Table 1: Selected bond lengths/Å, and angles/° within the inner coordination sphere of the iron(II) complexes discussed in this work. Crystal data determined at 133 K.

	Fe–Neq	Fe–Oeq	Fe–N/Oax	Oeq–Fe–Oeq	Nax–Fe–N/Oax
4/Fe1	2.071(3) 2.077(3)	2.016(3) 2.017(2)	2.235(3) 2.221(2)	106.10(10)	172.33(10)
Fe2	1.863(5) 1.903(4)	1.918(4) 1.933(4)	2.001(3) 2.002(4)	88.52(16)	173.85(15)
Fe3	2.074(3) 2.091(3)	2.020(2) 2.021(3)	2.224(3) 2.204(3)	107.85(10)	173.27(10)
5	2.041(7) 2.072(7)	2.001(6) 2.011(6)	2.179(6) 2.202(6)	107.6(2)	175.1(3)