Chemiluminescence of N,N′-Bistosyl-1H,4H-quinoxaline-2,3-dione
standard methods. Distyrylbenzenes were prepared by the
Horner-Wadsworth-Emmons reaction of 1,4-bis(diethylphos-
phonomethy)benzene and corresponding aromatic aldehydes
according to the literature procedure.17 The CL quantum yields
were measured by a photocounting method using a photomul-
tiplier (R464 Hamamatsu Photonics K.K.) connected with a
photocounting unit (C3866), a photocounting board (M3949),
and handling software (U3997). The calibration was made by
a standard method with luminol chemiluminescence in the
presence of tBuOK in dry DMSO (vide infra).
N,N′-Bistosyl-1H,4H-qu in oxa lin e-2,3-d ion e (TsQD). To
a suspension of N,N′-bistosyl-o-phenylenediamine (1.00 g, 2.4
mmol) and oxalyl chloride (0.5 mL, 5.80 mmol) in benzene (160
mL) was added dropwise a solution of triethylamine (1.60 mL,
1.5 mmol) in benzene (10 mL) at room temperature. After
the solution was stirred for 3 h, the precipitated triethylamine
hydrochloride was removed by filtration. After concentration
of the filtrate, the residue was washed with ether to give a
crude product (0.88 g, 79%), which was recrystallized from
benzene to yield an analytically pure product: mp 196-197
1
-
1
1
°
(
3
C; IR (Nujol) 1740 cm ; H NMR δ 2.45 (s, 6H, CH ), 7.35
d, 2H, J ) 10.1 Hz, H-6 and 7), 7.36 (d, 4H, J ) 8.6 Hz, o-H
in Ts), 7.82-7.84 (m, 2H, H-5 and 8), 8.01 (d, 4H, J ) 8.6 Hz,
F IGURE 3. Hammett relationship between σ +
of relative Φ in TsQD-CL in the presence of para,para′-
disubstituted distyrylbenzenes.
and logarithm
13
3
m-H in Ts); C NMR δ 24.0 (CH ), 122.1, 124.5, 126.9, 129.7,
p
130.4, 134.6, 147.1 (aromatic C), 153.4 (CdO); MS (m/z) 470
S
+
(M ). Anal. Calcd for C22
18 6 2 2
H O N S : C, 56.16; H, 3.86; N, 5.96.
Found: C, 56.14; H, 3.80; N, 6.01.
the fall of the σ +
HOMO energy. Both the σ
are known to be closely related to oxidation potentials.
value as well as with a rise in the
6-Ca r beth oxy-N,N′-bistosyl-1H,4H-qu in oxa lin e-2,3-d i-
on e (TsQDEs). This compound was prepared from ethyl (3,4-
N,N′-bistosylamino)benzoate (1.00 g, 2.05 mmol)), oxalyl chlo-
ride (0.21 mL, 2.45 mmol), and triethylamine (0.68 mL, 4.89
mmol) in a manner similar to that described above. Recrys-
tallization from ethyl acetate gave a product with 1 mol of ethyl
acetate in 48% yield (0.62 g): mp 182-183 °C (as TsQD‚
p
+
18
p
values and HOMO energies
1
9,20
1
9
Gollnick et al. documented a linear relationship be-
+
tween the σ values and the oxidation potentials of
substituted diarylethenes. Because of the difficulty in
measuring oxidation potentials due to poor solubility of
-
1
1
AcOEt); IR (Nujol) 1744, 1721 cm ; H NMR (as TsQDEs‚
AcOEt) δ 1.43 (t, 3H, CH COOCH CH
), 4.41 (q, 2H, CH COOCH
+
DSBs in most organic solvents, σ values were regarded
3
2
3
, J ) 7.0 Hz), 2.46 (s,
CH , J ) 7.0 Hz),
6
7
H, SO
2
C
6
H
4
CH
3
3
2
3
as excellent substitutes for the oxidation potentials. To
verify the CIEEL mechanism in the decomposition of
organic peroxides, a linear correlation of the logarithm
of corrected CL intensities (singlet excitation yields) with
the oxidation potential of the fluorophores has sometimes
.38 (d, 2H, J ) 8.1 Hz, o-H in Ts), 7.40 (d, 2H, J ) 8.4 Hz,
o-H in Ts), 7.90 (d, 1H, J ) 8.8 Hz, H-7), 7.97 (dd, 1H, J ) 8.8
Hz, H-8), 8.02 (d, 2H, J ) 8.3 Hz, m-H in Ts), 8.10 (d, 2H, J )
13
8
(
.6 Hz, m-H in Ts), 8.47 (d, J ) 1.8 Hz, H-5); C NMR δ 14.7
3 2 3 2 6 4 3 3 2
CH COOCH CH ), 22.2 (SO C CH CH ), 62.1 (CH COOCH -
been documented.21 As shown in Figure 3, the plot of log-
CH ), 121.8, 123.1, 124.5, 127.6, 127.9, 128.8, 129.7, 129.8,
3
+
(rel Φ
S
) against the σ
p
values showed an excellent
130.5, 130.6, 134.3, 134.6, 147.4, 147.5 (aromatic C), 153.0,
+
Hammett relationship, where the F value was -0.98. The
negative sign of the F value explains that the electron-
donating group of the fluorophore promotes the light
153.1 (NTsCO), 165.0 (CH
3 2 3
COOCH CH ); MS (m/z) 514 (M
-
Et). Anal. Calcd for C29
5.23; H, 4.79; N, 4.44. Found: C, 55.23; H, 4.43; N, 4.51.
