Localization-consistent electronic energy partitions

Electronic energy partitionings resulting from the classification of occupied molecular orbitals in disjoint subsets are seen to be consistent with localization procedures preserving that classification, regardless of the treatment given to the crossing terms between different subsets. To illustrate the utility of this result, the electronic energies of pyrazole and imidazole are partitioned into σ- and π-localized molecular orbital energy contributions, and the results are related with the aromaticity and basicity differences between both heterocycles. © 1997 John Wiley & Sons, Inc. Int J Quant Chem 65 : 121–126, 1997     

Tris(benzophenoneimino)phosphane and Related Compounds

A new group of bases with benzophenoneiminyl (bpi) moiety has been synthesized and characterized in this work. The title compound tris(benzophenoneimino)phosphane (P(bpi)₃) 1 was prepared with a convenient one-pot approach: benzophenone imine was deprotonated using MeMgCl and reacted with PBr₃ in diglyme. The method could be considered as a method of choice for preparing other (amino)phosphanes in case lithio-intermediates and/or protonated phosphane is out of consideration. Phosphane 1 is further used to prepare a range of related phosphonium cations and phosphazenes. Phosphonium cations were deprotonated to assess the stability of the resulting phosphonium ylides. In some cases, the bulky substances were capable of forming P−N heterocycles. Experimental (MeCN) and computational (MeCN, THF, gas-phase) basicities of benzophenone imine, phosphane 1 , phosphonium ylides, and phosphazenes, as well as some representative XRD structures, are presented and discussed.