A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene
© The Royal Society of Chemistry. The synthesis of a novel Rh(i)-Aryl complex is detailed and its ability to serve as an initiator in the stereospecific polymerisation of phenylacetylene evaluated. Targeting the Rh(i) species, (2-phenylnaphthalen-1-yl)rhodium(i)(2,5-norbornadiene)tris(para-fluorophe...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Journal Article |
| Language: | English |
| Published: |
ROYAL SOC CHEMISTRY
2019
|
| Subjects: | |
| Online Access: | http://hdl.handle.net/20.500.11937/77878 |
| _version_ | 1848763910586368000 |
|---|---|
| author | Tan, N.S.L. Nealon, G.L. Lynam, J.M. Sobolev, A.N. Rowles, Matthew Ogden, Mark Massi, Max Lowe, Andrew |
| author_facet | Tan, N.S.L. Nealon, G.L. Lynam, J.M. Sobolev, A.N. Rowles, Matthew Ogden, Mark Massi, Max Lowe, Andrew |
| author_sort | Tan, N.S.L. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | © The Royal Society of Chemistry. The synthesis of a novel Rh(i)-Aryl complex is detailed and its ability to serve as an initiator in the stereospecific polymerisation of phenylacetylene evaluated. Targeting the Rh(i) species, (2-phenylnaphthalen-1-yl)rhodium(i)(2,5-norbornadiene)tris(para-fluorophenylphosphine), Rh(nbd)(P(4-FC6H4)3)(2-PhNapth), following recrystallization we obtained the isomeric (2-(naphthalen-2-yl)phenyl)rhodium(i) complex, Rh(nbd)(P(4-FC6H4)3)(2-NapthPh), as determined by X-ray single-crystal structure analysis, and confirmed by X-ray powder diffraction. The isolation of the latter species was proposed to occur from the target (2-PhNapth) derivative via an intramolecular 1,4-Rh atom migration. This supposition was supported by density functional theory (DFT) calculations that indicated the isolated (2-NapthPh) derivative has lower energy (-19 kJ mol-1) than the targeted complex. The structure of the isolated (2-NapthPh) species was confirmed by multinuclear NMR spectroscopy including 2D 31P-103Rh{1H, 103Rh}, heteronuclear multiple-quantum correlation (HMQC) experiments; however, NMR analysis indicated the presence of a second, minor species in solution in an approximate 1:4 ratio with the 2-NapthPh complex. The minor species was identified as a second structural isomer, the 3-phenylnaphthyl derivative, proposed to be formed under a dynamic equilibrium with the 2-NapthPh derivative via a second 1,4-Rh atom migration. DFT calculations indicate that this 1,4-migration proceeds through a low-energy pathway involved in the oxidative addition of a C-H bond to Rh followed by a reductive elimination with the distribution of the products being thermodynamically controlled. The recrystallized Rh(nbd)(P(4-FC6H4)3)(2-NapthPh) complex was subsequently evaluated as an initiator in the polymerisation of phenylacetylene (PA); gratifyingly, the Rh(i) species was an active initiating species with the pseudo-first-order kinetic and molecular weight evolution vs time plots both linear implying a controlled polymerisation while yielding (co)polymers with low dispersities (= Mw/Mn typically ≤1.25) and high cis-Transoidal stereoregularity (>95%). Typical initiation efficiencies, while not quantitative (as judged by size exclusion chromatography), were nonetheless high at ca. 0.8. The presence of the minor 3-phenylnaphthyl species when in solution is proposed to be the cause of the observed non-quantitative initiation. |
| first_indexed | 2025-11-14T11:10:58Z |
| format | Journal Article |
| id | curtin-20.500.11937-77878 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| language | English |
| last_indexed | 2025-11-14T11:10:58Z |
| publishDate | 2019 |
