s- and p-Block Heteroboranes and Carboranes

Wesemann, Lars

doi:10.1016/b0-08-045047-4/00044-3

Cited by 12 publications

(7 citation statements)

References 209 publications

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“…The principal synthetic route to metallaboranes and metallaheteroboranes is to add metal fragments to preformed borane and heteroborane species. As the borane or heteroborane framework is quite robust, the majority of products contain a single metal center, and very often the result is a cluster with an additional vertex. − This synthetic approach has been particularly convenient in the preparation of 11-vertex nido -metallaheteroboranos of general formulation, [8,8-(L) 2 - nido -8,7-MEB 9 H 10 ], where M is Rh, L is PPh 3 , and E is S, CH, or NH; and where M is Pt, L is PMe 2 Ph, and E is CH. − These last species are all formally unsaturated according to the Wade−Williams cluster-geometry electron-counting paradigm, , with the “unsaturation” arising from the tendencies of rhodium and platinum to adopt square-planar 16-electron metal configurations. , Thus, treatment of Cs[ arachno -6-SB 9 H 12 ] with the Wilkinson catalyst [RhCl(PPh 3 ) 3 ] affords the 11-vertex rhodathiaborane [8,8-(PPh 3 ) 2 - nido -8,7-RhSB 9 H 10 ] ( 3 ) in high yield and allows the systematic study of its chemistry …”

Section: Resultsmentioning

confidence: 99%

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

Bould

Cunchillos²,

Lahoz³

et al. 2010

Inorg. Chem.

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The reaction between [IrCl(CO)(PMe(3))(2)] and the Cs[arachno-6-SB(9)H(12)] salt in CH(2)Cl(2) yields pale-yellow 11-vertex [8,8,8-(CO)(PMe(3))(2)-nido-8,7-IrSB(9)H(10)] (4). Reaction of this CO-ligated iridathiaborane with Me(3)N=O affords pale-yellow 11-vertex [1,1,1-(H)(PMe(3))(2)-isonido-1,2-IrSB(9)H(9)] (6), which is also formed from the thermal decarbonylation of 4. Compound 4 has a conventional cluster structure based on classical 11-vertex nido geometry, with the iridium center and the sulfur atom in the adjacent 8- and 7-positions on the pentagonal open face. Compound 6 exhibits an 11-vertex isonido structure based on an octadodecahedron with the {Ir(H)(PMe(3))(2)} occupying the apical position of connectivity six, but with one long non-bonding Ir-B distance generating the quadrilateral isonido open-face. Compound 6 reverts to 4 upon reaction with CO, and the Lewis acid character of 6 is further demonstrated in the reaction with EtNC to give [8,8,8-(EtNC)(PMe(3))(2)-nido-8,7-IrSB(9)H(10)] (7). The three new compounds 4, 6, and 7 have been characterized by single-crystal X-ray diffraction analyses and by NMR spectroscopy. Each of the nido iridathiaboranes 4 and 7 exhibits two different {Ir(L)(PMe(3))(2)}-to-{SB(9)H(10)} conformers in solution and in the solid state. Density functional theory (DFT) calculations reveal that the iridium atom inverts the nido-isonido-closo energy profile previously found for the rhodathiaborane congener [8,8-(PPh(3))(2)-nido-8,7-RhSB(9)H(10)] (3), demonstrating how the structure of these 11-vertex clusters can be controlled and fine-tuned by the tailoring of the metal center.

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Section: Resultsmentioning

confidence: 99%

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

Bould

Cunchillos²,

Lahoz³

et al. 2010

Inorg. Chem.

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“…The reactivity of metallacarboranes with organic molecules to give polyhedral clusters that feature metal–carbon bonds has been well studied . In contrast, the organometallic chemistry of metallaboranes and metallaheteroboranes (containing p-block elements other than carbon in the cluster framework) has been less well developed . There is a great potential for novel chemistry in this area that may be developed by a combination of the (oxidative and coordinative) flexibility of transition-metal centers together with the capability of boron-based clusters to exhibit redox flexibility in their classical closo – nido – arachno – hypho structural transformation .…”

