165131-50-0Relevant articles and documents
PHOSPHORUS-CONTAINING PODANDS. XII. EFFECT OF ALKYL AND PHENYL SUBSTITUENTS ON THE PHOSPHORUS ATOM ON THE COMPLEXING POWER OF NEUTRAL MONOPODANDS. "ANOMALOUS ALKYL EFFECT"
Evreinov, V. I.,Baulin, V. E.,Vostroknutova, Z. N.,Safronova, Z. V.,Bondarenko, N. A.,Tsvetkov, E. N.
, p. 190 - 197 (2007/10/03)
The stability constants of M+L complexes with monopodands o-RC6H4O(CH2CH2O)nC6H4R-o were determined by conductometry in the mixed solvent THF-CHCl3 (4:1, v/v) at 25 deg C.The results obtained were compared with data for previously studied monopodands with a similar structure but with phenyl substituents at the phosphorus.An anomalous phenomenon, viz., influence of terminal alkyl groups on the efficiency of monopodands ("anomalous alkyl effect"), was observed, which consists of a noticeable, and sometimes dramatic, decrease in the stability constants upon replacement of electron-acceptor substituents at the phosphorus by electron-donor alkyl groups, which contradicts the expected dependence of the complexing power of unidentate phosphoryl compunds on their structure.Procedures for synthesizing monopodands, fragments of their terminal groups, and some initial compounds are described.
