Trichloro(Dinitrogen)Platinate(II)

Zeise's salt, PtCl₃(H₂C=CH₂)]^?_, is the oldest known organometallic complex, featuring ethylene strongly bound to a platinum salt. Many derivatives are known, but none involving dinitrogen, and indeed dinitrogen complexes are unknown for both platinum and palladium. Electrospray ionization mass spectrometry of K₂PtCl₄] solutions generate strong ions corresponding to PtCl₃(N₂)]^?, the identity of which was confirmed through ion-mobility spectrometry and MS/MS experiments that proved it to be distinct from its isobaric counterparts PtCl₃(C₂H₄)]^? and PtCl₃(CO)]^?. Computational analysis established a gas-phase platinum–dinitrogen bond strength of 116 kJ mol^?1, substantially weaker than the ethylene and carbon monoxide analogues but stronger than for polar solvents such as water, methanol and dimethylformamide, and strong enough that the calculated N?N bond length of 1.119 Å represents weakening to a degree typical of isolated dinitrogen complexes.