Pentamethylbismuth is produced in a two step process. First, trimethylbismuth is reacted with sulfuryl chloride to yield dichloro trimethylbismuth, which is then reacted with two equivalents of methyllithium dissolved in ether.[4] The blue solution is cooled to −110 °C to precipitate the solid product.
Bi(CH3)3 + SO2Cl2 → Bi(CH3)3Cl2 + SO2
Bi(CH3)3Cl2 + 2LiCH3 → Bi(CH3)5 + 2LiCl
Propertiesedit
energy levels and shapes of pentamethylbismuth molecules
At -110 °C, Bi(CH3)5 is a blue-violet solid. The methyl groups are arranged in a trigonal bipyramid, and the bond-lengths of methyl with bismuth are all the same. However, the molecule is not rigid, as can be determined from the nuclear magnetic resonance spectrum that shows all methyl groups are equivalent.[4] It is stable as a solid, but in the gas phase, when heated or in solution decomposes to trimethylbismuth.[3][4] The colour is unusual for bismuth or other hypervalent pnictide compounds, which are colourless. Calculations show that the colour is due to HOMO-LUMO transition. The HOMO is ligand based, whereas the LUMO is modified by relativistically stabilised bismuth 6s orbitals.[5]
Reactionsedit
If excess methyllithium is used in production, an orange hexamethylbismuth salt, LiBi(CH3)6, is formed .[6] This is unusual as very few elements can form bonds with six organic groups.[4]
Referencesedit
^Urben, Peter (2013). Bretherick's Handbook of Reactive Chemical Hazards. Academic Press. p. 742. ISBN9780080523408.
^Hellwinkel, Dieter (1883). "Penta- and hexaorganyl derivatives of the main group five elements". Wittig Chemistry. Topics in Current Chemistry. Topics in Current Chemistry. 109: 1–63. doi:10.1007/BFb0018055. ISBN3-540-11907-8.
^ abGreene, Tim M.; Downs, Anthony J.; Pulham, Colin R.; Haaland, Arne; Verne, Hans Peter; Volden, Hans Vidar; Timofeeva, Tatjana V. (November 1998). "Molecular Structures of Pentamethylarsenic(V) and Trimethyldichloroarsenic(V) by Gas Electron Diffraction and ab Initio Calculations:? Molecular Mechanics Calculations on Pentamethylarsenic(V), Pentaphenylarsenic(V), and Related Compounds". Organometallics. 17 (24): 5287–5293. doi:10.1021/om980520r.
^ abcdWallenhauer, Stephan; Seppelt, Konrad (18 May 1994). "Methylbismuth(V) Compounds". Angewandte Chemie International Edition in English. 33 (9): 976–978. doi:10.1002/anie.199409761.
^Conradie, Jeanet; Ghosh, Abhik (February 2017). "The Blue-Violet Color of Pentamethylbismuth: A Visible Spin-Orbit Effect". ChemistryOpen. 6 (1): 15–17. doi:10.1002/open.201600131. PMC5288750. PMID 28168144.
^Wallenhauer, Stephan; Seppelt, Konrad (January 1995). "Antimony(V) and Bismuth(V) Methyl Compounds: A Structural Comparison". Inorganic Chemistry. 34 (1): 116–119. doi:10.1021/ic00105a021.
Extra readingedit
Gagnon, Alexandre; Dansereau, Julien; Le Roch, Adrien (2 March 2017). "Organobismuth Reagents: Synthesis, Properties and Applications in Organic Synthesis". Synthesis. 49 (8): 1707–1745. doi:10.1055/s-0036-1589482. S2CID 102471505.