| publisher | ROYAL SOC CHEMISTRY |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-778782020-05-07T07:12:42Z A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene Tan, N.S.L. Nealon, G.L. Lynam, J.M. Sobolev, A.N. Rowles, Matthew Ogden, Mark Massi, Max Lowe, Andrew Science & Technology Physical Sciences Chemistry, Inorganic & Nuclear Chemistry SENSE-SELECTIVE POLYMERIZATION BULKY ARYL ISOCYANIDE AUXILIARY BASIS-SETS LIVING POLYMERIZATION GEOMETRY OPTIMIZATION RHODIUM CATALYSTS LIGAND SHIFT POLYACETYLENES DERIVATIVES © The Royal Society of Chemistry. The synthesis of a novel Rh(i)-Aryl complex is detailed and its ability to serve as an initiator in the stereospecific polymerisation of phenylacetylene evaluated. Targeting the Rh(i) species, (2-phenylnaphthalen-1-yl)rhodium(i)(2,5-norbornadiene)tris(para-fluorophenylphosphine), Rh(nbd)(P(4-FC6H4)3)(2-PhNapth), following recrystallization we obtained the isomeric (2-(naphthalen-2-yl)phenyl)rhodium(i) complex, Rh(nbd)(P(4-FC6H4)3)(2-NapthPh), as determined by X-ray single-crystal structure analysis, and confirmed by X-ray powder diffraction. The isolation of the latter species was proposed to occur from the target (2-PhNapth) derivative via an intramolecular 1,4-Rh atom migration. This supposition was supported by density functional theory (DFT) calculations that indicated the isolated (2-NapthPh) derivative has lower energy (-19 kJ mol-1) than the targeted complex. The structure of the isolated (2-NapthPh) species was confirmed by multinuclear NMR spectroscopy including 2D 31P-103Rh{1H, 103Rh}, heteronuclear multiple-quantum correlation (HMQC) experiments; however, NMR analysis indicated the presence of a second, minor species in solution in an approximate 1:4 ratio with the 2-NapthPh complex. The minor species was identified as a second structural isomer, the 3-phenylnaphthyl derivative, proposed to be formed under a dynamic equilibrium with the 2-NapthPh derivative via a second 1,4-Rh atom migration. DFT calculations indicate that this 1,4-migration proceeds through a low-energy pathway involved in the oxidative addition of a C-H bond to Rh followed by a reductive elimination with the distribution of the products being thermodynamically controlled. The recrystallized Rh(nbd)(P(4-FC6H4)3)(2-NapthPh) complex was subsequently evaluated as an initiator in the polymerisation of phenylacetylene (PA); gratifyingly, the Rh(i) species was an active initiating species with the pseudo-first-order kinetic and molecular weight evolution vs time plots both linear implying a controlled polymerisation while yielding (co)polymers with low dispersities (= Mw/Mn typically ≤1.25) and high cis-Transoidal stereoregularity (>95%). Typical initiation efficiencies, while not quantitative (as judged by size exclusion chromatography), were nonetheless high at ca. 0.8. The presence of the minor 3-phenylnaphthyl species when in solution is proposed to be the cause of the observed non-quantitative initiation. 2019 Journal Article http://hdl.handle.net/20.500.11937/77878 10.1039/c9dt02953b English ROYAL SOC CHEMISTRY restricted |
| spellingShingle | Science & Technology Physical Sciences Chemistry, Inorganic & Nuclear Chemistry SENSE-SELECTIVE POLYMERIZATION BULKY ARYL ISOCYANIDE AUXILIARY BASIS-SETS LIVING POLYMERIZATION GEOMETRY OPTIMIZATION RHODIUM CATALYSTS LIGAND SHIFT POLYACETYLENES DERIVATIVES Tan, N.S.L. Nealon, G.L. Lynam, J.M. Sobolev, A.N. Rowles, Matthew Ogden, Mark Massi, Max Lowe, Andrew A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title | A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title_full | A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title_fullStr | A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title_full_unstemmed | A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title_short | A (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: Ortho-To-ortho ′ Rh metal-Atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| title_sort | (2-(naphthalen-2-yl)phenyl)rhodium(i) complex formed by a proposed intramolecular 1,4-: ortho-to-ortho ′ rh metal-atom migration and its efficacy as an initiator in the controlled stereospecific polymerisation of phenylacetylene |
| topic | Science & Technology Physical Sciences Chemistry, Inorganic & Nuclear Chemistry SENSE-SELECTIVE POLYMERIZATION BULKY ARYL ISOCYANIDE AUXILIARY BASIS-SETS LIVING POLYMERIZATION GEOMETRY OPTIMIZATION RHODIUM CATALYSTS LIGAND SHIFT POLYACETYLENES DERIVATIVES |
| url | http://hdl.handle.net/20.500.11937/77878 |