Macrocycles of the general formula trans-FeLy(P((CH2)n)3P) are derived from three-fold intramolecular ring closing metathesis using Grubbs' first generation catalyst. These macrocycles possess a cage within which the metal center and equatorial ligands may rotate about an axis mimicking a common toy gyroscope. Both [Fe(CO)3] and [Fe(CO)2(NO)]+ rotators have been established. Additionally, neutral dipolar rotators are of synthetic interest and have advantages for sustained unidirectional rotation in a rotating electric field. These rotators could be established by substituting a subsequent carbonyl ligand from the [Fe(CO)2(NO)]+ rotators with various halides including: Cl, Br, I, and CN. These gyroscope syntheses are extended to include arsine analogs of the phosphine ligands. Due to the longer iron-arsenic bond distances, diarsine cages would provide increased top/bottom �clearance� and lower rotational barriers, which are investigated with variable temperature 13C NMR of three gyroscopes with varying cage sizes. Finally, the crystal structures and variable temperature NMR data will be presented and discussed.

Synthesis and characterization of a series of diarsine and substituted diphosphine gyroscopes

244th National Meeting (2012)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.