The synthesized tin (II) iodide (SnI 2 , 0.2 mmol) and diaminoheptane (0.1 mmol) were precisely weighed and combined within an inert atmosphere in a clean, dry round bottom flask. Subsequently, the flask was sealed using septa and evacuated to create an oxygen-free environment. Concentrated hydriodic acid HI (57 wt %) was then carefully introduced into the flask using a syringe, while nitrogen gas was passed through to protect from oxygen exposure. The reaction mixture was placed in an oil bath and maintained at a controlled temperature. The bath's temperature was raised to 130 °C to ensure complete dissolution of all reactants. Once the solid reactants had entirely dissolved, the bath temperature was gradually lowered to a predetermined temperature, 65 °C, to facilitate crystallization. The reaction mixture was held at 65 °C for 14 days for proper crystallization. After crystallization, the oil bath temperature was gradually decreased to 30 °C and maintained at that level for 7 days. Following this carefully controlled process, dark-red crystals crystallized.