Pt-Containing Poly(aryleneethynylene)s with Thienyl Rings
A R T I C L E S
H2SO4 (ΦP ) 0.54).16 The decay curves were analyzed using a
Marquardt-based nonlinear least-squares fitting routine and were shown
to follow a single-exponential function in each case according to I )
I0 + A exp(-t/τ). Electrochemical measurements were made using a
Princeton Applied Research model 273A potentiostat. The cyclic
voltammetry experiment of the polymer film was performed by casting
the polymer on the glassy-carbon working electrode with a Pt wire as
the reference electrode, at a scan rate of 100 mV s-1. The solvent in
all measurements was deoxygenated MeCN, and the supporting
electrolyte was 0.1 M [nBu4N][BF4]. Ferrocene was added as an internal
reference after each set of measurements, and all potentials are quoted
31.90, 30.48, 29.55, 29.46, 29.42, 29.40, 29.31, 22.68, 14.12 (nonyl),
15.11, 8.03 ppm (Et); 31P NMR (CDCl3): δ ) 11.11 ppm (1JP-Pt
)
2626 Hz); FAB-MS: m/z: 1812 (M+). Anal. Calcd (%) for C80H116N2P4-
Pt2S6: C, 53.02; H, 6.45; N, 1.55. Found: C, 52.88; H, 6.35; N, 1.48.
M3: Dark red solid. Yield: 43% (Eluent: CH2Cl2/hexane (1:1, v/v)).
IR (KBr): ν(CtC) 2079 cm-1; 1H NMR (CDCl3): δ ) 7.31-7.29 (d,
4H, J ) 7.6 Hz, Ar), 7.11-7.07 (m, 6H, Ar), 7.01-6.95 (m, 8H, Ar),
6.82-6.79 (t, 2H, J ) 7.0 Hz, Ar), 6.76-6.75 (d, 2H, J ) 5.6 Hz,
Ar), 2.98-2.94 (t, 4H, J ) 7.4 Hz, alkyl), 1.79-1.71 (m, 28H, alkyl),
1.42-1.26 (m, 24H, alkyl), 1.13-1.05 (m, 36H, alkyl), 0.88-0.85 ppm
(t, 6H, J ) 6.6 Hz, alkyl); 13C NMR (CDCl3): δ ) 157.48, 155.76,
154.63, 139.02, 138.35, 137.70, 134.27, 132.84, 131.48, 129.95, 128.11,
127.71, 127.55, 127.38, 124.68, 123.77, 123.60, 123.31, 121.39, 102.18
(Ar and CtC), 31.91, 30.50, 29.56, 29.47, 29.43, 29.33, 22.70, 14.14
(nonyl), 15.11, 8.03 ppm (Et); 31P NMR (CDCl3): δ ) 11.10 ppm
(1JP-Pt ) 2625 Hz); FAB-MS: m/z: 1976 (M+); Anal. Calcd (%) for
C88H120N2P4Pt2S8: C, 53.48; H, 6.12; N, 1.42. Found: C, 53.50; H,
6.02; N, 1.47.
relative to that of the ferrocene-ferrocenium couple (taken as E1/2
)
+0.27 V relative to the reference electrode). The oxidation (Eox)
potentials and optical bandgaps (Eg) were used to determine the HOMO
and LUMO energy levels using the equations EHOMO ) -(Eox + 4.8)
eV and ELUMO ) (EHOMO + Eg) eV (versus the internal standard
ferrocene value of -4.8 eV with respect to the vacuum level).17 Thermal
analyses were performed with the Perkin-Elmer TGA6 thermal analyzer.
Synthesis of Platinum Model Complexes M0-M3. All of them
were synthesized following the dehydrohalogenating coupling between
trans-[PtCl(Ph)(PEt3)2]18 and the corresponding diterminal alkynes. A
typical procedure was given for M0 starting from L0.
Synthesis of Platinum Metallopolyynes P0-P3. The polymers were
prepared by the dehydrohalogenative polycondensation between trans-
[Pt(n-Bu3P)2Cl2]19 and each of L0-L3. A typical procedure was given
for P0 starting from L0.
Polymerization was carried out by mixing L0 (46.9 mg, 0.10 mmol),
trans-[Pt(n-Bu3P)2Cl2] (67.1 mg, 0.10 mmol), and CuI (3.00 mg) in
Et3N/CH2Cl2 (30 mL, 1:2, v/v). After stirring at room temperature
overnight under nitrogen, the solution mixture was evaporated to
dryness. The residue was redissolved in CH2Cl2 and filtered through a
short silica column using the same eluent to remove ionic impurities
and catalyst residues. After removal of the solvent, the crude product
was purified by precipitation in CH2Cl2 from MeOH two times.
