Singly and Doubly 1,2-Phenylene-Inserted Porphyrin Arch-Tape Dimers: Synthesis and Highly Contorted Structures

Article abstract of DOI:10.1002/anie.201802494

Singly and doubly 1,2-phenylene-inserted Ni^II porphyrin arch-tape dimers 3 and 9 were synthesized from the corresponding β-to-β 1,2-phenylene-bridged Ni^II porphyrin dimers 5 and 11 via Ni⁰-mediated reductive cyclization an

Full text of DOI:10.1002/anie.201802494

Angewandte
Communications
Chemie
International Edition: DOI: 10.1002/anie.201802494
German Edition: DOI: 10.1002/ange.201802494
Porphyrinoids
Singly and Doubly 1,2-Phenylene-Inserted Porphyrin Arch-Tape
Dimers: Synthesis and Highly Contorted Structures
Norihito Fukui and Atsuhiro Osuka*
Abstract: Singly and doubly 1,2-phenylene-inserted NiII
porphyrin arch-tape dimers 3 and 9 were synthesized from
the corresponding b-to-b 1,2-phenylene-bridged NiII porphyrin
dimers 5 and 11 via Ni0-mediated reductive cyclization and
DDQ/Sc(OTf)3-promoted oxidative cyclization as key steps,
respectively. Owing to the fused eight-membered ring(s), 3
showed a more contorted structure than those of previously
reported arch-tape dimers 2a and 2b possessing a fused seven-
membered ring. Furthermore, 9 displayed much larger molec-
ular contortion. As the molecular contortion increases, the Q
band of the absorption spectrum becomes more red-shifted and
the electrochemcial HOMO–LUMO gap becomes smaller,
reaching at 1294 nm and 0.77 eV in 9, respectively. The effect of
molecular contortion on the electronic properties was studied
by means of DFT calculations.
p-conjugation over the whole molecule, as evidenced by the
small optical and electrochemical HOMO–LUMO gaps,
despite the contorted structures. Furthermore, they displayed
characteristic properties such as improved solubilities, effec-
tive C60-binding behaviors, and arch-to-arch inversion dynam-
ics, which have been scarcely seen for porphyrin tapes 1.
From the structural point of view, the origin of the arch-
shaped contortion of 2 can be attributed to the embedded
seven-membered ring that causes a structural strain. Such
a strategy to incorporate seven-membered ring(s) has been
actively employed by a number of researchers.[3] Naturally,
incorporation of an eight-membered ring is expected to give
rise to larger molecular contortion but such examples have
been rather limited, which is probably due to synthetic
difficulty arising from large strains. Indeed, it had required
a period of two decades to accomplish the synthesis of
[8]circulene since the first synthesis of [7]circulene in
1983.[3a,4] To date, benzannulated [8]circulene derivatives[5]
and others[6] have been reported.
S
ince the first discovery in 2001, meso–meso b–b b–b triply
linked porphyrin arrays 1, namely porphyrin tapes, have
attracted considerable attentions owing to the intriguing
properties such as extremely narrow HOMO–LUMO gaps,
large two-photon absorption cross-sections, high single-
molecular conductance, and multi-charge storage capabilities
(Scheme 1).[1] In the porphyrin tapes 1, the component
porphyrin segments are connected by direct triple linkages,
It is widely known that NiII-porphyrins are structurally
flexible and can take non-planar structures such as ruffled and
saddle-like conformations.[7] Actually, the NiII-porphyrin units
of arch-tapes including 2a and 2b take highly ruffled
conformations to disperse the structural strain caused by the
embedded seven-membered ring(s). As a next and more
challenging attempt, we envisioned the incorporation of an
eight-membered ring into the porphyrin tape skeleton.
