The tetranuclear amidinato zinc hydride complex {C[C(Ni-Pr)2ZnH]4} 3 was synthesized by reaction of the Cl-substituted complex {C[C(Ni-Pr)2ZnCl]4} with CaH2. 3 was found to react with phenylacetylene and acetylene at ambient temperature with elimination of H2 and subsequent formation of C[C(Ni-Pr)2ZnCCPh]4 4 and {C[C(Ni-Pr)2ZnCCH]4 5, respectively. 3 -5 have been characterized by multinuclear NMR ( 1 H, 13 C) and IR spectroscopy, elemental analyses and by single-crystal X-ray diffraction.

Polynuclear amidinate zinc halide complexes of the general type{C[C(Ni-Pr) 2 ZnX] 4 } [X = Cl, 2; Br, 3; I, 4] were prepared in high yields via methyl/halide exchange reaction of {C[C(Ni-Pr) 2 ZnMe] 4 } (1a) with AlX 3 . 2-4 were characterized by elemental analysis, multinuclear NMR, and IR spectroscopy and singlecrystal X-ray diffraction. Computational calculations of halide-substituted complexes {C[C(Ni-Pr) 2 -ZnX] 4 } [X = F-I] were performed to clarify the influence of the halide atom on the structural parameters of the complexes and to elucidate their electronic structure and bonding situation. The capability of these halide-substituted complexes to serve as suitable starting reagents for further salt elimination reactions was proven by reaction of 2 with LiR (R = Me, n-Bu) and EtMgBr, which yielded the corresponding Zn-alkyl species {C[C(Ni-Pr) 2 ZnR] 4 } [R = Me, 1a; n-Bu, 5; Et, 6].

The acidity of the four N–H groups in methanetrisamidine 1c differs significantly, thereby allowing stepwise metalation by metal organic compounds such as ZnMe2, AlMe3, and GaMe3. Dinuclear complexes 3a–c were formed under kinetic control in the reactions of 1c with 2 equiv. of the metal organic compounds at low temperatures, whereas prolonged reaction times at elevated temperature (100 °C) with 4 equiv. of ZnMe2, AlMe3, and GaMe3 yielded the corresponding tetranuclear complexes 4a–c. The different acidity of the four N–H groups also allowed the stepwise metalation of 1c by two different metal organic complexes with the formation of the heterobimetallic complexes 5a and 5b. In addition, transmetalation by Zn/Al exchange was observed in the reaction of 3c with AlMe3, yielding the corresponding dinuclear aluminium complex 3a. The complexes were characterized by NMR and IR spectroscopy and single‐crystal X‐ray diffraction (3a, 4b, 5a).

Tout au contraire: Both tautomeric forms of a methanetrisamidine were structurally characterized for the first time by X‐ray diffraction and by ab initio calculations (see structures; gray C, red H, blue N). Their reactivity as proton acceptors and multianionic ligands was demonstrated.

The reactions of Me2Zn with carbodiimides RN=C=NR (R = Et, Ph) yielded the polynuclear zinc amidinate complexes {[MeZn]4[C(RNCNR)4]} [R = Et (1), Ph (3)] and {[MeZn]2[C(EtNCNEt)2(C2(NEt)3)]} (2). In addition, the reaction of {[ClZn]4[C(iPrNCNiPr)4]} with MCl3 gave the corresponding Lewis acid–base adducts {[MCl3]2[ClZn]4[C(iPrNCNiPr)4]} [M = Al (4), Ga (5)]. Compounds 1–5 were characterized by multinuclear NMR (1H, 13C) and IR spectroscopy, elemental analyses and single‐crystal X‐ray diffraction.