Yu. E. Begantsova

Terbium-containing copolymers based on the norbornene functional derivatives. Synthesis, photoluminescent and electroluminescent properties

New carbazole- and terpyridine- containing norbornene derivatives were synthesized and structurally characterized. On the basis of these compounds by the method of metathesis polymerization copolymers were obtained with carbazole and terpyridine fragments in side chains. The synthesized copolymers react with terbium pyrazolonate complex to form the terbium-containing polymeric materials exhibiting the metalcentered photo- and electroluminescence.

Cyclometallated Iridium(III) Complex with the Norbornene Substituted Pyrazolonate Ligand and Related Copolymers: Syntheses, Structures, and Photophysical Properties

New cyclometallated iridium(III) complex (NBEpz)Ir(Ppy)2 · 2CH2Cl2 (I) (NBEpzH is 1-phenyl-3-methyl-4-(5-bicyclo[2.2.1]hept-5-en-2-yl)-5-pyrazolone, PpyH is 2-phenylpyridine) is synthesized and structurally characterized. Compound I undergoes metathesis polymerization and forms new iridium-containing copolymers. The photophysical properties of complex I and related copolymers are studied.

Iridium-containing polymers based on functionalized norbornenes as new efficient electroluminophores

The copolymer with carbazole and iridium-containing groups in the side chains (P1) and the terpolymer with additional organosilicon units (P2) were synthesized by the ring-opening metathesis polymerization (ROMP). The photoluminescence (PL) and electroluminescence (EL) properties of the synthesized polymeric materials were investigated. The iridium-containing terpolymer exhibited the most efficient EL characteristics: the maximum brightness is 1780 cd m−2 (21 V), the maximum current efficiency is 23.3 cd A−1 (13 V), and the maximum power efficiency is 6.4 lm W−1 (11 V). The color coordinates of the emission in the CIE (Commision Internationale de l’Eclairage) diagram (0.21, 0.71) correspond to the green color and remain virtually unchanged in the whole driving voltage range.

Cyclometallated iridium(III) complex with 2-(2,4-difluorophenyl)pyridyl and norbornene-substituted pyrazolonate ligands and related electroluminescent polymers

New cyclometallated iridium(III) complex, NBEPzIr(Dfppy)2 · 2CH2Cl2 (I) (NBEPzH is 1-phenyl-3-methyl-4-(5-bicyclo[2.2.1]hept-5-en-2-yl)-5-pyrazolone, and DfppyH is 2-(2,4-difluorophenyl)pyridine), is synthesized and structurally characterized. Copolymers with carbazole and iridium-containing fragments in side chains (P1–P4) are obtained from monomer I by the ROMP method (ROMP is Ring-Opening Metathesis Polymerization). Their photoluminescence and electroluminescence properties are studied. Copolymers P1–P4 exhibit the green electroluminescence. The maximum current efficiency (2.60 cd/A) and power efficiency (0.63 Lm/W) are reached using emitter P3.

A cyclometalated platinum(II) complex with the 4-isobutyryl-3-methyl-1-phenylpyrazol-5-onate ligand as a new efficient emitter for organic light-emitting diodes

Cyclometalated platinum(II) complexes are widely used as emitting materials in organic light emitting diodes (OLEDs).1,2 Platinum complexes with arylpyridine and  diketonate ligands are rated among the most efficient electroluminophors.3,4 Platinum(II) complexes of this type with pyrazolonate ligands remain least studied.5,6 Howev er, it has been demonstrated with iridium(III) complexes that pyrazolonate ligands ensure stronger electrolumines cence (EL) than do acetylacetonate ligands.7 For this rea son, we obtained a new platinum(II) phenylpyridine com plex with the 4 isobutyryl 3 methyl 1 phenylpyrazol 5 onate ligand according to the following scheme.

Carbene complexes of molybdenum and tungsten Et3E-CH=M(NAr)(OR)2 (M = Mo, W; E = Si, Ge) and π-complex of molybdenum (RO)2(ArN)Mo(CH2=CH-GeEt3). Synthesis and catalytic properties

The heteroelement-containing alkylidene imide complexes with molybdenum and tungsten Et3SiCH=Mo(NAr)(OR)2 (I), Et3 ECH=W(NAr)(OR)2 (E = Si (II), Ge (III); Ar = 2,6-i-Pr2C6H3; R=CMe2 CF3) and π-complex (RO)2(ArN)Mo(CH2=CH-GeEt3) (IV) were synthesized by the reaction of Alkyl-CH=M(NAr) (OR)2 (M=Mo, W; Alkyl = t-Bu, PhMe2C) with organosilicon and organogermanium vinyl reagents Et3ECH=CH2 (E = Si, Ge). The structure of compounds I–III was determined by X-ray diffraction (XRD). The complexes I–IV are active initiators of metathesis polymerization of cycloolefins.

Electroluminescent platinum-containing polymers based on functionalized norbornenes

A cyclometallated platinum(II) complex with 2-(2,4-difluorophenyl)pyridinyl and norbornene-substituted pyrazolonate ligands (1) was synthesized. Based on monomer 1, the copolymers with carbazole and platinum-containing fragments in the side chains (P1, P2) and terpolymers with additional organosilicon units (P3, P4) were obtained by ring-opening metathesis polymerization (ROMP). Photoluminescent and electroluminescent properties of the synthesized polymers were investigated. Copolymer P1 exhibited green electroluminescence, and polymeric emitters P2—P4 generated white irradiation. The maximum current efficiency (15.69 cd A–1) and maximum power efficiency (2.17 lm W–1) were reached for emitter P3.

Synthesis and luminescent properties of iridium(III) ionic binuclear complexes with 1,4-bis[2-(2-pyridyl)benzimidazolato]butane as a bridging ligand

New ionic binuclear complexes of iridium(III) containing 1,4-bis[2-(2-pyridyl)benzimidazolato]butane as a bridging ligand were synthesized. These compounds exhibit intensive photo- and electroluminescence of yellow-green, green-yellow, and pink colors. The maximal electroluminescence brightness was 4565 cd/m2.

Synthesis and structure of potassium 2-(pyridin-2-yl)-1H-benzo[d]imidazolate and preparation of related bis(diimine) ligands

A potassium derivative of 2-(pyridin-2-yl)-1H-benzo[d]imidazole (BenzimidK) is synthesized and structurally characterized (СIF file CCDC no. 1478559). The complex is used for the preparation of new bis(diimine) ligands containing different diimine fragments linked by the bridging (CH2)4 group.

Cyclometallated ionic iridium(III) binuclear complexes with a bisphenanthroline bridging ligand: Synthesis and photophysical properties

New iridium(III) ionic binuclear complexes, in which iridium-containing cyclometallated fragments are bound by a bridging bisphenanthroline ligand were synthesized. The compounds obtained show intensive photoluminescence of yellow and yellow-green colors.