Density functional study of the structure of the FeMo cofactor with an interstitial atom and homocitrate ligand ring opening

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	Density functional study of the structure of the FeMo cofactor with an interstitial atom and homocitrate ligand ring opening
	Cao, Z. X. ; Jin, X. ; Zhang, Q. N. ; Zhang QE(张乾二)
刊名	http://dx.doi.org/10.1142/S0219633605001684
	2005
关键词	NITROGENASE MOFE-PROTEIN MOLYBDENUM NITROGENASE CORRELATION-ENERGY LEVEL MECHANISM REDUCTION DINITROGEN MOLECULES
英文摘要	The structure of the FeMo cofactor with the central X ligand (X = C4-, C2-, N3-, N-, or O2-) has been determined by the density functional approach. The FeMo cluster with one of the proposed central atoms C4-, C2-, N3-, or N- has an optimized geometry, comparable with the high-resolution X-Ray crystallographic structure of the nitrogenase FeMo cofactor. When the O2- species is present, the FeMo cofactor has an expanded cage. Calculations in the gas phase show that an Fe-4 facet of the FeMo cluster binds NO and CO in end-on coordination with an exothermicity of 25 and 8 kcal mol(-1), respectively, while the singlet O-2 coordinates to the FeMo cluster with an endothermicity of 12 kcal mol(-1). Deoxygenization of the bound NO and CO by the proton-electron addition is favored energetically, which leads to penetration of the C or N atom into the FeMo cage and yields the FeMo(mu(6)-X) cluster. Antiferromagnetic coupling between the Fe sites and vibrational properties of the FeMo(mu(6)-X) cluster, as well as the Mo-bound homocitrate ligand ring opening, have been explored theoretically. Present results suggest that O2- is unlikely as a central anion and the central ligands are identifiable by their IR spectra. Predicted energetics indicates that the protonation opening of the homocitrate ligand ring at the Mo site is feasible.
语种	英语
内容类型	期刊论文
源URL	[http://dspace.xmu.edu.cn/handle/2288/61873]
专题	化学化工－已发表论文
推荐引用方式 GB/T 7714	Cao, Z. X.,Jin, X.,Zhang, Q. N.,et al. Density functional study of the structure of the FeMo cofactor with an interstitial atom and homocitrate ligand ring opening[J]. http://dx.doi.org/10.1142/S0219633605001684,2005.
APA	Cao, Z. X.,Jin, X.,Zhang, Q. N.,&张乾二.(2005).Density functional study of the structure of the FeMo cofactor with an interstitial atom and homocitrate ligand ring opening.http://dx.doi.org/10.1142/S0219633605001684.
MLA	Cao, Z. X.,et al."Density functional study of the structure of the FeMo cofactor with an interstitial atom and homocitrate ligand ring opening".http://dx.doi.org/10.1142/S0219633605001684 (2005).