Facile Oxidative Rearrangement of Dispiro-Porphodimethenes to Nonplanar and Sheetlike Porphyrins with Intense Absorptions in the Near-IR Region

Article abstract of DOI:10.1002/anie.200352762

Exceedingly large, planar porphyrin systems composed of 49 non-hydrogen nuclei in highly delocalized it systems display exceptionally low-energy transitions in UV/Vis/NIR spectroscopy and in cyclic voltammetry. The spectra shown are for cis palladium comp

Full text of DOI:10.1002/anie.200352762

Angewandte
Chemie
Small-Bandgap Porphyrins
Facile Oxidative Rearrangement of Dispiro-
Porphodimethenes to Nonplanar and Sheetlike
Porphyrins with Intense Absorptions in the Near-
IR Region**
Hubert S. Gill, Michael Harmjanz, Javier Santamaría,
Isaac Finger, and Michael J. Scott*
The spectroscopy, redox potentials, spin states, and axial
coordination chemistry of metalloporphyrins, chlorins, and
related compounds can be modulated through distortions in
planarity or the presence of exocyclic ring systems fused to
the periphery of the macrocycle. In biological systems, the
reactivity and properties of tetrapyrrolic macrocycles are
often tuned through subtle combinations of these two
factors.[1] To help elucidate the origins resulting from mod-
ifications to the porphyrin frame, nonplanar porphyrins with
[*] H. S. Gill, Dr. M. Harmjanz, I. Finger, Prof. M. J. Scott
Department of Chemistry and Center for Catalysis
University of Florida
P.O. Box 117200, Gainesville, FL 32611-7200 (USA)
Fax: (+1)352-392-3255
E-mail: mjscott@chem.ufl.edu
Dr. J. Santamaría
Instituto Universitario de Química Organometµlica “Enrique
Moles”
Unidad Asociada al CSIC, Universidad de Oviedo
Juliµn Clavería 8, 33071-Oviedo (Spain)
[**] We thank the Deutsche Forschungsgemeinschaft (postdoctoral
fellowship for M. Harmjanz), the Research Corporation (Research
Innovation Award), and the Alfred P. Sloan Foundation for providing
financial support for this work. Support from the National Science
Foundation (CAREER Award - 9874966) isalso gratefully acknowl-
edged.
Supporting information for thisarticle isavailable on the WWW
under http://www.angewandte.org or from the author.
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DOI: 10.1002/anie.200352762
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485

Communications
unusual symmetries, as well as porphyrins exhibiting p-
and several of the metalated derivatives. In these experi-
ments, irreversible oxidations were observed, with the free
ligands having higher oxidation potentials than the metalated
derivatives by 0.5 Æ 0.2V. [10] Treatment of 1-H2 under various
oxidative conditions resulted in either no reaction or complex
mixtures of often insoluble products. Reactions of 1-Cu and 1-
Pd under the same sets of conditions led to green products
and/or sparingly soluble dark red products. By using light and
an excess of DDQ under anhydrous conditions, we optimized
the conversions of 1-Cu and 1-Pd to the cis and trans isomer
pairs of 2-Cu and 2-Pd to produce high combined yields of the
two isomers (Scheme 1). Photolysis experiments with UV/Vis
monitoring and initial photophysical measurements indicate
photolytic cleavage, likely a Norrish Type I process, for the
initiation of the reaction, but a donor–acceptor adduct with
the oxidant may be the initial step in this pathway.[11] The use
of excess DDQ to rapidly drive the oxidative processes, as
well as the rigorous exclusion of water and alcohols, was
necessary to avoid competitive reactions.[12]
electron delocalization with extremely low-energy electronic
transitions and multiple interacting ring systems, continue to
be desirable synthetic targets.[2] Along with providing theo-
retical insight into these biologically relevant but still poorly
understood phenomena,[3] synthetic porphyrins with small
bandgaps may find practical utility as novel optical, elec-
tronic, or therapeutic materials,[4] while nonplanar porphyrins
with engineered deformations exhibit enhanced properties
for a variety of applications in catalysis[5] and host–guest
chemistry.[6] Herein, we present a straightforward oxidative-
rearrangement method for the conversion of metalloporpho-
dimethenes to intrinsically nonplanar porphyrins with two
exocyclic naphthocycloheptanone ring systems. Further oxi-
dative dehydrogenation generates exceedingly large, almost
perfectly planar porphyrins, bearing bis(naphthoazulenone)
ring systems, in high yield, and to the best of our knowledge,
these compounds exhibit the longest absorption wavelength
reported for monomeric metalloporphyrins.
