Chemistry of the highly stable hindered cobalt sandwich compound (η5-Cp)Co(η4-C4Ph4) and its derivatives

Synthesis, bonding properties and ether activation reactivity of cyclobutadienyl-ligated hybrid uranocenes

“…[1][2][3] Cyclobutadienyl complexes of the late transition metals are numerous owing to the ease with which the h 4 -bound ligands assemble through the cycloaddition of two alkynes within the coordination sphere of low-valent metals. [4][5][6] Complementary routes to transition metal cyclobutadienyl complexes involving cyclization of dilithiobutadienes are also known. 7 An understanding of the bonding properties and reactivity of transition metal-cyclobutadienyl compounds has led to their application in catalytic and stoichiometric organic synthesis.…”

Synthesis and Characterization of the Complete Series [(C5H5‐n Cln)Co(C4Ph4)] (n=1–5)

“…Although there are a few compounds with alkyl, [1] alkynyl [2] or heteroatom bound functionalities, [3] the vast majority of known [CpCo(C 4 R 4 )] complexes contains an (eventually substituted) phenyl ring at the cyclobutadiene ring. [4] Thus, the first representative of this group, [(C 5 H 5 ) Co(C 4 Ph 4 )], was reported already 60 years ago as a product of the reaction of either [CpCo(COD)] or [CpCo(COT)] (COD is 1,5-cyclooctadiene, COT is cyclooctatetraene) and tolane (Ph 2 C 2 ). [5] Alternative procedures use the commercially available [CpCo(CO) 2 ] as starting compound [6] or a "one-pot synthesis" using a mixture of [CoCl(PPh 3 ) 3 ], Na(C 5 H 5 ) and tolane.…”

“…[5] Alternative procedures use the commercially available [CpCo(CO) 2 ] as starting compound [6] or a "one-pot synthesis" using a mixture of [CoCl(PPh 3 ) 3 ], Na(C 5 H 5 ) and tolane. [7] Both procedures work also with substituted cyclopentadienides, [3,4,[8][9][10][11] but also suffer from the formation of side-products as cyclopentadienone complexes, [3] metallacyclopentadienes, [6] alkyne oligomerization products like hexaphenylbenzene [3] and free triphenylphosphine. [12] An alternative "improved protocol for the synthesis" was therefore suggested, [9] that also allowed for large variations in the aryl moiety.…”

“…The cyclobutadiene moiety is always formed via 2+2 cycloaddition of two alkynes in the presence of an appropriate cobalt complex. Although there are a few compounds with alkyl, [1] alkynyl [2] or heteroatom bound functionalities, [3] the vast majority of known [CpCo(C 4 R 4 )] complexes contains an (eventually substituted) phenyl ring at the cyclobutadiene ring [4] . Thus, the first representative of this group, [(C 5 H 5 ) Co(C 4 Ph 4 )], was reported already 60 years ago as a product of the reaction of either [CpCo(COD)] or [CpCo(COT)] (COD is 1,5‐ cyclooctadiene, COT is cyclooctatetraene) and tolane (Ph 2 C 2 ) [5] .…”

Coordination‐Driven Self‐Assembly and Anticancer Potency Studies of Ruthenium–Cobalt‐Based Heterometallic Rectangles

“…[9] Recently, bimetallic complexes and metallacycles con-tainingF e-Au, Fe-Pd,A u-Ti, Pd-Ti, Ru-Ti, Ru-Fe, Ru-Au, and Ru-Ptw eref ound to show promising anticancer activities; [10,11] these results prompted us to explore the anticancer potency of Ru-Co metallacycles, especiallyb ecause both Ru and Co metals are known for anticancer properties. [12] Ligands based on cobalt sandwiches, [13] which are similart of errocene in termso fs tability,s olubility,a nd ease of synthesis, have previously been used to produce self-assembled metallacycles with Pt, Pd, and Ru acceptors, but their cytotoxic efficiencies have not been studied to date. [14] Most anticancer agents inhibit cancerc ell growth by activating cell deathp athways, such as the apoptosis or autophagy pathways.…”