Nitrosyl and nitroso complexes of group 8 metalloporphyrins.

Abstract

Chapter 3 of this dissertation describes the synthesis and characterization of osmium nitrosyl porphyrins containing organo, chloro and $\mu$-oxo ligands and the extensions of the synthetic methodology to the preparation of the first organoosmium thionitrosyl porphyrin. (Abstract shortened by UMI.)

Chapter 2 of this dissertation describes the adduct formation of nitrosamine and nitrosoarene compounds to Fe$\sp{\rm III}$ and Os$\sp{\rm II}$ porphyrins. The reaction of ((TTP)Fe(THF)$\sb2$) (SbF$\sb6)$ with Et$\sb2$NNO generates the ((TTP)Fe(Et$\sb2$NNO)$\sb2$) (SbF$\sb6)$ complex in 70% yield. Reaction of ((TTP)Fe(Et$\sb2$NNO)$\sb2$) (SbF$\sb6)$ with NO gas in CH$\sb2$Cl$\sb2$ results in the displacement of one of the Et$\sb2$NNO ligands to give the thermally unstable ((TTP)Fe(NO)(Et$\sb2$NNO)) (SbF$\sb6)$ complex. The (TTP)Os(CO)(Et$\sb2$NNO) and (OEP)Os(CO)(Et$\sb2$NNO) complexes are prepared in 74% and 66% yields, respectively, by Et$\sb2$NNO addition to the precursor (por)Os(CO) compounds in CH$\sb2$Cl$\sb2.$ The nitrosyl ((OEP)Os(NO)(Et$\sb2$NNO)) (BF$\sb4)$ derivative is obtained in quantitative yield by the reaction of (OEP)Os(CO)(Et$\sb2$NNO) with NOBF$\sb4.$ The solid-state structure of (TTP)Os(CO)(Et$\sb2$NNO) has been determined by single-crystal X-ray diffraction. The Et$\sb2$NNO ligand displays an $\eta\sp1$-O binding mode in (TTP)Os(CO)(Et$\sb2$NNO). The $\eta\sp1$-O binding mode has been extended to the binding of nitrosoarene ligands to Fe$\sp{\rm III}$ as well as Mn$\sp{\rm III}$ porphyrins. The reactions of ((por)Fe(THF)$\sb2$) (SbF$\sb6)$ (por = TPP, TTP; TPP = 5, 10, 15, 20-tetraphenylporphyrinato dianion) with para-dialkylamino substituted nitrosoarenes R$\sb2$NC$\sb6$H$\sb4$NO (R = Me, Et) result in the formation of bis-adducts ((por)Fe(ONC$\sb6$H$\sb4$NR$\sb2)\sb2$) (SbF$\sb6)$ in 55-83% yields.

Chapter 1 of this dissertation describes the formal trans addition of thionitrites (RSNO) and alkyl nitrites (RONO) to Os$\sp{\rm II}$ porphyrins, and the investigation of the reaction pathway of the thionitrite additions to Os$\sp{\rm II}$ porphyrins. The extension of the thionitrite reaction chemistry with a (OEP)Os$\sp{\rm III}$ complex is also described (OEP = 2, 3, 7, 8, 12, 13, 17, 18-octaethylporphyrinato dianion). The reactions of (OEP)Os(CO) with isoamyl thionitrite and phenyl thionitrite give the trans addition products (OEP)Os(NO)(S-i-C$\sb5$H$\sbÔΩ̜)$ and (OEP)Os(NO)(SPh), respectively. The related reactions of (por)Os(CO) (por = OEP, TTP; TTP = 5, 10, 15, 20-tetra-p-tolylporphyrinato dianion) with alkyl nitrites give the corresponding nitrosyl alkoxides (por)Os(NO)(OR). The reaction of isoamyl thionitrite and isoamyl nitrite with the non-carbonyl-containing ((OEP)Os) $\sb2$ also give the trans addition products.