Presumably due to their predisposition to form the fully
aromatic porphyrin, the porphodimethene macrocycle, a two-
electron reduced form of the porphyrin macrocycle with sp3
carbons at two trans meso positions, has yet to be found in
nature. Until only very recently,[7] porphodimethenes such as
1-H2 (Scheme 1) have been difficult to prepare in the
laboratory.[8,9] Reasoning that the conversion from porphodi-
methenes to porphyrins is a 2e, 2H + process, and given the
considerable driving force for forming the aromatic macro-
cycle, we undertook electrochemical investigations of 1-H2
The Soret bands in the UV/Vis spectra of these unusual
porphyrins appear at lower energy than those of tetraphe-
nylporphyrin and range from 466 nm (trans-2-Pd) to 490 nm
(cis-2*-Cu). The low-energy electronic transitions for these
porphyrins are also quite red-shifted (652nm for cis-2-Pd;
705 nm for trans-2*-Cu) as well as broad and intense (lge =
4.6) in comparison to the Q bands found for typical metal-
loporphyrins. In the solid-state (Figure 1),[13] the trans non-
planar porphyrin, trans-2-Pd, adopts an anti configuration
with respect to the carbonyl groups of the cycloheptanone
moieties. Steric clash of naphthyl (at C22, C33) and pyrrolic
hydrogens (at C7, C17) induces a distortion in the macrocycle,
resulting in a mean deviation of 0.32Š for the 20 carbon
atoms in the porphyrin core from the average plane defined
by the four nitrogen atoms. The macrocycle exhibits a ruffled
B1u deformation with the meso-carbon atoms displaced
alternately above and below this N-normal plane. Both the
nonplanar distortion and the delocalization of electron
density through the fused naphthocycloheptanone ring sys-
tems likely contribute to the bathochromic shifts observed for
porphyrins of the type 2-M and 2*-M.
In addition to multiple reductive currents and one
reversible oxidative wave, cyclic voltammograms of cis-2-Cu
and trans-2-Cu exhibit irreversible oxidations at 1.36 and
1.30 V vs Ag/AgCl, respectively. Chemical treatment of these
porphyrins with oxidants produces poorly soluble products
similar to those obtained from the treatment of 1-Cu and 1-Pd
with strong oxidants. In order to enhance the solubility of the
products, tBu groups were introduced at the 4- and 7-positions
of the acenaphthenequinone precursor, and 1*-H2 was
prepared in the same way as 1-H2 and other dispiro-
porphodimethenes.[9] Although both the syn- and anti-por-
phodimethenes react analogously, the anti isomer was used
exclusively for all reactions reported herein, because 1*-H2 is
easy to isolate.
Scheme 1. Synthetic methodology: a) for M=Cu: Cu(OAc)2, CHCl3/
MeOH, D, 1 h; for M=Pd: [(C6H5CN)2PdCl2], THF, D, 2.5 h; b) hn,
DDQ (2”1.2 equiv), CH2Cl2, RT, 25–120 min; c) DDQ (7.2 equiv),
FeCl3·6H2O (20 equiv), CH2Cl2, D, 5–6 h; d) DDQ (4.8 equiv),
FeCl3·6H2O (10 equiv), CH2Cl2, D, 15 min. DDQ= 2,3-dichloro-5,6-
Metalation of 1*-H2 with Cu or Pd and oxidation to the
corresponding nonplanar butylated cycloheptanone porphyr-
ins proceed as expected. Chromatographic separation of the
isomers for both palladium and copper results in the cis and
trans porphyrins in an approximately 2:1 ratio, as observed for
dicyano-1,4-benzoquinone, RT= room temperature. ImpliesR =tBu,
*
otherwise, R=H.
