In: Chemistry
Which of the following species is least likely to function as a ligand in a transition-metal coordination compound?
a. BH3
b. CO32–
c. H2O
d. NF3
e. Cl–
Ligand must be an electron-rich species for functioning as a ligand in a transition-metal coordination compound.
Lewis structure of given species are shown below.
| s.no. | Species | Lewis structure | electron rich or deficient |
| a | BH3 | ![]() |
deficient |
| b | CO32– | ![]() |
rich |
| c | H2O | ![]() |
rich |
| d | NF3 | ![]() |
rich |
| e | Cl– | ![]() |
rich |
From above structures it is clear that
is least likely to function as a ligand in a transition-metal
coordination compound because central atom of
is electron-deficient or only 6 electrons around boron
(should 8 i.e. incomplete octet).
Therefore, option (a) is correct.