Synthesis of Tris(arylphosphite)-ligated Cobalt(0) Complexes [Co2(CO)6{P(OAr)3}2], and their Reactivity towards Phenylacetylene and Diphenylacetylene

Abstract

The dinuclear complexes [Co2(CO)6{P(OAr)3}2] (1a, Ar = Ph; 1b, Ar = o-Tol) were prepared and reacted with PhC≡CH and PhC≡CPh to yield dimetallatetrahedranes [{(ArO)3P}(OC)2Co-Co(μ-RC≡CPh)(CO)2{P(OAr)3}] (3a, Ar = Ph, R = H; 3b, Ar = o-Tol, R = H; 3c, Ar = Ph, R = Ph; 3d, Ar = o-Tol, R = Ph). The main reaction of diphenylacetylene was accompanied by a side reaction, leading to the dissociation of a P(OAr)3 ligand for the formation of mono(phosphite) complexes [{(ArO)3P}(OC)2Co-Co(μ-PhC≡CPh)(CO)3] (2b, R = Ph; 2d, R = o-Tol). The crystal structures of 1b, 3a, and 3d were determined along with that of the mono(phosphite) complex [{(PhO)3P}(OC)2Co-Co(μ-PhC≡CPh)(CO)3] 2b.

Tris(m2-carbonyl)-octacarbonyl-triphenylphosphite-tetracobalt

“…Note that with P(OMe)3 and P(OPh)3, even formation of tetra-substituted clusters [Co4(CO)8{P(OR)3}4] can be achieved [8]. In the context of our research on P(OPh)3-substituted Co-Co carbonyl complexes towards alkynes producing dicobaltatetrahedranes [15,16], we attempted also to synthetize the monosubstituted dinuclear complex [Co2(CO)7{P(OPh)3}] 1 by addition of a stoichiometric amount of P(OPh)3 to a solution of [Co2(CO)8] in toluene. The existence of this substitution product has been mentioned in the literature, but apart of its IR spectrum, no further characterization data have been communicated [17].…”

(µ2-η4-N-(2-Butynyl)phthalimide)(hexacarbonyl)dicobalt

“…In 2005, Gust et al also reported the reaction of propargyl phtalimide with [Co 2 (CO) 8 ] and determined the cytotoxicity and DNA binding efficiency of the resulting complex N-(2-propynyl)phthalimide]hexacarbonyldicobalt (see compound V of Scheme 1) [21]. In the context of our research on Co-Co carbonyl complexes towards various alkynes producing dicobaltatetrahedranes [25,26], we attempted to synthetize a Co-Co complex ligated using an internal alkyne, namely 1-Phthalimido-2-butyne 1, for upcoming biological studies. Apart from the purely synthetic aspect, one of the objectives was to compare the impact of the replacement of a terminal alkyne by an internal one (Phtal-C≡CH vs. Phtal-C≡CMe).…”

Tris(μ2-carbonyl)octacarbonyl(triphenylphosphite)tetracobalt

“…It is worth noting that P(OMe) 3 and P(OPh) 3 can even form tetra-substituted clusters [Co 4 (CO) 8 {P(OR) 3 } 4 ] [8]. In the context of our research on P(OPh) 3 -substituted Co-Co carbonyl complexes towards alkynes producing dicobaltatetrahedranes [15,16], we attempted ]. The existence of this substitution product has been mentioned in the literature, but apart from its IR spectrum, no further characterization data have been communicated [17].…”

“…carbonyl complexes towards alkynes producing dicobaltatetrahedranes [15,16], we attempted to synthetize the monosubstituted dinuclear complex [Co2(CO)7{P(OPh)3}] 1 by adding a stoichiometric amount of P(OPh)3 to a solution of [Co2(CO)8]. The existence of this substitution product has been mentioned in the literature, but apart from its IR spectrum, no further characterization data have been communicated [17].…”