Determination of 1J(59Co–59Co) scalar coupling constants in the tetrahedral mixed-metal cluster HFeCo3(CO)10(PCyH2)(PPh2[CH2C(O)Ph]) using COSY-type NMR experiments

The COSY and DQF‐COSY NMR spectra of an AX system of spins I = 3/2

“…Finally, it can be seen from Figs. 5 and 6 that in addition to the usual advantages that the DQF-COSY NMR experiment offer compared with the conventional COSY NMR experiment (observation of only-coupled spins, antiphase character of both diagonal and cross-peaks and intensity of the cross peaks comparable with the intensity of the diagonal peaks), the DQF-COSY NMR experiment appear to be more reliable for interpretation and analysis than the conventional COSY NMR experiment and this is particularly true for quadrupolar nuclei relaxing usually very quickly, as was recently concluded (19).…”

“…In addition to the standard proton experiment, correlations between metal nuclei, which often have nuclear spins greater than 1/2, are of interest, if chemically different sites are present and if scalar spin-spin coupling exists. Homonuclear COSY experiments for 11 B (3-11), 51 V (12), 6 Li (13-15), 7 Li (14-16), 59 Co (17)(18)(19), and 2 H (20) are early examples from this area which demonstrated the power of 2D NMR methods for structural studies. On the theoretical side, and to the best of our knowledge, a numerical approach was used by Moskau et al (15) to simulate 2D COSY spectra for two spin-1 and two spin-3/2 systems.…”

The density matrix theory of triple‐quantum filtered COSY (TQF‐COSY) NMR experiments applied to an AX system of spins S=1: An example of passive coupling in two‐dimensional NMR spectroscopy

“…The standard homonuclear COSY experiment 1 is probably the most popular two-dimensional (2D) NMR experiment and has been used for the detection of scalar coupling interaction in spin systems of NMR active quadrupolar nuclei such as 11 B, 2-10 51 V, 11 6 Li, 12-14 7 Li, 13,14 59 Co [15][16][17] and 2 H. 18 From a COSY experiment it is possible to assign signals to individual substituents in a molecular structure and using the coupling constants the coupling interaction can be interpreted to describe the whole molecular structure. However, the COSY experiment does have some disadvantages.…”

“…By contrast to what happen with the conventional COSY experiment, it is also sometimes possible to observe cross peaks with a DQF-COSY experiment when dealing with quadrupolar nuclei relaxing usually very quickly and relatively small coupling constants. 17,19 The density matrix theories of the COSY experiment for an AX system of spin-1/2 20 and for an AX or AMX system of any spin number 21 have been described elsewhere. The density matrix theory of the DQF-COSY NMR experiment for an AX or AMX system of any spin number has also been described elsewhere.…”

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)

“…However, most of the investigations performed so far concern nuclei with small quadrupole moments such as 11 B [2]- [10], 51 V [11], 2 H [12], 6 Li [13]- [16] and 7 Li [14]- [16], whose lines are relatively narrow in the conventional 1D spectrum. The DQF-COSY NMR experiment has only been scarcely used in the field of quadrupolar nuclei, and only when the lines were broad in the 1D spectrum [17]- [19]. Recently, we have shown theoretically the superiority of the DQF-COSY NMR experiment when trying to detect and determine relatively small J couplings in the case of fast relaxing nuclei and broad peaks in the quadrupolar nucleus 1D NMR spectrum [20]- [24].…”