Synthesis and structural characterization of zinc complexes of the imido–amido phosphate anions OP[(NHR)3–x(NR)]x– (R=Me, t-Bu; x=1–3) and EP[(NH-t-Bu)2(N-t-Bu)]– (E=S, NSiMe3)

The reaction of OP(NH-t-Bu) 3 with 1 equiv. of ZnMe 2 generates the dimeric eight-membered ring {MeZn[(µ-NH-t-Bu)(µ-N-t-Bu)P(NH-t-Bu)(µ-O)]} 2 (5) and the cubane {[MeZn] 3 [OP(N-t-Bu) 3 ][OP(NH-t-Bu) 3 ]} (6), which contains the first known trisimidophosphate trianion. A related complex {Zn[ZnMe] 2 [OP(N-t-Bu)(NH-t-Bu) 2 ][OP(N-t-Bu) 3 ]} (7) is obtained by the reaction of OP(NH-t-Bu) 3 with ZnMe 2 in a 2:3 molar ratio. The treatment of OP(NHMe) 3 with 1 equiv. of ZnMe 2 produces the oxide-templated cluster {Zn 4 (µ 4 -O)[OP(NMe)(NHMe) 2 ] 4 [OP(NMe) 2 (NHMe)]} 2 (8). Each half of this centrosymmetric dimer contains a tetrahedral arrangement of four 4-coordinate Zn 2+ ions surrounding the central µ 4 -O 2- anion. The reaction of SP(NH-t-Bu) 3 with ZnMe 2 in a 1:1 molar ratio generates the dimer {MeZn(µ-S)(µ-N-t-Bu)P(NH-t-Bu) 2 } 2 (10), which has a ladder-type structure. When a 2:1 molar ratio of the same reagents is employed, the bis(N,S)-chelated complex {Zn[(µ-S)(µ-N-t-Bu)P(NH-t-Bu) 2 ] 2 } (11) is obtained. The monomeric N,N′-chelated complex {MeZn[(µ-N-t-Bu)(µ-NSiMe 3 )P(NH-t-Bu) 2 ]} (12) results from the reaction of Me 3 SiNP(NH-t-Bu) 3 with 1 equiv. of dimethylzinc. All new compounds have been characterized by multinuclear ( 1 H, 13 C, and 31 P) NMR spectroscopy and, in the case of 5, 6, 7, 8, and 10, by X-ray structural determinations.Key words: zinc, phosphate, imido ligands, sulfur.