Identification and electronic characterization of four cyclodehydrogenation products of H2TPP molecules on Au(111).

C-H bond activation and dehydrogenative coupling reactions have always been significant approaches to construct microscopic nanostructures on surfaces. By using scanning tunneling microscopy/spectroscopy (STM/STS) and non-contact atomic force microscopy (nc-AFM) combined with density functional theory (DFT), we systematically characterized the atomically precise topographies and electronic properties of H2TPP cyclodehydrogenation products on Au(111). Through surface-assisted thermal excitation, four types of cyclodehydrogenation products were obtained and clearly resolved in the nc-AFM images. The electronic characterization depicts the predominant resonances and their spatial distributions of the four products.

Tuning Anti-Klein to Klein Tunneling in Bilayer Graphene.

We show that in gapped bilayer graphene, quasiparticle tunneling and the corresponding Berry phase can be controlled such that they exhibit features of single-layer graphene such as Klein tunneling. The Berry phase is detected by a high-quality Fabry-Pérot interferometer based on bilayer graphene. By raising the Fermi energy of the charge carriers, we find that the Berry phase can be continuously tuned from 2π down to 0.68π in gapped bilayer graphene, in contrast to the constant Berry phase of 2π in pristine bilayer graphene. Particularly, we observe a Berry phase of π, the standard value for single-layer graphene. As the Berry phase decreases, the corresponding transmission probability of charge carriers at normal incidence clearly demonstrates a transition from anti-Klein tunneling to nearly perfect Klein tunneling.

Tailoring supercurrent confinement in graphene bilayer weak links.

The Josephson effect is one of the most studied macroscopic quantum phenomena in condensed matter physics and has been an essential part of the quantum technologies development over the last decades. It is already used in many applications such as magnetometry, metrology, quantum computing, detectors or electronic refrigeration. However, developing devices in which the induced superconductivity can be monitored, both spatially and in its magnitude, remains a serious challenge. In this work, we have used local gates to control confinement, amplitude and density profile of the supercurrent induced in one-dimensional nanoscale constrictions, defined in bilayer graphene-hexagonal boron nitride van der Waals heterostructures. The combination of resistance gate maps, out-of-equilibrium transport, magnetic interferometry measurements, analytical and numerical modelling enables us to explore highly tunable superconducting weak links. Our study opens the path way to design more complex superconducting circuits based on this principle, such as electronic interferometers or transition-edge sensors.

2-Amino-6-(naphthalen-1-yl)-4-phenyl-pyridine-3-carbonitrile.

In the title compound, C(22)H(15)N(3), the naphthyl ring system makes dihedral angles of 67.40 (2) and 59.80 (3)° with the pyridyl and phenyl rings, respectively. In the crystal, the mol-ecules are connected via inter-molecular N-H⋯N hydrogen bonds, forming a three-dimensional network.

5-(4-Methyl-piperazin-1-yl)-2-nitro-aniline.

In the title compound, C(11)H(16)N(4)O(2), the dihedral angle between the benzene ring and the plane of the four carbon atoms in the piperazine ring is 12.17 (3)°; the latter ring adopts a chair conformation. An intramolecular N-H⋯O hydrogen bond generates an S(6) ring. In the crystal, the molecules are linked by N-H⋯N hydrogen bonds, forming chains.

2-Amino-4-(2-fluoro-phen-yl)-5,6-dihydro-benzo[h]quinoline-3-carbonitrile.

In the title compound, C(20)H(14)FN(3), the F atom of the fluoro-substituted benzene ring in the 4-position of the 5,6-dihydro-benzo[h]quinoline system is disordered over two positions (0.80 and 0.20 occupancy). The dihedral angle between the pyridine and fluorobenzene rings is 73.2 (2) Å. The crystal structure is established by inter-molecular N-H⋯N hydrogen bonds, forming a three-dimensional network.

Poly[di-µ(2)-chlorido-µ(2)-(1,4-dioxane-κO:O')-cadmium(II)].

In the title complex, [CdCl(2)(C(4)H(8)O(2))](n), two different Cd(II) ions are present, one in a general position and one with site symmetry 2. The Cd(II) ions are coordinated by two O atoms from two 1,4-dioxane ligands and four chloride anions in a slightly distorted octa-hedral geometry and is connected to neighboring Cd(II) ions by two bridging chloride anions, generating infinite linear chains along the a axis. These chains are further inter-connected by bridging 1,4-dioxane ligands, affording a three-dimensional network.

2-Methyl-sulfanyl-4-(3-pyrid-yl)pyrimidine.

In the title compound, C(10)H(9)N(3)S, the dihedral angle between the aromatic rings is 8.09 (14)°. In the crystal, a C-H⋯N interaction links the molecules, forming chains.

4-Bromo-2-(4-fluoro-benzyl-idene)indan-1-one.

In the mol-ecule of the title compound, C(16)H(10)BrFO, the indane ring system is planar with a maximum deviation of 0.020 (3) Å. An intra-molecular C-H⋯O inter-action results in the formation of a planar ring, which is oriented at dihedral angles of 2.24 (3) and 2.34 (3)° with respect to the adjacent rings. π-π contacts between the benzene and indane rings [centroid-centroid distances = 3.699 (1) and 3.786 (1)Å] may stabilize the crystal structure.