Luminescence properties of PPV derivatives bearing substituted carbazole pendants

Abstract

A series of PPV derivatives bearing substituted and unsubstituted carbazole and 2‐ethylhexyloxy pendants were prepared and their photo‐ (PL) and electroluminescence (EL) properties were studied. Substituted carbazole structures were N‐phenylcarbazole and 3,6‐dimethoxycarbazole. The substituents on the carbazole pendants caused little change in UV‐vis absorption, PL, and EL when compared with the polymer bearing the unsubstituted carbazole pendants. The presence of the benzene ring between the main chain and the carbazole pendant increased the threshold electric field in EL. We could obtain maximum brightness of ca. 17,000 ‐ 30,000 cd/m2 for the polymers carrying the unsubstituted and dimethoxy substituted carbazole pendants.

Substituent Effects on Crosslike Packing of 2′,7′‐Diaryl‐ spiro(cyclopropane‐1,9′‐fluorene) Derivatives: Synthesis and Crystallographic, Optical, and Thermal Properties

“…Commercially available arylboronic acids and phenylacetylene were used without further purification, except for pyren-1-ylboronic acid, [13] 9,9′-diethylfluoren-2-ylboronic acid, [14] 4-(carbazol-9-yl)phenylboronic acid, [15] and 5-(carbazol-9-yl)thiophen-2-ylboronic acid, [16] which were prepared in good-to-excellent yields by halogen-metal exchange and subsequent trapping of the aryl lithium compounds with trialkylborates. Pd-catalyzed cross-coupling reactions were applied to prepare DA-SCFs in good yields (70-90 %).…”

“…These intermolecular CH(sp 3 )_p interactions are the key forces for the dimer formation. The driving forces of the stacking along the a-and c-axes are the intermolecular CH(sp 2 )_p interactions between C(14)-H (14) and P 2 (3.03 Å, 143.9°), C (14)-H (14) and P 3 (3.28 Å, 123.2°), C(15)-H(15) and P 3 (3.09 Å, 131.0°), respectively. On the other hand, the face-to-face intermolecular p-p interactions between naphthalene rings, and not interactions between fluorene rings, could be regarded as the key driving force for 1 stacking along the c-axis, as shown in Figure 4.…”