Abstract
This research uses [(BimH)3Fe(NCCH3)][BF4]2 (1) as starting material, binding of small molecules nitrite、nitrate、nitric oxide to formation of [(BimH)3Fe(2-O2N)] [BF4] (2)、[(BimH)3Fe(1-ONO)][BF4] (3)、[(BimH)3Fe(2-O2NO)][BF4] (4)、[(BimH)3Fe(NO)] [BF4]2 (5). Reaction of complex 2 with nitric oxide gives [(BimH)3- Fe(1-ONO)(NO)][BF4] (6). Fe2+ binding with nitrite produces different binding modes displayed by complex 2 (2-O2N), complex 3 (1-ONO). Complex 5 and 6 have similar magnetic properties. Both of them have axial EPR pattern but some rhombic S=3/2 EPR spectra: g1eff ≈ g2eff ≈ 4、g3eff ≈ 2. EPR, SQUID fitting display D>0, very small E/D and negative θ that means they have antiferromagnetic coupling. The μeff in SQUID shows Stotal = 3/2 {FeⅢ(NO– )}7 electronic structure. Because of D>0 in complex 5 and 6, their ground state are assigned to ms = ±1/2 and excited state ms = ±3/2. Reaction of complex 2 with nitric oxide shows scrambling mechanism. Adding of 2 equivalent of acetic acid to complex 2 resease 80~90% nitric oxide, and the formation of [(BimH)3Fe(μ-O)(OAc)Fe(BimH)3][BF4]3 (7) and the [(BimH)3Fe- (μ-O)(OAc)2Fe(BimH)3]2+ (8) under the excess of acetic acid.