You cannot predict electron transport on the basis of the MOs alone. You need a method based on Green's Functions. See for example Pecchia and di Carlo, Rep. Prog. Phys. v67 pp 1497-1561 (2004)

please provide the reference to Prof Seminaro's publication

Sorry for the delay. It's been quite a week.

The paper provides a qualitative assessment of what makes a good molecular conductor and switch. When the MOs are delocalized across the entire molecule then it is in a conducting state. Adding charge can change the conjugation so they no longer delocalize across the entire molecule. Hence you can use charge as a way to switch these between conducting and insulating states.

I don't know of a text book that covers this, Your best approach is to read Seminaro's paper and the references in it

Please, see:

https://www.researchgate.net/publication/40882756_On_the_metallicity_of_some_carbon_nanotubes?ev=prf_pub

https://www.researchgate.net/publication/40883642_On_the_use_of_the_whole_eigenvalue_spectrum_to_obtain_single_molecule_band_structures_and_solid_band_gaps_for_molecular_electronics_studies?ev=prf_pub

https://www.researchgate.net/publication/40878826_Short_nanotubes_or_big_molecules_The_concept_of_minimal_length?ev=prf_pub

Regards.

Juan Sebastian

Article On the metallicity of some carbon nanotubes

Article On the use of the whole eigenvalue spectrum to obtain single...

Article Short nanotubes or big molecules? The concept of minimal length

And this one:

https://www.researchgate.net/publication/229088248_Minimal_Molecular_Models_for_the_Study_of_Nanostructures?ev=prf_pub

Article Minimal Molecular Models for the Study of Nanostructures