Note. Two-dimensional nuclear magnetic resonance for the analysis of the carbon-13 spectra of carbonyl groups in metallocarbonyls

Abstract

The ¹³C homonuclear two-dimensional n.m.r. shift correlation experiment COSY on the ¹³C-enriched complex [Os₃H₂(CO)₁₀] established the presence of two-and three-bond scalar couplings which partially invalidates previous assignement of the ¹³C spectrum. A related two-dimensional experiment (NOESY) was used to detect slow localised carbonyl group exchange. The intensities of the slowly exchanging peak and the associated correlation peak in the NO ESY experiment were analysed quantitatively to yield ¹³C spin-lattice relaxation rates and a value for the exchange rate constant (1.21 s^1–).