On complex formation in chemical copper plating processes from solutions with organophosphorus ligands

Abstract

Nowadays the processes of chemical vapor deposition of metals are widely used in mechanical engineering, both for the production of materials with desired functional properties and for decorative purposes. One of the most widely used chemical vapor deposition processes is chemical copper plating. The paper aims to study the complexation of copper (II) with nitrilotrimethylene phosphonic acid and to identify the possibility of using nitrilotrimethylene phosphonic acid as ligands of copper (II) ions for obtaining stable solutions of chemical copper plating. The formation of copper (II) complexes with nitrilotrimethylene phosphonic acid has been studied by the electron paramagnetic resonance (EPR) method. The paper proposes a method for processing EPR data – measurements to calculate the distribution of complex forms in the form of dependence = dP/dpH – f(pH), where P – the EPR spectrum parameter, which seems promising for describing paramagnetic systems characterized by complex equilibria with small changes in the magnetic parameters relative to the line width. The significance of the results for the engineering industry is that the authors studied the new materials based on copper complexes with nitrilotrimethylene phosphonic acid. The article establishes compositions and calculates the stability constants of the complexes at various pH of the medium. The research also shows the possibility of obtaining high-quality metal coatings based on copper (II) complexes with nitrilotrimethylene phosphonic acid.