Abstract:

The copper(Ⅱ)-ammonia coordination ion represents a quintessential model for understanding the coordination equilibrium and distribution characteristics of coordination compounds in the teaching of analytical chemistry. Current textbooks, however, often limit their scope to providing stability constants for select copper-ammonia coordination ions, without delving into the correlation between their coordination numbers and stability. This study leverages density functional theory to firstly establish a connection between the stability of copper-ammonia coordination ions and their coordination numbers, achieved through structural optimization. Subsequently, it offers a qualitative interpretation by examining the molecule spatial configuration, shedding light on the fundamental nature of these structures. This research not only enhances the effectiveness of pedagogical approaches, but also cultivates students' interest in the application of the theoretical calculations within the realm of analytical chemistry.

Key words: Coordination compounds, Copper-ammonia coordination ions, Stability constants, Ligand field theory, Computational chemistry