Structural Characterization of Meso Aryl Sapphyrins

Full text of DOI:10.1021/jo990729u

J . Org. Chem. 1999, 64, 8693-8697
8693
Notes
Sch em e 1. Syn th esis of Cor e Mod ified Meso Ar yl
Str u ctu r a l Ch a r a cter iza tion of Meso Ar yl
Sa p p h yr in s
Sa p p h yr in s
Alagar Srinivasan, Anand V. G.,
S. J eyaprakash Narayanan, Simi K. Pushpan,
M. Ravi Kumar, and Tavarekere K. Chandrashekar*
Department of Chemistry, Indian Institute of Technology,
Kanpur, U.P. 208 016, India
Ken-ichi Sugiura and Yoshiteru Sakata
Institute of Scientific and Industrial Research, Osaka
University, Osaka 567, J apan
Received April 30, 1999
Studies on expanded porphyrins are receiving in-
creased attention in view of their diverse applications.1
Among the expanded porphyrins, the chemistry of â-sub-
stituted sapphyrins has been well studied because of the
availability of easy and efficient synthetic methods.2 In
contrast, the meso aryl sapphyrin 1 was isolated only
recently as a byproduct in 1% yield in the Rothemund
reaction.3 Later studies from Dolphin’s group,4 Latos-
Grazynski’s group,3,6 and from this laboratory5 have
reported synthesis of a variety of meso aryl sapphyrins.
Unlike â-substituted sapphyrins, the meso aryl sapphy-
rins show structural diversity.3 On the basis of spectro-
scopic studies, Latos-Grazynski3,6a and co-workers sug-
gested that 1 has an inverted structure in its free base
form in which the pyrrole ring opposite to the bipyrrole
unit is inverted and on protonation a 180° ring flipping
takes place to get a planar structure. Recent spectroscopic
and X-ray structural data from this laboratory5b sug-
gested that 3 and 4 has a planar structure where the
pyrrole ring opposite to bipyrrole is not inverted and
protonation does not lead to any structural change. On
the other hand, spectroscopic data7 reveal that meso aryl
sapphyrins 5a -5e (Chart 1) exhibit an inverted structure
* Corresponding author. Telefax: Int. code + (512) 590 007/597 436.
e-mail: tkc@iitk.ernet.in.
(1) (a) Sessler, J . L.; Weghorn, S. J . Expanded, Contracted and
Isomeric Porphyrins; Elsevier: Oxford, 1997. (b) J asat, A.; Dolphin,
D. Chem. Rev. 1997, 97, 2267-2340 and references therein.
(2) (a) Sessler, J . L.; Lisowski, K. A.; Boudreaux, K. A.; Lynch, V.;
Barry, J .; Kodadek, T. J . J . Org. Chem. 1995, 60, 5975-5978. (b)
Paolesse R.; Licoccia, S.; Spagnoli, M.; Boschi, T.; Khoury, R. G.; Smith,
K. M. J . Org. Chem. 1997, 62, 5133-5137. (c) Lash, T. D.; Richter, D.
T. J . Am. Chem. Soc. 1998, 120, 9965-9966.
(3) Chmielewski, P. J .; Latos-Grazynski, L.; Rachlewicz, K. Chem.
Eur. J . 1995, 1, 68-73.
(4) Bruckner, C.; Sternberg, E. D.; Boyle, R. W.; Dolphin, D. J . Chem.
