Investigations on organozinc compounds XI. Coordination chemistry of organozinc compounds RZnX: organozinc-nitrogen compounds of the type EtZnNPhCOZ

Abstract

The coordination chemistry of the organozinc-nitrogen compounds EtZnNPh2 and EtZnNPhCOZ (Z=H, Me, OMe, SMe and NPh2) has been studied. Whereas EtZnNPh2 is dimeric [as in Zn(NPh2)2], with three-coordinate zinc, replacement of a Ph group in EtZnNPh2 by COZ leads to higher association and four-coordination of zinc. Such compounds are trimeric in solution with Z=OMe and NPH2, tetrameric with Z=Me, and polymeric (n > 6) with Z=H. The compound with Z=SMe decomposes into EtZnSMe and PhNCO above 5°. All compounds readily form four-coordinate complexes with pyridine (Py) and N,N,N′,N′-tetramethylethylenediamine (TMED). EtZnNPh2 and EtZnNPhCOZ (Z=OMe, SMe, NPh2) yield mononuclear complexes (RZnX·2 Py and RZnX·TMED). The organozinc amides (Z=H, Me) yield binuclear complexes [(RZnX·Py)2 and (RZnX)2·TMED]. Possible structures for these compounds in benzene solution are considered.