Synthesis of conjugated copolymers containing phenothiazinylene vinylene moieties and their electrooptic properties

Abstract

Four different types of conjugated copolymers, consisting of alternating structures of phenothiazinylene vinylene and phenylene vinylene derivatives such as phenylene vinylene, 1,1′‐biphenyl‐4,4′‐ylene vinylene, 2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene, and 9,10‐anthrylene vinylene, were prepared by Horner–Emmons condensation between appropriate diphosphonates and dialdehydes. Single‐layer and double‐layer light‐emitting diodes were fabricated with the synthesized conjugated polymers, and their electroluminescent properties were investigated. Poly(N‐2‐ethylhexyl‐3,6‐phenothiazinylene vinylene‐alt‐9,10‐anthrylene vinylene), containing phenothiazinylene vinylene and anthrylene vinylene as repeat units, emitted a reddish‐orange color with Commission Internationale de l'Eclairage coordinates of x = 0.6173 and y = 0.3814 that was very similar to the National Television System Committee standard red, and it showed a bipolar carrier‐injection/transporting capability caused by electron‐withdrawing anthracene and electron‐donating amino groups. Poly[N‐2‐ethylhexyl‐3,6‐phenothiazinylene vinylene‐alt‐2‐methoxy‐5‐(2‐ethylhexyloxy)‐1,4‐phenylene vinylene], containing phenothiazinylene vinylene and dialkoxy phenylene vinylene moieties, showed excellent hole‐injection/transporting capability. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 2502–2511, 2003

Electroluminescent Properties of Heterocyclic Conjugated Random Copolymers Containing Phenothiazine and Carbazole Moieties

“…N-(2-ethylhexyl)-3,6-diformylphenothiazine (DFPZ) [12] Phosphoryl chloride (122.7 g, 0.8 mol) was added dropwise over a period of 30 min to a mixture of N-(2-ethylhexyl)phenothiazine (EHPZ) (12.36 g, 0.04 mol) and N,N-dimethylformamide (DMF) (58.5 g, 0.8 mol) in 1,2-dichloroethane (15 ml) in an ice bath. The solution was refluxed for 72 h. DFPZ was obtained as liquid in 69% yield.…”

“…1 N-(2-ethylhexyl)-3,6-diformylcarbazole (DFCZ) [13] Phosphoryl chloride (122.7 g, 0.8 mol) was added dropwise over a period of 30 min to a mixture of N-(2-ethylhexyl)carbazole (EHCZ) (11.18 g, 0.04 mol) and DMF (58.5 g, 0. 1,4-Bis(diethoxyphosphinylmethyl)benzene (PHBZ) [12] PHBZ was synthesized by reacting a,a 0 -dichloro-p-xylene (33 g, 0.2 mol) with triethylphosphite (33 g, 0.2 mol) at 120 C for 12 hr. The unreacted triethylphosphite was removed under reduced pressure.…”

“…Poly(N-2-ethylhexyl-3,6-phenothiazinylene vinylene-alt-1,4-phenylene vinylene) [poly(PZV-PV)] [12] To a solution of DFPZ (1.85 g, 0.005 mol) and PHBZ (1.90 g, 0.005 mol) in anhydrous tetrahydrofuran (THF) (40 ml) was added dropwise a solution of potassium tert-butoxide ( t BuOK) (4.73 g of purity 95%, 0.04 mol) in dry THF (20 ml) at room temperature under nitrogen atmosphere. After the addition of t BuOK the solution was stirred for 7 hr to give a polymer product as precipitate.…”

Luminescence properties of PPV-based conjugated polymers containing phenothiazine and phenothiazine-5-oxide units

“…Phenothiazine is a well-known heterocyclic compound with electron-rich nitrogen and sulfur heteroatom. Conjugated polymers and copolymers based on phenothiazine have been investigated [1][2][3][4][5][6][7]. It has been demonstrated that phenothiazine unit is an excellent p-type building block for lowering ionic potential of conjugated polymers due to its readily injection and transport of hole and the non-planarity of phenothiazine impedes p-stacking aggregation and intermolecular excimer formation which may lead to the poor quantum efficiency.…”

Synthesis and characterization of novel poly(p‐phenylenevinylene) derivatives containing phenothiazine‐5‐oxide and phenothiazine‐5, 5‐dioxide moieties

“…Known as fluorescent dyes, phenothiazine monomer can be easily tailored by connecting flexible groups to the N‐position to improve solubility or varying the aromatic structure with functional groups for further polymerization. Conjugated copolymers based on phenothiazine have been investigated in recent years 3–12. It has been demonstrated that phenothiazine unit is an excellent p ‐type building block for lowering ionic potential of conjugated polymers due to its readily injection and transport of hole.…”