Syntheses and Properties of Copolymers with N‐Alkyl‐2,2′‐bithiophene‐3,3′‐dicarboximide Unit for Polymer Solar Cells

Abstract

We report new random copolymers using the electron-deficient unit N-alkyl-2,2 0 -bithiophene-3,3 0 -dicarboximide (BTI) for organic solar cells. For absorption over a broader range of the solar spectrum, push-pull types of conjugated polymers PBTIBDT-3, PBTIBDT-5, and PBTIBDT-7, containing 4,8-bis(2-octyldodecyloxy) benzo[1,2-b;3,4-b']dithiophene (BDT) as electron-pushing unit and BTI as electron-pulling unit, were synthesized. The polymers were synthesized by coupling electron-pushing and electron-pulling units by Stille polymerization with Pd(0) catalyst. The incorporation of more BTI units induced more red shift of the absorption spectra of the polymer thin films. The device comprising PBTIBDT-5 and PC 71 BM (1:1) showed V OC = 0.76 V, J SC = 3.28 mA/cm 2 , and fill factor (FF) = 0.51, giving a power conversion efficiency of 1.26%.

Microdiplanol and microdiplane: a newm-anisaldehyde and a new 24-methylcholestanol derivative from the endophytic fungusMicrodiplodiasp.

“…The ether linkage at C-3 was established in the b-orientation on the basis of strong NOESY interactions of H-3 with H-2a, and H-4a. Furthermore, the 24a configuration of 2 was determined by comparison of its NMR data with those of the 24a-(24R) isomer of other 24-methylcholesterol derivatives [9,10]. In addition, the carbon shifts of C 20 -C 28 in the 13 C NMR spectrum are in excellent agreement with those reported for (24R)-methylcholesterol derivatives [9,10].…”

“…In our derivation of the structure, all four of these deficiencies were assigned to the four rings of the steroid skeleton. The 1 H NMR spectrum of 2 (see Section 3) showed six methyl signals at d 1.02 (s, 3H, Me-19), 0.91 (d, J ¼ 6.2 Hz, 3H, Me-21), 0.85 (d, J ¼ 6.5 Hz, 3H, Me-26), 0.80 (d, J ¼ 6.5 Hz, 3H, Me-28), 0.78 (d, J ¼ 6.2 Hz, 3H, Me-27), and 0.68 (s, 3H, Me-18), and the values of these six methyl groups confirmed the 24a-(24R) skeletal isomer of a 24-methylcholesterol derivative [9]. This was further substantiated from 13 C NMR values for the same six methyl groups at d 20.2 (C-26), 18.6 (C-21), 18.2 (C-27), 12.3 (C-19), 12.1 (C-18), and 15.4 (C-28) [10].…”

“…The 1 H-1 H and 1 H-13 C connectivities were determined from the 1 H-1 H COSY and HMQC spectra. Assignment of the carbon skeleton was established by HMBC (Figure 2) as well as by a comparison of the 1 H and 13 C NMR chemical shifts and coupling constants observed for the 24-methylcholesterol derivative [9,10]. On the basis of the these observations, the identity of compound 2 comprising the skeleton of the 24a-isomer of a 24-methylcholesterol derivative [9,10] could easily be deduced.…”

“…Assignment of the carbon skeleton was established by HMBC (Figure 2) as well as by a comparison of the 1 H and 13 C NMR chemical shifts and coupling constants observed for the 24-methylcholesterol derivative [9,10]. On the basis of the these observations, the identity of compound 2 comprising the skeleton of the 24a-isomer of a 24-methylcholesterol derivative [9,10] could easily be deduced. The 1 H NMR spectra of 2 also illustrated peaks for the presence of a typical tetradecyl group with pertinent signals at d In the NOESY spectrum of 2, correlations between H-8 and Me-18 and Me-19 as well as between Me-18 and H-20 indicated that these protons adopt a borientation.…”

“…Furthermore, the 24a configuration of 2 was determined by comparison of its NMR data with those of the 24a-(24R) isomer of other 24-methylcholesterol derivatives [9,10]. In addition, the carbon shifts of C 20 -C 28 in the 13 C NMR spectrum are in excellent agreement with those reported for (24R)-methylcholesterol derivatives [9,10]. Consequently, the structure was established to be the (24R)-methylcholesterol derivative, named microdiplane 2, after the producing organism, Microdiplodia sp.…”