Tris phosphines, with iron carbonyls

Cyclododecene may be prepared from 1,5,9-cyclododecatriene by the catalytic reduction with Raney nickel and hydrogen diluted with nitrogen, with nickel sulfide on alumina, with cobalt, iron, or nickel in the presence of thiophene, with palladium on charcoal, with palladimn chloride in the presence of water, with palladium on barium sulfate, with cobalt acetate in the presence of cobalt carbonyl, and with cobalt carbonyl and tri- -butyl phosphine. It may also be obtained from the triene by reduction with lithium and ethylamine, by disproportionation, - by epoxidation followed by isomerization to a ketone and WoliT-Kishner reduction, and from cyclododecanone by the reaction of its hydrazone with sodium hydride. ... 

Tris(amido)phosphines 40-43 react with Fc2(CO)9 to give mononuclear iron carbonyl complexes Fe(CO)4(PR3). IR data collected from these complexes, combined with data from similar complexes, revealed the TT-acidity of the phosphines to be 41 w 40 > 43 > P(OPh>3 >42 > PPh3 > P(NMe2)3- Variable-temperature NMR on the Fe(GO)4 complexes of 41-43 showed rapid exchange of axial and equatorial carbonyls from —80 to 20 °C, while complex 40 showed slow axial-equatorial carbonyl exchange even at room temperature, attributed to the steric bulk and rigidity of the ligand. 

Some iron and nickel cyanide and carbonyl complexes have been reported as models of the [FeNi]-hydrogenase enzymes. The preparation and structures of the trigonal bipyramidal nickel and iron complexes with the tetradentate ligands tris(2-phenylthiol)phosphine (PS3) and tris(3-phenyl-2-thiophenyl)phosphine (PS3 ) have been reported [70, 71]. The nickel carbonyl complex [Ni(PS3 )(CO)] exhibits vco at 2029 cm compared with the value of 1940 em" for the iron earbonyl complex [Fe(PS3 )(CO)]. Both of these complexes lose CO upon oxidation. The use of cyanide in place of carbon monoxide allows for the preparation of both [Fe (PS3)(CN)] and [Fe (PS3 )(CN)] eomplexes. The IR properties of... 

WN303C,jH27, Tungsten, tris(fert-butyl iso-cyanide)tricarbonyl-,/flc-, 28 143 WN4P4C4JHS2, Tungsten, bis(dinitro-gen)bis[ 1,2-ethanediylbis(diphenyl-phosphine)]-, irons-, 28 41 WNa03CjHj2C4H o02, Tungstate(l-), tri-carbonyl(Ti -cyclopentadienyl)-, sodium, compd. with 1,2-dimethoxy-ethane(l 2), 26 343... 

Di- and Tri-nuclear. References which deal with metal-metal bond cleavage in dinuclear carbonyls, particularly Mn2(CO)io and RejCCOjio, will be found in the metal-metal bond cleavage section. Only references to reactions in which metal-carbonyl bond cleavage is the principal step will be mentioned here. FeaCCO), reacts with phosphines by two parallel paths, one of which involves reversible breaking of the iron-bridging carbonyl bond as the first and rate-determining step, as shown in Scheme 1. 

---