Organometallic chemistry of extended periodic π-electron systems: hexahapto-chromium complexes of graphene and single-walled carbon nanotubes

Stabilizing graphene-based organometallic sandwich structures through defect engineering

“…As will be shown here, the nature of in-plane defects affects the structural (stability), electronic and magnetic properties of the final graphene-based complexes that are either stabilized or destabilized relative to the pristine (defect-free) Bz|M|Gr. Our results may help to shed light on the experimental report by Sarkar et al [6] where the sandwich structures may have been created successfully. In the future, a greater understanding of how to use defects to fabricate such designer structures may prove useful in the fields of nano-electronics, spintronics and nano-magnetism.…”

“…Experimentally, this would appear as a substantial increase in the intensity of D-band in the Raman spectra, as well as a decrease in the mobility compared to pristine graphene. In fact, a large increase in D-band intensity was indeed observed experimentally [6] upon formation of the Bz|M|Gr complexes, possibly indicating complex-formation at the defect sites. Sarkar et al [6,7] also reported a decrease in conductance upon complex formation for a related structure, Gr|M|(CO) 3 , that is isoelectronic to the sandwich structures of interest here.…”

“…In fact, a large increase in D-band intensity was indeed observed experimentally [6] upon formation of the Bz|M|Gr complexes, possibly indicating complex-formation at the defect sites. Sarkar et al [6,7] also reported a decrease in conductance upon complex formation for a related structure, Gr|M|(CO) 3 , that is isoelectronic to the sandwich structures of interest here. Although the aforementioned experimental works did not report the transport properties of the Bz|M|Gr complexes themselves, the reported loss of conductivity for the related structures is also consistent with the complex-formation at defect sites.…”

“…However, experimentally, it has proven harder to create such complexes [10]. There is only a single report for these specific complexes [6], although some related structures were recently reported [7,11]. Some of the difficulties encountered in creating these structures stem from: (a) the high mobility of TMs on graphene, and (b) the high cohesive energies of the TMs [12].…”

“…To this end, several different avenues are being explored (see, for example, the review article by Terrone et al [3] and the articles therein), such as creating vacancies, doping graphene with heteroatoms such as nitrogen, or creating more elaborate organometallic complexes [4][5][6][7].…”