Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid
Benzo[ a ]fluoranthene ( 4a ) is one of non‐alternate polycyclic aromatic hydrocarbons. A reaction of 4a in CF 3 SO 3 H yielded a dark yellow solution. Direct NMR observation indicated the exclusive formation of carbocation 4aH + by protonation at the C(8) position. The most deshielded 1 H and 13 C...
Gespeichert in:
| Veröffentlicht in: | Journal of physical organic chemistry 2024-10, Vol.37 (10) |
|---|---|
| Hauptverfasser: | , , |
| Format: | Artikel |
| Sprache: | eng |
| Online-Zugang: | Volltext |
| Tags: |
Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
|
| container_end_page | |
|---|---|
| container_issue | 10 |
| container_start_page | |
| container_title | Journal of physical organic chemistry |
| container_volume | 37 |
| creator | Okazaki, Takao Yamashita, Haruki Kitagawa, Toshikazu |
| description | Benzo[
a
]fluoranthene (
4a
) is one of non‐alternate polycyclic aromatic hydrocarbons. A reaction of
4a
in CF
3
SO
3
H yielded a dark yellow solution. Direct NMR observation indicated the exclusive formation of carbocation
4aH
+
by protonation at the C(8) position. The most deshielded
1
H and
13
C signals were observed at 8.99 ppm for H(12) and 8.29 ppm for H(1), 182.6 ppm for C(12b), 155.6 ppm for C(8a), and 149.4 ppm for C(7a). The signals for H(4) and H(5) were significantly more shielded than those of
4a
. A reaction of 3‐
tert
‐butylbenzo[
a
]fluoranthene (
4b
) in CF
3
SO
3
H afforded carbocation
4bH
+
by the protonation at the C(8) position.
4bH
+
was gradually converted to
4aH
+
. The changes in
13
C NMR chemical shifts (Δδ
13
C) suggested that positive charge was delocalized into mainly seven carbons in
4aH
+
and
4bH
+
. The observed cations were found to be the most stable cations among the possible protonation cations by the DFT method. The NICS(1)
zz
values for the five‐membered rings were calculated to be 35.6 for
4aH
+
and 34.4 for
4bH
+
by GIAO‐B3LYP/6‐311+G(2d,p). The experimental NMR and the NICS(1)
zz
data indicated that the five‐membered rings in
4aH
+
and
4bH
+
exhibited anti‐aromaticity. |
| doi_str_mv | 10.1002/poc.4647 |
| format | Article |
| fullrecord | <record><control><sourceid>crossref</sourceid><recordid>TN_cdi_crossref_primary_10_1002_poc_4647</recordid><sourceformat>XML</sourceformat><sourcesystem>PC</sourcesystem><sourcerecordid>10_1002_poc_4647</sourcerecordid><originalsourceid>FETCH-LOGICAL-c118t-58cc04f867925e00c4988f772f3c98bf49ea5357b04ffa26dc209b49a264a41e3</originalsourceid><addsrcrecordid>eNotkEFOwzAQRS0EEqEgcQQv2aSMYyexl6gCilQJFrBCKHIcuzVK48h2kdoV3IAzchJcymI0oz_v_8VH6JLAlAAU16NTU1ax-ghlBITICRXlMcqAC5bTgsIpOgvhHSD9yjpDX08u2Gg_NFYr6Zcad7p3SvZ2J6N1A5ZDlyban89v6d06icrGLXYGqz8g4KUetJdRd7jd4tG76IaDNTGtHnbuFUv8ZvqN8yloleiA7YDDZkw2ZbtzdGJkH_TF_56gl7vb59k8XzzeP8xuFrkihMe85EoBM7yqRVFqAMUE56auC0OV4K1hQsuSlnWbICOLqlMFiJaJdDLJiKYTdHXIVd6F4LVpRm_X0m8bAs2-uiZV1-yro7_TWWXd</addsrcrecordid><sourcetype>Aggregation Database</sourcetype><iscdi>true</iscdi><recordtype>article</recordtype></control><display><type>article</type><title>Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid</title><source>Wiley Online Library</source><creator>Okazaki, Takao ; Yamashita, Haruki ; Kitagawa, Toshikazu</creator><creatorcontrib>Okazaki, Takao ; Yamashita, Haruki ; Kitagawa, Toshikazu</creatorcontrib><description>Benzo[
a
]fluoranthene (
4a
) is one of non‐alternate polycyclic aromatic hydrocarbons. A reaction of
4a
in CF
3
SO
3
H yielded a dark yellow solution. Direct NMR observation indicated the exclusive formation of carbocation
4aH
+
by protonation at the C(8) position. The most deshielded
1
H and
13
C signals were observed at 8.99 ppm for H(12) and 8.29 ppm for H(1), 182.6 ppm for C(12b), 155.6 ppm for C(8a), and 149.4 ppm for C(7a). The signals for H(4) and H(5) were significantly more shielded than those of
4a
. A reaction of 3‐
tert
‐butylbenzo[
a
]fluoranthene (
4b
) in CF
3
SO
3
H afforded carbocation
4bH
+
by the protonation at the C(8) position.
