METAL COMPLEXES OF SYM-DIETHYL TETRAMETHYLDIAMIDOPYROPHOSPHATE

Metal complexes of sym-diethyl tetramethyldiamidopyrophosphate (SYM) which have been isolated include Mg(SYM)3 (ClO4)2, Ba(SYM)2(ClO4)2, Co(SYM)3(ClO4)2, Ni(SYM)3(ClO4)2, Cu(SYM)3(ClO4)2, and Zn(SYM)3(ClO4)2. These complexes are much less stable than the corresponding complexes of octamethylpyrophosphoramide (OMPA). Over-all stability constants have been determined in acetone solution for complexes of Co(II) and Ni(II) with both SYM and OMPA. The values for OMPA are consistently larger than those for SYM. This is just the opposite of the order obtained for Dq toward Ni(II) [SYM, 741 cm-1; OMPA, 726cm-1]. © 1969, American Chemical Society. All rights reserved.