Section: Introductionmentioning

confidence: 99%

Hydridorhodathiaboranes: Synthesis, Characterization, and Reactivity

et al. 2014

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The reaction between pyridine and [8, (17, 18, 19). These series of  2 -C 2 H 4 -and CO-ligated 11-vertex isonido / closorhodathiaboranes result from the substitution of one PPh 3 ligand by ethylene or CO together with H 2 loss and a concomitant nido-to-closo / isonido-cluster structural transformation. The reactivity of 3-5 with propene, 1-hexene and cyclohexene in a hydrogen atmosphere is also reported and compared with the reactivity of the pyridine-ligated analogue, [8,8,8-(H)(PPh 3 ) 2 -9-(NC 5 H 5 )-nido-8,7-RhSB 9 H 9 ] (2). Low temperature NMR studies have allowed the characterization of intermediates which undergo inter-and intramolecular exchange processes, depending on the nature of the N-heterocyclic ligand. The CO ligand enhances the non-rigidity of the cluster, opening mechanisms of H 2 loss from the clusters.) 3MANUSCRIPT TEXT

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“…In the [μ-8,9-O-anti-B 18 H 21 ] − anion, 52 the distance is also somewhat long at 1.839(4) Å. Thus, together with the B(7)−B(8) and B(5)−B(10) distances of 2.0845 (18) and 1.9897 (18) Å in 8, which are longer than those in [syn-B 18 H 20 ] 2− of 1.806(4) and 1.971(4) Å, this suggests a noticeable expansion of the subcluster, and this, as mentioned earlier, is of potential interest to us in the investigation of the photophysics 5,23,25−29 of macropolyhedral species.…”

Section: ■ Results and Discussionmentioning

confidence: 96%

“…Our intent is to investigate the effects that the incorporation of selenium atoms into borane cages bring, specifically here to the two known macropolyhedral binary borane isomers anti - and syn -B 18 H 22 (for schematic structures, see Scheme below). Whereas these are the first macropolyhedral selenaboranes to be investigated, the variety of known macropolyhedral thiaborane chemistry − presages a corresponding rich selenaborane behavior. The anti -B 18 H 22 isomer has been shown to have potential utility both in microelectronics , and as the gain medium for blue laser emission .…”

Section: Introductionmentioning

confidence: 99%

Macropolyhedral Chalcogenaboranes: Insertion of Selenium into the Isomers of B₁₈H₂₂

et al. 2022

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High yields of novel macropolyhedral selenaboranes are reported. Reactions of the monoanions of the syn- and anti-isomers of B18H22 with powdered selenium in THF variously give new macropolyhedral selenaboranes: 19-vertex [SeB18H19]− anion 1, 19-vertex [SeB18H21]− anion 2, 20-vertex [Se2B18H19]− anion 3, and 19-vertex [Se2B17H18]− anion 4. Single-cluster [hypho-Se2B6H9]− anion 5 and neutral arachno-Se2B7H9 6 also result. All of the macropolyhedrals 1, 2, 3, and 4 are characterized by NMR spectroscopy and mass spectrometry, and by single-crystal X-ray diffraction analyses. Anions 1 and 2 each consist of an 11-vertex subcluster joined by a common two-boron edge to a 10-vertex subcluster. Anion 3 consists of an 11-vertex subcluster joined by a common boron atom and an interboron link to an arachno-type 10-vertex subcluster. Unusually, anion 3 incorporates a hexagonal pyramidal intracluster structural motif in its 11-vertex subcluster. Anion 4 entails two arachno-type 10-vertex subclusters joined by a common boron atom, and with an additional intercluster boron–boron link. NMR data for syn-B18H22 and its mono- and dianions 7 and 8 and single-crystal X-ray diffraction results for these anions and also the monoanion 9 of anti-B18H22 are also reported. The oxaborane [μ-(8,9)-O-syn-B18H20]2– dianion 10 was serendipitously formed during the work and also characterized by a single-crystal X-ray diffraction study. Experimental NMR and structural findings are supported by DFT calculations throughout.

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s- and p-Block Heteroboranes and Carboranes

Cited by 12 publications

References 209 publications

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

Hydridorhodathiaboranes: Synthesis, Characterization, and Reactivity

Macropolyhedral Chalcogenaboranes: Insertion of Selenium into the Isomers of B₁₈H₂₂

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s- and p-Block Heteroboranes and Carboranes

Cited by 12 publications

References 209 publications

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

New Iridathiaboranes with ReversibleIsonido↔NidoCluster Flexibility

Hydridorhodathiaboranes: Synthesis, Characterization, and Reactivity

Macropolyhedral Chalcogenaboranes: Insertion of Selenium into the Isomers of B18H22

Contact Info

Product

Resources

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Macropolyhedral Chalcogenaboranes: Insertion of Selenium into the Isomers of B₁₈H₂₂