensional Metal-Organic Frameworks M (HAT) (M=Ni, Fe, Co, HAT=1,4,5,8,9,12-hexaazatriphenylene) Using an On-Surface Reaction.

1,4,5,8,9,12-Hexaazatriphenylene (HAT) is one of the smallest polyheterocyclic aromatic building blocks for forming conjugated metal-organic frameworks (cMOFs). However, the strong inter-molecular steric hindrance impedes the growth of HAT-based cMOFs. Here we employ on-surface synthesis to grow single-layer two-dimensional cMOFs of M (HAT) (M=Ni, Fe, Co).

New dating of the Homo erectus cranium from Lantian (Gongwangling), China.

The Homo erectus cranium from Gongwangling, Lantian County, Shaanxi Province is the oldest fossil hominin specimen from North China. It was found in 1964 in a layer below the Jaramillo subchron and was attributed to loess (L) L15 in the Chinese loess-palaeosol sequence, with an estimated age of ca. 1.