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The cationic isocyanide alkenyl-carbyne complexes [dppe = κ 2-(P,P)-Ph2P(CH2)2PPh2; R = Bun, n = 1 (2a); R = But, n = 1 (2b), 4 (2c); R = Cy, n = 1 (2d), 4 (2e); R = PhCH2, n = 1 (2f), 4 (2g); R = 2,6-Me2C6H3, n = 1 (2h), 4 (2i)] were prepared by reactions of the corresponding acetonitrile complexes [n = 1 (1a), 4 (1b)] with the appropriate isocyanide. Ab initio quantum-chemical methods at the RHF and single-point MP2 levels of theory were applied to the investigation of the structure, bonding, oxidation potential, and relative isomeric stability at the model complexes trans- and cis-[(PH3)2(CO)2(L)W(⋮C−CHCH2)] m + [L = Cl- (m = 0), NCMe (m = 1), CNMe (m = 1), or CO (m = 1)], which also comprise the related carbonyl and chloride species, allowing a comparison of the effects of the Cl-, NCMe, CNMe, and CO ligands, which are shown to follow their electron π-donor/acceptor properties. The electrochemical behavior of complexes 2a−i, as well as that of the related carbonyl, phosphine [L = CO; n = 1 (3a), 4 (3b); L = PMe3, n = 1 (4a)] and phosphinodithiocarboxylate [n = 1 (5a), 4 (5b)] compounds, was investigated by cyclic voltammetry and controlled potential electrolysis in aprotic media and at a Pt electrode. The oxidation potential follows the order of the net π-electron acceptor minus σ-donor character of the ligands, and from the observed linear dependence on the electrochemical P L ligand parameter it was possible to estimate the values of the electron-richness (E S) and polarizability (β) parameters for the binding metal fragments containing alkenyl-carbyne ligands, indicating they exhibit rather low electron-richness and polarizability, which are accounted for by the very strong π-electron acceptance of the coordinated alkenyl-carbyne groups. These ligands are activated toward proton loss by anodic oxidation of their complexes.

In the di(organocyanamide) complexes trans-[PtCl 2 (NCNR 2 ) 2 ] (R = Me 1a, Et 1b), prepared by reaction of PtCl 2 with the appropriate NCNR 2 , the cyanamide ligands, activated by coordination, undergo an unprecedented nucleophilic addition, at room temperature, of an haloalcohol (ClCH 2 CH 2 OH/LiBu n ) or of an alcohol (MeOH) to give theThe X-ray crystal structure of 2b is also reported, indicating a π-bond delocalization along the N ؒؒ ᎐C ؒؒ ᎐N group of the aminooxazoline ligands.

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