Ammonia and potassium iodide solutions are added to an aqueous solution of Cr(NO₃)₃. A solid is isolated (compound A), and the following data are collected:

i. When 0.105 g of compound A was strongly heated in excess O₂, 0.0203 g CrO₃ was formed.

ii. In a second experiment it took 32.93 mL of 0.100 M HCl to titrate completely the NH₃ present in 0.341 g compound A.

iii. Compound A was found to contain 73.53% iodine by mass.

iv. The freezing point of water was lowered by 0.64^οC when 0.601 g compound A was dissolved in 10.00 g H₂O (K_f = 1.86^οC ? kg/mol).  

What is the formula of the compound? What is the structure of the complex ion present?