The number of unpaired electrons can be determined as follows:
As we know that, magnetic moment $=\sqrt{n(n+2)}$
$5.9=\sqrt{n(n+2)}$
On squaring both sides, the above equation becomes
$(5.9)^{2}=n^{2}+2 n$
$n^{2}+2 n-35=0$
On solving the above equation, we get $n=5$
,$[M \,(AB)\, (CD) \,ef]^{n\,±}$ (જ્યાં $AB,\,CD-$ અસમમિતીય દ્વિદંતીય લિગાન્ડ્, $e$, $f-$ એકદંતીય લિગાન્ડ્)