Trichloro(Dinitrogen)Platinate(II)

Zeise's salt, [PtCl 3 (H 2 C=CH 2 )] − , 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 K 2 [PtCl 4 ] solutions generate strong ions corresponding to [PtCl 3 (N 2 )] − , the identity of which was confirmed through ion‐mobility spectrometry and MS/MS experiments that proved it to be distinct from its isobaric counterparts [PtCl 3 (C 2 H 4 )] − and [PtCl 3 (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.