Soc., Chem. Commun. 1997, 1689-1690.
where the heterocyclic ring opposite to bithiophene unit
is inverted and protonation does not show any of the ring
flipping observed for 1. To understand the reasons and
the circumstances which lead to ring inversion, we have
synthesized a new series of sapphyrins 6a -6e and solved
first single-crystal X-ray structures of two inverted
sapphyrins 5e and 6b. In addition, in this paper we
report a comparative X-ray structural data as well as
spectroscopic data. The data analysis reveal that larger
core sizes and the presence of small heteroatoms
(N or O) adjacent to the heterocyclic ring lead to inverted
structures, while the presence of bigger heteroatoms
(5) (a) Srinivasan, A.; Mahajan, S.; Pushpan, S. K.; Ravi Kumar,
M.; Chandrashekar, T. K. Tetrahedron Lett. 1998, 39, 1961-1964. (b)
J eyaprakash Narayanan, S.; Sridevi, B.; Chandra shekar, T. K.; Vij,
A.; Roy, R. Angew. Chem., Int. Ed. 1998, 37, 3394-3397. (c) Jeyaprakash
Narayanan, S.; Sridevi, B.; Srinivasan, A.; Chandrashekar, T. K.; Roy,
R. Tetrahedron Lett. 1998, 39, 7389-7392. (d) Pushpan, S. K.;
J eyaprakash Narayanan, S.; Srinivasan, A.; Mahajan, S.; Chan-
drashekar, T. K.; Roy, R. Tetrahedron Lett. 1998, 39, 9249-9252.
(6) (a) Rachlewicz, K.; Sprutta, N.; Latos-Grazynski, L.; Chmielews-
ki, P. J .; Szterenberg, L. J . Chem. Soc., Perkin Trans. 2 1998, 959-
968. (b) Rachlewicz, K.; Sprutta, N.; Chmielewski, P. J .; Latos-
Grazynski, L, J . Chem. Soc., Perkin Trans. 2 1998, 969-975.
(7) Srinivasan, A.; Pushpan, S. K.; Ravi Kumar, M.; Mahajan, S.;
Chandrashekar, T. K.; Roy, R.; Ramamurthy, P. J . Chem. Soc., Perkin
Trans. 2 1999, 961-968.
10.1021/jo990729u CCC: $18.00 © 1999 American Chemical Society
Published on Web 10/23/1999

8694 J . Org. Chem., Vol. 64, No. 23, 1999
Notes
Ch a r t 1
Ta ble 1. 1H NMR Ch em ica l Sh ifts of â-CH P r oton s of th e
Ta ble 2. Selected X-r a y Str u ctu r a l Da ta for P la n a r a n d
In ver ted Rin g befor e a n d a fter P r oton a tion
In ver ted Meso Ar yl Sa p p h yr in s
free base
(ppm)
dicationb
(ppm)
bond lengths (Å)
compd
inverted ring
pyrrole
∆δ
compd
ring
pyrrole
pyrrole
selenophene
N-methylpyrrole
CR-Xb
CR-Câ
Câ-Câ
5a
6a
1a
5b
6b
5c
6c
2a
5d
6d
5e
6e
-0.84
-0.55
-1.49
-1.15
-0.36
0.61
9.70
9.54
11.60
10.03
9.34
9.18
9.13
10.64
9.40
9.47
9.10
9.58
-1.06
-0.32
8.58
-1.09
-0.38
0.31
-0.31
-2.20
-1.20
-0.65
-1.17
-0.98
3a
4a
5e
6b
1.361(5)
1.366(6)
1.907(6)
1.383(5)
1.451(6)
1.446(7)
1.406(7)
1.411(6)
1.337(6)
1.328(7)
1.338(8)
1.378(6)
N-methylpyrrole
furan
nonbonded distances (Å)
0.31
3a
26S‚‚‚‚‚‚‚‚‚‚28S
26Se‚‚‚‚‚‚‚‚‚‚28Se
26N‚‚‚‚‚‚‚‚‚‚28N
26N‚‚‚‚‚‚‚‚‚‚28N
4.346
-0.85
-0.73
-0.68
-0.27
-0.82
4a
3.932
6.449
6.403
thiophene
5e
6b
selenophene
torsion angles (deg)
a
b
Data taken from refs 3 and 6b, respectively. Dications are
generated by adding a dilute solution of CF3COOH in CDCl3.
