Enantiomerically pure zinc phosphonates based on mixed phosphonic acid-phosphine oxide chiral building blocks

The coordination chemistry of enantiomerically pure phosphonic acids H2O3PC H2P(O)(C6H5)(R) [R = CH3 and C2H5] with zinc is described. The structures o f two new optically active layered zinc phosphonates (R)-alpha -Zn(O3PCH2P( O)(C6H5)(CH3)) and (R)-alpha -Zn(O3PCH2P(O)(C6H5)(C2H5)).H2O were determine d, in which the phosphine oxide is coordinated to zinc. This coordination c an be avoided when the synthesis is performed in a slightly acidic medium, as evidenced by the structure of (R)-beta -Zn(O3PCH2P(O)(C6H5)(CH3)).H2O.