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with other metals such as Sc(OTf)3 will induce the oxidative
coupling of triarylporphyrins to generate coplanar diporphyr-
ins,[16] and although the Sc(OTf)3/DDQ procedure was not
attempted for the oxidation of 2*-M to 3*-M, numerous other
reagents and conditions were tested. None of these trials
produced the desired products in yields as high as those
achieved with the FeCl3/DDQ procedures described herein,
and the isolation of the porphyrins was often more problem-
atic.
Slow diffusion of diethyl ether into a saturated CH2Cl2
solution of cis-3*-Cu produced single crystals as purple plates
with a green metallic luster. Structure analysis by X-ray
diffraction reveals a relatively planar porphyrin interior, with
a mean deviation of only 0.08(6) Š for the 20 carbon atoms in
the porphyrin core from the average plane defined by the four
nitrogens (Figure 2). The naphthyl moieties at the periphery
of the ring system deviate slightly from this nitrogen plane
with a mean deviation of 0.27(16) Š for the 22 carbon atoms
in the two naphthyl groups (max. deviation 0.53 Š for C26).
These minor deviations are likely induced by packing forces
in the solid state. Interestingly, the largest displacement
(0.78 Š) from the N4 plane in the macrocyclic core is found at
one of the carbonyl oxygens, O2. Many unusual bond angles
are found in this ring system, which, discounting tBu and
mesityl aryl groups, contains 49 non-hydrogen nuclei
arranged as eight six-, six five-, and two seven-membered
Figure 1. a) X-ray structure of trans-2-Pd (ellipsoids at 30% probabil-
ity). Hydrogen atomshave been omitted for clarity. Only one of the
two symmetry-inequivalent porphyrins found in the asymmetric unit
isdepicted. Selected bond lengths[Š] and angles[ 8]: Pd1-N1
1.990(6), Pd1-N2 1.986(7), Pd1-N3 2.005(7), Pd1-N4 2.002(6), N1-
Pd1-N2 88.4(2), N1-Pd1-N3 175.7(2), N1-Pd1-N4 91.2(2). b) Side
view of trans-2-Pd (arbitrary radii for carbon atoms) illustrating the
ruffled deformation of the macrocycle.
the conversion of 1-M to cis- and trans-2-M porphyrins.
Reaction of cis-2*-M with an excess of both DDQ and
FeCl3·6H2O in refluxing CH2Cl2, followed by aqueous
workup and filtration over silica produces the cis-bisnaph-
thoazuleneone porphyrins, cis-3*-M. The flat trans isomer,
trans-3*-M, can be generated similarly from trans-2*-M.
Compared to the conversion of the cis isomers, however,
reaction times are longer,[14] and the procedure requires
additional equivalents of oxidants and a reductive aqueous
workup. The two oxidative processes can be performed in
one pot, generating a mixture of cis- and trans-3*-M
directly from 1*-M, but chromatographic resolution of the
isomer pairs is considerably easier for the 2*-M porphyrins
than for the 3*-M compounds. While oxidative biaryl-
coupling reactions utilizing FeCl3 or DDQ as an oxidant
are common, it seems the only report of their use in
combination involved the deprotection of methoxy phenyl
methyl esters using catalytic amounts of DDQ with excess
FeCl3. In this system, FeIII regenerates the active oxidant
from its reduced form (H2DDQ).[15] DDQ in conjunction
Figure 2. a) Top view and b) side view of the X-ray structure of cis-3*-Cu (30% ellip-
soids). Hydrogen atoms have been omitted for clarity. Selected bond lengths [Š]
and angles[ 8]: Cu-N1 2.002(2), Cu-N2 1.952(2), Cu-N3 1.949(2), Cu-N4 1.997(2),
N1-Cu-N2 92.33(8), N1-Cu-N3 176.86(9).