Subsequent washing with hexane and drying in Vacuo gave a yellow
solid of P0 (92.7 mg, 87%). IR (KBr): ν(CtC) 2087 cm-1; 1H NMR
(CDCl3): δ ) 2.78 (br, s, 4H, alkyl), 2.08 (br, s, 16H, alkyl), 1.55-
1.25 (m, 48H, alkyl), 0.91-0.85 ppm (m, 24H, alkyl); 31P NMR
(CDCl3): δ ) 5.04 ppm (1JP-Pt ) 2324 Hz). Anal. Calcd (%) for
(C52H92N2P2PtS2)n: C, 58.56; H, 8.70; N, 2.63. Found: C, 58.46; H,
8.78; N, 2.47.
To a stirred mixture of L0 (46.9 mg, 0.10 mmol) and trans-[PtPh-
(Cl)(PEt3)2] (109 mg, 0.20 mmol) in Et3N (30 mL) and CH2Cl2 (30
mL) was added CuI (5.00 mg). The solution was stirred at room
temperature under nitrogen over a period of 12 h, after which all volatile
components were removed under vacuum. The crude product was taken
up in dichloromethane and purified on preparative silica TLC plates
with CH2Cl2/hexane (1:1, v/v) as eluent. The product M0 was obtained
1
as a yellow solid (107 mg, 72%). IR (KBr): ν(CtC) 2083 cm-1; H
NMR (CDCl3): δ ) 7.30-7.29 (m, 4H, Ar), 6.98-6.94 (t, 4H, J )
7.6 Hz, Ar), 6.82-6.78 (t, 2H, J ) 7.6 Hz, Ar), 2.81-2.77 (t, 4H, J )
8.0 Hz, alkyl), 1.74-1.70 (m, 28H, alkyl), 1.34-1.25 (m, 24H, alkyl),
1.12-1.04 (m, 36H, alkyl), 0.88-0.85 ppm (t, 6H, J ) 6.8 Hz, alkyl);
13C NMR (CDCl3): δ ) 157.30, 155.58, 155.01, 139.00, 127.98,
127.38, 121.39, 120.95, 99.11 (Ar + CtC), 31.91, 30.68, 29.85, 29.81,
29.70, 29.67, 29.35, 22.68, 14.11 (nonyl), 15.11, 8.00 ppm (Et); 31P
NMR (CDCl3): δ ) 11.38 ppm (1JP-Pt ) 2627 Hz); FAB-MS: m/z:
1483 (M+). Anal. Calcd (%) for C64H108N2P4Pt2S2: C, 51.81; H, 7.34;
N, 1.89. Found: C, 51.90; H, 7.23; N, 1.77.
1
P1: Yellow solid. Yield: 79%. IR (KBr): ν(CtC) 2085 cm-1; H
NMR (CDCl3): δ ) 6.97-6.95 (m, 2H, Ar), 6.79-6.78 (d, 2H, J )
4.4 Hz, Ar), 2.93-2.90 (t, 4H, J ) 7.2 Hz, alkyl), 2.13-2.09 (m, 12H,
alkyl), 1.76-1.72 (m, 4H, alkyl), 1.61-1.56 (m, 12H, alkyl), 1.52-
1.45 (m, 12H, alkyl), 1.39-1.26 (m, 24H, alkyl), 1.00-0.92 (m, 18H,
alkyl), 0.88-0.85 ppm (t, 6H, J ) 6.8 Hz, alkyl); 31P NMR (CDCl3):
δ ) 4.49 ppm (1JP-Pt ) 2320 Hz). Anal. Calcd (%) for (C60H96N2P2-
PtS4)n: C, 58.56; H, 7.86; N, 2.28. Found: C, 58.62; H, 7.66; N, 2.10.
M1: Red-brown solid. Yield: 73%. (Eluent: CH2Cl2/hexane (1:1,
1
v/v)). IR (KBr): ν(CtC) 2082 cm-1; H NMR (CDCl3): δ ) 7.31-
7.30 (d, 4H, J ) 6.8 Hz, Ar), 6.98-6.95 (m, 6H, Ar), 6.82-6.79 (d,
4H, J ) 12.4 Hz, Ar), 2.94-2.90 (t, 4H, J ) 7.8 Hz, alkyl), 1.76-
1.71 (m, 28H, alkyl), 1.41-1.26 (m, 24H, alkyl), 1.14-1.06 (m, 36H,
alkyl), 0.88-0.85 (t, 6H, J ) 7.0 Hz, alkyl); 13C NMR (CDCl3): δ )
