Nanostructures fabricated by focused electron beam induced deposition (FEBID) often have low deposit purities that can be traced back to incomplete precursor decomposition. Among others, removal of halide ligands is particularly slow under electron irradiation. Herein, we report on the electron-induced decomposition of cisplatin (cis-Pt(NH 3 ) 2 Cl 2 ), a potential precursor for Pt deposition. Cisplatin samples were irradiated with electrons, and the resulting compositional and chemical changes were monitored by surface analysis tools. The results reveal that electron exposure yields nearly pure Pt deposits, and the ligands are transformed into the gas-phase species N 2 , NH 3 , and HCl. Also, surface-bound NH x (x < 3) species were identified that can act as reducing agents. Production of such reactive intermediates and N 2 implies that the electron-induced decomposition of the NH 3 ligands releases atomic hydrogen, a species known to efficiently remove surface Cl via HCl formation. Furthermore, proton transfer from NH 3 to Cl − triggered by ionization is deduced from the formation of NH 4 + and proposed as a second reaction pathway producing HCl. Overall, this leads to rapid loss of the Cl ligands. We thus provide evidence that NH 3 is favorable either as a ligand in FEBID precursors or as a postdeposition purification agent for halide-contaminated FEBID deposits.

The local chemical activation of surfaceanchored metal−organic frameworks is a novel electron beam-based lithographic technique with a high potential for the fabrication of chemically and spatially well-defined nanostructures in the sub-10 nm regime. In this context, we have performed a detailed investigation of electron beaminduced surface activation (EBISA) on the surface-anchored layers of HKUST-1 and copper(II) oxalate with the subsequent autocatalytic growth (AG) of deposits from the precursors Fe(CO) 5 and Co(CO) 3 NO. We use reflection absorption infrared spectroscopy and measurements on electron-stimulated desorption to identify the chemical species that trigger decomposition of the precursors on the activated surfaces. EBISA on HKUST-1 works for Fe(CO) 5 but not for Co(CO) 3 NO and is therefore chemical selective. On the other hand, we demonstrate that copper(II) oxalate is not susceptible to EBISA for both precursors, ruling out that Cu nanoparticles are active sites for initiating AG. A detailed discussion and comparison of the experimental results for both substrates and precursors is supported by a review of the current state of knowledge regarding the electron-induced chemistry of the investigated materials and on the precursor reactivity. On the basis of this analysis, we discuss specific species that are likely to trigger AG following EBISA of HKUST-1.

The structure of the linker anions is decisive for the efficiency and outcome of electron-induced chemistry in surface-grown layers of copper(ii) containing materials.