John Emsley, Lewina Y.Y. Ma, Paul A. Bates
1989
Citations
0
Influential Citations
40
Citations
Journal
Journal of The Chemical Society-perkin Transactions 1
Abstract
Three new derivatives of pentane-2,4-dione (PD) have been synthesized: 3-(4-nitrophenyl), 3-(4-phenoxyphenyl) and 3-(4-isopropylphenyl). The X-ray crystal structures of these compounds show them to have very short hydrogen bonds with R(O ⋯ O)= 2.445, 2.443, and 2.419 A, respectively. Those parameters most sensitive to hydrogen bonding—1H chemical shift, change in chemical shift on deuteriation [Δδ(H, D)], and stretching frequencies [νCO and νmax.(OHO)]—have been measured for these, and other 3-derivatives of PD, with a view to probing the potential energy well of this type of bond. The conclusion is that in all of the compounds with R(O ⋯ O) < 2.45 A, the hydrogen bonding is very strong with the proton zero point energy above the internal barrier.