Interacting resonances and antiresonances in conjugated hydrocarbons: exceptional points and bound states in the continuum

Quantum interference dramatically modulates electron transport that provides exciting prospects for molecular electronics. We develop a holistic picture of quantum interference phenomena in molecular conductors based on conjugated hydrocarbons taking...

Digraph Energy of Directed Polygons

Background: The energy E(G) of G is defined as the sum the absolute values of the eigenvalues of its adjacency matrix. In theoretical chemistry, within the Hu ̈ckel molecular orbital (HMO) approximation, the energy levels of the π-electrons in molecules of conjugated hydrocarbons are related to the energy of the molecular graphs. Objective: Generally, the energy to digraphs was proposed. Methodology: Let Δ_n be the set consisting of digraphs with n vertices and each cycle having length≡2 mod(4). The set of all the n-order directed hollow k-polygons in Δ_n based on a k-polygon G is denoted by H_k (G). Results: In this research, by using the quasi-order relation over Δ_n and the characteristic polynomials of digraphs, we describe the directed hollow k-polygon with the maximum digraph energy in H_k (G). Conclusion: The n-order oriented hollow k-polygon with the maximum digraph energy among Hk(G) only contains a cycle. Moreover, such a cycle is the longest one produced in G.

Hybrid Boron-Carbon Chemistry

The recently proved one-to-one structural equivalence between a conjugated hydrocarbon CnHm and the corresponding borane BnHm+n is applied here to hybrid systems, where each C=C double bond in the hydrocarbon is consecutively substituted by planar B(H2)B moieties from diborane(6). Quantum chemical computations with the B3LYP/cc-pVTZ method show that the structural equivalences are maintained along the substitutions, even for non-planar systems. We use as benchmark aromatic and antiaromatic (poly)cyclic conjugated hydrocarbons: cyclobutadiene, benzene, cyclooctatetraene, pentalene, benzocyclobutadiene, naphthalene and azulene. The transformation of these conjugated hydrocarbons to the corresponding boranes is analyzed from the viewpoint of geometry and electronic structure.

Complete Characterization of Resistance Distance for Linear Octagonal Networks

Computing the resistance distance of a network is a fundamental and classical topic. In the aspects of considering the resistances between any two points of the lattice networks, there are many studies associated with the ladder networks and ladderlike networks. But the resistances between any two points for more complex structures than ladder networks or ladderlike networks are still unknown. In this paper, a rather complicated structure which is named linear octagonal network is considered. Treelike octagonal systems are cata-condensed systems of octagons, which represent a class of polycyclic conjugated hydrocarbons. A linear octagonal network is a cata-condensed octagonal system with no branchings. Moreover, the resistances between any two points of a linear octagonal network are first determined. One finds that the effective resistances between new inserted points and others points of a linear octagonal network can be given by the effective resistances between two initial points which are inherited from the linear polyomino network.

Synthetic Advances in the C–H Activation of Rigid Scaffold Molecules

The remarkable structural and electronic properties of rigid non-conjugated hydrocarbons afford attractive opportunities to design molecular building blocks for both medicinal and material applications. The bridgehead positions provide the possibility to append diverse functional groups at specific angles and in specific orientations. The current review summarizes the synthetic development in CH functionalization of three rigid scaffolds namely: (a) cubane, (b) bicyclo[1.1.1]pentane (BCP), (c) adamantane.1 Introduction2 Cubane2.1 Cubane Synthesis2.2 Cubane Functionalization3 Bicyclo[1.1.1]pentane (BCP)3.1 BCP Synthesis3.2 BCP Functionalization4 Adamantane4.1 Adamantane Synthesis4.2 Adamantane Functionalization5 Conclusions and Outlook

A theoretical study on a series of polycyclic conjugated hydrocarbons—dinaphthobenzo[1,2:4,5]dicyclobutadienes with tunable charge transport properties by controlling [N]phenylenes and (anti)aromaticity

A multi-dimensional relationship founded on the targeted [N] number, the energy gap (Eg) and the aromatic degree was constructed for predicting cyclobutadienoid-containing dinaphthobenzo[1,2:4,5]dicyclobutadienes (DNBDCs) with better charge transport properties.

The pseudo-π model of the induced magnetic field: fast and accurate visualization of shielding and deshielding cones in planar conjugated hydrocarbons and spherical fullerenes

Hydrogen skeletal models accurately reproduce the π-induced magnetic field of planar PAHs and spherical fullerenes.

Iterative Synthesis of Edge-Bent [3]Naphthylene

Polycyclic conjugated hydrocarbons (PCHs) containing antiaromatic rings are of fundamental and technical interest. [N]naphthylene is an intriguing family of PCHs consisting of alternatingly fused naphthalenoids and antiaromatic cyclobutadienoids (CBDs). We recently reported the first three regioisomers of the [N]naphthylene family, synthesized by catalytic arene-norbornene annulation (CANAL) reaction followed by acidic aromatization. We now report an iterative strategy for CANAL synthesis allowing us to synthesize the forth regioisomer, edge-bent [3]naphthylene. The optoelectronic properties, local paratropicity, and crystal packing of the edge-bent [3]naphthylene were studied and compared with its closely related regioisomer, center-bent [3]naphthylene.