FeIIITPPCl reacts reversibly with nitric oxide to form FeTPP(Cl)(NO) which is spectroscopically studied in toluene solution, glass media, and Nujol mulls. This diamagnetic nitric oxide complex is formulated as FenTPP(Cl-)(NO+). In the presence of methanol, FeIIITPPCl reacts with excess nitric oxide to produce Fe II-TPP(NO). This reaction is thought to proceed via the methanolysis of coordinated NO+ in the intermediate FeII-TPP(Cl-)(NO+) complex. FeIITPP(NO) has a doublet ground state with the odd electron in a molecular orbital with Fe (d,z2) and NO (σN) character. FeIITPP(NO) adds nitrogen donors in the sixth coordination position which have epr spectra showing 14N hyperfine from both nitrogen bonded ligands. A second nitric oxide is reversibly coordinated by FeIITPP(NO) to form FeTPP(NO)2, which on the basis of magnetic and spectroscopic properties is formulated as FeIITPP(NO-)(NO+). Two N-O stretching frequencies are observed consistent with linear FeII- NO+ and bent FeIINO- units. Bonding models are presented for the nitric oxide complexes and generalized for related complexes of diatomic molecules.
ASJC Scopus subject areas
- Colloid and Surface Chemistry