Review Reports

Round 1

Reviewer 1 Report

In this manuscript, the authors used the non-equilibrium Green's function method to calculate the electron transport between two electrodes of the M₆-DMT-M₆ (M=Li,Al,Ti) semi-infinite one-dimensional monatomic chain systems embedded with Mo₂(O₂CCH₃)₄ molecules. At the same time, the role of quadrupole bonds in the transport properties of the system is analyzed. This work is of special significance to the study of the role of electron transport through molecules, because it explains the increase of electron transport function value in this system from the perspective of D (MO-M) value.. I recommend this work to be published in Molecules.

Author Response

Thank you!

Reviewer 2 Report

The authors' proposal in this manuscript is quite interesting. They have studied how the δ bonding affects electronic transport in one-dimensional conductors. This is an innovative design, especially in the context of current one-dimensional electronic conductors mainly based on π (p-p, d-p) interactions. Moreover, I would prefer to see the authors discuss the theoretical feasibility of δ bonding in the field of designing (semi)conductors. 

Some questions and suggestions:

1. The authors' background profile appears to be ambiguous--Perhaps the point of the authors' paper is to discuss how DMT changes the electronic properties of one-dimensional conductors? In my opinion, more background of the one-dimensional conductor and its modification is needed.

2. For the M₆–(Mo₂(O₂CCH₃)₄)–M₆ (M = Li, Al, Ti) system, I am curious how the authors model it. Is it geometrically optimized (although I think that's a bit surprising)? If not, how to determine the distance between M (M = Li, Al, Ti) and Mo?

3. Inspired by the authors' research, I believe that embedding DMT fragments into semiconductor molecules to modulate their electron transport behavior could be considered. The authors may theoretically consider whether new one-dimensional semiconductor materials can be designed based on δ bonding via doping one DMT molecule in the chain of one-dimensional structure. This may be more realistic than the system the authors designed in the current version of their manuscript.

Author Response

The authors' proposal in this manuscript is quite interesting. They have studied how the δ bonding affects electronic transport in one-dimensional conductors. This is an innovative design, especially in the context of current one-dimensional electronic conductors mainly based on π (p-p, d-p) interactions. Moreover, I would prefer to see the authors discuss the theoretical feasibility of δ bonding in the field of designing (semi)conductors.

Response: We didn’t discuss “the theoretical feasibility of δ bonding in the field of designing (semi)conductors”, since in the literature the discussion of this question is not started (at least as far as we know) and our investigation is at early stage.

Some questions and suggestions:

1. The authors' background profile appears to be ambiguous--Perhaps the point of the authors' paper is to discuss how DMT changes the electronic properties of one-dimensional conductors? In my opinion, more background of the one-dimensional conductor and its modification is needed.

Response: The main idea of the work was to show the participation of MO’s of quadruple bond in electron transport. We used the 1D conductors, since it is the simplest model for electron container needed to calculate transmission function in molecular system. The 1D conductor cannot be considered as a simple bulk electron container, since the transmission functions of unperturbed 1D conductors have complex shapes with humps, dips and plateau. Thus, the part of MO’s of DMT falls into the zero transmission regions of the 1D conductor and we have to discuss these features of the systems “1D conductors plus DMT”. However, the main question stay the same: the revealing of the quadruple bond in electron transport. We added some clarification to the text.

2. For the M₆–(Mo₂(O₂CCH₃)₄)–M₆ (M = Li, Al, Ti) system, I am curious how the authors model it. Is it geometrically optimized (although I think that's a bit surprising)? If not, how to determine the distance between M (M = Li, Al, Ti) and Mo?

Response: We calculated the set of transmission functions at different M-Mo distances from the sum of crystal radii to 5-7Å with 0.05 Å step without optimization. Then we chose two the most suitable for our purpose: revealing the role of quadruple bond. The transmission functions at some other indicative distances (the shortest, the point of the peaks narrowing sharply, the longest, and points between them) are given in SI. We added some clarification to the text.

3. Inspired by the authors' research, I believe that embedding DMT fragments into semiconductor molecules to modulate their electron transport behavior could be considered. The authors may theoretically consider whether new one-dimensional semiconductor materials can be designed based on δ bonding via doping one DMT molecule in the chain of one-dimensional structure. This may be more realistic than the system the authors designed in the current version of their manuscript.

Response: Thank you for your idea. In fact, we trying to do NEGF calculations with 1D structure from the work https://www.nature.com/articles/ncomms2696. We can try to embed DMT to such type of the chains in future.

 

Thank you!