30 10 2 2
H O N S (as TsQD‚AcOEt): C,
5
Bis(N-p h en yl-N-tosyl)oxa m id e (1). This compound was
S
emission. Additionally, the log(rel Φ ) is also a linearly
prepared in 55% yield (1.82 g) from N-phenyltosylamide (3.00
g, 12.15 mmol)), oxalyl chloride (0.53 mL, 6.17 mmol), and
triethylamine (1.72 mL, 12.36 mmol) in a manner similar to
that described above. Recrystallization from ethyl acetate gave
a product with 0.5 mol of ethyl acetate: mp 209-211 °C (with
increasing function of the HOMO energy of 3. These
results corroborate the contribution of the CIEEL mech-
anism in the present TsQD-CL. Various DSBs are readily
prepared by the Wittig type of reactions; therefore, they
are expected to be utilized in the field of CL hereafter.
-1 1
0.5 mol of AcOEt); IR (Nujol) 1680, 1708 cm ; H NMR δ 2.41
s, 6H, CH
(
4
1
3
), 7.18-7.43 (m, ArH and o-ArH of Ts), 7.72 (d,
) 7.8, m-ArH of Ts); 13C NMR δ 24.0 (CH
), 129.8,
30.0, 130.4, 130.8, 133.7, 134.4, 146.1 (aromatic C), 162.8 (Cd
H, J
H
3
Exp er im en ta l Section
Gen er a l Meth od s. H NMR (400 MHz) and 13C NMR (100
1
+
56 4 14 4
H N O S (as
O); MS (m/z) 548 (Μ ). Anal. Calcd for C60
MHz) spectra were recorded in CDCl
3
as the solvent, and
oxamide, AcOEt ) 2:1): C, 60.79; H, 4.76; N, 4.73. Found: C,
chemical shifts (δ) were given in ppm relative to tetrameth-
ylsilane (TMS) as the internal standard. Mass spectra were
determined at an ionizing voltage of 70 eV. Melting points are
uncorrected. Solvents and commercially available compounds
were purchased from standard suppliers and purified by
60.74; H, 4.61; N, 4.93.
2,4,6-Tr ich lor op h en yl (N-P h en yl-N-tosyl)oxa m oylfor -
m a te (2). To a solution of oxalyl chloride (0.78 mL, 9.11 mmol)
in benzene (20 mL) were successively added a solution of
N-phenyl-N-tosylamide (1.50 g, 6.70 mmol) in benzene (20 mL)
and a solution of triethylamine (0.84 mL, 6.07 mmol) in
benzene (25 mL). After the solution was stirred for 30 min at
room temperature, triethylamine hydrochloride was removed
by filtration. The filtrate was concentrated in vacuo to yield
N-phenyl-N-tosylchlorocarbonylformamide (1.71 g, 83%), which
was subjected to the next reaction without purification. To a
solution of the thus-prepared crude N-phenyl-N-p-toluene-
sulfonylchlorocarbonylformamide (1.71 g, 5.06 mmol) in ben-
(
18) Brown, H. C.; Okamoto, Y. J . Am. Chem. Soc. 1958, 89, 4979-
4
987.
(
19) Gollnick, K.; Schnatterer, A.; Utschick, G.J . Org. Chem. 1993,
5
8, 6049-6056.
(20) Fukui, K.; Morokuma, K.; Kato, H.; Yonezawa, T. Bull. Chem.
Soc. J pn. 1963, 36.
21) Dixon, B. G.; Schuster, G. R. J . Am. Chem. Soc. 1979, 101,
116-3118.
(
3
J . Org. Chem, Vol. 67, No. 21, 2002 7317