156.82, 155.68, 153.67, 138.99, 131.53, 129.05, 128.31, 127.37, 126.86,
124.06, 121.40, 101.87 (Ar + CtC), 31.91, 30.55, 29.60, 29.58, 29.50,
29.47, 29.31, 22.67, 14.12 (nonyl), 15.11, 8.02 ppm (Et); 31P NMR
(CDCl3): δ ) 11.07 ppm (1JP-Pt ) 2623 Hz); FAB-MS: m/z: 1648
(M+). Anal. Calcd (%) for C72H112N2P4Pt2S4: C, 52.48; H, 6.85; N,
1.70. Found: C, 52.30; H, 6.67; N, 1.62.
P2: Red-brown solid. Yield: 59%. IR (KBr): ν(CtC) 2083 cm-1
;
1H NMR (CDCl3): δ ) 7.05 (br, s, 4H, Ar), 6.98-6.97 (d, 2H, J )
2.8 Hz, Ar), 6.75-6.74 (d, 2H, J ) 2.8 Hz, Ar), 2.94 (br, s, 4H, alkyl),
2.10 (br, s, 12H, alkyl), 1.78 (br, s, 4H, alkyl), 1.60-1.25 (m, 48H,
alkyl), 0.97-0.84 ppm (m, 24H, alkyl); 31P NMR (CDCl3): δ ) 4.53
ppm (1JP-Pt ) 2322 Hz); Anal. Calcd (%) for (C68H100N2P2PtS6)n: C,
58.55; H, 7.23; N, 2.01. Found: C, 58.43; H, 7.12; N, 1.94.
P3: Dark brown solid. Yield: 41%. IR (KBr): ν(CtC) 2083 cm-1
;
M2: Red solid. Yield: 63%. (Eluent: CH2Cl2/hexane (1:1, v/v)).
IR (KBr): ν(CtC) 2080 cm-1; 1H NMR (CDCl3): δ ) 7.32-7.30 (d,
4H, J ) 6.8 Hz, Ar), 7.06-7.04 (t, 4H, J ) 4.2 Hz, Ar), 6.98-6.95
(m, 6H, Ar), 6.82-6.79 (d, 2H, J ) 14.4 Hz, Ar), 6.76-6.75 (d, 2H,
J ) 4.0 Hz, Ar), 2.97-2.93 (t, 4H, J ) 7.8 Hz, alkyl), 1.81-1.70 (m,
28H, alkyl), 1.42-1.34 (m, 24H, alkyl), 1.14-1.06 (m, 36H, alkyl),
0.88-0.85 ppm (t, 6H, J ) 7.0 Hz, alkyl); 13C NMR (CDCl3): δ )
157.30, 155.72, 154.36, 139.16, 139.00, 132.54, 130.69, 130.16, 127.98,
127.72, 127.37, 123.76, 123.58, 123.09, 121.39, 102.16 (Ar + CtC),
1H NMR (CDCl3): δ ) 7.13-7.09 (m, 4H, Ar), 7.02-6.96 (m, 6H,
Ar), 6.82-6.79 (t, 2H, J ) 6.0 Hz, Ar), 2.95 (br, s, 4H, alkyl), 2.11
(br, s, 12H, alkyl), 1.79 (br, s, 4H, alkyl), 1.57-1.30 (m, 48H, alkyl),
0.98-0.84 ppm (m, 24H, alkyl); 31P NMR (CDCl3): δ ) 4.50 ppm
(1JP-Pt ) 2319 Hz). Anal. Calcd (%) for (C76H104N2P2PtS8)n: C, 58.55;
H, 6.72; N, 1.80. Found: C, 58.34; H, 6.79; N, 1.67.
Solar Cell Fabrication and Characterization. The device structure
was ITO/poly(3,4-ethylene-dioxythiophene):poly(styrene sulfonate)
(PEDOT:PSS)/polymer:PCBM blend/Al. ITO glass substrates (10 Ω
per square) were cleaned by sonication in toluene, acetone, ethanol,
and deionized water, dried in an oven, and then cleaned with UV ozone
(16) Dawson, W. R.; Windsor, M. W. J. Phys. Chem. 1968, 72, 3251.
(17) (a) Thelakkat, M.; Schmidt, H.-W. AdV. Mater. 1998, 10, 219. (b) Ashraf,
R. S.; Shahid, M.; Klemm, E.; Al-Ibrahim, M.; Sensfuss, S. Macromol.
Rapid Commun. 2006, 27, 1454.
(18) Chatt, J.; Shaw, B. L. J. Chem. Soc. 1960, 4020.
(19) Chatt, J.; Hayter, R. G. J. Chem. Soc., Dalton Trans. 1961, 896.
9
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