Inorganic Chemistry
Article
an easier comparison with the experiment, the obtained absorption
and emission energies were converted into wavelengths and broadened
138.2 (s, C5/C9), 135.9 (s, C14/C18), 132.8 (s, C3/C7), 132.7 (s,
C2/C6), 131.6 (s, C15/C19), 125.5 (s, C12), 116.2 (s, C4/C8), 111.9
−1
2
1
by a Gaussian distribution (full width at half-maximum = 3000 cm )
(s, with satellites J = 231 Hz, C11), 17.6 (s, C22/C26), 15.5 (t, J
P
t
C
P
C
1
07
using the program GaussSum.
MOs were visualized with the
= 17.6 Hz, PCH −), 15.0 (s, C24/C28), 12.9 (s, C21/C25), 12.7 (br
2
108
GaussView program. Atomic coordinates of the calculated structures
are provided in Tables S2−S5 in the SI.
Synthesis and Characterization. 4-(2-Trimethylsilyl)ethynyl-N-
ethyl-1,8-naphthalimide (SiEtNI). A suspension of 4-bromo-N-ethyl-
s, C23/C27), 8.0 (s, with shoulders originating from platinum
1
95
satellites, PCH CH ). Pt NMR (85.6 MHz, C D , 298 K): δ −4446
2
3
6
6
1
(t, J = 2390 Hz). Anal. Calcd for C H B F N P Pt: C, 50.59; H,
PtP 40 58 2 4 4 2
6.16; N, 5.90. Found: C, 50.82; H, 6.52, N, 5.97.
1
1
,8-naphthalimide (1 g, 3.29 mmol), trimethylsilylacetylene (2.3 mL,
trans-(4,4-Difluoro-4-bora-3a,4a-diaza-s-indacen-8-yl)(N-ethyl-
1,8-naphthalimid-4-ylethynyl)bis(triethylphosphine)platinum(II)
(EtNIPtB-1). A NMR tube was charged with cis-1 (60 mg, 85.4 μmol),
6 mmol), CuI (62.6 mg, 0.329 mmol), PPh (86.3 mg, 0.329 mmol),
3
and PdCl (PPh ) in 12.5 mL of NEt and 37.5 mL of THF was
2
3
2
3
heated at 70 °C for 22 h. After 100 mL of water was added, the
AgBF
(16.6 mg, 85.4 μmol), and 0.5 mL of CDCl . The mixture was
4 3
mixture was extracted with CH Cl (3 × 80 mL) and the combined
heated to reflux for 10 min. Completeness of bromide abstraction and
2
2
1
31
organic phases were washed with 80 mL of water and dried over
cis/trans isomerization were confirmed by H and P NMR
experiments. The precipitate was filtered off, and the filtrate was
dried under vacuum. HEtNI (21.3 mg, 85.4 μmol), 3 mL of THF, and
Na SO . The solvent was removed, and the crude product was purified
2
4
by column chromatography (silica gel, pentane/ethyl acetate = 5/1)
1
and subsequently recrystallized from petroleum ether. Yield: 34%. H
2 mL of NEt were added, and the mixture was degassed by three
3
3
NMR (400.13 MHz, acetone-d , 298 K): δ 8.70 (dd, J = 8.4 Hz,
freeze−pump−thaw cycles. CuI (8.2 mg, 43.1 μmol) was added, and
the suspension was stirred at room temperature for 19 h. The solvent
was removed, and the crude product was purified by column
chromatography (pentane/ethyl acetate = 5/1, silica gel). Further
purification was achieved by crystallization of the product from a
saturated acetone solution at −28 °C to obtain 32 mg of the
6
HH
4
3
4
JHH = 1.1 Hz, 1H, H7), 8.60 (dd, J = 7.3 Hz, J = 1.1 Hz, 1H,
HH
HH
3
3
H9), 8.51 (d, J = 7.6 Hz, 1H, H3), 8.00 (d, J = 7.6 Hz, 1H, H2),
HH
HH
3
3
3
7
.97 (dd, J = 8.4 Hz, J = 7.3 Hz, 1H, H8), 4.17 (q, J = 7.1
HH HH HH
3
Hz, 2H, H13), 1.28 (t, J = 7.1 Hz, 3H, H14), 0.37 (s, 9H, H17).
HH
4
-Ethynyl-N-ethyl-1,8-naphthalimide (HEtNI). SiEtNI (359 mg,
.12 mmol) was dissolved in 5.5 mL of MeOH and 10.5 mL of THF.
