. Author manuscript; available in PMC: 2014 Mar 18.

Published in final edited form as: Inorg Chem. 2013 Mar 7;52(6):3170–3177. doi: 10.1021/ic3026396

Table 3.

Experimental stiffness values (in pN/pm) characterize the effect of imidazole deprotonation on nearest neighbor interactions with the iron in imidazole ligated porphyrins. NRVS measurements on oriented single crystals with the X-ray beam direction parallel and perpendicular to the porphyrin plane determined equatorial and axial stiffnesses, respectively, while measurements on polycrystalline powders average stiffness over all orientations.

compound	powder	equatorial	axial
[K(222)][Fe(TPP)(2-MeIm⁻)]	171 ± 5	166 ± 23	n.d.^a
[K(222)][Fe(OEP)(2-MeIm⁻)]	178 ± 3	167 ±7	n.d.^a
[Fe(TPP)(2-MeHIm)]	188 ± 1	209 ± 6	153 ± 9

n.d. = not determined.