TITLE:
The DQF-COSY NMR Experiment, a Way to Detect Small J Couplings in the Case of Fast Relaxing Nuclei: Application to 59Co in the Tetrahedral Mixed-Metal Cluster HRuCo3(CO)11(PPh3)
AUTHORS:
Jacky Rosé, Pierre Kempgens
KEYWORDS:
NMR, Cobalt-59, 2D COSY and DQF-COSY, Scalar Couplings, Tetrahedral Mixed-Metal Cluster
JOURNAL NAME:
Open Access Library Journal,
Vol.1 No.3,
June
16,
2014
ABSTRACT: The first investigation and analysis of 59Co 2D NMR homonuclear chemical shift correlation spectra for a ruthenium-based tetrahedral mixed-metal cluster HRuCo3(CO)11(PPh3) are reported. For this cluster in solution and by contrast to the conventional COSY NMR experiment, the double-quantum filtered (DQF) COSY NMR spectrum proves the existence of a scalar coupling constant between 59Co nuclei. In order to obtain a value of this coupling, the 2D COSY spectrum for a three-spin 7/2 AX2 system has been simulated by numerical density matrix calculations. The comparison between experimental and theoretical 2D NMR COSY spectra gives a spin-coupling constant |1J(59Co-59Co)|