As the first target molecule, we designed a singly 1,2-
phenylene-inserted porphyrin arch-tape dimer 3. The syn-
thesis of 3 is depicted in Scheme 2. Initially, b-to-b 1,2-
phenylene-bridged porphyrin dimer 5 was synthesized by
Suzuki–Miyaura cross-coupling reaction of 2-iodoporphyrin
4
[8] with 1,2-phenylenediboronic acid bis(pinacol) ester. Then,
Scheme 1. Structures of porphyrin tapes 1 and porphyrin arch-tape
dimers 2a,b.
we examined the synthetic procedure used for the synthesis of
carbonyl-inserted arch-tape dimer 2a.[2] Namely, 5 was
oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone
(DDQ) and Sc(OTf)3. However, this oxidation unexpectedly
produced rearranged product 6 in 59% yield. The X-ray
diffraction analysis has revealed that 6 has a skeleton of meso-
b meso-b doubly linked porphyrin dimer with an additional
1,2-phenylene unit connecting the 3- and 18’-positions (Sup-
porting Information, Figure S65). The structure of 6 indicates
that the oxidation of 5 induced 1,2-migration of the phenylene
bridge to the neighboring b-position. Although the reaction
mechanism remained unclear, meso–meso bond formation
would be avoided to prevent the formation of a more strained
eight-membered ring and instead a less strained six-mem-
bered ring was formed, which might trigger the observed
rearrangement (Supporting Information, Scheme S1).
giving rise to highly planar structures with full conjugation. In
contrast, we recently succeeded in the development of an
arch-shaped molecular contortion by inserting carbonyl
group(s) or methylene group(s) between one of the b–b
linkages of porphyrin tapes.[2] Importantly, the resulting
porphyrin arch-tapes such as 2a and 2b preserved effective
[*] N. Fukui, Prof. Dr. A. Osuka
Department of Chemistry, Graduate School of Science
Kyoto University, Sakyo-ku, Kyoto 606-8502 (Japan)
E-mail: osuka@kuchem.kyoto-u.ac.jp
Supporting information and the ORCID identification number(s) for
the author(s) of this article can be found under:
https://doi.org/10.1002/anie.201802494.
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
1
These are not the final page numbers!

Angewandte
Communications
Chemie
crystal structure, the two porphyrin units are crystallograph-
ically equivalent, taking a ruffled conformation with a mean
plane deviation (MPD)[12] of 0.406 ꢀ. The dihedral angle
between the two porphyrin units is 1138, which is smaller than
those of 2a (1318) and 2b (1248) (Supporting Information,
Figure S67). Moreover, the inserted 1,2-phenylene unit is
almost perpendicular to the fused diporphyrin segment with
a dihedral angle of 848. These structural features of 3 suggest
increased structural strain due to the embedded eight-
membered ring as compared with those of 2a and 2b.
As an extension, we designed doubly 1,2-phenylene-
inserted arch-tape dimer 9. The synthesis of 9 is shown in
Scheme 3. The Suzuki–Miyaura cross-coupling reaction of
Scheme 2. Synthesis of singly 1,2-phenylene-inserted arch-tape dimer
3. Reaction conditions: i) 1,2-phenylenediboronic acid bis(pinacol)
ester, chloro(2-dicyclohexylphosphino-2’,6’-dimethoxy-1,1’-biphenyl)[2-
(2’-amino-1,1’-biphenyl)]palladium(II) (SPhos-Pd-G2), K3PO4, THF/
H2O, 658C, 9 h, 87%; ii) DDQ, Sc(OTf)3, toluene, 608C, 1 h, 59%;
iii) Palau’Chlor, CHCl3, RT, 6 h, 59%; iv) Ni(cod)2, 1,5-cyclooctadiene,
DMF, 1008C, 9 h, 64%; v) DDQ, Sc(OTf)3, toluene, 808C, 2 h, 49%.
Ar=3,5-di-tert-butylphenyl.
Scheme 3. Synthesis of doubly 1,2-phenylene-inserted arch-tape dimer
9. Ar=3,5-di-tert-butylphenyl.
These results indicate that oxidative meso–meso coupling
is unsuitable to install an embedded eight-membered ring.
