A series of structurally characterized magnesium and zinc complexes of the form L4-tBuPh-M{N(SiMe3)(2)}(2) [M = Mg (1) and Zn (2); L4-tBuPh = 1,3-diethyl-4,5-dimethylimidazolirun-2{N,N'-bis(4-tert-butylphenyl)-amidinate}], L4-tPrPh-M{N(SiMe3)(2)}(2) [M = Mg (3) and Zn (4); L4-iPrPh = 1,3-diethyl-4,5- ditnethylimid azolium,2-{N,N'-bis(4-isopropylphenyl)amidinate} and' L4-iPrPh-ZnEt2 (5) bearing a zwitterionic-type neutral amidinate or N-heterocyclic carbene-carbodiimide ("NHC-CDI") adduct and monoanionic amido or alkyl ligands have been reported. "The synthesis of compounds 1-5 was achieved by the direct addition of a "NHC-CDI" adduct to corresponding metal bis(amide) or diallcyl reagent. All 'compoUnds 1=5 exist as monomers in the solid state. In all cases) the metal (magnesitim or zinc) centers adopt-a distorted four-coordinate tetrahedral geometry-bonded to one N,N'-chelated neutral zwitterionic liganci' and two monoanionic amido or alkyl Moieties. hi contrast, sterically bulky zwitterionic amidinate 1,3,cliethy1-4,5-climethylimidazolium-2-{N,N'-bis(2,6-dlisopropylphenyl)amidinate} (L-Dipp) upon treatment with lithium bis[(trimethylsilyl)amide], Li{N(SiMe3)(2)}, affords the NHC-lithium complex (IEt)-I-Me-[Li{N(SiMe3)(2)}](2) (6), in which-one molecule of NHC ((IEt)-I-Me = 1,3-diethyl-4,5-dirnethylitnidazol-2-ylidene) coordinates, to one of the two lithium centers. In a similar way, the reaction between L-Dipp and Mg{N(SiMe3)(2)}(2) allowed the formation of a NHC adduct of metal bis(amide), (IEt)-I-Me-Mg{N(SiMe3)(2)}(2) (7), instead of a zwitterionic adduct of metal bis(amicle). Alternatively, the synthesis of both compounds.and 7 was achieved' by the direct addition of 1 equiv of NHC, i.e., (IEt)-I-Me to Li{N(SiMe3)(2)} (2.0 equiv) and Mg{N(SiMe3)(2)}(2) (1.0 equiv) in benzene-d(6), respectively. All compounds (1-7) were characterized by multinuclear {H-1, C-13, and Si-29 (for 1-4, 6, and 7) arid Li-7 (for compound 6)} magnetic resonance spectroscopy, mass spectrometry, elemental analysis, and single-crystal X-ray structural analysis. In addition, preliminary reactivity studies of zwitterion-supported metal complexes have been investigated. Furthermore, density functional theory calculations have been carried out to obtain the energetics of zwitterion-supported lithium and magnesium complexes.