Indenylmetallacarboranes. 1. The 18-valence-electron complex 3-(.eta.5-C9H7)-3,1,2-CoC2B9H11 and comparative molecular structures of this complex and 3-(.eta.5-C5H5)-3,1,2-CoC2B9H11

Synthesis and structure of 3-fluorenyl-3-cobalta-1,2-dicarba-closo-nonaborane(11), 3-(η5-C13H9)-3,1,2-closo-CoC2B9H11

“…Compound (1) crystallizes with no important intermolecular contacts. The lengths of the Co-cage atom connectivities in (1) compare well with those of the equivalent connectivities in (2) and (3) (Smith & Welch, 1986). The metal-bonded C2B3 face is, as usual, folded into an envelope conformation about B(4).-.B(7), with fold angles (Mingos, Forsyth & Welch, 1978;Smith & Welch, 1986) C ( …”

“…To the best of our knowledge (1), which has been synthesized (albeit in low yield) by an analogous route to that which has previously afforded 3-075-CsHs)-3,1,2-closo-CoC2BgH11 (2) (Jones & Hawthorne, 1973) and 3-('r/5-C9HT)-3,1,2-closoCoC2B9Hll (3) (Smith & Welch, 1986), is the first reported fluorenyl carbametallaborane. Moreover, it is one of relatively few fluorenyl transition-metal compounds to have been structurally characterized;…”

“…61.1 (7) 60.4 (7) l lO.O (8) 116.3 (9) 133.7 (9) 106.2 (8) 122.3 (9) 131.4 (9) 132.5 (9) 107.0 (8) 120.5 (9) 106.5 (9) 116.6 (9) 109.8 (9) 121.4 (9) 128.5 (9) 116.2 (10) 123.3 (11) 122.0 (11) ll6.1 (9) ll9.1 (10) 124.3 (11) 120.8 (10) (Smith & Welch, 1986). Indeed, the fluorenyJ as a whole is tilted such that C(37) is ca 0.25 A to the B5 plane than is C(313).…”

“…To these ends we have already reported the compound 3-('qs-C9H7)-3,1,2-closo-CoC2BgHll and its 1 eand 2e-reduced forms (Smith & Welch, 1986). The conformation of, and slipping distortions in, the neutral compound are rationalized (via frontier molecular orbital analysis) in terms of the influence of the six-carbon ring fused to the side of the r/5-3-(r/5-C13H9)-3,2,1-closo-CoC2B9Hll pentagon.…”

Synthesis and X-ray crystal structure of 3-cyclopentadienyl- 9-(acetomercuro)-3-cobalta-1,2-dicarba-closo-dodecaborane

“…8 In our previous work9 we reported the structure of 8-chlormercuro-3,6-bis(η5-cyclopentadienyl)-3,6-dicobalta-1,2-dicarba-closo-dodecaborane with the Hg-B bond length of 2.106 Å which appears to be very similar to the Hg(1)-B(9) bond length in 2 (2.10(1) Å). Our search through the Cambridge Structural Database 10 yielded only two structures with the Hg-B σ-bonds involving polyhedral borane clusters, namely the cationic complex bis(µ2-hydroxo)-(1,7-dicarbaboradodecaborane-9,10-diyl)dimercury (2.101 and 2.096 Å) 11 and the macrocyclic complex cyclo-tris(bis-(t-butyldimethylsilyl)-m-dicarbaundecaborane(8)-mercury (2.187 and 2.120 Å).…”