Thus, we examined a reductive coupling approach as an
alternative route. Treatment of 5 with 2-chloro-1,3-bis(me-
thoxycarbonyl)guanidine (Palau’Chlor)[9] led to meso-selec-
tive chlorination to afford 7 in 59% yield.[10] The subsequent
reductive coupling[11] of 7 with Ni(cod)2 proceeded efficiently
to give meso–meso directly linked b-to-b 1,2-phenylene-
bridged porphyrin dimer 8 in 64% yield. Finally, oxidation
of 8 with DDQ and Sc(OTf)3 furnished the desired 1,2-
phenylene-inserted arch-tape dimer 3 in 49% yield.
2,18-diiodo NiII porphyrin 10 with 1,2-phenylenediboronic
acid bis(pinacol) ester under the Pd/SPhos catalysis furnished
b-to-b doubly 1,2-phenylene-bridged NiII porphyrin dimer 11
in 26% yield. The intermediate 11 was subjected to oxidation
with DDQ and Sc(OTf)3 at high temperature of 1308C. In this
case, formation of rearranged products was not observed and
the desired doubly 1,2-phenylene-inserted arch-tape dimer 9
was obtained in 71% yield.
The structure of 3 has been revealed by X-ray diffraction
analysis (Figure 1). In analogy with the arch-tape dimers 2a
and 2b, 3 exhibits an arch-shaped molecular shape. In the
The structure of 9 was unambiguously determined by X-
ray diffraction analysis (Figure 2). Owing to the large
structural strain caused by the two incorporated eight-
Figure 1. X-Ray crystal structure of 3.[18] a) Top and b) side views.
Ellipsoids are drawn at the 50% probability level. Solvent molecules,
tert-butyl groups, and all hydrogen atoms are omitted for clarity.
Figure 2. X-Ray crystal structure of 9.[18] a) Diagonal and b) side views.
Ellipsoids are drawn at the 50% probability level. Solvent molecules,
tert-butyl groups, and all hydrogen atoms are omitted for clarity.
2
www.angewandte.org
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
These are not the final page numbers!

Angewandte
Communications
Chemie
membered rings, 9 displays an extremely contorted structure.
HOMO–LUMO gap (DE) was calculated to be 1.63 eV.
The large structural curvature can be outlined by a small
dihedral angle of 558 between the two porphyrin units. The
MPDs of the two porphyrin units were calculated to be 0.372
and 0.391 ꢀ, indicating that the degree of curvature of the
component porphyrin units is comparable to that of 3.
Furthermore, the inserted 1,2-phenylene units are almost
perpendicular to the fused diporphyrin segment. Therefore,
the conjugative interaction through the 1,2-phenylene units
seems to be negligible.
The UV/Vis/NIR absorption spectra of 2a, 2b, 3, 6, 9, and
12 are shown in Figure 3. The rearranged product 6 displays
split Soret bands at 425 and 512 nm, and a red-shifted Q band
at 740 nm. The observed spectral features are quite similar to
Singly 1,2-phenylene-inserted arch-tape dimer 3 exhibited
three reversible oxidation waves at 0.10, 0.42, and 0.99 V, and
two reversible reduction waves at À1.06 and À1.29 V. The DE
value of 3 (1.16 eV) was smaller than those of 2b (1.31 eV)
and 12 (1.34 eV), and comparable to that of 2a (1.20 eV).
Doubly 1,2-phenylene-inserted arch-tape dimer 9 exhibited
four reversible oxidation waves at À0.16, 0.18, 0.99, and
1.12 V, and two reversible reduction waves at À0.93 and
À1.11 V. Importantly, the first oxidation potential was neg-
atively shifted from that of 3 by 0.26 V while the first
reduction potential was positively shifted by 0.13 V, giving rise
to a remarkably small DE value of 0.77 eV. These results are
in accord with the optical HOMO–LUMO gaps.
Density functional theory (DFT) calculations were con-
ducted at the B3LYP/6-31G(d) (for C,H,N) + LANL2DZ (for
Ni) level using the Gaussian 16 software package (Figure 4;
Figure 3. UV/Vis/NIR absorption spectra of 2a, 2b, 3, 6, 9, and 12 in
CH2Cl2. l=wavelength, e=extinction coefficient, Ar=3,5-di-tert-butyl-
phenyl.