13C-14C-15C-16C
13C-14C-15C-Xb
3a
4a
5e
6b
168.5(4)
170.0(5)
7.6(8)
-11.1(6)
-9.1(8)
-165.0(4)
-149.0(4)
(S or Se) leads to planar structures. NMR data indicates
that the inverted structures show reduced diatropic ring
currents.
35.3(7)
a
b
Data taken from ref 5b. X: N1 or Se1 or N2.
Resu lts a n d Discu ssion
2). The sapphyrin skeleton show small deviation from
planarity; the deviation of meso carbons for 6b8 are
C(9) -0.035(4), C(14) 0.051(4), C(19) -0.049(4), C(24)
0.031(4) except for the pyrrole ring containing N-methyl
group. The pyrrole ring is inverted where the N-methyl
group is pointing away from the macrocyclic ring. The
â-CH protons of this ring are near the ring current region
consistent with the solution1H NMR chemical shifts. The
dihedral angle between the N-methyl pyrrole ring and
the mean plane of the sapphyrin is 46.48°. For 5e,9 the
deviations for meso carbons are C(9) 0.094(5), C(14)
-0.133(5), C(19) 0.139(5), C(24) -0.091(5) except for the
selenophene ring which is inverted, and the selenium
atom is pointing away from the ring current of the
macrocycle while the â-CH protons are experiencing the
ring current of the macrocycle. The dihedral angle
between the inverted selenophene ring and the mean
plane of the sapphyrin is 20.56°.
The synthesis of core-modified meso aryl sapphyrins
6a -6e was accomplished by a TFA-catalyzed condensa-
tion reaction between biselenophene diol 8 with modified
tripyrranes 9a -9e7 followed by chloranil oxidation
(Scheme 1).1H NMR, analytical, mass, and UV-visible
spectral data are consistent with the proposed composi-
tion.
The first clue that the heterocyclic ring opposite to the
bipyrrole, bithiophene, and biselenophene unit is inverted
came from chemical shift observed for â-CH protons of
the inverted ring (Table 1). It is seen from Table 1 that
the â-CH protons of the inverted ring are highly shielded
and appear in the range from +0.61 ppm to -1.49 ppm,
suggesting that these protons are experiencing the ring
current of the macrocycle. Upon protonation, there are
only small differences in the chemical shift of these
protons, suggesting that the heterocyclic ring remains
inverted on protonation. This observation is in total
contrast to that observed for 1 where dramatic shielding
and deshielding of pyrrole NH and â-CH protons sug-
gested the 180° ring flipping to get back the planar
structure.3,6a The ∆δ values3 which represent the extent
of aromaticity are reduced considerably in the inverted
sapphyrins relative to 3 and 4 which show a planar
structure (∆δ value for 3 and 4 are 14.87 and 15.32,
respectively).5b,6b
(8) Crystal data for 6b: C50H34N3Se2Cl3, crystal from CHCl3:CH3-
OH (1:1), crystal dimensions 0.50 × 0.25 × 0.20 mm, M ) 941.12,
monoclinic, space group P21/n, a ) 17.1534(3), b ) 9.8246(3), c )
25.0922(6) Å, â ) 106.151(1)°, V ) 4061.8(2) Å3, Z ) 4, Dc ) 1.539
g/cm3, F(000) ) 1896, T ) 199 K, µ(Mo KR) ) 20.59 cm-1, 6826
reflections, [I > 3.00σ], R ) 0.058, Rw ) 0.083.
(9) Crystal data for 5e: C49H32N2S2SeCl2, crystal from CH2Cl2:CH3-
OH, crystal dimensions 0.53 X 0.18 X 0.03 mm, M ) 862.79, monoclinic,
space group P21/n, a ) 17.752(2), b ) 11.020(1), c ) 21.341(2) Å, â )
106.958(3)°, V ) 3993.47(7) Å3, Z ) 4, Dc ) 1.435 g/cm3, F(000) ) 1760,
T ) 199 K, µ(Mo KR) ) 12.17 cm-1, 7767 reflections, [I > 3.00σ], R )
0.070, Rw ) 0.083.
