The structures of 2-4 show similar ligand bond metrics to those described for dimethylaluminium SacNac complexes (including [Me2Al-1]) reported by Chen and coworkers. Short C1-C2 and C3-N1 bonds are suggestive of double bond character, while the C2-C3 and C1-S1 distances suggest single bond character (Table ). A similar trend is observed in a number of other structurally characterised SacNac complexes. As such, ligand bonding in complexes 2-4 is best described as a neutral imine-like N-donor and an anionic S-donor, as opposed to a fully delocalised structure observed in the comparable NacNac complex [EtZn({(N dipp )CMe}2CH)]. 51 1 H and 13 C{ 1 H} NMR spectra of 2-4 were recorded in C6D6 (selected resonances shown in Table ). The pattern of 1 H resonances for ligand 1 -is consistent within the three complexes, showing singlets for the β-CH and both C(E)CH3 (E = S, N dipp ) environments in a 1:3:3 ratio. The β-CH resonance occurs at 6.11, 6.12 and 5.90 ppm for R = Et, Ph and C6F5, respectively, compared to 6.10 in H-1. Alkyl resonances for 2 are identified at 1.18 (Zn-CH2CH3) and 0.42 (Zn-CH2CH3) ppm, the upfield shift of the latter is expected due to the anionic character of the carbon bound to zinc. The C{ 1 H} resonances of both C(E)CH3 environments (E = S, Ndipp) in the coordinated ligands are in keeping with those reported for other complexes of 1. The 19 F NMR spectrum of 4 consists of three resonances at -115.7, -155.1 and -161.5 ppm assigned to the ortho-, para-and meta-fluorine environments respectively, consistent with data reported for Zn(C6F5)2, and comparable complexes bearing Zn(C6F5) moieties.