Attempts are described to synthesize ionic 14e [(π-allyl)Pd(NHC)]Y complexes (NHC ) C(N( t Bu)-CH) 2 , C(N(C 6 H 3 -2,6-i Pr 2 )CH) 2 ). Reaction of {(η 3 -2-RC 3 H 4 )Pd(µ-Cl)} 2 (R ) H, Me) with AgOTf yields polymeric, helical {(η 3 -C 3 H 5 )Pd(µ-OTf)} n (5a) and dimeric {(η 3 -2-MeC 3 H 4 )Pd(µ-OTf)} 2 (5b). Treatment of (η 3 -2-RC 3 H 4 )Pd(NHC)Cl (R ) H, Me) (6a-d) with LiMe or (tmeda)MgMe 2 affords the Pd-methyl complexes (η 3 -2-RC 3 H 4 )Pd(NHC)CH 3 (7a-d). Adduct formation of 5a,b with NHC, metathesis of 6a-d with AgOTf, and protolysis of 7c,d with HOTf yield the triflate complexes (η 3 -2-RC 3 H 4 )Pd(NHC)(OTf) (8a-d), whereas protolysis of 7a,b with acids (HOTf, HBF 4 ) results in complex degradation. From the reactions of 6a,c with AgBF 4 in THF, and AgPF 6 and AgAlR F 4 (R F ) OC(CF 3 ) 3 ) in THF and CH 2 Cl 2 , respectively, the ionic THF-solvates 9c(BF 4 ); PF 6 , 9c(PF 6 )) and the CH 2 Cl 2 -solvates [(η 3 -C 3 H 5 )Pd{C(N( t Bu)CH) 2 }(CH 2 Cl 2 )]AlR F 4 (11a(AlR F 4 )) and [(η 3 -C 3 H 5 )Pd{C(N(C 6 H 3 -2,6-i Pr 2 )CH) 2 }(CH 2 Cl 2 )]PF 6 ‚2CH 2 Cl 2 (11c(PF 6 )) have been isolated. In contrast, reaction of 6a,c with AgBF 4 in toluene or CH 2 Cl 2 yields the neutral solvent-free BF 4 adducts (η 3 -C 3 H 5 )Pd{C(N( t Bu)CH) 2 }(BF 4 ) (12a) and (η 3 -C 3 H 5 )Pd{C(N(C 6 H 3 -2,6-i Pr 2 )CH) 2 }(BF 4 ) (12c), consistent with the marked nucleophilicity of the BF 4 anion. Drying the CH 2 Cl 2 -solvates 11a,c(Y) (Y ) PF 6 , AlR F 4 ) at ambient temperature under vacuum affords the PF 6 and AlR F 4 adducts (η 3 -C 3 H 5 )Pd{C(N( t Bu)CH) 2 }-Reaction of 8-14 with water produces the (nonisolated) water adducts [(η 3 -C 3 H 5 )Pd(NHC)(H 2 O)]Y (10a-d(Y)). The molecular structures of 5a, 9a(BF 4 ), 11c(PF 6 ), and 12a have been determined. The various anions and solvate ligands are arranged in their order of donor strength/nucleophilicity toward the [(π-allyl)Pd(NHC)] + moiety.

We present a novel, scaled-up sol-gel synthesis which enables one to produce 20 g batches of highly active and stable carbon supported PtCu3 nanoparticles as cathode materials for low temperature fuel cell application. We confirm the presence of an ordered intermetallic phase underneath a multilayered Pt-skin together with firm embedment of nanoparticles in the carbon matrix.

The ligand properties of cis,cis,cis-1,5,9-cyclododecatriene (c,c,c-cdt) have been explored. For the known (c,c,c-cdt)Ni (1b) and (c,c,c-cdt)(AgNO3)3 (5) complexes and the new [(c,c,c-cdt)Cu(MeOH)]BF4 (6b), [(c,c,c-cdt)Cu][Al{OC(CF3)3}4] (6d), and ( t Bu2PC2H4P t Bu2)Ni(η2-c,c,c-cdt) (7b) complexes, the molecular structures have been determined. The c,c,c-cdt ligand in 5 and 7b retains the C 2 symmetrical helical conformation of the free c,c,c-cdt, whereas in 1b and 6b,d, it assumes a C 3 symmetrical ratchet conformation. The coordination geometry of the metal in 6b is tetrahedral, and it is trigonal pyramidal in 1b and 6d. Details of the synthesis and chemical and spectroscopic properties of the complexes are reported.

A series of tris-ene trigonal-planar nickel(0), palladium(0), and platinum(0) complexes M(η 2 ,η 2 ,η 2 -C 10 H 16 N 2 Me 2 ) (M ) Ni-Pt (2a-4a)) and M(η 2 ,η 2 ,η 2 -C 10 H 16 N 2 (C 3 H 5 ) 2 ) (M ) Ni-Pt (2b-4b)) have been prepared using the open-chain aminoalkenes N,N′-dimethyl-4,9-diazadodeca-1,trans-6,11-triene (1,4-bis(allylmethylamino)-trans-2-butene, 1a) and N,N′-diallyl-4,9-diazadodeca-1,trans-6,11-triene (1,4bis(diallylamino)-trans-2-butene, 1b). The ligands comprise a central diamino-trans-2-butene moiety with terminal N-allyl groups, so that the CdC groups are positioned in a repetitive 1,6-sequence. This confers useful properties on the metal complexes. The molecular structure of 2b has been determined by X-ray crystallography.