Transition Metal Metallacarbaboranes

Coordination Ability of 10-EtC(NHPr)=HN-7,8-C2B9H11 in the Reactions with Nickel(II) Phosphine Complexes

“…This promises the possibility of synthesizing complexes with simultaneous coordination of the carborane and amidine components. For our study we chose amidine 10-PrNHC(Et)=HN-7,8-C 2 B 9 H 11 (1) prepared by the nucleophilic addition of propyl amine to 10-EtC≡N-7,8-C 2 B 9 H 11 . For the complexation reactions, we used nickel(II) phosphine complexes [(R 2 R'P) 2 NiCl 2 ] with ligands having different steric parameters (Tolman cone angles, θ)-R 2 R'P = Me 2 PhP (θ = 122 • ), PBu 3 (θ = 132 • ), PPh 3 (θ = 145 • ) [23].…”

“…The amidine 10-PrNHC(Et)=HN-7,8-C 2 B 9 H 11 (1) was prepared according to procedure from the literature [20]. Dichlorobis(triphenylphosphine)nickel(II), dichlorobis (dimethylphenylphosphine)nickel(II) and dichlorobis(tributylphosphine)nickel(II) were synthesized according to the previously described methods [28].…”

“…The crystals suitable for X-ray analysis were obtained by slow evaporation from chloroform/hexane (3:1) solution. 1…”

“…The dicarbollide dianion [7,8-C 2 B 9 H 11 ] 2− , which is the deprotonated form of 7,8dicarba-nido-undecaborate anion [7,8-C 2 B 9 H 12 ] − (nido-carborane), is known as the inorganic isolobal analogue of the cyclopentadienyl ligand. This makes it the perfect building block in complexation reactions with a wide range of transition metals [1][2][3]. The possibility to substitute hydrogen atoms at the carbon and boron vertices of the carborane cage with various functional groups [4] makes it possible to vary the properties of ligands based on nido-carborane by combining the properties of the nido-carborane nest with the properties of an exo-polyhedral substituent.…”

Unique chemical properties of metal-carbon bonds in metal-carboranyl and metal-carboryne complexes

“…Reaction of 21 with two equivalents of 4-methylphenylacetylene or 1-hexyne gives selectively ruthenium aminocarbene complexes [η 5 :σ-Me 2 C(C 5 H 4 )(C 2 B 10 H 10 )]-Ru[= C(NH n Pr)CHR-η 2 -CH = CHR] (22). On the other hand, interaction of 21 with two equivalents of 4-Xphenylacetylene (X = Cl, Br) produces exclusively ruthenium diene complexes [η 5 :σ-Me 2 C(C 5 H 4 )(C 2 B 10 -H 10 )]Ru[η 4 -CHAr = C(NH n Pr)CH = CHAr] (23) (Scheme 8) [51] .…”