Table 2. Comparison between the metal–oxygen distances of the Fe compound (I) and the isostructural Co, Ni and Zn compounds from the literature (Amel’chenkova et al., 2006 ▸).

The atom names of the Co and Ni complexes have been changed for consistency.

	M = Fe	M = Co	Δ Fe/Co	M = Ni	Δ Fe/Ni	M = Zn	Δ Fe/Zn
M—O1	2.1279 (14)	2.115 (3)	0.013 (3)	2.034 (3)	0.094 (3)	2.078 (3)	0.050 (3)
M—O4	2.1179 (14)	2.098 (3)	0.020 (3)	2.031 (3)	0.087 (3)	2.080 (3)	0.038 (3)
M—O7	2.1239 (12)	2.088 (3)	0.036 (3)	2.054 (2)	0.070 (2)	2.087 (3)	0.037 (3)
M—O8	2.1024 (13)	2.076 (3)	0.026 (3)	2.036 (2)	0.066 (2)	2.088 (3)	0.014 (3)
M—O9	2.1187 (13)	2.093 (3)	0.026 (3)	2.051 (2)	0.068 (2)	2.092 (3)	0.027 (3)
M—O10	2.1153 (13)	2.103 (3)	0.012 (3)	2.039 (3)	0.076 (3)	2.084 (3)	0.031 (3)