Figure 4. a) Energy diagrams of 2b, 3, and 9. Kohn–Sham orbital
representations of the HOMO and LUMO of b) 3 and c) 9. All of the
calculations were performed at the B3LYP/6-31G(d) (for
C,H,N)+LANL2DZ (for Ni) level. tert-Butyl groups were replaced to
hydrogen atoms to simplify the calculations.
those of a meso-b meso-b doubly linked porphyrin dimer,[1c]
suggesting negligible electronic perturbation by the inserted
1,2-phenylene unit. The small conjugative interaction through
the phenylene unit has been supported by the theoretical
calculations (Supporting Information, Figure S78). Singly 1,2-
phenylene-inserted arch-tape dimer 3 exhibits split Soret
bands at 412, 535, and 566 nm, and a largely red-shifted Q
band at 927 nm. The optical HOMO–LUMO gap of 3 is
apparently smaller than those of methylene-inserted arch-
tape dimer 2b and porphyrin tape dimer 12, and comparable
to that of carbonyl-inserted arch-tape dimer 2a. Interestingly,
doubly 1,2-phenylene-inserted arch-tape dimer 9 displays
a more red-shifted absorption spectrum, with a Q band at
1249 nm. It is worth noting that the intensity of a low-energy
Soret band decreases as the molecular contortion increases,
which may be attributed to decreased transition dipole
moment along the longer molecular axis.
The electrochemical properties of 3, 5–9, and 11 were
examined by cyclic voltammetry and differential pulse
voltammetry (Supporting Information, Figures S68–S74).
The selected redox potentials are listed in the Supporting
Information, Table S2 along with those of 2a, 2b, and 12. The
rearranged product 6 displayed three reversible oxidation
waves at 0.28, 0.62, and 0.93 V, and two slightly irreversible
reduction waves at À1.35 and À1.60 V. The electrochemical
Supporting Information, Figure S75).[13] In line with the
experimental results, the HOMO–LUMO gap of 3 (1.63 eV)
was calculated to be smaller than those of 2b (1.80 eV) and 12
(1.78 eV), and comparable to that of 2a (1.66 eV). Further-
more, the smallest HOMO–LUMO gap of 1.25 eV was
calculated for 9. Our previous report attributed the small
HOMO–LUMO gap of 2a to an active conjugative involve-
ment of the inserted carbonyl group.[2] In the cases of 3 and 9,
however, the Kohn–Sham orbital representations show no
involvement of the inserted 1,2-phenylene parts in the
HOMOs and LUMOs (Figure 4b,c), which is rather similar
to methylene-bridged arch-tape dimer 2b. As compared with
2b, the HOMOs of 3 and 9 are destabilized by 0.090 and
0.334 eV, respectively, and the LUMOs are stabilized by 0.081
and 0.217 eV, respectively (Figure 4a). These results suggest
that the increase of molecular contortion significantly
decreases the HOMO–LUMO gap.
Investigation into the effect of structural curvature on
electronic properties of p-electronic systems has been an
attractive research topic in modern physical organic chemis-
try. Bodwell and co-workers actively explored curved pyrene-
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
3
These are not the final page numbers!

Angewandte
Communications
Chemie
and teropyrene-derivatives with changing the degree of
curvature.[14] Especially, they revealed that the HOMO–
LUMO gaps of curved teropyrene-derivatives were widened
as the molecular curvature increased, which is opposite to the
trend observed in the present research.[14b] Thus, the observed
tendency that more contorted porphyrin arch-tape dimers
exhibited narrower HOMO–LUMO gaps is characteristic of
the porphyrin arch-tapes.
