INTRAMOLECULAR COORDINATION AT PHOSPHORUS - DONOR-ACCEPTOR INTERACTION IN 3-COORDINATED AND 4-COORDINATED PHOSPHORUS-COMPOUNDS

The phosphorus derivatives P(X)(O2C6H4-1,2)(2)[C6H4(CH(2)NMe(2))(2)-2] (9-11) undergo ready extension of coordination by N-->P intramolecula r donor-acceptor interaction as shown by P-31 NMR and dynamic H-1 NMR spectroscopy. This extension of coordination does not occur with P(X)( OEt)(2)[C6H4(CH(2)NMe(2))(2)-2] (7 and 8). The Delta G(not equal) of p seudo-rotation was calculated by dynamic H-1 NMR spectroscopy to be 57 -58 kJ mol(-1) for the three compounds P(X)(O2C6H4-1,2)(2)[C10H6(NMe(2 )-8)] (19-21).