Formation of ferraboranes from pentaborane(9) or BH3·thf and an electron-rich cyclopentadienyl iron phosphine hydride

Diborane and Triborane Species in the Coordination Sphere of Group-8 Transition Metals

“…They also reported an alternate synthetic procedure from the reaction of [Cp*Ru(PMe 3 )BH 4 ] and pentaborane(9) . Furthermore, the CpFe analogue of arachno -[2-{Cp*Ru(PMe 3 )B 3 H 8 }] was also reported by the Kelland group from the reaction of [CpFe(PMe 3 ) 2 H] with pentaborane(9) . Ruthena-octahydrotetraborane 2 was characterized by 1 H, 31 P{ 1 H}, 11 B{ 1 H}, 13 C{ 1 H} NMR spectroscopy, mass spectrometry, and single-crystal diffraction study.…”

“…In order to confirm this hypothesis, X-ray diffraction analysis was performed on a suitable crystal of 2 . As expected, the crystal structure of 2 , shown in Figure , is the PPh 3 analogue of arachno -2-[Cp*M­(PMe 3 )­B 3 H 8 ] (M = Fe and Ru), , which can be described as an arachno butterfly cluster.…”

“…Furthermore, the Cp* ligand is situated at the exo -position, whereas the PPh 3 ligand is at the endo -position of Ru-atom. The geometry of compound 2 is similar to arachno -2-metallatetraboranes [LFe­(CO)­B 3 H 8 ] (L = Cp* or Cp), [Cp*Fe­(PMe 3 )­B 3 H 8 ], [(Cp*ReH 3 )­B 3 H 8 ], [Cp 2 Nb­(B 3 H 8 )], [Mn­(CO) 4 B 3 H 8 ], [Cu­(PPh 3 ) 2 B 3 H 8 ], [M­(CO) 2 (dppe)­(B 3 H 8 )] (M = Mn, Re), and [Cp*M­(CO) 2 B 3 H 8 ] (M = Mo, W) . However, if we neglect the crystallographic distortions, then the core geometry of 2 has a C s symmetry, where a mirror plane (σ) passes through B1 and Ru1.…”

An Efficient Route to Group 6 and 8 Metallaborane Compounds: Synthesis of arachno‐[Cp*Fe(CO)B3H8] and closo‐[(Cp*M)2B5H9] (M = Mo, W)

“…In molecule 2, there is a noncrystallographic mirror plane through Fe1, B3, and C11, and the dihedral angle between the planes B2-B1-Fe1 and B1-B2-B3 is 122.7°, typical of all known arachno-2-metallatetraboranes. Relative to the differences in the covalent radii, the average Fe-B distance (2.24 Å) is shorter than those of the heavier metal analogues ( [37] in which the pentamethylcyclopentadienyl ligand is shown to be in the exo position. Although compound 2 is isoelectronic with [Cp*M(CO)B 3 H 7 ] (M = Ir, Co) [31b,32] and [Cp*IrB 3 H 9 ], [21a] the latter two types, that is, group 9 metals, prefer the borallyl structure.…”

Thermal C–H borylation using a CO-free iron boryl complex

“…The stoichiometric iron byproducts, CpFe(PR 3 ) 2 D (6-d 1 ), also were observed clearly by NMR spectroscopy and apparently did not decompose upon photolysis, unlike CpFe(CO) 2 H produced from stoichiometric C-H borylation reactions with 1 or CpFe(CO) 2 (Bcat). 11 While similar CpFe(PR 3 ) 2 H species were known previously, 16 full synthesis and spectral characterization of CpFe(PEt 3 ) 2 H ( 6) are provided here in the ESI. †…”