Synthesis and Structural Characterization of closo- and exo-nido-Lanthanacarboranes

Abstract

Treatment of anhydrous LaCl3 with 1 equiv of Na2[7,8-R2-nido-7,8-R2C2B9H9] in THF afforded sandwich complexes closo-{(THF)2Na}{(R2C2B9H9)2La(THF)2} (R = H (1), R = C6H5CH2 (2)) in good yield. Reaction of SmI2 with an equimolar amount of Na2[7,8-nido-7,8-(C6H5CH2)2C2B9H9] in THF, followed by the addition of 1,2-dimethoxyethane (DME), generated the dimeric exo-nido-[((C6H5CH2)2C2B9H9)Sm(DME)2]2·DME (3) in 70% yield. All complexes were characterized by 1H, 13C, and 11B NMR and IR spectroscopy as well as complexometric metal analyses. The molecular structures of complexes 1 and 3 were further confirmed by X-ray analyses. The coordination geometry of complex 1 is best described as distorted tetrahedral with two η5-bonded C2B9H11 ligands and two coordinated THF molecules. In the centrosymmetric dimer 3, each of the two dibenzyldicarbollide ligands serves as a bridging ligand for two Sm atoms while bonding to one via upper belt B−H bonds (containing two carbon atoms) and the other through lower belt B−H bonds.

Synthesis and Structural Chemistry of Non-Cyclopentadienyl Organolanthanide Complexes

“…192 In the case of the smaller lanthanides Y and Yb, a half-sandwich lanthanacarborane chloride seems to be formed. But only the recrystallization product from a wet THF solution was characterized for Yb, which is the ionic compound [YbCl 2 -(THF) 5 ][nido-C 2 B 9 H 12 ] (108).…”

“…Bonding occurs to the Sm atoms via two B-H bonds from the upper and two from the lower CB belt, respectively. 192 Treatment of 2 equiv of Na 2 [(C 6 H 5 CH 2 ) 2 C 2 B 9 H 9 ] with divalent Sm and Yb gives isomorphous structures [exo-nido-{(C 6 H 5 CH 2 ) 2 C 2 B 9 H 9 }Ln(THF) 3 ] 2 (110, Ln ) Sm, Yb), where the bonding situation is more complicated. The metal atoms are bonded to both belts and there again in different fashions as well.…”

Another example of carborane based trianionic ligand: Syntheses and catalytic activities of cyclohexylamino tailed ortho-carboranyl zirconium and titanium dicarbollides

“…As these compounds are isoelectronic with their respective Cp analogues, one would expect similar, but polar group tolerable, catalytic behaviors in the polymerization of a-olefins. The coordination chemistry of carborane clusters derived from the carborane cages systems has been widely studied, and substituted and unsubstituted dicarbollide metal complexes have been reported [14][15][16][17][18][19][20]. However, to the best of our knowledge, the study of carborane trianion-based metallocene analogues is limited with only a few reported examples [21][22][23][24][25][26].…”

Silyl group mediated linkage of closo-C2B10-cage to nido-C2B4-carborane: synthesis of the novel carborane ligand, 1-R-2-[5′-(SiMe2CH2)-2′,3′-(SiMe3)2-2′,3′-C2B4H5]-1,2-C2B10H10 (R=Me, Ph)

“…The study of the coordination chemistry of carborane clusters derived from the 1-R-2-R 0 -1,2-C 2 B 10 H 10 and 2-R-n-R 0 -2,n-C 2 B 4 H 6 (n ¼ 3, 4; R, R 0 ¼ H or a C ðcageÞ derivative) cage systems have most often been studied separately [1][2][3][4][5][6][7]. Since each cage system offers its own attractions, the targeted syntheses of specific linkedcarborane compounds containing both large and small coordinating cages capable of having charges ranging from )1 to )4 could lead to a series of ligands having unique properties.…”