K CO (301 mg, 2,18 mmol) was added, and the reaction mixture was
1
1
analytically pure, crystalline, yellow product. Yield: 43%. H NMR
3
(399.8 MHz, CD
Cl
2
, 298 K): δ 8.80 (d, JHH = 8.22 Hz, 1H, H20),
2
3
2
3
3
stirred for 150 min at room temperature. A total of 100 mL of water
8.57 (d, JHH = 7.09 Hz, 1H, H18), 8.45 (d, JHH = 7.65 Hz, 1H, H14),
3
was added, and the mixture was extracted with CH Cl (4 × 50 mL).
7.77 (vt, J = 7.80 Hz, 1H, H19), 7.68 (d, JHH = 7.80 Hz, 1H, H13),
2
2
The combined organic phases were washed with 100 mL of water and
dried over Na SO , and the solvent was removed in vacuo. The
7.65 (br s, 2H, H5/H9), 7.41 (vd, J = 3.04 Hz, 2H, H4/H8), 6.48 (vq,
3
J = 1.73 Hz, 2H, H3/H7), 4.20 (q, JHH = 7.07 Hz, 2H, H24), 1.95−
2
4
3
obtained yellow solid was used without further purification. Yield:
1.77 (m, 12H, PCH
(m, 18H, PCH CH
(s, with satellites JPtP = 2408 Hz). C NMR (100.5 MHz, CD
2
−), 1.30 (t, JHH = 7.07 Hz, 3H, H25), 1.20−1.08
1
3
31
9
8
8%. H NMR (400.13 MHz, acetone-d , 298 K): δ 8.71 (dd, J
=
2
3
). P NMR (161.8 MHz, CD
2
Cl
2
, 298 K): δ 9.37
Cl ,
2
6
HH
4
3
4
1
13
.4 Hz, J = 1.1 Hz, 1H, H7), 8.62 (dd, J = 7.3 Hz, J = 1.1
Hz, 1H, H9), 8.53 (d, J = 7.6 Hz, 1H, H3), 8.06 (d, J = 7.6 Hz,
H, H2), 7.99 (dd, J = 8.4 Hz, J = 7.3 Hz, 1H, H8), 4.50 (s, 1H,
H16), 4.18 (q, J = 7.1 Hz, 2H, H13), 1.28 (t, J = 7.1 Hz, 3H,
2
HH
HH
HH
3
3
298 K): δ 164.6 (s, C23), 164.3 (s, C22), 145.2 (m, C2/C6), 137.1 (s
br, C5/C9), 133.6 (br s, C4/C8), 133.5 (s, C20), 132.6 (s, C21),
131.5 (s, C18), 131.2 (s, C14), 129.5 (br s, C13), 129.0 (s, C16),
126.9 (s, C19), 123.7 (s, C17), 119.7 (s, C15), 116.6 (br s, C3/C7),
HH
HH
3
3
1
HH HH
3
3
HH
HH
H14).
1
13
trans-(4,4-Difluoro-4-bora-3a,4a-diaza-s-indacen-8-yl)(4,4-di-
fluoro-1,3,5,7-tetramethyl-2,4-diethyl-4-bora-3a,4a-diaza-s-inda-
cen-8-ylethynyl)bis(triethylphosphine)platinum(II) (EtBPtB). A
NMR tube was charged with complex cis-1 (30 mg, 42.7 μmol),
110.2 (C11, obtained by H− C gHMBC cross peak), 35.8 (s, C24),
16.1 (vquin, J = 17.6 Hz, PCH −), 13.7 (s, C23), and 8.5 (s, with
2
2
satellites J = 23.7 Hz, PCH CH ); the resonance signals of atoms
PtC
2
3
1
95
C1 and C10 were not detected. Pt NMR (85.6 MHz, CD Cl , 298
2
2
1
AgOTf (11 mg, 42.7 μmol), and 0.6 mL of CDCl . After 10 min at
K): δ −4447 (t, JPtP = 2408 Hz). Anal. Calcd for
C H BF N O P Pt: C, 51.04; H, 5.33; N, 4.83. Found: C, 51.55;
3
31
reflux, bromide abstraction was complete, as indicated by P NMR
experiments. The precipitated AgBr was filtered off, and the solvent
was stripped from the filtrate in a vacuum. In a 25 mL Schlenk tube,
the residual solid was combined with CuI (4.7 mg, 24.7 μmol) and
HEtB (14 mg, 42.7 μmol). The mixture was dissolved in 2 mL of THF
37
46
2
3
2 2
H, 5.42, N, 5.05.