4bH
+
was gradually converted to
4aH
+
. The changes in
13
C NMR chemical shifts (Δδ
13
C) suggested that positive charge was delocalized into mainly seven carbons in
4aH
+
and
4bH
+
. The observed cations were found to be the most stable cations among the possible protonation cations by the DFT method. The NICS(1)
zz
values for the five‐membered rings were calculated to be 35.6 for
4aH
+
and 34.4 for
4bH
+
by GIAO‐B3LYP/6‐311+G(2d,p). The experimental NMR and the NICS(1)
zz
data indicated that the five‐membered rings in
4aH
+
and
4bH
+
exhibited anti‐aromaticity.</description><identifier>ISSN: 0894-3230</identifier><identifier>EISSN: 1099-1395</identifier><identifier>DOI: 10.1002/poc.4647</identifier><language>eng</language><ispartof>Journal of physical organic chemistry, 2024-10, Vol.37 (10)</ispartof><lds50>peer_reviewed</lds50><woscitedreferencessubscribed>false</woscitedreferencessubscribed><cites>FETCH-LOGICAL-c118t-58cc04f867925e00c4988f772f3c98bf49ea5357b04ffa26dc209b49a264a41e3</cites><orcidid>0000-0001-7218-5217 ; 0000-0002-5384-9441</orcidid></display><links><openurl>$$Topenurl_article</openurl><openurlfulltext>$$Topenurlfull_article</openurlfulltext><thumbnail>$$Tsyndetics_thumb_exl</thumbnail><link.rule.ids>314,777,781,27905,27906</link.rule.ids></links><search><creatorcontrib>Okazaki, Takao</creatorcontrib><creatorcontrib>Yamashita, Haruki</creatorcontrib><creatorcontrib>Kitagawa, Toshikazu</creatorcontrib><title>Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid</title><title>Journal of physical organic chemistry</title><description>Benzo[
a
]fluoranthene (
4a
) is one of non‐alternate polycyclic aromatic hydrocarbons. A reaction of
4a
in CF
3
SO
3
H yielded a dark yellow solution. Direct NMR observation indicated the exclusive formation of carbocation
4aH
+
by protonation at the C(8) position. The most deshielded
1
H and
13
C signals were observed at 8.99 ppm for H(12) and 8.29 ppm for H(1), 182.6 ppm for C(12b), 155.6 ppm for C(8a), and 149.4 ppm for C(7a). The signals for H(4) and H(5) were significantly more shielded than those of
4a
. A reaction of 3‐
tert
‐butylbenzo[
a
]fluoranthene (
4b
) in CF
3
SO
3
H afforded carbocation
4bH
+
by the protonation at the C(8) position.
4bH
+
was gradually converted to
4aH
+
. The changes in
13
C NMR chemical shifts (Δδ
13
C) suggested that positive charge was delocalized into mainly seven carbons in
4aH
+
and
4bH
+
. The observed cations were found to be the most stable cations among the possible protonation cations by the DFT method. The NICS(1)
zz
values for the five‐membered rings were calculated to be 35.6 for
4aH
+
and 34.4 for
4bH
+
by GIAO‐B3LYP/6‐311+G(2d,p). The experimental NMR and the NICS(1)
zz
data indicated that the five‐membered rings in
4aH
+
and
4bH
+
exhibited anti‐aromaticity.</description><issn>0894-3230</issn><issn>1099-1395</issn><fulltext>true</fulltext><rsrctype>article</rsrctype><creationdate>2024</creationdate><recordtype>article</recordtype><recordid>eNotkEFOwzAQRS0EEqEgcQQv2aSMYyexl6gCilQJFrBCKHIcuzVK48h2kdoV3IAzchJcymI0oz_v_8VH6JLAlAAU16NTU1ax-ghlBITICRXlMcqAC5bTgsIpOgvhHSD9yjpDX08u2Gg_NFYr6Zcad7p3SvZ2J6N1A5ZDlyban89v6d06icrGLXYGqz8g4KUetJdRd7jd4tG76IaDNTGtHnbuFUv8ZvqN8yloleiA7YDDZkw2ZbtzdGJkH_TF_56gl7vb59k8XzzeP8xuFrkihMe85EoBM7yqRVFqAMUE56auC0OV4K1hQsuSlnWbICOLqlMFiJaJdDLJiKYTdHXIVd6F4LVpRm_X0m8bAs2-uiZV1-yro7_TWWXd</recordid><startdate>202410</startdate><enddate>202410</enddate><creator>Okazaki, Takao</creator><creator>Yamashita, Haruki</creator><creator>Kitagawa, Toshikazu</creator><scope>AAYXX</scope><scope>CITATION</scope><orcidid>https://orcid.org/0000-0001-7218-5217</orcidid><orcidid>https://orcid.org/0000-0002-5384-9441</orcidid></search><sort><creationdate>202410</creationdate><title>Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid</title><author>Okazaki, Takao ; Yamashita, Haruki ; Kitagawa, Toshikazu</author></sort><facets><frbrtype>5</frbrtype><frbrgroupid>cdi_FETCH-LOGICAL-c118t-58cc04f867925e00c4988f772f3c98bf49ea5357b04ffa26dc209b49a264a41e3</frbrgroupid><rsrctype>articles</rsrctype><prefilter>articles</prefilter><language>eng</language><creationdate>2024</creationdate><toplevel>peer_reviewed</toplevel><toplevel>online_resources</toplevel><creatorcontrib>Okazaki, Takao</creatorcontrib><creatorcontrib>Yamashita, Haruki</creatorcontrib><creatorcontrib>Kitagawa, Toshikazu</creatorcontrib><collection>CrossRef</collection><jtitle>Journal of physical organic chemistry</jtitle></facets><delivery><delcategory>Remote Search Resource</delcategory><fulltext>fulltext</fulltext></delivery><addata><au>Okazaki, Takao</au><au>Yamashita, Haruki</au><au>Kitagawa, Toshikazu</au><format>journal</format><genre>article</genre><ristype>JOUR</ristype><atitle>Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid</atitle><jtitle>Journal of physical organic chemistry</jtitle><date>2024-10</date><risdate>2024</risdate><volume>37</volume><issue>10</issue><issn>0894-3230</issn><eissn>1099-1395</eissn><abstract>Benzo[
a
]fluoranthene (
4a
) is one of non‐alternate polycyclic aromatic hydrocarbons. A reaction of
4a
in CF
3
SO
3
H yielded a dark yellow solution. Direct NMR observation indicated the exclusive formation of carbocation
4aH
+
by protonation at the C(8) position. The most deshielded
1
H and
13
C signals were observed at 8.99 ppm for H(12) and 8.29 ppm for H(1), 182.6 ppm for C(12b), 155.6 ppm for C(8a), and 149.4 ppm for C(7a). The signals for H(4) and H(5) were significantly more shielded than those of
4a
. A reaction of 3‐
tert
‐butylbenzo[
a
]fluoranthene (
4b
) in CF
3
SO
3
H afforded carbocation
4bH
+
by the protonation at the C(8) position.
4bH
+
was gradually converted to
4aH
+
. The changes in
13
C NMR chemical shifts (Δδ
13
C) suggested that positive charge was delocalized into mainly seven carbons in
4aH
+
and
4bH
+
. The observed cations were found to be the most stable cations among the possible protonation cations by the DFT method. The NICS(1)
zz
values for the five‐membered rings were calculated to be 35.6 for
4aH
+
and 34.4 for
4bH
+
by GIAO‐B3LYP/6‐311+G(2d,p). The experimental NMR and the NICS(1)
zz
data indicated that the five‐membered rings in
4aH
+
and
4bH
+
exhibited anti‐aromaticity.</abstract><doi>10.1002/poc.4647</doi><orcidid>https://orcid.org/0000-0001-7218-5217</orcidid><orcidid>https://orcid.org/0000-0002-5384-9441</orcidid></addata></record> |
| fulltext | fulltext |
| identifier | ISSN: 0894-3230 |
| ispartof | Journal of physical organic chemistry, 2024-10, Vol.37 (10) |
| issn | 0894-3230 1099-1395 |
| language | eng |
| recordid | cdi_crossref_primary_10_1002_poc_4647 |
| source | Wiley Online Library |
| title | Positive charge delocalization and anti‐aromaticity of cations generated by protonation of benzo[ a ]fluoranthenes in superacid |
| url | https://sfx.bib-bvb.de/sfx_tum?ctx_ver=Z39.88-2004&ctx_enc=info:ofi/enc:UTF-8&ctx_tim=2025-01-17T17%3A19%3A01IST&url_ver=Z39.88-2004&url_ctx_fmt=infofi/fmt:kev:mtx:ctx&rfr_id=info:sid/primo.exlibrisgroup.com:primo3-Article-crossref&rft_val_fmt=info:ofi/fmt:kev:mtx:journal&rft.genre=article&rft.atitle=Positive%20charge%20delocalization%20and%20anti%E2%80%90aromaticity%20of%20cations%20generated%20by%20protonation%20of%20benzo%5B%20a%20%5Dfluoranthenes%20in%20superacid&rft.jtitle=Journal%20of%20physical%20organic%20chemistry&rft.au=Okazaki,%20Takao&rft.date=2024-10&rft.volume=37&rft.issue=10&rft.issn=0894-3230&rft.eissn=1099-1395&rft_id=info:doi/10.1002/poc.4647&rft_dat=%3Ccrossref%3E10_1002_poc_4647%3C/crossref%3E%3Curl%3E%3C/url%3E&disable_directlink=true&sfx.directlink=off&sfx.report_link=0&rft_id=info:oai/&rft_id=info:pmid/&rfr_iscdi=true |