Palladium selenocyanates

Tabic 1 Typical Palladium(II)-Thiocyanate and -Selenocyanate Complexes and IR Data ... 

Most palladium (II) selenocyanate complexes have a Pd—Se bond, but the compound [Pd(Et4dien)(SeCN)]BPh4, isolated at low temperatures, isomerizes in a number of different solvents via a dissociative process, whereas [Pd(dien)(SeCN)]BPh4 shows no signs of such isomerization. Further, if [Pd(Et4dien)NCSe]BPh4 is isolated it reisomerizes to the Se-bonded form at room temperature in the solid state 153, 156). This behavior parallels that of the thiocyanate group under similar circumstances and provides evidence for a steric effect modified by the nature of the anion. 

ALKENES Allyl dimethyldithiocarbamate. Bis(t -cyclopentadienyl)niobium trihydride. Cyanogen bromide. Di-n-butylcopperlithium. a,o-Dichloromethyl methyl ether. 2,3-Dimethyl-2-butylborane. N,N-Dimethyl dichlorophosphoramide. Diphenyl diselenide. Di-n-propylcopperlithium. Ferric chloride. Grignard reagents. Iodine. Lithium phenylethynolate. Lithium 2,2,6,6-tetramethylpiperidide. Methyl iodide. o-Nitro-phenyl selenocyanate. Propargyl bromide. rra s-l-Propenyllithium. Selenium. Tetrakis(triphenylphosphine)palladium. Titanium(IH) chloride. Titanium trichloride-Lithium aluminum hydride. p-Toluenesulfonylhydrazine. Triphenylphosphine. Vinyl-copper reagents. Vinyllithium. Zinc. 

There is yet one other factor which can affect the form of the rate law, and that is the nature of the outgoing ligand. The case reported again relates to palladium(ii) rather than to platinum(n), in fast substitution at [Pd dien X]+. Thiocyanate substitution conforms to the pseudo-octahedral pattern, but substitution by selenocyanate follows a two-term rate law. This is claimed to be a unique example of mechanistic control by an outgoing group. ... 

Related Reagents. Copper(II) Chloride Copper(II) Chloride-Copper(II) Oxide lodine-Copper(II) Chloride Copper(I) Chloride-Oxygen Copper(I) Chloride-tetrabutylammonium Chloride Copper(I) Chloride-Sulfur Dioxide lodine-Alutninum(III) Chloride-Copper(II) Chloride lodine-Copper(I) Chloride-Copper(II) Chloride Methylmagnesium lodide-Copper(I) Chloride Palladium(II) Chloride-Copper(I) Chloride Palladium(II) Chloride-Copper(II) Chloride Phenyl Selenocyanate-Copper(II) Chloride nyl-magnesium Chloride-Copper(I) Chloride Zinc-Copper(I) Chloride. 

Thiolates and selenocyanates displace halogen from ArHal with a palladium(o) compound and copper(i) iodide, respectively, as catalysts. 

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