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Communications
rings, interlocked in a highly delocalized p system, with two
carbonyls in the plane of hybridization. Among the 42sp
reduction potential less negative for trans-3*-Cu (ox1 =
0.73 V, red1 = À0.44 V) than for cis-3*-Cu (ox1 = 0.87 V,
red1 = À0.46 V). Special attention was paid to the difference
in the first 1e oxidation and 1e reduction potentials for the
macrocycles in comparison to the potentials for simple
porphyrins such as CuII tetramesitylporphyrin (CuTMP).
Relative to CuTMP (ox1 = 1.18 V, red1 = À1.36 V), the sepa-
ration between the first reduction and oxidation potentials
are quite small for both cis-3*-Cu and trans-3*-Cu (Figure 4).
Even the second reversible 1e reductions for both trans-3*-
Cu (À0.85 V) and cis-3*-Cu (À0.89 V) occur at potentials far
less negative than the first 1e reduction for CuTMP.
2
carbons in the porphyrin plane, 17 have a bond angle of 1108
or less, and 9 have a bond angle of 1308 or more, with
extremes represented at the C7 and C13 vertices (C8-C7-C6:
104.58(2); C8-C7-C22: 149.88(2)). The distance between the
two furthest separated sp2 carbon atoms (C27, C38) in the
sheetlike macrocycle is 1.69 nm.
The UV/Vis/NIR spectra of these porphyrins display
numerous exceptional features, including low-energy (Q-
type) absorptions with dramatic bathochromic shifts relative
to the absorptions of typical Cu and Pd porphyrins (Figure 3).
Figure 3. UV-Vis/NIR spectra of the sheetlike copper porphyrins trans-
3*-Cu (c) and cis-3*-Cu (a).
All porphyrins of the type 3*-M have a band at ꢀ 450 nm; the
location of the other transitions is metal dependant, with
copper species having spectra further red-shifted than those
of their palladium analogues. Otherwise, the shapes of the
spectra are very similar for each isomer, regardless of the
metal incorporated. For both the cis and trans isomers, the
most intense absorption band (lge = 4.9) occurs in the visible
region (l = 540–579 nm), and these bands approach the
record low-energy Soret absorption of l = 625 nm noted by
Lash and co-workers.[17] In addition to the aforementioned
high-energy bands, the cis isomers exhibit a rather intense
(lge = 4.2), Q-like band at l = 850 nm for cis-3*-Pd and at l =
894 nm for cis-3*-Cu. While the trans isomers have visible
spectra that are only slightly red-shifted relative to the spectra
of their cis counterparts, their Q-like bands exhibit extreme
bathochromic shifts and are split into two less intense
transitions in the near-IR region. For trans-3*-Pd these low-
energy bands are found at l = 994 nm and 1145 nm, and for
trans-3*-Cu they are found at l = 1038 nm and 1204 nm.
Although the absorptions of triply fused, multiporphyrin
tapes have been shown to reach further into the IR
region,[16b,18] the extremely red-shifted transitions observed
for trans-3*-Cu are, to the best of our knowledge, the lowest
energy electronic transitions ever observed for a monomeric
porphyrin species.
Figure 4. Cyclic voltammogram of trans-3*-Cu (bottom) compared to
that of CuTMP (top).