The stabilization of LUMO is attributable to more
effective through-space interaction between the b-positions
accompanied with the decrease of a dihedral angle between
the two porphyrin planes. Indeed, overlap of p-orbitals at the
b-positions became larger in 9 rather than 3 (Supporting
Information, Figure S80). Meanwhile, it is known that struc-
turally distorted porphyrins exhibit higher HOMO levels.[15]
Marchon, Medforth, Shelnutt, and co-workers claimed that
interrupted bonding interaction between the meso- and a-
positions should be responsible for HOMO destabilization.[16]
Indeed, the HOMOs of various distorted porphyrins have
2b ((3.48 Æ 0.12) ꢂ 104 LmolÀ1), respectively. These results
indicate that the highly contorted structure of 3 is more
suitable for the interaction with the curved p-surface of C60. In
contrast, addition of C60 to a dilute toluene solution of 9
caused no distinguishable spectral changes probably because
the inner cavity of 9 is too narrow to capture C60 (Supporting
Information, Figure S82).
The arch-tape dimer 2b has been reported to undergo
arch-to-arch inversion with a barrier of 13.3 kcalmolÀ1 at
308C.[2] To investigate the arch-to-arch inversion barrier of 3
and 9, mesityl-substituted analogue 3Mes and 9Mes were
newly prepared (Supporting Information, Scheme S2). Inter-
estingly, the signals that are due to the ortho-methyl groups of
the mesityl groups were observed as two sharp singlets at 2.13
and 1.57 ppm for 3Mes and 1.99 and 1.60 ppm for 9Mes even
at 1458C (Supporting Information, Figures S83 and S84).
These results indicate that the arch-to-arch inversion barriers
of 3Mes and 9Mes at 1458C are higher than 20 kcalmolÀ1,[17]
and they do not undergo arch-to-arch inversion on the NMR
time scale at room temperature. The observed large activation
energies can be attributed to the increased structural con-
tortion.
À
À
been demonstrated to be more destabilized as a Ca Cmeso
À
Ca N torsion angle q increases. The q values and HOMO
energy levels of 2b, 3, 9, and 12 in the optimized structures are
summarized in Figure 5. These results suggest that the
In summary, 1,2-phenylene-inserted arch-tape dimers 3
and 9 were synthesized from b-to-b 1,2-phenylene-bridged
porphyrin dimers 5 and 11, respectively. Owing to the large
structural strain imposed by the embedded eight-membered
ring(s), 3 and 9 display more contorted structures as
compared with carbonyl- and methylene-inserted arch-tape
dimers 2a and 2b. As the molecular contortion increases,
HOMO–LUMO gap becomes smaller, reaching at a remark-
ably small value in 9. The DFT calculations have suggest that
1) the inserted 1,2-phenylene parts are not conjugated with
the electronic networks of the porphyrins; 2) the effective
through-space interaction between the phenylene-substituted
b-positions stabilizes the LUMOs; and 3) the contorted
structures cause the high-lying HOMO levels. Further
attempts to explore novel arch-shaped porphyrin tapes by
inserting different segments are actively in progress in our
laboratory and will be reported elsewhere.
1
2
À
À À
Figure 5. Ca Cmeso Ca N torsion angles (q and q ) and HOMO
energy levels of 2b, 3, 9, and 12. All calculations were performed at
the B3LYP/6-31G(d) (for C,H,N) + LANL2DZ (for Ni) level. tert-Butyl
groups were replaced to hydrogen atoms to simplify the calculations.
Acknowledgements
HOMO levels become more destabilized as the q values
increase. Namely, the introduction of large inserted units
between the b-positions results in large tilts of the neighbor-
ing pyrrole units, which remarkably destabilizes the HOMO
levels of the porphyrins by interrupting the bonding inter-
action between the meso- and a-positions.
This work was supported by Grants-in-Aid from JSPS (Nos.:
25220802 (Scientific Research (S)), 16K13952 (Exploratory
Research). N.F. acknowledges a JSPS Fellowship for Young
Scientists. The authors acknowledge Prof. Dr. Hideki Yor-
imitsu (Kyoto University) for the HRMS measurement.
