Hydrogen–deuterium exchange in tetrahydroborate salts

1979 ◽  
Vol 57 (5) ◽  
pp. 503-505 ◽  
Author(s):  
Ian A. Oxton ◽  
A. Gavin McInnes ◽  
John A. Walter

1H nmr spectroscopy has been used to demonstrate hydrogen–deuterium exchange in solutions of NaBH4/NaB2H4 in diglyme and KBH4/KB2H4 in 18-crown-6 ether/chloroform. Earlier observations of such exchange with LiBH4/LiB2H4 in an ethereal solvent were confirmed. Spectra were simplified by broadband decoupling of deuterium, facilitating quantitative measurement of the degree of exchange.

Holzforschung ◽  
2007 ◽  
Vol 61 (5) ◽  
pp. 488-491 ◽  
Author(s):  
Le Xuan Phuong ◽  
Masato Takayama ◽  
Satoshi Shida ◽  
Yuji Matsumoto ◽  
Tetsuo Aoyagi

Abstract A new approach based on hydrogen-deuterium exchange is proposed for measuring accessible OH groups in wood. The deuterium (D) exchanged for hydrogen in OH groups in wood was converted to D2O by combustion in oxygen gas then diluted in deionized water, and subsequently determined by 2H NMR spectroscopy. The amount of accessible OH groups in Styrax tonkinensis wood is approximately 6.8 mmol g-1. This measurement is very accurate, with an error of approximately 0.2 mmol g-1. Heat-treated wood has a lower amount of accessible OH groups than non-treated wood. This finding is in agreement with the decreased hygroscopicity of heat-treated wood and explains, at least partially, its increased fungal resistance.


FEBS Letters ◽  
1993 ◽  
Vol 331 (1-2) ◽  
pp. 165-172 ◽  
Author(s):  
David N.M. Jones ◽  
Mark Bycroft ◽  
Michael J. Lubienski ◽  
Alan R. Fersht

1977 ◽  
Vol 55 (1) ◽  
pp. 50-55 ◽  
Author(s):  
A. K. Cheng ◽  
J. B. Stothers

Bicyclo[3.2.1]oct-2-ene undergoes hydrogen–deuterium exchange through allyl and vinyl carbanionic intermediates under strongly basic conditions, tert-BuO−/tert-BuOD) at 185 °C. Only allylic exchange had been observed in previous studies with tert-BuO−/DMSO. Since the 2-tert-butoxybicyclo[3.2.1]octanes are stable under these conditions an addition–elimination sequence cannot account for exchange at C-3. The relative rates of exchange at C-2, -3, and -4, and the stereoselectivity at the allylic site were determined by 2H nmr. For comparison, the rate of olefinic exchange in bicyclo[2.2.2]octene was also measured.


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