| Abstrakt: |
The tetraanilino phosphonium cation, PNHPh4, 1, is sequentially deprotonated by BunLi in thf. The deprotonation reaction of the chloride derivative, 1Cl, was monitored by 31P NMR, which revealed the successive formation of the neutral PNHPh3NPh, 2, the monoanionic PNHPh2NPh2−, 3−, the dianionic PNHPhNPh32−, 42−, and finally the trianionic species PNPh43−, 53−. Considering the isoelectronic relationship of oxo, O, and imino groups, NR, as well as hydroxy, –OH, and amino groups, –NHR, the neutral complex 2corresponds to phosphoric acid, H3PO4, whereas the anions 3−, 42−and 53−are analogues of dihydrogen phosphate, H2PO4−, monohydrogenphosphate, HPO42−, and orthophosphate ions, PO43−, respectively. Solid state structures were obtained of 1Cl, 2LiClthf2, 3Lithf3.5, 3Li2Clthf4.25, 3Li2Clthf6and 5Li4Clthf4. All systems provide two separate N–P–N chelation sites at opposite ligand faces, either consisting of the diamino arrangement PNH2, acting as a double H-bond donor, the diimino arrangement PN2, donating two electron pairs, or the mixed amino imino arrangement PNNH, which supplies both electron pair and H-donor site. Interesting in this aspect is the mixed amino imino derivative 3−which has the ability to chelate a Lewis acid, such as a metal ion, at one face and a Lewis base, such as an anionic or neutral donor at the opposite ligand face. The formation of 1-D aggregates and the entrapment of lithium chloride are key characteristics of the supramolecular structures of the discussed complexes. |
