On the [Fe(H2O)5XO]2+ (XC, N, O) complex ions via density functional theory

The coordination of XO (XC, N, O) to metal iron is important in biochemistry. In this paper, the properties of spin ground states for [Fe(H2O)5XO]2+ are studied via UB3LYP method. The spin ground states for [Fe(H2O)5CO]2+, [Fe(H2O)5NO)]2+, and Fe(H2O)5O2]2 are determined to be S=2, 3/2, and 1, respectively. Both the Fe-C-O bond in [Fe(H2O)5CO]2+ and Fe-N-O bond in [Fe(H2O)5NO]2+ are linear. The Fe-O-O bond in [Fe(H2O)5O2]2+ is bent. The order of the Fe-X distances is Fe-N