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### [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 8:58 am
In lecture, Dr. Lavelle used the example [Fe(CN)6]4-:

a. How is CN a ligand? Unless it's CN-, it would have an unpaired electron and wouldn't be able to form a coordinate covalent bond?
b. Why is the charge 4-?

### Re: [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 11:39 am
I believe it is CN-, meaning it can form the coordinate covalent bond. However, I'm not exactly sure why the total charge is 4-.

### Re: [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 12:27 pm
The total charge is given so that you can calculate the charge of the Fe ion. In this case, since the total charge of 4-, and CN has a charge of -1, the charge of the Fe ion is +2

### Re: [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 1:03 pm
The CN- ions are considered the ligands, and these ions provide the electron pairs that form bonds to Fe2+

### Re: [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 6:04 pm
CN binds to the Fe ion. The Fe ion is the central TM. By definition CN is a ligand. The charge is -4 because the Fe ion is +2. Since there are 6 CN- it becomes:
+2-6=-4

### Re: [Fe(CN)6]4-

Posted: Sat Nov 23, 2019 6:09 pm
Since CN has a -1 charge, the -4 overall charge is given to calculate the charge of iron (Fe), which is +2.