Vibrational Assignments of Six-Coordinate Ferrous Heme Nitrosyls: New Insight From Nuclear Resonance Vibrational Spectroscopy

Journal Article · Thu May 21 04:00:00 EDT 2009 · Inorg. Chem.47:11449,2008

OSTI ID:953042

Paulat, F; Berto, T C; George, S DeBeer; Goodrich, L; Praneeth, V K.K.; Sulok, C D; Lehnert, N

This Communication addresses a long-standing problem: the exact vibrational assignments of the low-energy modes of the Fe-N-O subunit in six-coordinate ferrous heme nitrosyl model complexes. This problem is addressed using nuclear resonance vibrational spectroscopy (NRVS) coupled to {sup 15}N{sup 18}O isotope labeling and detailed simulations of the obtained data. Two isotope-sensitive features are identified at 437 and 563 cm{sup -1}. Normal coordinate analysis shows that the 437 cm{sup -1} mode corresponds to the Fe-NO stretch, whereas the 563 cm{sup -1} band is identified with the Fe-N-O bend. The relative NRVS intensities of these features determine the degree of vibrational mixing between the stretch and the bend. The implications of these results are discussed with respect to the trans effect of imidazole on the bound NO. In addition, a comparison to myoglobin-NO (Mb-NO) is made to determine the effect of the Mb active site pocket on the bound NO.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 953042
• Report Number(s): SLAC-REPRINT-2009-242
• Journal Information: Inorg. Chem.47:11449,2008, Journal Name: Inorg. Chem.47:11449,2008 Journal Issue: 24 Vol. 47; ISSN 0020-1669; ISSN INOCAJ
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
59 BASIC BIOLOGICAL SCIENCES
HEME
IMIDAZOLES
IRON COMPLEXES
MYOGLOBIN
NITRIC OXIDE
ORGANIC NITROGEN COMPOUNDS
Other
OTHER
CHEM
SPECTROSCOPY
VIBRATIONAL STATES