149610-55-9Relevant academic research and scientific papers
Synthesis and reactivity of 10-vertex arachno-platinacarboranes
Carr, Michael J.,McGrath, Thomas D.,Stone, F. Gordon A.
, p. 2099 - 2106 (2009/02/01)
Reaction of [Pt3(CNR)6] with arachno-4-R′-4- CB8H13 in THF (tetrahydrofuran) gives the platinamonocarborane species [9,9-(CNR)2-6-R′-arachno-9,6- PtCB8H11] (R = But, R′ = H (1); R - Xyl (C6H3Me2-2,6), R′ = H (2); R = Bu t, R′ = Ph (3)). The related compound [9,9-(PMe 2Ph)2-arachno-9,6-PtCB8H12] (5) can be synthesized by treating arachno-4-CB8H14 with [PtMe2(PMe2Ph)2] in CH2Cl 2. Compounds 1-3 and 5 are all formed in high yields (>80%), enabling reactivity studies to be carried out. A single isocyanide ligand in 1 can be easily exchanged for a phosphine, as is the case with [9-CNBu t-9-PPh3-arachno-9,6-PtCB8H12] (6), or, by using bidentate dppe (Ph2PCH2CH2PPh 2), both isocyanide groups are replaced, giving [9,9-dppe-arachno-9, 6-PtCB8H12] (7). Treatment with [NEt4][CN] allows the isocyanides in 1 to be replaced by cyanide ligands, giving the dianionic complex [NEt4]2[9,9-(CN)2-arachno-9, 6-PtCB8H12] (8) or the monoanionic species [NEt 4] [9-CNBut-9-CN-arachno-9,6-PtCB8H 12] (9) depending on the stoichiometry of the reaction. Reaction of 1 or 3 with I2 yields the platinum(IV) complexes [9,9-(CNBu t)2-9,9-I2-6-R′-arachno-9,6-PtCB 8H11] (R′ = H (10), Ph (11)), respectively, by an oxidative addition reaction. Using the same reagent, compound 7 forms solvent-dependent, boronsubstituted products: [9,9-dppe-4,8-I 2-arachno-9,6-PtCB8H10] (12) is obtained in CH2Cl2, whereas [9,9-dppe-4-{O(CH2) 4I}-8-I-arachno-9,6-PtCB8H10] (13) results when THF is used as solvent.
Eleven-vertex Polyhedral Monocarbaplatinaborane Chemistry. Structure and Fluxionality of
Stibr, Bohumil,Jelinek, Tomas,Kennedy, John D.,Fontaine, Xavier L. R.,Thornton-Pett, Mark
, p. 1261 - 1268 (2007/10/02)
Reaction between and arachno-6-CB9H14>(1-) in CH2Cl solution at room temperature yields yellow air-stable eleven-vetex 1 (46-64percent) together with small quantities of ten-vertex 2 (0-3percent).Crystals of compound 1 are monoclinic, space group P21/n, with a = 1186.8(1), b = 1554.1(2), c = 1344.1(2) pm, β = 95.02(1) deg and Z = 4.The structure refined to R,R'= 0.0297, 0.0310 using 3938 data with I > 3?(I).The cluster structure is of the nido eleven-vertex type, with the platinum and carbon atoms occupying adjacent positions on the open face.There is some geometrical closure from pure nido, so that the gross cluster structure tends towards intermediacy between those of 4 and of the closo-structured species 3.The NMR properties of 1 are reported and assessed for intermediacy between those of 3 and 4, and the analytical utility of NMR spectroscopy in assessing the metal-to-cluster bonding is developed by comparison with non-metallated species.The metal-to-carborane bonding sphere of compound 1 is fluxional, with ΔG(excit.)313 ca. 62 kJ mol1.The fluxional process involves and interconversion of enantiomers with the platinum centre and the bridging hydrogen atom migrating around the open face of the cage while the exo polyhedral ligand sphere undergoes a half-twist.
