Heteronuclear multiple bond correlation measurements

Notably, two isomeric products can be generated. The usual infrared (IR) and mass spectra as well as H and 13C NMR chemical shifts could not define which isomer was formed. The authors used different NMR techniques, such as 2-D heteronuclear multiple bond correlation (HMBC) experiments and phase-sensitive nuclear overhauser enhancement spectroscopy (NOESY) measurements to elucidate the product s structure. 

The Si NMR spectrum of pentaorganosilicate 25 was recorded at —50°C to minimize signal broadening <2004AGE3440>. H NMR, NMR, heteronuclear multiple quantum correlation (HMQC), and heteronuclear multiple bond correlation (HMBC) spectroscopic measurements were also performed. The observed 7c2,si value of 86 Hz was similar to that of a typical Si(sp )-C(sp ) bond, while the /c 2, si value of 30 Hz was much smaller than that of a Si(sp )-C(sp ) bond (64-70 Hz). 

More recently, a gradient-enhanced heteronuclear single quantum multiple bond correlation (HSQMBC) experiment and its variants34,47,60-62 have been proposed for the measurement of heteronuclear coupling... 

Now a simple, general and pratical method is available for direct measurement of V(ch) coupling constants [73]. ID and 2D heteronuclear single quantum multiple bond correlation (HSQMBC) experiments are easily performed in a routine manner. These experiments are based on the evolution of heteronuclear single quantum coherence (SQC) in... 

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