April 15, 2024
pentamethylbismuth, pentamethylbismuthorane, organometalllic, compound, containing, five, methyl, groups, bound, bismuth, atom, with, formula, example, hypervalent, compound, molecular, shape, trigonal, bipyramid, namespreferred, iupac, name, pentamethyl, bism. Pentamethylbismuth or pentamethylbismuthorane 2 is an organometalllic compound containing five methyl groups bound to a bismuth atom with formula Bi CH3 5 It is an example of a hypervalent compound The molecular shape is trigonal bipyramid 3 Pentamethylbismuth NamesPreferred IUPAC name Pentamethyl l5 bismuthaneIdentifiersCAS Number 148739 67 7 Y 1 3D model JSmol Interactive imagePubChem CID 21933141UNII MYP8RT4JE2 YInChI InChI 1S 5CH3 Bi h5 1H3 NKey ARMZEJAYUBQCRQ UHFFFAOYSA N NSMILES C Bi C C C CPropertiesChemical formula C 5H 15BiMolar mass 284 155 g mol 1Appearance blue violet solidRelated compoundsRelated compounds Trimethylbismuth Pentamethylarsenic Pentamethylantimony Pentamethyltantalum PentaphenylbismuthExcept where otherwise noted data are given for materials in their standard state at 25 C 77 F 100 kPa N what is Y N Infobox references Contents 1 Production 2 Properties 3 Reactions 4 References 5 Extra readingProduction editPentamethylbismuth is produced in a two step process First trimethylbismuth is reacted with sulfuryl chloride to yield dichloro trimethylbismuth which is then reacted with two equivalents of methyllithium dissolved in ether 4 The blue solution is cooled to 110 C to precipitate the solid product Bi CH3 3 SO2Cl2 Bi CH3 3Cl2 SO2 Bi CH3 3Cl2 2LiCH3 Bi CH3 5 2LiClProperties edit nbsp energy levels and shapes of pentamethylbismuth moleculesAt 110 C Bi CH3 5 is a blue violet solid The methyl groups are arranged in a trigonal bipyramid and the bond lengths of methyl with bismuth are all the same However the molecule is not rigid as can be determined from the nuclear magnetic resonance spectrum that shows all methyl groups are equivalent 4 It is stable as a solid but in the gas phase when heated or in solution decomposes to trimethylbismuth 3 4 The colour is unusual for bismuth or other hypervalent pnictide compounds which are colourless Calculations show that the colour is due to HOMO LUMO transition The HOMO is ligand based whereas the LUMO is modified by relativistically stabilised bismuth 6s orbitals 5 Reactions editIf excess methyllithium is used in production an orange hexamethylbismuth salt LiBi CH3 6 is formed 6 This is unusual as very few elements can form bonds with six organic groups 4 References edit Urben Peter 2013 Bretherick s Handbook of Reactive Chemical Hazards Academic Press p 742 ISBN 9780080523408 Hellwinkel Dieter 1883 Penta and hexaorganyl derivatives of the main group five elements Wittig Chemistry Topics in Current Chemistry Topics in Current Chemistry 109 1 63 doi 10 1007 BFb0018055 ISBN 3 540 11907 8 a b Greene Tim M Downs Anthony J Pulham Colin R Haaland Arne Verne Hans Peter Volden Hans Vidar Timofeeva Tatjana V November 1998 Molecular Structures of Pentamethylarsenic V and Trimethyldichloroarsenic V by Gas Electron Diffraction and ab Initio Calculations Molecular Mechanics Calculations on Pentamethylarsenic V Pentaphenylarsenic V and Related Compounds Organometallics 17 24 5287 5293 doi 10 1021 om980520r a b c d Wallenhauer Stephan Seppelt Konrad 18 May 1994 Methylbismuth V Compounds Angewandte Chemie International Edition in English 33 9 976 978 doi 10 1002 anie 199409761 Conradie Jeanet Ghosh Abhik February 2017 The Blue Violet Color of Pentamethylbismuth A Visible Spin Orbit Effect ChemistryOpen 6 1 15 17 doi 10 1002 open 201600131 PMC 5288750 PMID 28168144 nbsp Wallenhauer Stephan Seppelt Konrad January 1995 Antimony V and Bismuth V Methyl Compounds A Structural Comparison Inorganic Chemistry 34 1 116 119 doi 10 1021 ic00105a021 Extra reading editGagnon Alexandre Dansereau Julien Le Roch Adrien 2 March 2017 Organobismuth Reagents Synthesis Properties and Applications in Organic Synthesis Synthesis 49 8 1707 1745 doi 10 1055 s 0036 1589482 S2CID 102471505 nbsp Retrieved from https en wikipedia org w index php title Pentamethylbismuth amp oldid 1213398395, wikipedia, wiki, book, books, library,