trans-(4,4-Difluoro-4-bora-3a,4a-diaza-s-indacen-8-yl)(N-ethyl-
1,8-naphthalimid-4-ylethynyl)bis(triphenylphosphine)platinum(II)
(EtNIPtB-2). In an NMR tube, cis-2 (70 mg, 70.7 μmol) and AgBF
4
and 1 mL of NEt and then heated to 65 °C. UV−vis spectra recorded
(13.8 mg, 70.7 μmol) were dissolved in 0.6 mL of CDCl
and refluxed
3
3
on regularly sampled aliquots of the reaction mixture indicated that the
for 10 min. Complete bromide abstraction and cis/trans isomerization
1
31
reaction was complete after 1 h at 65 °C. The solvent was removed,
were confirmed by H and P NMR experiments. The precipitate was
−
and the residue was redissolved in 2 mL of CHCl . The solution was
filtered off and dried under vacuum. The BF
with HEtNI (17.6 mg, 70.7 μmol) dissolved in 5 mL of THF and 2
mL of NEt . The mixture was degassed by three freeze−pump−thaw
4
adduct was combined
3
extracted with water (3 × 1 mL), dried over Na SO , and then dried in
2
4
vacuo. The obtained red solid was washed with n-pentane and
3
dissolved in 0.3 mL of CHCl . Under light exclusion, that solution was
cycles. CuI (6 mg, 31.5 μmol) was added, and the reddish suspension
was heated at 60 °C for 24 h. The solvent was removed, and 20 mL of
3
layered with n-pentane and left for 2 days, after which time well-
shaped crystals had formed that were suitable for single-crystal X-ray
diffraction. In order to remove cocrystallized n-pentane, the crystalline
material was dissolved in 2 mL of benzene and the solution was frozen.
Benzene was sublimed off in vacuo, giving an analytically pure red
product. Yield: 37%. The following peak assignment follows the atom
water was added. The aqueous phase was extracted with CHCl
20 mL), and the combined organic phases were washed with 20 mL of
water and dried over MgSO . The solvent was removed, and the
obtained orange solid was redissolved in 1 mL of CHCl . A total of 3
mL of Et O was added, and the mixture was sonicated for 10 min. The
(3 ×
3
4
3
2
1
numbering in Figure 1. H NMR (600.3 MHz, C D , 298 K): δ 7.88
precipitate was separated, washed with benzene (2 × 1 mL), and dried
in vacuo. A further aliquot of the complex was obtained by adding 5
6
6
3
(
br s, 2H, H5/H9), 7.39 (d, J = 3.80 Hz, 2H, H3/H7), 6.43 (dd,
JHH = 3.80 Hz, J = 2.0 Hz, 2H, H4/H8), 2.64 (2s, 12H, H21/H25
HH
3
3
mL of Et
under reduced pressure. Yield: 53%. H NMR (600.3 MHz, CDCl ,
3
O to the mother liquor. The combined solids were dried
HH
2
3
1
and H23/H27), 2.28 (q, J = 7.56 Hz, 4H, H22/H26), 1.49−1.40
HH
3
3
4
(
(
m, 12H, PCH −), 0.98 (t, J = 7.56 Hz, 6H, H24/H28), 0.71−0.65
298 K): δ 8.35 (dd, JHH = 7.3 Hz, JHH = 1.2 Hz, 1H, H18), 8.09 (d,
2
HH
31
3
m, 18H, PCH CH ). P NMR (161.8 MHz, C D , 298 K): δ 7.56 (s,
JHH = 7.7 Hz, 1H, H14), 7.66−7.55 (m, 12H, P−o-H), 7.39−7.33 (m,
2
3
6
6
1
19
2
with satellites J = 2390 Hz). F NMR (376.1 MHz, C D , 298 K):
δ −144.6 (q, J = 32.6 Hz, 2F), −145.2 (q, J = 29.8 Hz, 2F).
NMR (151.0 MHz, C D , 298 K): δ 193.7 (t, J = 8.9 Hz, with
satellites J = 692 Hz, C1), 150.0 (s, C16/C20), 144.9 (s, C13/
C17), 141.8 (t, JPC = 15.5 Hz, with satellites J = 870 Hz, C10),
6H, P−p-H), 7.32−7.29 (m, 12H, P−m-H), 7.27 (br d, J = 2.0 Hz,
3 3
PtP
6
6
HH
1
1
13
C
1H, H3/H7), 7.26 (d, J = 8.3 Hz, 1H, H20), 7.07 (dd, J = 8.3
FB
FB
HH HH
2
3
3
4
Hz, J = 7.3 Hz, 1H, H19), 6.96 (dd, J = 3.9 Hz, J 1.2 Hz,
HH HH HH
1H, H3/H7), 6.34 (d, J = 7.7 Hz, 1H, H13), 5.97 (dd, J = 3.9
Hz, J = 2.0 Hz, 2H, H4/H8), 4.16 (q, J = 7.1 Hz, 2H, H24),
HH HH
6
6
PC
1
3
3
PtC
HH HH
2
1
3
3
PtC
M
Inorg. Chem. XXXX, XXX, XXX−XXX