Transformation of η¹‐Nitrosyl to η²‐Hydroxylaminyl Ligands in the Reduction of [Mo(NO)₂(‘S₄’)] to [Mo(η²‐NH₂O)(NO)(‘S₄’)]: A Model Reaction for a Partial Step in the Enzymatic NO→NH₃ Conversion

Abstract

We thank a referee for bringing to our attention recent publications on other systematic investigations on the large effect of changes on hostguest complexes: a) F. Diederich, Angew. Chem. 100 (1988) 372 (especially p. 382); Angew. Chem. Int. Ed. Engl. 27 (1988) 362; b) T. J. Shepodd, M. A. Petti, D. A. Dougherty, J. Am. Chem. Soc llO(1988) 1983. 131 All new compounds gave satisfactory analytical data ( ' H and ''C NMR, elemental analyses) [4] H.-J. Schneider, R. Kramer, J. Pdhlmann, U. Schneider, J . Am. Chem. Soc. 110 (1988), in press. [5] H.-J. Schneider, R. Pohlmann, Bioorg. Chem. 15 (1987) 183. 161 Compare the hydrophobic increments of -NHCH3, whicheare roughly five orders of magnitude larger compared with those of -NMe, substituents: C. Hansch, A. Leo: Substituent Constants for Correlation Analysis in Chemistry and Biology, Wiley, New York 1979, p. 49ff. 0 VCH VerlagsgesellschaJi mbH, 0-6940 Weinheim, 1988 0570-0833/88/0909-1164 $ 02.50/0 Angew. Chem. Int. Ed. Engl. 27 11988) No. 9

Synthesis of Methylated, Hydroxylated, and Aminated Metallaaromatics via Ring-Opening Reactions of the Fused Three-Membered Ring Units

“…When the reaction conditions were altered from air to a nitrogen atmosphere at a lower temperature, product 13 could be isolated in an increased yield of 72% (Figure b). The X-ray crystal structure analysis of compound 13a with a BF 4 counteranion revealed that the chloride ligand on the osmium center had been replaced by a three-electron donor hydroxylamido (NH 2 O) ligand, adopting an η 2 -N,O coordination mode . Subsequently, heating a methanol solution of compound 13 under an air atmosphere resulted in its nearly complete conversion to compound 5 through the oxidation of the NH 2 O moiety to NO, thereby demonstrating the role of the reaction intermediate of the osmium hydroxylamido complex.…”