The crystal and molecular structure of μ-carbonato-bis(tetraphenylantimony): a system containing penta- and hexacoordinated antimony

Abstract

The structure of μ‐carbonato‐bis(tetraphenylantimony), , has been determined from 2394 independent X‐ray intensities measured on a four‐circle diffractometer. The material is triclinic, space group P1, with a = 10.108, b = 14.018, c = 15.702 Å, α = 73.92, β = 79.84, β = 74.39°, Z = 2. The structure was solved by the heavy‐atom method and refined by least‐squares calculations to R = 0.049. The structure consists of well separated molecules. One antimony atom, Sb(1), is in a slightly distorted trigonal bipyramidal environment with a carbonato oxygen apical. The mean C(axial)‐Sb(1)‐C(equatorial) angle is 95.2° and corresponds to a displacement of Sb(1) 0.19 Å out of the plane of the three equatorial carbon atoms towards the apical phenyl group. The other antimony, Sb(2), has distorted octahedral coordination. The two antimony polyhedra are linked by a planar carbonato group whose C‐O distances do not differ significantly from their mean value 1.292 (13) Å. The Sb‐O distances are Sb(1)‐O(1), 2.257 (7), Sb(2)‐O(2) 2.325 (7), Sb(2)‐O(3) 2.185 (7). At Sb(1), the mean Sb‐C (equatorial) bond length is 2.120 (11) and the Sb‐C(apical) distance is 2.153 (11) Å. The mean value of the Sb(2)‐C bonds is 2.152 (11) Å.

Tris(p-chlorophenyl)-5,5,5-trifluoro-4,4-dihydroxy-2-pentanonatoantimony(V)

“…The new ligand behaves as a terdentate, (1)is longer than the other metal-donor atom distances, a weak interaction may exist because Vc= o is shifted to a lower wavenumber region in the IR spectrum. The O(2)-Sb-O(3) bond angle is similar to that of carbonato and dithiocarbamato complexes (Ferguson & Hawley, 1974;Raston & White, 1976). No remarkable interaction between the molecules is observed.…”

Unusual mixed-metal carbonate-bridged complexes via oxidation of a carbonyl ligand in [RhM(CO)4(Ph2PCH2PPh2)2] (M = Mn, Re) and [IrRe(CO)5(Ph2PCH2PPh2)2]

“…The carbonate coordination mode is reflected in the shorter C(4)-0(6) distance of 1.16 (2) Á for this noncoordinated oxygen atom, compared with the values involving the coordinated oxygens, for which the C(4)-0(4) and C(4)-0(5) distances both equal 1. 37 (2) Á; both values are close to the values expected for double and single C-0 bonds, respectively.32 This observed bridging mode for the carbonate group in compound 4 is highly unusual. In other compounds containing bridging carbonate ligands either this group binds through all three oxygen atoms30"32,34"38 or only two oxygens are bound, such that each oxygen binds to only one metal, functioning as a 2-electron donor to each.39-43.…”

Binding, Sensing, And Transporting Anions with Pnictogen Bonds: The Case of Organoantimony Lewis Acids

“…Donation of a fluoride lone pair into the σ*(Sb−C) orbital prevents access to such a dark state in 56-F thus restoring the π−π* emission of the anthracene chromophore. This mechanism also applies to other stibonium cations such as the pyrenyl and perylenyl systems [57] + and [58] + , 92 and the BODIPY derivative [59] + (Figure 26). 93 All three cations see their fluorescence readily increase upon fluoride binding at the antimony center.…”

“…92 A proportionally similar response is observed for [58] + , since fluoride binding elicits a fluorescence increase from Φ F = 7.3% to Φ F = 59.2%. Like [56] + , [57] + and [58] + are potent fluoride binders with K(F − ) values of 10,000 ± 800 M −1 and 10,000 ± 500 M −1 for [57] + and [58] + in a water:DMSO solution (9:1 (v/v), pH 4.8, 10 mM pyridine, 10 mM cetyltrimethylammonium bromide). The BODIPY derivative [59] + could only be evaluated in MeCN, a medium in which it displays a K(F − ) greater than 10 7 M −1 and a noticeable fluorescence turn-on response from Φ F = 0.15 to Φ F = 0.30 upon fluoride complexation.…”

“…Our work on these bidentate systems has also explored 33 and 34, two derivatives based on the o-phenylene backbones and featuring the octafluorophenanthrene-9,10-diolate ligand on each antimony, as opposed to the o-tetrachlorocatecholate ligand found in 30 and 32 (Scheme 8). 57 These compounds, which could be accessed using the corresponding distibines following oxidation with 9,10-perfluorophenanthraquinone, differ from one another via the nature of the o-phenylene backbone, which is perfluorinated in the case of 34. Each readily complexes fluoride upon addition of TBAT to form the 12).…”