Preparation of a stable small ferraborane, B4H8Fe(CO)3

Abstract

The orange liquid B,H,Fe(CO), has been prepared by direct reaction of pentaborane(9) with iron pentacarbonyl and also by the reaction of tetraborane( 10) with enneacarbonyldi-iron ; spectroscopic evidence shows that the Fe(CO), group has replaced the apex BH group in BSHQ and that the compound has structural and bonding affinities with C4H4Fe(CO), and C[Fe(C0),ls.

π-Complexes of transition metal tricarbonyls with cyclopolyenes and their boron analogs

“…Tricarbonyl(η 3 cyclopropenyl)cobalt (η 3 C 3 H 3 )Co(CO) 3 (6). According to calculations, the energy minimum (λ = 0) on the PES corresponds to pyramidal structure 6а (C 3v symmetry) with staggered orientation of the metal tricarbonyl fragment relative to the cyclopropenyl ring ( Fig.…”

“…4, 5 The first metallaborane synthesized was ferraborane 2 (Scheme 1) in which the cyclobutadiene ring is replaced by borane. 6 This compound is isostructural and isoelec tronic to the hydrocarbon analog 1. Similarly to the cy clobutadiene fragment, which is stable in the rectangular form with alternating bonds (system with equalized bonds is unstable), the planar four membered borane ring B 4 H 8 is also unstable and has a boat structure in the free state.…”

“…[6][7][8] One can expect that stabilization of other borane rings B n H 2n (n = 3, 5, 6) by the corresponding metal tricarbonyl fragments will lead to a new family of metallaborane sys tems 3-5 isoelectronic and isostructural to the tricarbon yl hydrocarbon complexes 6-8 (Scheme 2). In the present Scheme 1 work we studied the geometry and electronic structure of, and internal rotation in, pyramidal metallaboranes 2-5 by the B3LYP/6 311+G(df,p) method.…”

Transition Metal—Main Group Cluster Compounds

“…THF or the degradation of the [B3H8]-anion ( Figure 12a) and may be viewed either as a metal-rich derivative ofB5H9 (Figure 12b)(l5) or as an inorganic analog ofa metal supported unsaturated hydrocarbon ( Figure 12c). As the former, HRu3-(CO )9B2H5 follows as a member of a series of group 8 metalloboranes (55)(56)(57)(58) which are formally derived from pentaborane (9) in which BH fragments are successively replaced by isolobal M (CO h (M = Fe or Ru) units as illustrated in Figure 13. (59,60) The structural relationship that exists between HRu3-(CO~B2H5 and H2Ru3(CO)9C2H2 underlines the different bonding requirements of boron and carbon atoms.…”

Alan Davison. 24 March 1936 — 14 November 2015

“…Other noteworthy contributions in these early years were his fundamental studies at the intersection of transition metal and boron chemistry. While studying the carbon-metal binding properties of cyclichydrocarbons (5), he expanded to the reactions of metal complexes with borane clusters (8) and synthesized a novel but stable compound in which the iron tricarbonyl unit replaced an apical BH moiety of pentaborane-9 (9). This was an early demonstration of the isolobal principle developed by Roald Hoffmann, ForMemRS, as described in his 1976 Nobel prize lecture.…”