Covalent crystals such as diamonds are a class of fascinating materials that are challenging to fabricate in the form of thin films. This is because spatial kinetic control of bond formation is required to create covalently bonded crystal films. Directional crystal growth is commonly achieved by chemical vapor deposition, an approach that is hampered by technical complexity and associated high cost. Here we report on a liquid-liquid interfacial approach based on physical-organic considerations to synthesize an ultrathin covalent crystal film. By distributing reactants into separate phases using hydrophobicity, the chemical reaction is confined to an interface that orients the crystal growth. A molecular-smooth interface combined with in-plane isotropic conditions enables the synthesis of films on a centimeter size scale with a uniform thickness of 13 nm. The film exhibits considerable mechanical robustness enabling a free-standing length of 37 µm, as well as a clearly anisotropic chemical structure and crystal lattice alignment.

Inherently porous materials that are chemically and struc-turally robust are challenging to construct. Conventionally, dynamic chemistry is thought to be needed for the for-mation of uniform porous organic frameworks, but dynamic bonds can limit the stability of these materials. For this rea-son, all carbon linked frameworks are expected to exhibit higher stability performance than more traditional porous frameworks. However, the limited reversibility of carbon-carbon bond forming reactions has restricted the explora-tion of these materials. In particular, the challenges associ-ated with producing uniform thin films of all carbon-linked frameworks has inhibited the study of these materials in applications where well-defined films are required. Here, we synthesize continuous and homogenous films of two differ-ent all carbon linked 3D porous aromatic frameworks with nanometer precision thickness (PAF-1 and BCMP-2). This was accomplished by kinetically promoting surface reactivi-ty while suppressing homogenous nucleation. By connecting the PAF film to a gold substrate via a self-assembled mono-layer and using flow conditions to continually introduce monomers, smooth and continuous PAF films can be grown with controlled thickness. This strategy allows traditional transition metal-mediated carbon-carbon cross-coupling reactions to form porous, organic thin films. We expect that the chemical principles uncovered in this study will enable the synthesis of a variety of chemically and structurally diverse carbon-carbon linked frameworks as high-quality films, which are inaccessible by conventional methods.

We quantitatively evaluate resource efficiency enabled by mode-group-division multiplexing (MGDM) and light-trail (LT) in optical metro networks. Combining MGDM with LT reduces 95% of MIMO complexity of Full-MIMO with only 11% additional spectrum occupation.

Carbon is arguably the most versatile element in the periodic table. It can form bonds to other elements in one-, two- and three-dimensions, allowing the formation of structurally and electronically diverse materials. Carbon allotropes, materials made only of carbon, were for long limited to diamond, graphite, fullerene, carbon nanotubes, and graphene. However, recently a series of zero- one- and two-dimensional carbon allotropes have been made. Until now, diamond is the only known three-dimensional carbon allotrope. Here we report the successful synthesis of a new 3D carbon allotrope, which we refer to as diamondiyne. The synthesis of diamondiyne is performed using inexpensive laboratory glassware. It is formed as a film at a liquid-liquid interface, and we show that the method is scalable in both the thickness and lateral area of the film. The received films are polycrystalline, and the crystal structure has been confirmed using transmission electron microscopy. Our results enrich the carbon allotrope family, enabling non-naturally occurring ones extending in full 3D space. New carbon allotropes have historically found widespread use in materials science, and we look forward to what applications might emerge for diamondiyne.

The creation of carbon allotropes is synthetically highly challenging, but their practical significance to science and technology cannot be underestimated. Here, we report the synthesis of a new carbon allotrope, diamondiyne, which is the second known one (after diamond) that forms covalent bonds in all three dimensions. Diamondiyne has a mixed sp–sp ³ hybridization, resulting in a carbo‐mer of diamond with an expanded diamond‐topology network. On the nanoscopic scale, two asymmetrically interpenetrated 3D networks form the tetragonal space group I 4 ₁ / amd with unit cell parameters a = b =  11.47 Å and c =  16.22 Å. Amorphous carbon films containing diamondiyne crystals are formed using a cascade reaction at a liquid–liquid interface. Just as for a covalent organic framework, molecular nodes are connected based on geometrical constraints to form an extended structure, and we show that the method is scalable in both the thickness and the lateral direction of the film. New carbon allotropes have historically found widespread use in materials science, and we look forward to what applications might emerge for diamondiyne.

For more than a century, electricity and magnetism have been believed to always exhibit inextricable link due to the symmetry in electromagnetism. At the interface, polar groups that have polar charges, are indispensable to be considered, which interact directly with other polar charges/external charges/external electric fields. However, there is no report on the corresponding magnetic properties on these polar groups. Clearly, such asymmetry, that is, only the interaction between the polar groups and charges, is out of bounds. Here we show that those molecules with considerable polar groups, such as cellulose acetate (CA) and other cellulose derivatives with different polar groups, can have strong magnetic response, indicating that they are strongly paramagnetic. Density functional theory (DFT) calculation shows that the polarity greatly reduces the excitation energy from the state without net spin (singlet) to the state with net spin (triplet), making the considerable existence of magnetic moments on the polar groups. We note that the hydrophobic groups in these molecules have no magnetic moments, however, they make the molecules aggregate to amply the magnetic effect of the magnetic moments in the polar groups, so that these magnetic moments can induce the strong paramagnetism. Our observations suggest a recovery of the symmetry with inextricable link between the electricity and magnetism at the interface. The findings leave many imaginations of the role of the magnetic interaction in biological systems as well as other magnetic applications considering that many of those polar materials are biological materials, pharmaceutical materials, chemical raw materials, and even an essential hormone in agricultural production.