Deprotonated Iminophosphoraneo-C6H4Ph2PNSiMe3as a Novel Ligand To Stabilize a Diarylstannylene and -plumbylene via Side Arm Donation

Lithiation of triphenyl(trimethylsilylimino)phosphorane Ph 3 P NSiMe 3 with MeLi gives the ortho -metalated species [Li( o -C 6 H 4 PPh 2 NSiMe 3 )] 2 ·Et 2 O ( 1 ). It has all the requirements of an organometallic ligand capable of side arm donation: the deprotonated ortho phenyl carbon atom leads to metal−carbon σ bonds in reactions with metal halides, and the Ph 2 P NSiMe 3 moiety donates an electron pair to that metal via the imine nitrogen atom. In reactions with SnCl 2 the Sn(II) organometallic complex [Sn( o -C 6 H 4 PPh 2 NSiMe 3 ) 2 ] ( 2 ) was obtained, while with PbCl 2 a new example of the rare lead(II) organometallic complexes was obtained. In [Pb( o -C 6 H 4 PPh 2 NSiMe 3 ) 2 ] ( 3 ) the lead(II) center is bonded to the two ortho -carbon atoms and additionally stabilized by two Pb←N donor bonds. In all metal complexes the Ph 2 P NSiMe 3 unit acts as a side arm donating group via nitrogen.