Pt(0) and Pd(0) olefin complexes of the metalloid N-heterocyclic carbene analogues [E(I)(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga): ligand substitution, H--H and Si--H bond activation, and cluster formation

Various products of the reaction of E(ddp)] (ddp=2-{(2,6-diisopropylphenyl)amino}-4-{(2,6-diisopropylphenyl)imino}-2-pentene; E=Al, Ga) with Pt(0) and Pd(0) olefin complexes are reported. Thus, the reaction of Pt(cod)(2)] (cod=1,5-cyclooctadiene) with two equivalents of Ga(ddp)] yields Pt(1,3-cod){Ga(ddp)}(2)] (1), whereas treatment of Pd(2)(dvds)(3)] (dvds=1,1,3,3-tetramethyl1,3-divinyldisiloxane) with E(ddp)] leads to the monomeric compounds (dvds)Pd{E(ddp)}] (E=Ga (2 a), Al (2 b)) by substitution of the bridging dvds ligand. Both 1 and 2 a readily react with strong pi-acceptor ligands such as CO or tBuNC to give the dimeric compounds M{mu(2)-Ga(ddp)}(L)] (L=CO, tBuNC; M=Pt (3 a, 5 a), Pd (3 b, 5 b)), respectively. Based on (1)H NMR spectroscopic data, Pt{Ga(ddp)}(2)(CO)] is likely to be an intermediate in the formation of 3 a. Furthermore, reactions of 1 with H(2) and HSiEt(3) yield the monomeric compounds Pt{Ga(ddp)}(2)(H)(2)] (7) and Pt{Ga(ddp)}(2)(H)(SiEt(3))] (8). Finally, the reaction of Pt(cod)(2)] with one equivalent of Ga(ddp)] in the presence of H(2) in hexane gives the new dimeric cluster Pt{mu(2)-Ga(ddp)}(H)(2)](2) (9).