ધરાવે છે અને નબળા લિગાન્ડ્સ ક્ષેત્રથી ઘેરાયેલાનું ......
(Atomic nos. $Mn = 25,\,Fe = 26,\,Co = 27$)
($en=$ ઇથિલીન ડાય એમાઈન)
$\left[\mathrm{V}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cr}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+},\left[\mathrm{Fe}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Ni}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{3+},\left[\mathrm{Cu}\left(\mathrm{H}_2 \mathrm{O}\right)_6\right]^{2+}$
[ આપેલ પરમાણુ ક્રમાંક : $\mathrm{V}=23, \mathrm{Cr}=24, \mathrm{Fe}=26, \mathrm{Ni}=28 \mathrm{Cu}=29$ ]
($R $ = alkyl group; $en$ = ethylenediamine)