With their tendency to form fully aromatic porphyrins,
dispiro-porphodimethene macrocycles are excellent synthons
for the preparation of distorted porphyrins bearing two
naphthocycloheptanones fused to the macrocycle core as well
as 1.69-nm wide, planar porphyrins with two naphthoazulen-
8-one moieties. These unusual, soluble macrocycles can be
isolated in high yields in one- or two-pot procedures from
metalloporphodimethenes, allowing for the preparation of
large quantities of material. Detailed investigations into the
reactivity and photochemistry of the macrocycles, as well as
the extension of the rearrangement and coupling procedures
to other dispiro-porphodimethenes and biaryl systems,
respectively, are underway.
Experimental Section
Complete experimental details including MS, NMR, and elemental
data for all compounds are available in the Supporting Information.
General procedure for the preparation of bis(naphthocyclohepta-
none) porphyrins 2-M and 2*-M: Metalloporphodimethenes 1-M or
1*-M were treated under an inert atmosphere, with excess DDQ in
anhydrous, degassed CH2Cl2. The solution was irradiated from a
distance of 10 cm with a 20-W halogen light source fitted with a UV
filter. Reaction times varied from 25 min (2-Cu) to 2h ( 2*-Pd).
Reaction mixtures were subsequently diluted with CH2Cl2, washed
with water, and dried over Na2SO4, and the solvents removed. In the
separation by silica gel column chromatography the trans isomers
In light of the spectral features in the NIR region
indicating very small band-gaps, cyclic voltammetric studies
of compounds cis-3*-Cu and trans-3*-Cu were carried out in
benzonitrile. As expected based upon their spectrophotom-
etry, the first oxidation potential was less positive and the first
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eluted as the first major green bands. trans-2-Cu: 36% yield; UV/Vis
(CH2Cl2): lmax (lge) = 470 (5.2), 700 (4.5) nm. cis-2-Cu: 59% yield;
UV/Vis (CH2Cl2): lmax (lge) = 488 (5.2), 678 (4.5) nm. trans-2*-Cu:
32% yield; UV/Vis (CH2Cl2): lmax (lge) = 473 (5.3), 705 (4.6) nm. cis-
2*-Cu: 57% yield; UV/Vis (CH2Cl2): lmax (lge) = 490 (5.3),
681(4.6) nm; trans-2-Pd: 37% yield; UV/Vis (CH2Cl2): l (lge) = 466
(5.3), 674 (4.6) nm; cis-2-Pd: 59% yield (88 mg); UV/Vis (CH2Cl2): l
(lge) = 483 (5.4), 652(4.6) nm. trans-2*-Pd: 32% yield; UV/Vis
(CH2Cl2): lmax (lge) = 470 (5.4), 678 (4.7) nm. cis-2*-Pd: 62% yield;
UV/Vis (CH2Cl2): lmax (lge) = 486 (5.4), 656 (4.6) nm.
S. Dalosto, S. A. Vinogradov, Inorg. Chem. 2002, 41, 6944; p) E.
Sigfridsson, U. Ryde, J. Biol. Inorg. Chem. 2003, 8, 273.
[2] a) L. Barloy, D. Dolphin, D. Dupre, T. P. Wijesekera, J. Org.
Chem. 1994, 59, 7976; b) H. J. Callot, R. Ocampo in The
Porphyrin Handbook, Vol. 1 (Eds.: K. M. Kadish, K. M. Smith,
R. Guilard), Academic, San Diego, 2000, p. 349; c) T. D. Lash in
The Porphyrin Handbook, Vol. 2 (Eds.: K. M. Kadish, K. M.
Smith, R. Guilard), Academic, San Diego, 2000; d) S. Richeter,
C. Jeandon, R. Ruppert, H. J. Callot, Tetrahedron Lett. 2001, 42,
2103; e) H. Aihara, L. Jaquinod, D. J. Nurco, K. M. Smith,
Angew. Chem. 2001, 113, 3547; Angew. Chem. Int. Ed. 2001, 40,
3439; f) S. Richeter, C. Jeandon, J. P. Gisselbrecht, R. Ruppert,
H. J. Callot, J. Am. Chem. Soc. 2002, 124, 6168.
[3] a) A. Forman, M. W. Renner, E. Fujita, K. M. Barkigia, M. C. W.
