1 radual and selective lengthening of the Fe-N(axial bond).

2 which has a relatively short Cu(II)-S(Met89) axial bond (2.6 A).

3 dal structure with two longer and more ionic axial bonds and two shorter and more covalent equatorial

4 om out of the porphyrin plane, and a shorter axial bond compared to its counterpart with no hydrogen

5                                     A strong axial bond [Cu(II)-Oepsilon1 approximately 2.2 A] is som

6  as well as significant lengthening of trans axial bond distances.

7 at this kind of bonding is characteristic of axial bonding in d(8) complexes was supported by model c

8 noid intermediate that lacks any significant axial bonding interactions, to stabilize the redox-activ

9 nar Co(2+) center that lacks any significant axial bonding interactions.

10 adducts thought to have long and normal Co-N axial bond lengths, respectively.

11 retation of this similarity is that the Co-N axial bond of the bound cofactor is not hyper-long in an

12 tion 1H NMR has been used to investigate the axial bonding of the proximal His and the hydrogen-bondi

13  No adduct (and hence no hyper-long Co(II)-N axial bond) was formed even by 8 M 2-pic, if the 2-pic w

14 ric interactions are weak for the respective axial bonds where relative lengths are determined by int