2024-03-29T01:21:21Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1556462020-12-10T16:19:05Zcom_10261_52707com_10261_5col_10261_52708
2017-09-26T10:31:58Z
urn:hdl:10261/155646
Postsynthetic modifications of [2,2,2-(H)(PPh3)2-closo-2,1-RhSB8H8] with Lewis bases: cluster modular tuning
Luaces, Susana
Passarelli, Vincenzo
Artigas, María José
Lahoz, Fernando J.
Oro, Luis A.
Macías, Ramón
Ministerio de Ciencia e Innovación (España)
It has been demonstrated that the reaction of [2,2,2-(H)(PPh)-closo-2,1-RhSBH] (1) with PPh affords the boron substituted rhodathiaborane-PPh adduct, [6,6-(PPh)-9-(PPh)-arachno-6,5-RhSBH] (2). Building upon this reaction, we report herein that the 10-vertex hydridorhodathiaborane 1 reacts with the Lewis bases, PCy, py, 2-Mepy, 2-Etpy, 3-Mepy and 4-Mepy to form the rhodathiaborane-ligand adducts, [6,6-(PPh)-9-(L)-arachno-6,5-RhSBH], where L = PCy (3), 2-Mepy (4), 2-Etpy (5), py (6a), 3-Mepy (7a) or 4-Mepy (8a), and [8,9-μ-(H)-9-(PPh)-8-(L)-arachno-9,6-RhSBH], where L = py (6b), 3-Mepy (7b) or 4-Mepy (8b). The selectivity of the reactions depended on the nature of the entering Lewis bases, affording the 6,5-isomers, 2, 3, 4 and 5 as single products for PPh, PCy, 2-Mepy and 2-Etpy; and mixtures of the 6,5-/9,6-regioisomers, 6a/6b, 7a/7b and 8a/8b for py, 3-Mepy and 4-Mepy, respectively. The molecular structures of both regioisomers were characterized by X-ray diffraction analysis for the 6,5-isomers, 3 and 4, and for the 9,6-isomers, 7b and 8b. Variable temperature NMR studies of the reaction between 1 and PPh or 2-Mepy demonstrated that at low temperatures there is formation of the 9,6-species that subsequently isomerizes to the 6,5-regioisomer, indicating that for the more sterically hindered Lewis bases, PPh, 2-Mepy and PCy, the latter isomer is more stable and accessible through an intramolecular {Rh(PPh)} vertex flip. The formation of both isomers with py, 3-Mepy and 4-Mepy indicates that the kinetic and thermodynamic energies of the 6,5 and 9,6 rhodathiaborane-ligand adducts are similar for these Lewis bases. Lewis base bonding to exo-polyhedral boron vertices results in a change of the metal coordination from pseudo-octahedral Rh(iii) in 1 to pseudo-square planar Rh(i) in the adducts. The chemistry described here highlights the remarkable structural flexibility of these polyhedral boron-containing compounds, their modular architecture and their easy postsynthetic modification.
2017-09-26T10:31:58Z
2017-09-26T10:31:58Z
2016
2017-09-26T10:31:58Z
artículo
Dalton Transactions 45(20): 8622-8636 (2016)
http://hdl.handle.net/10261/155646
10.1039/C6DT00856A
http://dx.doi.org/10.13039/501100004837
eng
Postprint
https://doi.org/10.1039/C6DT00856A
Sí
openAccess
Royal Society of Chemistry (UK)