Scalar Coupling between the15N Centres in Methylated 1,8-Diaminonaphthalenes and 1,6-Diazacyclodecane: To What Extent is2HJNN a Reliable Indicator of NN Distance?
作者:Guy C. Lloyd-Jones、Jeremy N. Harvey、Paul Hodgson、Martin Murray、Robert L. Woodward
DOI:10.1002/chem.200304890
日期:2003.9.22
in the protonated series as the degree of methylation increases. The effect in the free-base forms is much less pronounced (2.9 to 3.7 Hz) with no scalar N,N couplingdetected in the permethylated compound (protonsponge) due to the lack of hydrogenbond between the N,N centres. Neither the pK(a) nor the N-N distance in the protonated forms correlates with (2H)J(NN). However, the sum of the (13)C NMR