In coordination chemistry, it is common to use “non-coordinating” anions as counterions for cationic complexes. These anions are essentially inert, and do not interfere in the study of the coordination complexes. A very common example is hexafluorophosphate, PF6–. Why do you think that PF6– is used more often than BF4–? Ignore any solubility concerns.

nacl or sodium chloride is an ionic compound. this is because an ionic compound pertains to a compound that consists of positively and negatively charged ions. in this case, na (sodium) has a tendency to lose one electron when it reacts with with other atoms, so the resulting sodium ion contains 11 protons and 10 electrons, thus making it positively charged (na+), when chlorine reacts, it usually gains one electron to form an ion called chloride, thus making it negatively charged ( since the ions are oppositely charged, they attract.