Evans, K. M. Smith, J. Fajer, Isr. J. Chem. 1989, 29, 57; b) M. O.
Senge, J. Photochem. Photobiol. B 1992, 16, 3; c) T. D. Lash, J.
Porphyrins Phthalocyanines 2001, 5, 267; d) H. Ryeng, A.
Ghosh, J. Am. Chem. Soc. 2002, 124, 8099; e) R. E. Haddad, S.
Gazeau, J. Pecaut, J. C. Marchon, C. J. Medforth, J. A. Shelnutt,
J. Am. Chem. Soc. 2003, 125, 1253.
[4] a) J. G. Moser, A. Ruck, H. J. Schwarzmaier, C. Westphalfrosch,
Opt. Eng. 1992, 31, 1441; b) J. H. Chou, H. S. Nalwa, M. E.
Kosal, N. A. Rakow, S. S. Suslick in The Porphyrin Handbook,
Vol. 6 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard), Academic,
San Diego, 2000, p. 43; c) R. K. Pandey, G. Zheng in The
Porphyrin Handbook, Vol. 6 (Eds.: K. M. Kadish, K. M. Smith,
R. Guilard), Academic, San Diego, 2000, p. 157; d) A. Wiehe, H.
Stollberg, S. Runge, A. Paul, M. O. Senge, B. Roder, J.
Porphyrins Phthalocyanines 2001, 5, 853.
General procedures for the preparation of bis(naphthoazule-
none) porphyrins 3*-M: trans Isomers: A solution of trans-2*-M in
CH2Cl2 was treated with an excess of both DDQ and FeCl3·6H2O. The
mixture was heated at reflux for 6 h, allowed to cool to room
temperature, and decanted. Freshly prepared aqueous NaBH4 was
added to the solution, and the resulting biphasic mixture was stirred.
After dilution with CH2Cl2 and water, the organic phase was
separated, washed with water, dried over Na2SO4, and filtered over
silica (4 ” 4-cm, CHCl3). The solvents were removed, and the residue
was redissolved in o-C6H4Cl2. Addition of hexanes to this solution
causes the precipitation of trans-3*-M as a metallic, red-gray powder.
cis Isomers: The cis isomers, cis-2*-M, were treated in analogy to the
trans isomers, but the reaction times were considerably shorter (15–
20 min) and less of the oxidant mixture was required. Filtration over
silica (6 ” 4-cm, CH2Cl2/hexanes 1:1) and slow removal of the solvents
afforded cis-3*-M as purple-green microcrystalline solids. Normally,
for convenience sake, the reactions were run on scales to produce the
products in approximately 50-mg quantities, but the synthetic
procedures allow for the isolation of the materials in amounts over
a gram. trans-3*-Cu: 90% yield; UV/Vis (CH2Cl2): lmax (lge) = 314
(4.8), 449 (4.8), 519 (4.7), 579 (4.9), 706 (3.8), 1038 (3.9), 1204
(3.9) nm. cis-3*-Cu: 98% yield; UV/Vis (CH2Cl2): lmax (lge) = 308
(4.6), 441 (4.6), 540 (4.9), 894 (4.2) nm. trans-3*-Pd: 92% yield; UV/
Vis (CH2Cl2): lmax (lge) = 307 (4.6), 445 (4.7), 502(4.5), 522(4.5), 567
(4.9), 682(3.8), 994 (3.8), 1145 (3.8) nm. cis-3*-Pd: 96% yield; UV/
Vis (CH2Cl2): lmax (lge) = 285 (4.6), 445 (4.8), 553 (4.9), 850 (4.2) nm.
[5] S. Gazeau, J. Pecaut, R. Haddad, J. A. Shelnutt, J. C. Marchon,
Eur. J. Inorg. Chem. 2002, 2956.
[6] a) M. Mazzanti, J. C. Marchon, M. Y. Shang, W. R. Scheidt, S. L.
