title: Formation of a G-quartet-Fe complex and modulation of electronic and magnetic properties of the Fe center.
abstract: Although the G-quartet structure has been extensively investigated due to its biological importance, the formation mechanism, in particular, the necessity of metal centers, of an isolated G-quartet on solid surfaces remains ambiguous. Here, by using scanning tunneling microscopy under well-controlled ultra-high-vacuum conditions and density functional theory calculations we have been able to clarify that besides the intraquartet hydrogen bonding a metal center is mandatory for the formation of an isolated G-quartet. Furthermore, by subtly perturbing the local coordination bonding schemes within the formed G-quartet complex via local nanoscale scanning tunneling microscopy manipulations, we succeed in modulating the d orbitals and the accompanying magnetic properties of the metal center. Our results demonstrate the feasibility of forming an isolated G-quartet complex on a solid surface and that the strategy of modulating electronic and magnetic properties of the metal center can be extended to other related systems such as molecular spintronics.
authors.affiliation: Tongji-Aarhus Joint Research Center for Nanostructures and Functional Nanomaterials and College of Materials Science and Engineering, Tongji University , Caoan Road 4800, Shanghai 201804, People's Republic of China.
authors.forename: Likun
authors.initials: L
authors.lastname: Wang
authors.forename: Huihui
authors.initials: H
authors.lastname: Kong
authors.forename: Chi
authors.initials: C
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Sun
authors.forename: Liangliang
authors.initials: L
authors.lastname: Cai
authors.forename: Qinggang
authors.initials: Q
authors.lastname: Tan
authors.forename: Flemming
authors.initials: F
authors.lastname: Besenbacher
authors.forename: Wei
authors.initials: W
authors.lastname: Xu
mesh_terms: D006860:Hydrogen Bonding; D007501:Iron / Q000737:chemistry*; D008280:Magnetics; D016252:Microscopy, Scanning Tunneling
chemical_list: D007501:Iron
keywords: G-quartet; coordination bond; density functional theory; nanoscale manipulation; scanning tunneling microscopy