The ring inversion in the solid state was confirmed by
single-crystal X-ray analysis of 5e and 6b (Figures 1 and

Notes
J . Org. Chem., Vol. 64, No. 23, 1999 8695
F igu r e 1. Single-crystal X-ray structure of 6b: (A) top view, (B) side view showing the atomic labeling scheme. The meso aryl
rings are deleted for clarity in the side view.
Table 2 lists the relevant bond distances of the inverted
ring, the nonbonded distances, and the torsion angles. A
comparison of bond lengths of CR-X, CR-Câ and Câ-Câ
observed for the heterocyclic ring opposite to the bipyr-
role, bithiophene, and biselenophene unit in 3, 4, 5e and
6b with that of the free heterocyclic ring system suggests
small decreases in CR-X and CR-Câ distances and small
increases in Câ-Câ distances due to the modified aro-
matic delocalization5b pathway in sapphyrins relative to
free heterocyclic rings. The bonding pattern in the
biselenophene moiety for 6b is reversed if we look at the
CR-Câ and Câ-Câ bond length of biselenophene 1.424 and
1.378 Å, respectively, compared to free selenophene ring
(CR-Câ 1.369 and 1.433 Å). However, the CR-Se (1.899
Å) bond experiences very little change relative to free
selenophene ring (1.855 Å).10 There are no significant
differences in these bond lengths for the planar and the
inverted sapphyrins. However, there are significant
differences in the torsion angles C13-C14-C15-C16 and
C13-C14-C15-X. Furthermore, between 5e and 6b, the
higher torsion angle observed for 6b clearly suggests
significant deviations from the planarity relative to 5e,
and this is clearly seen in the side view of Figures 1
and 2.
adjacent ring contains a small heteroatom like N, the ring
is inverted as in 1, 2, 5a -5e, and 6a -6e, while in 3 and
4, which shows a planar structure, the adjacent ring
contains bigger S or Se atoms. A comparison of the
nonbonding distances shown in Table 2 clearly suggests
that this distance depends on the nature of X-atom
present at the 26th and 28th positions and significant
decreases are observed for X ) S or Se. For example, in
4 this distance is 3.932 Å, while for 5e it is 6.449 Å. This
decrease in the distance will not only prevent accom-
modation of two carbon atoms separated by at least ∼1.35
Å (average Câ-Câ distance) but also hinders any possible
free rotation along C14-C15 or C18-C19 required for
the inversion of the ring, and consequently the sapphyrin
is forced to adopt a planar structure. If this is true, then
one would expect that replacement of S or Se atoms at
26 and 28 positions by O atoms (which has similar size
as that of N) in 3 and 4 should lead to inversion of the
ring. Indeed, very recently independent work from this
laboratory5b as well as that of Latos-Grazynski6b reveals
that the analogous 26,28-dioxasapphyrin shows an in-
verted structure.
An analysis of X-ray structural data of 3, 4, 5e, and
1
6b and the H NMR chemical shifts shown in the Table
The ring inversions in the sapphyrins are found to be
dependent on the nature of the heterocyclic ring which
is adjacent to the inverted ring. For example, when the
1 reveal the following: (a) The inverted sapphyrins show
significantly smaller ∆δ values relative to planar sap-
phyrins due to the reduced aromaticity caused by non-
planar structures of inverted sapphyrins. (b) The pres-
ence of bigger heteroatoms such as S or Se at the 26 and
28 positions leads to planar structures, while the pres-
(10) Latos-Grazynski, L.; Pacholska, E.; Chmielewski, P. J .; Olm-
stead, M. M.; Balch, A. L. Inorg. Chem. 1996, 35, 566-573.

8696 J . Org. Chem., Vol. 64, No. 23, 1999
Notes
F igu r e 2. Single-crystal X-ray structure of 5e: (A) top view, (B) side view showing the atomic labeling scheme. The meso aryl
rings are deleted for clarity in the side view.
