PMID- 23875582
OWN - NLM
STAT- MEDLINE
DCOM- 20140225
LR  - 20211021
IS  - 1520-510X (Electronic)
IS  - 0020-1669 (Print)
IS  - 0020-1669 (Linking)
VI  - 52
IP  - 15
DP  - 2013 Aug 5
TI  - Structural, spectroscopic, and computational characterization of the azide adduct 
      of Fe(III)(2,6-diacetylpyridinebis(semioxamazide)), a functional analogue of iron 
      superoxide dismutase.
PG  - 8909-18
LID - 10.1021/ic401098x [doi]
AB  - We have prepared and thoroughly characterized, using X-ray crystallographic, 
      spectroscopic, and computational methods, the diazide adduct of 
      [Fe(III)(dapsox)(H2O)2](+) [dapsox = 2,6-diacetylpyridinebis(semioxamazide)], 
      (1), a low-molecular weight, functional analogue of iron superoxide dismutase 
      (FeSOD). The X-ray crystal structure of the dimeric form of 1, 
      (Na[Fe(III)(dapsox)(N3)2].DMF)2 (2) shows two axially coordinated, symmetry 
      inequivalent azides with differing Fe-N3 bond lengths and Fe-N-N2 bond angles. 
      This inequivalence of the azide ligands likely reflects the presence of an 
      interdimer hydrogen bonding interaction between a dapsox NH group and the 
      coordinated nitrogen of one of the two azide ligands. Resonance Raman (rR) data 
      obtained for frozen aqueous solution and solid-state samples of 2 indicate that 
      the azides remain inequivalent in solution, suggesting that one of the azide 
      ligands of 1 engages in an intermolecular hydrogen bonding interaction with a 
      water molecule. Density functional theory (DFT) and time-dependent DFT 
      calculations have been used to study two different computational models of 1, one 
      using coordinates taken from the X-ray crystal structure of 2, and the other 
      generated via DFT geometry optimization. An evaluation of these models on the 
      basis of electronic absorption, magnetic circular dichroism, and rR data 
      indicates that the crystal structure based model yields a more accurate 
      electronic structure description of 1, providing further support for the proposed 
      intermolecular hydrogen bonding of 1 in the solid state and in solution. An 
      analysis of the experimentally validated DFT results for this model reveals that 
      the azides have both sigma- and pi-bonding interactions with the Fe(III) center and 
      that more negative charge is located on the Fe-bound, rather than on the 
      terminal, nitrogen atom of each azide. These observations are reminiscent of the 
      results previously reported for the azide adduct of FeSOD and provide clues 
      regarding the origin of the high catalytic activity of Fe-dapsox for superoxide 
      disproportionation.
FAU - Gutman, Craig T
AU  - Gutman CT
AD  - Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 
      53706, United States.
FAU - Guzei, Ilia A
AU  - Guzei IA
FAU - Brunold, Thomas C
AU  - Brunold TC
LA  - eng
GR  - R01 GM064631/GM/NIGMS NIH HHS/United States
GR  - GM 64631/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, U.S. Gov't, Non-P.H.S.
DEP - 20130722
PL  - United States
TA  - Inorg Chem
JT  - Inorganic chemistry
JID - 0366543
RN  - 0 (Azides)
RN  - 0 (Organometallic Compounds)
RN  - 0 (Pyridines)
RN  - E1UOL152H7 (Iron)
RN  - EC 1.15.1.1 (Superoxide Dismutase)
RN  - NH9L3PP67S (pyridine)
SB  - IM
MH  - Azides/*chemistry
MH  - Biomimetic Materials/*chemistry
MH  - Crystallography, X-Ray
MH  - Hydrogen Bonding
MH  - Iron/*chemistry
MH  - Models, Molecular
MH  - Molecular Conformation
MH  - Organometallic Compounds/*chemistry
MH  - Pyridines/*chemistry
MH  - Quantum Theory
MH  - Spectrum Analysis
MH  - Superoxide Dismutase/*chemistry/metabolism
PMC - PMC3974274
MID - NIHMS508891
EDAT- 2013/07/24 06:00
MHDA- 2014/02/26 06:00
PMCR- 2014/08/05
CRDT- 2013/07/24 06:00
PHST- 2013/07/24 06:00 [entrez]
PHST- 2013/07/24 06:00 [pubmed]
PHST- 2014/02/26 06:00 [medline]
PHST- 2014/08/05 00:00 [pmc-release]
AID - 10.1021/ic401098x [doi]
PST - ppublish
SO  - Inorg Chem. 2013 Aug 5;52(15):8909-18. doi: 10.1021/ic401098x. Epub 2013 Jul 22.