Decoupling of the copper core in a single copperphthalocyanine molecule

Here, we show how a copper atom in a copperphthalocyanine (CuPc) molecule can be decoupled from its environment. This is realized by trapping the CuPc molecule between two adjacent nanowires that are 1.6 nm apart. Using low-temperature scanning tunnelling microscopy and spectroscopy, the structural and electronic properties of CuPc in the stable "molecular bridge" configuration have been studied. Constant current and differential conductivity maps are recorded to reveal the spatial variation of the electronic structure of the cores and the lobes of CuPc molecules. The core of CuPc molecule is dim at low voltages, but suddenly becomes bright at a voltage of 5 V. Time-resolved scanning tunnelling microscopy measurements show that some of the CuPc lobes are very stable, while other lobes are very dynamic.