1
1040, 825, 760, 690 cm-1. H NMR (400 MHz, CDCl3): δ 7.87-
ence of smaller heteroatom like N or O leads to inverted
structures. (c) The ring inversion does not depend on the
heteroatom present on the bipyrrolic unit. These conclu-
sions are in accordance with the structures of all the meso
7.86 (d, J ) 4 Hz, 2H), 7.21-7.27 (m, 4H). 13C NMR (100.4 MHz,
CDCl3): δ 144.7, 130.2, 129.6, 126.7. EI mass: m/z 260 (100%)
[M+].
5,5′-Bis-(p h en ylh yd r oxym eth yl)-2,2′-biselen op h en e d iol
aryl sapphyrins reported to date.
(8). To a solution of N,N,N′,N′-tetramethylethylenediamine (1.8
mL, 11.4 mmol) in dry n-hexane (90 mL) was added n-butyl-
Exp er im en ta l Section
lithium (7.3 mL, 11.4 mmol) followed by 2,2′-biselenophene
(1 g, 3.82 mmol) under an argon atmosphere. The reaction
mixture was stirred at room temperature for 1 h and later heated
under reflux for 1 h. The reaction mixture was then allowed to
attain 25 °C. Benzaldehyde (1 mL, 9.53 mmol) in dry THF (25
mL) was added dropwise to the reaction mixture at 0 °C. After
the addition was over, the reaction mixture was allowed to attain
25 °C, saturated ammonium chloride solution (40 mL) was
added, and it was then extracted with ether or chloroform (100
mL). The organic layers were combined and washed with brine
(100 mL) and dried over anhydrous Na2SO4. The crude product
obtained on evaporation of the solvent was recrystallized from
dry toluene to afford the diol as a pale yellow solid. Yield 940
mg, 52%; mp112 °C. Anal. Calcd for C22H18O2Se2: C, 55.95; H,
3.84. Found: C, 56.32; H, 4.12%. IR νmax(Nujol) 3500-3100 (br),
2920, 2860, 1450, 1370, 1040 cm-1. 1H NMR (300 MHz, CDCl3):
δ 7.26-7.47 (m, 10H), 7.00-7.01 (d, J ) 3 Hz, 2H), 6.88-6.89
(d, J ) 3 Hz, 2H), 5.97 (s, 2H), 2.5 (brs, 2H). 13C NMR (75.5
MHz, CDCl3): δ 154.6, 145.0, 143.1, 128.6, 128.1, 127.2, 126.2,
125.9, 74.2. EI mass: m/z 472 (100%) [M+].
All the chemicals used for the synthesis were reagent grade
unless otherwise specified. Solvents for spectroscopic measure-
ments were purified and dried according to the standard
methods. Compounds 9a -9e were synthesized following the
literature procedure.7 The instrumentation used for UV-visible,
IR, H NMR, 13C NMR, mass, and elemental analysis were the
1
same as described previously.7 Crystal measurements were made
on a Rigaki TAXIS-IV imaging plate area detector with graphite
monochromated Mo-KR radition. Indexing was performed from
four oscillations which were exposed for 3.3 min. The crystal-
to-detector distance was 86.60 mm with the detector at the zero
swing position. Readout was performed in the 0.100 mm pixel
mode. All calculations were performed using the teXsan crystal-
lographic software package of Molecular Structure Corporation.
Syn th eses. 2,2′-Biselen op h en e (7). To a solution of sele-
nophene (1 g, 7.63 mmol) in a 1:1 mixture of dry ether (20 mL)
and dry THF (20 mL) was added n-butyllithium (5.4 mL, 8.39
mmol) at -70 °C and allowed to stir for 2 h at the same
temperature. Then, CuCl2 (1.85 g, 13.7 mmol) was added to the
above mixture at -70 °C followed by dry THF (20 mL) and
allowed to stir for 2 h. The reaction mixture was quenched with
saturated NH4Cl solution (25 mL) at -30 °C and extracted with
ethyl acetate (100 mL). The organic layers were combined and
washed with brine (100 mL) and dried over anhydrous Na2SO4
and evaporated under reduced pressure. The crude product was
purified by column chromatography (silica gel 100-200 mesh).