The arch-shaped structures of 2a and 2b were reported to
capture C60 effectively.[2] Thus, we examined the complexation
behaviors of 3 and 9 with C60. Addition of C60 to a dilute
toluene solution of 3 caused distinct spectral changes
(Supporting Information, Figure S81a). The complexation
stoichiometry was confirmed to be 1:1 by Jobꢁs plot (Support-
ing Information, Figure S81b), and the curve fitting of [C60]total
versus DAbs at 922 nm gave an association constant K of
(1.07 Æ 0.02) ꢂ 105 LmolÀ1, which is about ten times and three
times larger than those of 2a ((1.03 Æ 0.02) ꢂ 104 LmolÀ1) and
Conflict of interest
The authors declare no conflict of interest.
Keywords: curved p-conjugated networks ·
eight-membered rings · NIR-absorption · phenylenes ·
porphyrinoids
4
www.angewandte.org
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
These are not the final page numbers!

Angewandte
Communications
Chemie
[7] The Porphyrin Handbook, Vol. 3 (Eds.: K. M. Kadish, K. M.
Smith, R. Guilard), Academic Press, San Diego, 2000.
[8] K. Fujimoto, H. Yorimitsu, A. Osuka, Org. Lett. 2014, 16, 972.
[9] R. A. Rodriguez, C.-M. Pan, Y. Yabe, Y. Kawamata, M. D.
Eastgate, P. S. Baran, J. Am. Chem. Soc. 2014, 136, 6908.
[10] A recent study demonstrated that chlorination of a b-substituted
porphyrin underwent regioselectively at the most reactive meso-
position despite the steric hindrance by the neighboring b-
substituent. N. Fukui, H. Yorimitsu, A. Osuka, Angew. Chem.
Int. Ed. 2015, 54, 6311; Angew. Chem. 2015, 127, 6409.
[11] a) X.-Q. Lu, Y. Guo, Q.-Y. Chen, Synlett 2011, 1, 77; b) M.
Kitano, J. Sung, K. H. Park, H. Yorimitsu, D. Kim, A. Osuka,
Chem. Eur. J. 2013, 19, 16523; c) N. Fukui, S.-K. Lee, K. Kato, D.
Shimizu, T. Tanaka, S. Lee, H. Yorimitsu, D. Kim, A. Osuka,
Chem. Sci. 2016, 7, 4059.
[12] The mean planes are defined by the 24 core atoms consisting of
meso-carbons and four pyrrole units.
[13] M. J. Frisch et al., Gaussian 16, Revision A.03; Gaussian, Inc.:
Wallingford, CT, 2016.
[14] a) G. J. Bodwell, J. N. Bridson, M. K. CyraÇski, J. W. J. Kennedy,
T. K. Krygowski, M. R. Mannion, D. O. Miller, J. Org. Chem.
2003, 68, 2089; b) B. L. Merner, K. S. Unikela, L. N. Dawe, D. W.
Thompson, G. J. Bodwell, Chem. Commun. 2013, 49, 5930.
[15] K. M. Barkigia, L. Chantranupong, K. M. Smith, J. Fajer, J. Am.
Chem. Soc. 1988, 110, 7566.
[1] a) A. Tsuda, H. Furuta, A. Osuka, Angew. Chem. Int. Ed. 2000,
39, 2549; Angew. Chem. 2000, 112, 2649; b) A. Tsuda, A. Osuka,
Science 2001, 293, 79; c) A. Tsuda, H. Furuta, A. Osuka, J. Am.
Chem. Soc. 2001, 123, 10304; d) H. S. Cho, D. H. Jeong, S. Cho,
D. Kim, Y. Matsuzaki, K. Tanaka, A. Tsuda, A. Osuka, J. Am.
Chem. Soc. 2002, 124, 14642.
[2] N. Fukui, T. Kim, D. Kim, A. Osuka, J. Am. Chem. Soc. 2017,
139, 9075.
[3] Selected examples: a) K. Yamamoto, T. Harada, M. Nakazaki, J.
Am. Chem. Soc. 1983, 105, 7171; b) J. Luo, X. Xu, R. Mao, Q.
Miao, J. Am. Chem. Soc. 2012, 134, 13796; c) E. U. Mughal, D.
Kuck, Chem. Commun. 2012, 48, 8880; d) K. Kawasumi, Q.
