DFT Insights into FEBID Stability: Condensed Study of Gold(I) Complexes with Phosphine Ligands

This work examines the durability and responsiveness of XAuL precursors in the context of synthesizing Au-nanomaterials. The study used density functional theory (DFT) simulations to look at the shapes, bond dissociation energies, and thermodynamic properties of a number of XAuL precursors. Within this framework, X denotes halogens Cl, Br, or I, whereas L denotes ligands such as PH3, PF3, PMe3, P(OMe)3, and P(NH2)3. Our investigations indicate that there is no discernible relationship between the lengths of XAuL bonds and binding energies. Small changes in bond dissociation free energy (BDG) serve as indicators of neutral precursors with low stability. The aforementioned precursors are essential for chemical vapor deposition. There are clear patterns that depend on the size of the halogen and the type of ligand when the BDG values and interatomic distances in the XAuL precursors are looked at. Adding an electron to the precursor changes the length of the XAuL bond, which makes the Delta BDG values of anionic precursors lower than those of neutral precursors. The study is mostly about looking at how ligands L and XAu fragments interact with each other by looking at frontier molecular orbitals (FMOs). It has been shown that higher energy gap (Delta BDG) values lead to better interaction between the HOMO and LUMO orbitals of ligand L and XAu fragments. Furthermore, the research of electrophilicity emphasizes the significance of pi-back donation and the covalent energy involved in the bonding between XAu-PR3. Thermodynamic study indicates that the dissociation processes exhibit more spontaneity under elevated temperatures and reduced pressures. The size of halogens affects spontaneity, with larger halogens exhibiting higher negative BDG values. The study shows that IAuPMe3, BrAuPMe3, and ClAuPMe3 are stable starting materials for making gold nanoparticles using focused electron beam-induced deposition (FEBID) in normal situations. This extensive study enhances our understanding of precursor design for Au-nanofabrication by providing valuable insights into the stability, reactivity, and thermodynamic characteristics of XAuL precursors. This study explores analysis of the geometrical, energetic, frontier molecular orbital, and thermodynamic properties of various XAuL precursors. The objective is to investigate how different neutral (L) and anion (X) ligands can be employed to develop suitable Au(I) complexes for use as precursors in the FEBID technique. image