A colorless fraction eluted with petroleum ether gave a yellow
solid identified as 2,2′-biselenophene. Yield 480 mg, 48%; mp
40-42 °C. Anal. Calcd for C8H6Se2: C, 36.95; H, 2.33. Found:
C, 37.36; H, 2.12%. IR νmax (Nujol) 2920, 2860, 1460, 1380, 1250,
5,10,15,20-Tetr aph en yl-25,29-diselen asapph yr in (6a). 5,5′-
Bis(phenylhydroxymethyl)-2,2′-biselenophene (200 mg, 0.424
mmol) and 5,10-diphenyltripyrrane (160 mg, 0.424 mmol) in dry
dichloromethane (200 mL) were stirred under nitrogen atmo-
sphere for 15 min at room temperature. TFA (0.033 mL, 0.424
mmol) was added to the above mixture. The solution was stirred
for further 1 h under dark conditions. The resulting solution was
opened to the air, chloranil (313 mg, 1.272 mmol) was added,
and the mixture was heated to reflux in a preheated oil bath at
50 °C for 1 h. After removal of the solvent, the crude product
was purified by column chromatography (basic alumina). An

Notes
J . Org. Chem., Vol. 64, No. 23, 1999 8697
orange band eluted with CCl4:CH2Cl2 (40:60) and gave a green
lustrous solid identified as 5,10,15,20-tetraphenyl-25,29-disel-
enasapphyrin. Yield 70 mg, 20%; mp decomposes above 350 °C.
1H NMR (300 MHz, CDCl3): δ 11.99 (br s, 1H), 10.57 (d, J ) 6
Hz, 2H), 10.30 (d, J ) 6 Hz, 2H), 8.99 (d, J ) 4 Hz, 2H), 8.88 (d,
J ) 4 Hz, 2H), 8.41-8.45 (m, 4H), 7.91-7.77 (m, 16H), -0.55
(s, 2H). MS (electro spray): m/z 810 (100%) [(M + 2)+]. Anal.
Calcd for C48H31N3Se2: C, 71.38; H, 3.87; N, 5.20. Found: C,
71.42; H, 3.64; N, 5.39%. UV-vis (CH2Cl2) λmax [nm] (ꢀ): 530
(48000), 659 (5100), 714 (8900), 787 (2600), 889 (3200); UV-vis
(CH2Cl2/1 equiv of TFA) λmax[nm] (ꢀ): 538 (33000), 755 (6400),
mg, 0.424 mmol), 5,10-diphenyl-16-thiatripyrrane (167 mg, 0.424
mmol), TFA (0.033 mL, 0.424 mmol), and chloranil (313 mg,
1.272 mmol) under similar reaction conditions as mentioned
above gave a purple solid identified as 5,10,15,20-tetraphenyl-
27-thia-25,29-diselenasapphyrin. Yield 112 mg, 32%; mp decom-
poses above 350 °C. 1H NMR (300 MHz, CDCl3): δ 10.57 (d, J
) 6 Hz, 2H), 10.27 (d, J ) 6 Hz, 2H), 8.79 (d, J ) 3 Hz, 2H),
8.75 (d, J ) 3 Hz, 2H), 8.40-8.37 (m, 4H), 7.94-7.72 (m, 16H),
1
-0.68 (s, 2H). H NMR (300 MHz, CDCl3/TFA): δ 10.16 (d, J )
4 Hz, 2H), 10.01 (d, J ) 4 Hz, 2H), 9.26 (d, J ) 4 Hz, 2H), 9.16
(d, J ) 4 Hz, 2H), 8.63 (m, 8H), 7.84-8.09 (m, 12H), -0.65 (s,
2H). MS (electro spray): m/z 827 (50%) [(M+2)+]. Anal. Calcd
for C48H30N2SSe2: C, 69.90; H, 3.67; N, 3.40. Found: C, 69.63;
H, 3.82; N, 3.33%. UV-vis (CH2Cl2) λmax[nm] (ꢀ): 523 (84200),
644 (12400), 695 (17400), 795 (4000), 903 (4300); UV-vis (CH2-
Cl2/1 equiv of TFA) λmax[nm] (ꢀ): 535 (62000), 699 (9700), 767
800 (9000), 840 (8000). UV-vis (CH2Cl2/2.5 equiv of TFA) λmax
-
[nm] (ꢀ): 545 (48000), 815 (15800).
