Synthesis of reduced tungsten and rhenium complexes with multiple bonds to carbon and nitrogen

Thesis/Dissertation · Fri Jan 01 04:00:00 EST 1993

OSTI ID:7179338

Williams, D S

Reduction of W(NAr)[sub 2]Cl[sub 2](DME) with sodium amalgam in the presence of phosphine produces W(NAr)[sub 2](PR[sub 3])[sub 2]. This compound reacts readily with [pi]-acceptor ligands to give four-coordinate complexes or five-coordinate complexes. Extensive comparisons between the 14 electron M(NAr)[sub 2] core and the 14 electron Cp[sub 2]M core are drawn. The cores are isobal and the structural analogy is borne out in the two systems. Re(C[sup t]Bu) (NAr)Cl[sub 2](PR[sub 3]) is obtained in high yield by deprotonation of [Et[sub 4]N][Re(C[sup t]Bu)(NHAr)CL[sub 4]] in the presence of phosphine. [Re(NAr)[sub 3]][sup [minus]] ion can be alkylated to give RE(NAr)[sub 3]R and protonated to give RE(NAr)[sub 3]H. Reactions of Re(NAr)[sub 3]H with [pi]-acceptor ligands yield Re(NAr)[sub 2] (NHAr) ([eta][sup 2]-L). Reduction of Re(NAr)[sub 2]Cl[sub 3] (py) with sodium amalgam in THF in the presence of NpC[triple bond]CNp (NP = neopentyl) yields Re(NAr)[sub 2]([eta][sup 2]-C[sub 2]R[sub 2])Cl. Reduction of Re(NAr)[sub 2]([eta][sup 2]-C[sub 2]Np[sub 2])Cl yields pentane-soluble Na(THF)[sub 2]Re (NAr)[sub 2]([eta][sup 2]-C[sub 2]Np[sub 2]). Re(NAr)Cl[sub 3](py)[sub 2] is reduced in refluxing THF to afford Re(NAr) ([eta][sup 2]-C[sub 2]Np[sub 2])[sub 2]Cl. Reduction of Re(NAr) ([eta][sup 2]-C[sub 2]Np[sub 2])[sub 2]Cl by one or two equivalents of sodium amalgam in THF yields Na(THF)[sub 2]Re(NAr)([eta][sup 2]-C[sub 2]Np[sub 2]). Cyclic voltammograms were obtained for the chloride derivatives and sodium salts of the tris, bis, and mono imido complexes in a solution of 0.5 M [NBu[sub 4]][PF[sub 6]] in THF. Reduction of Re[sub 2] (CO)[sub 10] in a mixture of ether and THF and subsequent acylation with aryl acid chlorides affords the compounds (OC)[sub 5]ReC(O)R [R = Ar', Ar[sup *]]. Reaction of these compounds with triflic anhydride in dichloromethane quantitatively affords [Re(CR)(CO)[sub 4]](OTf)[sub 2].

• Research Organization: Massachusetts Inst. of Tech., Cambridge, MA (United States)
• OSTI ID: 7179338
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKALI METAL COMPOUNDS
ALLOYS
CHEMICAL BONDS
CHEMICAL PREPARATION
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
COMPLEXES
COORDINATION VALENCES
MERCURY ALLOYS
PHOSPHINES
PHOSPHORUS COMPOUNDS
REDUCTION
RHENIUM COMPLEXES
SODIUM COMPOUNDS
SYNTHESIS
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES
VALENCE
YIELDS