I have come across a following line in my textbook:
$\ce{PI5}$ does not exist due to steric hindrance.
I searched for the explanation of steric hindrance in Wikipedia but couldn't understand it. Can anyone explain steric hindrance in simpler language?
Wikipedia says:
The existence of $\ce{PI5}$ has been claimed intermittently since the early 1900s. The claim is disputed: "The pentaiodide does not exist (except perhaps as $\ce{PI3\cdot I2}$, but certainly not as $\ce{PI4+I-}$)".
What does this mean?