5,10,15,20-Tetr a p h en yl-27-N-m eth yl-25,29-d iselen a sa p -
p h yr in (6b). 5,5′-Bis(phenylhydroxymethyl)-2,2′-biselenophene-
(200 mg, 0.424 mmol), 5,10-diphenyl-16-N-methyltripyrrane (166
mg, 0.424 mmol), TFA (0.033 mL, 0.424 mmol), and chloranil
(313 mg, 1.272 mmol) under similar reaction conditions as
mentioned above gave a green lustrous solid identified as
5,10,15,20-tetraphenyl-27-N-methyl-25,29-diselenasapphyrin.
(14000), 856 (11100). UV-vis (CH2Cl2/2.5 equiv of TFA) λmax
-
[nm] (ꢀ): 546 (103000), 731 (17000), 805 (34300), 856 (26600).
5,10,15,20-Tetr a p h en yl-25,27,29-tr iselen a sa p p h yr in (6e).
5,5′-Bis(phenylhydroxymethyl)-2,2′-biselenophene (200 mg, 0.424
mmol), 5,10-diphenyl-16-selenatripyrrane (188 mg, 0.424 mmol),
TFA (0.033 mL, 0.424 mmol), and chloranil (313 mg, 1.272 mmol)
under similar reaction conditions as mentioned above gave a
purple solid identified as 5,10,15,20-tetraphenyl-25,27,29-trise-
lenasapphyrin. Yield 105 mg, 28%; mp decomposes above 350
°C. 1H NMR (300 MHz, CDCl3): δ 10.54 (d, J ) 6 Hz, 2H), 10.24
(d, J ) 3 Hz, 2H), 8.76 (d, J ) 3 Hz, 2H), 8.61 (d, J ) 3 Hz, 2H),
8.39-8.36 (m, 6H), 7.93-7.69 (m, 14H), -0.82 (s, 2H). 1H NMR
(300 MHz, CDCl3/TFA): δ 10.36 (d, J ) 4 Hz, 2H), 10.14 (d, J )
6 Hz, 2H), 8.99 (d, J ) 6 Hz, 2H), 8.89 (d, J ) 4 Hz, 2H), 8.45-
8.38 (m, 8H), 8.00-7.75 (m, 12H), -0.98 (s, 2H). MS (electro
spray): m/z 873 (50%) [(M + 1)+]. Anal. Calcd for C48H30N2Se3:
C, 66.14; H, 3.47; N, 3.21. Found: C, 66.32; H, 3.21; N, 3.42%.
