title: Interactions and Self-Assembly of Stable Hydrocarbon Radicals on a Metal Support.
abstract: Stable hydrocarbon radicals are able to withstand ambient conditions. Their combination with a supporting surface is a promising route toward novel functionalities or carbon-based magnetic systems. This will remain elusive until the interplay of radical-radical interactions and interface effects is fundamentally explored. We employ the tip of a low-temperature scanning tunneling microscope as a local probe in combination with density functional theory calculations to investigate with atomic precision the electronic and geometric effects of a weakly interacting metal support on an archetypal hydrocarbon radical model system, i.e., the exceptionally stable spin-1/2 radical α,γ-bisdiphenylene-β-phenylallyl (BDPA). Our study demonstrates the self-assembly of stable and regular one- and two-dimensional radical clusters on the Au(111) surface. Different types of geometric configurations are found to result from the interplay between the highly anisotropic radical-radical interactions and interface effects. We investigate the interaction mechanisms underlying the self-assembly processes and utilize the different configurations as a geometric design parameter to demonstrate energy shifts of up to 0.6 eV of the radicals' frontier molecular orbitals responsible for their electronic, magnetic, and chemical properties.
authors: Institute of Semiconductor and Solid State Physics,  Johannes Kepler University Linz , 4040 Linz, Austria.
authors: Stefan
authors: S
authors: Müllegger
authors: Mohammad
authors: M
authors: Rashidi
authors: Michael
authors: M
authors: Fattinger
authors: Reinhold
authors: R
authors: Koch
references: Phys Rev Lett. 2006 Nov 24;97(21):216405
references: 17155759
references: ACS Nano. 2010 Dec 28;4(12):7545-51
references: 21080665
references: J Am Chem Soc. 2006 Mar 1;128(8):2530-1
references: 16492025
references: Org Lett. 2009 May 7;11(9):1871-4
references: 19331359
references: Phys Rev Lett. 1991 Apr 1;66(13):1721-1724
references: 10043290
references: Science. 2001 Nov 16;294(5546):1503-5
references: 11711668
references: Phys Rev B Condens Matter. 1990 Nov 15;42(15):9307-9318
references: 9995168
references: J Am Chem Soc. 2010 Aug 11;132(31):10648-9
references: 20681685
references: Phys Rev B Condens Matter. 1989 Apr 15;39(11):7988-7991
references: 9947487
references: Phys Rev Lett. 2009 Jan 30;102(4):046802
references: 19257455
references: J Am Chem Soc. 2011 Sep 14;133(36):14240-3
references: 21834574
references: J Am Chem Soc. 2009 Dec 16;131(49):17740-1
references: 19995071
references: Phys Rev Lett. 2002 Oct 21;89(17):176801
references: 12398693
references: Nature. 2000 Oct 19;407(6806):883-5
references: 11057661
references: J Am Chem Soc. 2002 Sep 18;124(37):11122-30
references: 12224960
references: Org Biomol Chem. 2007 May 7;5(9):1321-38
references: 17464399
references: Nature. 2000 Nov 16;408(6810):342-6
references: 11099037
references: J Phys Chem C Nanomater Interfaces. 2012 Oct 25;116(42):22587-22594
references: 23378866