Zhang, Y. Segawa, L. T. Scott, K. Itami, Nat. Chem. 2013, 5, 739;
e) A. Pradhan, P. Dechambenoit, H. Bock, F. Durola, J. Org.
˙
´
Chem. 2013, 78, 2266; f) M. Zyła, E. Gonka, P. J. Chmielewski, J.
´
´
Cybinska, M. Ste˛pien, Chem. Sci. 2016, 7, 286; g) I. R. Mꢃrquez,
N. Fuentes, C. M. Cruz, V. Puente-MuÇoz, L. Satorrios, M. L.
Marcos, D. Choquesillo-Lazarte, B. Biel, L. Crovetto, E. Gꢄmez-
Bengoa, M. T. Gonzꢃlez, R. Martin, J. M. Cuerva, A. G.
CampaÇa, Chem. Sci. 2017, 8, 1068.
[4] C.-N. Feng, M.-Y. Kuo, Y.-T. Wu, Angew. Chem. Int. Ed. 2013, 52,
7791; Angew. Chem. 2013, 125, 7945.
[16] R. E. Haddad, S. Gazeau, J. Pꢅcaut, J.-C. Marchon, C. J.
Medforth, J. A. Shelnutt, J. Am. Chem. Soc. 2003, 125, 1253.
[17] F. P. Gasparro, N. H. Kolodny, J. Chem. Educ. 1977, 54, 258.
[18] CCDC 1587765 (3), 1587764 (6), and 1824554 (9) contain the
supplementary crystallographic data for this paper. These data
are provided free of charge by The Cambridge Crystallographic
Data Centre.
[5] a) Y. Sakamoto, T. Suzuki, J. Am. Chem. Soc. 2013, 135, 14074;
b) R. W. Miller, A. K. Duncan, S. T. Schneebeli, D. L. Gray,
A. C. Whalley, Chem. Eur. J. 2014, 20, 3705; c) R. W. Miller, S. E.
Averill, S. J. V. Wyck, A. C. Whalley, J. Org. Chem. 2016, 81,
12001; d) K. Y. Cheung, C. K. Chan, Z. Liu, Q. Miao, Angew.
Chem. Int. Ed. 2017, 56, 9003; Angew. Chem. 2017, 129, 9131.
[6] a) Y. Zhen, W. Yue, Y. Li, W. Jiang, S. D. Motta, E. D. Donato, F.
Negri, S. Ye, Z. Wang, Chem. Commun. 2010, 46, 6078; b) L.
Hao, C. Xiao, J. Zhang, W. Jiang, W. Xu, Z. Wang, J. Mater.
Chem. C 2013, 1, 7812; c) W. Jiang, L. Ye, X. Li, C. Xiao, F. Tan,
W. Zhao, J. Hou, Z. Wang, Chem. Commun. 2014, 50, 1024;
d) C.-N. Feng, W.-C. Hsu, J.-Y. Li, M.-Y. Kuo, Y.-T. Wu, Chem.
Eur. J. 2016, 22, 9198.
Manuscript received: February 27, 2018
Accepted manuscript online: March 26, 2018
Version of record online: && &&, &&&&
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
5
These are not the final page numbers!

Angewandte
Communications
Chemie
Communications
Porphyrinoids
Arch-shaped NiII porphyrin tapes with
single and double 1,2-phenylene inser-
tions were prepared. These porphyrin
arch-tapes display highly contorted
N. Fukui, A. Osuka*
&&&& — &&&&
Singly and Doubly 1,2-Phenylene-Inserted
Porphyrin Arch-Tape Dimers: Synthesis
and Highly Contorted Structures
structures owing to the presence of the
embedded eight-membered ring(s). The
more contorted doubly inserted dimer
exhibits the lowest energy Q-band at
1294 nm and a remarkably small electro-
chemical HOMO–LUMO gap of 0.77 eV.
6
www.angewandte.org
ꢀ 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
Angew. Chem. Int. Ed. 2018, 57, 1 – 6
These are not the final page numbers!