UV-Vis (CH2Cl2) λmax[nm] (ꢀ): 527 (88000), 643 (18900), 690
(18300), 803 (sh, 8100), 899 (7500); UV-Vis (CH2Cl2/1 equiv of
TFA) λmax[nm] (ꢀ): 536 (63300), 646 (13500), 698 (15600), 756
1
Yield 90 mg, 26%; mp decomposes above 350 °C. H NMR (300
MHz, CDCl3): δ 10.48 (d, J ) 4 Hz, 2H), 10.22 (d, J ) 6 Hz,
2H), 8.98 (d, J ) 4 Hz, 2H), 8.83 (d, J ) 4 Hz, 2H), 8.37-8.40
(m, 4H), 7.94-7.84 (m, 16H), 2.36 (s, 3H), -0.36 (s, 2H). MS
(electro spray): m/z 824 (30%) [(M + 2)+]. Anal. Calcd for
C
49H33N3Se2: C, 71.62; H, 4.05; N, 5.11. Found: C, 71.89; H, 4.42;
N, 5.32%. UV-vis (CH2Cl2) λmax[nm] (ꢀ): 531 (19600), 662 (1600),
715 (3300), 784 (1100), 883 (1100); UV-vis (CH2Cl2/1 equiv of
TFA) λmax[nm] (ꢀ): 538 (13500), 807 (3300), 847 (3200). UV-vis
(CH2Cl2/2.5 equiv of TFA) λmax[nm] (ꢀ): 548 (15800), 757 (sh,
1700), 822 (4600).
5,10,15,20-Te t r a p h e n yl-27-oxa -25,29-d ise le n a sa p p h y-
r in (6c). 5,5′-Bis(phenylhydroxymethyl)-2,2′-biselenophene (200
mg, 0.424 mmol), 5,10-diphenyl-16-oxatripyrrane (160 mg, 0.424
mmol), TFA (0.033 mL, 0.424 mmol), and chloranil (313 mg,
1.272 mmol) under similar reaction conditions as mentioned
above gave a green lustrous solid identified as 5,10,15,20-
tetraphenyl-27-oxa-25,29-diselenasapphyrin. Yield 72 mg, 21%;
mp decomposes above 350 °C. 1H NMR (300 MHz, CDCl3): δ
10.19 (d, J ) 3 Hz, 2H), 10.01 (d, J ) 6 Hz, 2H), 8.82 (d, J ) 6
Hz, 2H), 8.70 (d, J ) 3 Hz, 2H), 8.35-8.28 (m, 8H), 7.91-7.73
(m, 12H), 0.31 (s, 2H). 1H NMR (300 MHz, CDCl3/TFA): δ 10.18
(d, J ) 4 Hz, 2H), 10.00 (d, J ) 4 Hz, 2H), 8.80 (d, J ) 4 Hz,
2H), 8.70 (d, J ) 4 Hz, 2H), 8.36-8.26 (m, 8H), 7.88-7.71 (m,
12H), -0.31 (s, 2H). MS (electro spray): m/z 811 (55%) [(M +
2)+]. Anal. Calcd for C48H30N2OSe2: C, 71.29; H, 3.74; N, 3.46.
Found: C, 71.42; H, 3.96; N, 3.27%. UV-vis (CH2Cl2) λmax[nm]
(ꢀ): 532 (96000), 652 (9800), 709 (14300), 818 (1100), 928 (4200);
UV-vis (CH2Cl2/1 equiv of TFA) λmax[nm] (ꢀ): 541 (71200), 662
(3700), 714 (5600), 796 (11300), 862 (11200). UV-Vis (CH2Cl2/
2.5 equiv of TFA) λmax[nm] (ꢀ): 550 (91400), 785 (15700), 856
(13000).
(19500), 862 (13300). UV-vis (CH2Cl2/2.5 equiv of TFA) λmax
[nm] (ꢀ): 543 (65000), 686 (15000), 759 (21300), 862 (16000).
-
Ack n ow led gm en t. This work was supported by a
grant from the Department of Science and Technology
and Council of Scientific and Industrial Research, New
Delhi, India, to T.K.C.
Su p p or tin g In for m a tion Ava ila ble: X-ray structural
data for 5e and 6b, including X-ray experimental, summaries
of crystallographic parameters, atomic coordinates, anisotropic
displacement parameters, bond lengths and bond angles. This
material is available free of charge via the Internet at
http://pubs.acs.org.
5,10,15,20-Tet r a p h en yl-27-t h ia -25,29-d iselen a sa p p h y-
r in (6d ). 5,5′-Bis(phenylhydroxymethyl)-2,2′-biselenophene (200
J O990729U