Effect of Hybridization on Structure and Bonding of Cluster Compounds Possessing a Square-Pyramidal Fe₃(CO)₉E₂Core (E = Element of Group 15 or 16)

Abstract

The pyrolysis of [NEt 4 ] 2 [Bi 4 Fe 4 (CO) 13 ] in MeCN cleanly produces the square-pyramidal cluster [NEt 4 ] 2 [Fe 3 (CO) 9 -Bi 2 ]. An X-ray crystallographic study was carried out on this compound at 223 K (orthorhombic space group P2 1 2 1 2 1 (No. 19) with a ) 7.280(1) Å, b ) 20.642(4) Å, c ) 22.365(4) Å, V ) 3360.9(10) Å 3 , and Z ) 4) showing it to belong to the square-pyramidal class of 50 electron E 2 M 3 clusters. When the E atom bears a substituent, the E‚‚‚E distances are shorter, and the M basal -E-M basal angles are larger than when a lone pair of electrons resides on E. It has become fashionable to attribute such changes in bond parameters to the formation of E-E bonding, but rehybridization of the main group element could also explain this phenomenon. In order to shed light on this fundamental aspect of bonding in E-M clusters, a detailed extended Hückel molecular orbital analysis was undertaken. It appears that weak E-E bonding may be present in some cases but that this is not the dominant effect.

Crystallographic and Structural Analysis of Iron Heterometallic Compounds Part IV: Heteropentameric Compounds

“…The structure of the anion consists of a square pyramid with two bismuth and two iron atoms forming the basal array and the third iron atom in the apical position. The angles in the basal plane of the cluster (Fe -Bi -Fe, 96 6 Ρε 2 (μ 3 -Βϊ) 2 Ρε(αθ)4]" anion have been found in red brown complex [43]. The complex anion contains a tetrahedral Bi 2 Fe 2 core.…”

“…There are three coloured Fe 3 Bi 2 clusters [41][42][43]. The black crystal [41] consists of discrete molecules of Bi 2 Fe 3 (CO) 9 which lie on sites of crystallographic C 2v symmetry.…”

“…Structure of dark brown Fe 3 Bi 2 cluster consists [42] of well-separated two [NEt^* cations and [(ΟΟ)9Ρε 3 (μ 3 -Βϊ) 2 ] 2 " anion . The structure of the anion consists of a square pyramid with two bismuth and two iron atoms forming the basal array and the third iron atom in the apical position.…”

Contents

“…The Os-Os distances range from 2.7476 (9) to 3.1038(6) A. Only four FeM 3 clusters contain a non-transition metal, namely Sn [245], Bi [246] and Te [247,248]. All remaining clusters contain the following transition metals with the number of specimen in parenthesis: Ag [249], Zn [252], Ta [253], W [66], Rh [290], Ir [236] (each xl); Au [250,251], Cr [254,254], Ni [273,274] (each x2); Mo (x4) [177,256,257]; Co (xl8) [258][259][260][261][262][263][264][265][266][267][268][269][270][271][272]; Os (x26) [288,[291][292][293][294][295][296][297][298][299][300]…”

Biomimetic hydrogen generation catalyzed by triironnonacarbonyl disulfide cluster

“…1 Wei and Dahlz 6 structurally characterized Fe 3 S 2 (CO) 9 using X-ray crystallography revealing its nido-type square pyramidal or trigonal bipyramidal arrangement. Fe 3 S 2 (CO) 9 is stable and its electronic structure and electrochemical properties have been extensively investigated using photoelectron spectroscopy, 7 computational methods, 7,8 cyclic voltammetry, 9 and spectroelectrochemical technique. 10 The reactivity of Fe 3 S 2 (CO) 9 has been explored and continues to be of great interest.…”