We describe the synthesis of the linear N-heterocyclic carbene (NHC)-based chromium(I) silylamide [(IMes)Cr(N{Dipp}-Si i Pr 3 )] (IMes = 1,3-dimesityl-imidazol-2-ylidene, Dipp = 2,6-di-isopropylphenyl) via protolytic ligand displacement of the homoleptic chromium(I) silylamide [KCr(N{Dipp}Si i Pr 3 )] with the imidazolium salt IMes•HCl. This could also be extended to the bulkier NHC IDipp (IDipp = 1,3-bis(2,6-di-iso-propylphenyl)imidazol-2-ylidene). Analysis of the magnetic properties of [(IMes)Cr(N{Dipp}Si i Pr 3 )] reveals an isotropic high-spin S = 5/2 state. First reaction studies with this linear chromium(I) complex yields with CO the four-coordinate chromium dicarbonyl complex [(IMes)Cr(CO) 2 (N{Dipp}Si i Pr 3 )], with benzyl bromide oxidation to the trigonal chromium(II) bromide [(IMes)-Cr(Br)(N{Dipp}Si i Pr 3 )], and with DippN 3 the first three-coordinate chromium(III) imide ([(IMes)Cr(NDipp)(N{Dipp}Si i Pr 3 )]).

The behavior of the N‐heterocyclic carbene (NHC) stabilized ‘parent’ phosphinidene [(sIDipp)PH] (Dipp=2,6‐di‐isopropylphenyl) towards 3d‐metal(II) hexamethyldisilazanides is described. This leads to formation of the three‐coordinated phosphinidene adducts [M{PH(sIDipp)}{N(SiMe3)2}2] (M=Mn−Co), as evidenced by X‐Ray diffraction analysis. In solution, all compounds exhibit strong paramagnetism that limited NMR spectroscopic examinations to cobalt. Here it shows that the system is coordinatively highly fluxional, which is mitigtated upon cooling. At low temperatures, small amounts of free phosphinidene becomes further evident by 31P NMR spectroscopy that implicates in part ligand coordination competes with [M{N(SiMe3)2}2] dimerisation and an overall weak binding of the phosphinidene ligand. The rapid chemical exchange is evidenced in the presence of an excess of phosphinidene or a phosphine (PCy3), whereas diethyl ether proved as a stronger donor ligand.