Front Cover: Basicity of N-(Tetramesityltetraphosphacyclopentylidene)cyclohexylamine: An Unusual Diphospha(III)guanidine Derivative (Eur. J. Inorg. Chem. /2017)

The Front Cover shows the pK_a value of the unusual cyclic hetero-oligophosphane cyclo-P₄Mes₄C(NCy), whose C–N double bond does not exhibit the reactivity expected for imines, but can in fact be regarded as part of a substituted diphospha(III)guanidine moiety. According to quantum mechanical calculations, its basicity is comparable to that of methyl-substituted monophospha(III)guanidine. Thus, the nitrogen atom can be protonated with HCl or HBF₄. The pK_a value of cyclo-P₄Mes₄C(NCy) was measured by reactions with so-called indicator bases and is in the range 4.9–5.2 in THF. More information can be found in the Full Paper by E. Hey-Hawkins et al. For more on the story behind the cover research, see the Cover Profile.

from #MedicinebyAlexandrosSfakianakis via xlomafota13 on Inoreader http://ift.tt/2BtPlFK
via IFTTT