[PHP(S)(NMENH(2))(2)]ZNCL2 - A REAGENT FOR THE SYNTHESIS OF POLYMETALLIC COMPLEXES - X-RAY STRUCTURE OF THE ELECTROACTIVE COMPOUND [PHP(S)(NMEN=CHC(5)H(4)FECP)(2)]ZNCL2

The zinc complex [PhP(S)(NMeNH(2))(2)]ZnCl2 (2), cleanly obtained by r eaction of the phosphodihydrazide PhP-(S)(NMeNH(2))(2) (1) with ZnCl2, is a good reagent in producing new polymetallic compounds by condensa tion reaction with aldehydes. The reaction of 2 with terephthalaldehyd e (3) in a 2/1 or 1/1 stoichiometry leads selectively to the acyclic z inc compound [C6H4-1,4-(CH=NNMePhP(S)NMeNH(2))(2)] [ZnCl2](2) (6) or t o the macrocyclic zinc complex [PhP(S)C6H4-1,4-(CH=NNMe)(2)](2)[ZnCl2] (2) (7). Reaction of compound 2 with 2 equiv of ferrocenecarbaldehyde affords the zinc-iron phosphodihydrazone complex [PhP(S)(NMeN=CHC(5)H( 4)FeCp)(2)]ZnCl2 (8) whose structure has been determined by X-ray crys tallography. Crystal data: triclinic P $($) over bar$$ 1, with a 12.79 8(1) Angstrom, b = 14.639(2) A, c = 11.744(2) Angstrom, alpha = 111.74 (1)degrees, beta = 115.92(1)degrees, gamma = 68,36(1)degrees, V = 1780 .9 Angstrom(3), Z = 2; R 0.037, Rw = 0.044 for 3345 observations and 4 48 variable parameters. In this neutral trimetallic complex, the Zn(II ) center adopts a pseudotetrahedral geometry. This structure is charac terized by a five-membered ring with the Zn(II) bonded to the S atom a nd to one of the N atoms of the phosphodihydrazone ligand PhP(S)-(NMeN =CHC(5)H(4)FeCp)(2) (9). Variable-temperature NMR investigations of 8 show that 9 can act as a hemilabile ligand toward ZnCl2 through an exc hange process between the two hydrazone arms in solution. Electrochemi cal study of complex 8, when compared to the ferrocenyl ligand 9, show s that ZnCl2 complexation induces a shift of 80 mV toward a more anodi c potential. Reaction of 2 with the ferrocene-1,1'-dicarbaidehyde also produces the bisferrocenyl dizinc macrocycle [Fe(C5H4CH=NNMePhP(S)NMe N=CHC5H4)(2)Fe][ZnCl2](2) (10).