Jia, J. A. Shelnutt, J. Am. Chem. Soc. 1997, 119, 12 400; b) S.
Gazeau, J. Pecaut, J. C. Marchon, Chem. Commun. 2001, 1644.
[7] a) J. W. Buchler, L. Puppe, Liebigs Ann. Chem. 1974, 1046b) A.
Botulinski, J. W. Buchler, K. L. Lay, J. Ensling, H. Twilfer, J.
Billecke, H. Leuken, B. Tonn, Adv. Chem. Ser. 1982, 253.
[8] a) V. Krµl, J. L. Sessler, R. S. Zimmerman, D. Seidel, V. Lynch, B.
Andrioletti, Angew. Chem. 2000, 112, 1097; Angew. Chem. Int.
Ed. 2000, 39, 1055; b) L. Bonomo, E. Solari, R. Scopelliti, C.
Floriani, N. Re, J. Am. Chem. Soc. 2000, 122, 5312.c) M. O.
Senge, S. Runge, M. Speck, K. Ruhlandt-Senge, Tetrahedron
2000, 56, 8927; d) J. L. Sessler, R. S. Zimmerman, C. Bucher, V.
Krµl, B. Andrioletti, Pure Appl. Chem. 2001, 73, 1041; e) D. H.
Burns, Y. H. Li, D. C. Shi, T. M. Caldwell, J. Org. Chem. 2002, 67,
4536.
Received: September 1, 2003 [Z52762]
Keywords: fused-ring systems · photochemistry · porphyrinoids ·
.
rearrangements· redox chemistry
[1] a) P. D. Smith, B. R. James, D. H. Dolphin, Coord. Chem. Rev.
1981, 39, 31; b) M. H. Barley, D. Dolphin, B. R. James, J. Chem.
Soc. Chem. Commun. 1984, 1499; c) M. W. Renner, R. J. Cheng,
C. K. Chang, J. Fajer, J. Phys. Chem. 1990, 94, 8508; d) C. J.
Medforth, M. O. Senge, K. M. Smith, L. D. Sparks, J. A. Shel-
nutt, J. Am. Chem. Soc. 1992, 114, 9859; e) W. Jentzen, E. Unger,
X. Z. Song, S. L. Jia, I. Turowska-Tyrk, R. Schweitzer-Stenner,
W. Dreybrodt, W. R. Scheidt, J. A. Shelnutt, J. Phys. Chem. A
1997, 101, 5789; f) J. A. Shelnutt, X. Z. Song, J. G. Ma, S. L. Jia,
W. Jentzen, C. J. Medforth, Chem. Soc. Rev. 1998, 27, 31;
g) M. O. Senge, J. Porphyrins Phthalocyanines 1998, 2, 107;
h) S. L. Jia, W. Jentzen, M. Shang, X. Z. Song, J. G. Ma, W. R.
Scheidt, J. A. Shelnutt, Inorg. Chem. 1998, 37, 4402; i) T. J. Neal,
B. S. Cheng, J. G. Ma, J. A. Shelnutt, C. E. Schulz, W. R. Scheidt,
Inorg. Chim. Acta 1999, 291, 49; j) M. O. Senge in The Porphyrin
Handbook, Vol. 1 (Eds.: K. M. Kadish, K. M. Smith, R. Guilard),
Academic, San Diego, 2000, p. 239; k) K. M. Barkigia, M. W.
Renner, J. Fajer, J. Porphyrins Phthalocyanines 2001, 5,
415,l) M. W. Renner, K. M. Barkigia, D. Melamed, J. P. Gissel-
brecht, N. Y. Nelson, K. M. Smith, J. Fajer, Res. Chem. Intermed.
2002, 28, 741; m) D. J. Nurco, K. M. Smith, J. Fajer, Chem.
Commun. 2002, 2982; n) L. N. Todd, M. Zimmer, Inorg. Chem.
