title: Structural features of aliphatic N-nitrosamines of 7-azabicyclo[2.2.1]heptanes that facilitate N-NO bond cleavage.
abstract: N-Nitrosamines can be considered as potential nitric oxide (NO)/nitrosonium ion (NO(+)) donors. However, the relation of the structures of N-nitrosamines, in particular of aliphatic N-nitrosamines, to the characteristics of release of NO or NO(+) remains unclear. Here we show that aliphatic N-nitrosoamines of 7-azabicyclo[2.2.1]heptanes can undergo heterolytic N-NO bond cleavage. On the basis of the observation of reduced rotational barriers of the N-NO bonds in solution and nitrogen-pyramidal structures of the N-nitroso group in the solid state, we postulate that N-NO bond cleavage of N-nitrosamines is enhanced by a reduction of the resonance in the N-NO group. Computational studies suggest that these structural features of the N-nitrosamines of 7-azabicyclo[2.2.1]heptane are derived from angle strain imposed on the CNC angles.
authors.affiliation: Contribution from the Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ohwada
authors.forename: M
authors.initials: M
authors.lastname: Miura
authors.forename: H
authors.initials: H
authors.lastname: Tanaka
authors.forename: S
authors.initials: S
authors.lastname: Sakamoto
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: H
authors.initials: H
authors.lastname: Ikeda
authors.forename: S
authors.initials: S
authors.lastname: Inagaki
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D018360:Crystallography, X-Ray; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008968:Molecular Conformation; D015394:Molecular Structure; D020030:Nitric Oxide Donors / Q000737:chemistry*; D009584:Nitrogen / Q000737:chemistry; D009602:Nitrosamines / Q000737:chemistry*; D013329:Structure-Activity Relationship
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; D020030:Nitric Oxide Donors; D009602:Nitrosamines; D009584:Nitrogen