2002, 41, 6831; o) O. S. Finikova, A. V. Cheprakov, P. J. Carroll,
[9] a) M. Harmjanz, M. J. Scott, Chem. Commun. 2000, 397; b) M.
Harmjanz, H. S. Gill, M. J. Scott, J. Org. Chem. 2001, 66, 5374;
c) M. Harmjanz, I. Bozidarevic, M. J. Scott, Org. Lett. 2001, 3,
2281.
[10] We measured a reversible oxidation at 0.94 V for the Cu(ca-
lix[4]phyrin) prepared by Sessler and co-workers (ref. [8a]).
[11] O. L. Chapman, D. S. Weiss in Organic Photochemistry, Vol. 3,
(Ed.: O. L. Chapman), Dekker, New York, 1973, p. 197.
[12] Details of some of these competitive reactions will be published
in an upcoming paper.
[13] Crystal structure data for trans-2-Pd·2CHCl3·1= C5H12: mono-
4
clinic, space group P21/c, a = 12.085(3), b = 31.100(8), c =
28.596(7) Š, b = 98.472(4)8, V= 10630(4) Š3, T= 193 K, Z = 8,
, , 50631 reflections
1cald = 1.555 gcmÀ3 m(MoKa) = 0.702mm À1
collected, 16688 unique, of which 8508 with I > 2s were used
in the refinement. R1 = 0.0700 [I > 2s(I)], wR2 = 0.1543, GOF =
0.902for 1307 parameters. Crystal structure data for cis-3*-
Cu·2CH2Cl2·1= Et2O: monoclinic, space group C2/c, a =
2
29.5740(14), b = 12.4738(6), c = 41.109(2) Š, b = 100.309(1)8,
V= 14920.3(12) Š3, T= 193 K, Z = 8, 1cald = 1.193 gcmÀ3
,
m(MoKa) = 0.484 mmÀ1
,
45023 reflections collected, 14679
Angew. Chem. Int. Ed. 2004, 43, 485 –490
www.angewandte.org
ꢀ 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
489

Communications
unique, of which 10048 with I > 2s were used in the refinement.
R1 = 0.0558 [I > 2s(I)], wR2 = 0.1550, GOF = 1.098 for 811
parameters. CCDC-218523 (trans-2-Pd) and CCDC-218524
(cis-3*-Cu) contain the supplementary crystallographic data
for this paper. These data can be obtained free of charge via
www.ccdc.cam.ac.uk/conts/retrieving.html (or from the Cam-
bridge Crystallographic Data Centre, 12, Union Road, Cam-
bridge CB21EZ, UK; fax: (+ 44)1223-336-033; or deposit@
ccdc.cam.ac.uk).
À
[14] For the trans isomers, the partially oxidized (2H+, 2 e ) species
with one naphthocycloheptanone and one naphthoazulenone
peripheral group have been isolated. The details of the synthesis
of these intermediates and their properties are forthcoming.
[15] S. Chandrasekhar, G. Sumithra, J. S. Yadav, Tetrahedron Lett.
1996, 37, 1645.
[16] a) M. D. Watson, A. Fechtenkꢀtter, K. Mꢁllen Chem. Rev. 2001,
101, 1267; b) M. Kamo, A. Tsuda, Y. Nakamura, N. Aratani, K.
Furukawa, T. Kato, A. Osuka, Org. Lett. 2003, 5, 2079.
[17] J. D. Spence, T. D. Lash, J. Org. Chem. 2000, 65, 1530.
[18] a) A. Tsuda, A. Osuka, Science 2001, 293, 79; b) 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; c) D. H. Yoon, S. B.
Lee, K. H. Yoo, J. Kim, J. K. Lim, N. Aratani, A. Tsuda, A.
Osuka, D. Kim, J. Am. Chem. Soc. 2003, 125, 11062.
490
ꢀ 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim
www.angewandte.org
Angew. Chem. Int. Ed. 2004, 43, 485 –490