ISSN 10703284, Russian Journal of Coordination Chemistry, 2015, Vol. 41, No. 10, pp. 681–687. © Pleiades Publishing, Ltd., 2015.
Original Russian Text © A.V. Rozhkov, E.V. Baranov, V.A. Il’ichev, A.O. Korshunov, L.N. Bochkarev, 2015, published in Koordinatsionnaya Khimiya, 2015, Vol. 41, No. 10,
It is known that some boron complexes with
chelating O,O and N,Oligands manifest efficient EL
properties and can generate radiation in the blue,
green, and red spectral ranges [1, 2]. As compared to
the presently known most efficient electrolumino
phores based on the iridium and platinum compounds
[3, 4], the organoboron emitters are favorable due to a
significantly lower cost, a less laborconsuming syn
thesis, and the absence of toxic properties. Therefore,
studies on the synthesis of new electroluminescent
boron compounds are being continuously developed.
The EL efficiency and color of organoboron emitters
are determined, to a significant extent, by the nature of
the ligands bound to the boron atom. It was shown in
a series of works that the inclusion of oxyquinoline and
aryl ligands into the boron complexes induced effi
cient EL properties in these complexes [5–7].
In this work, we report the syntheses, structures,
and the PL and EL properties of the new boron com
plexes with mesityl and 8oxyquinoline ligands.
All procedures with easily oxidizable and hydrolyz
able substances were carried out in vacuo or in argon
according to the standard Schlenk procedure. The sol
vents used were thoroughly purified and degassed.
) was synthesized
using a known procedure . 8Hydroxyquinoline
(QH), 2methyl8hydroxyquinoline (Q
bazole (PVK), and 4,7diphenyl1,10phenanthroline
(BATH) (Aldrich) were used without additional puri
B NMR spectra were recorded on a
Bruker Avance III–400 spectrometer (
C NMR: 100 MHz,
128 MHz). Chemical shifts were given in ppm relative
to tetramethylsilane as an internal standard. IR spec
tra were measured on an FSM 1201 FTIR spectrome
ter. Samples of complexes
were prepared by
pressing pellets (ratio substance : KBr = 1 : 200).
Electronic absorption spectra were recorded on a
PerkinElmer Lambda 25 UV/VIS spectrometer. Pho
toluminescence spectra were obtained on a Perkin
Elmer LS 55 fluorescence spectrometer. The relative
quantum yield in a
solution was determined at
room temperature (excitation wavelength 360 nm).
The values of quantum yields were calculated relative
to Rhodamine 6G in alcohol (
= 0.95)  using a
known procedure .
Electroluminescence spectra, current densityvolt
age and luminancevoltage characteristics, and CIE
chromaticity coordinates were obtained on model
OLED devices without encapsulation using an auto
mated computerconjugated complex including a GW
INSTEK PPE3323 power source, a GW INSTEK
GDM8246 digital multimer, and an Ocean Optics
USB 2000 spectrofluorimeter.
A suspension of NaH
(0.018 g, 0.74 mmol) in THF (3 mL) was added to a
solution of QH (0.11 g, 0.74 mmol) in THF (6 mL).
The mixture was stirred at room temperature for 2 h.
The obtained solution of the sodium salt was added by
Boron Complexes with Mesityl and Oxyquinoline Ligands:
Syntheses, Structures, and Luminescence Properties
A. V. Rozhkov
, E. V. Baranov
, V. A. Il’ichev
, A. O. Korshunov
, and L. N. Bochkarev
G.A. Razuvaev Institute of Organometallic Chemistry, Russian Academy of Sciences,
ul. Tropinina 49, Nizhny Novgorod, 603600 Russia
Nizhny Novgorod State University, pr. Gagarina 23, Nizhny Novgorod, 603600 Russia
Received March 4, 2015
—New oxyquinoline boron complexes Mes
) and Mes
), where QH is 8hydrox
yquinoline and Q
H is 2methyl8hydroxyquinoline, (CIF files CCDC 1051351 (
) and 1051352 (
synthesized and structurally characterized. Their photoluminescence (PL) and electroluminescence (EL)
properties are studied. The compounds have an intense green PL. The EL characteristics of complexes
doped in polyNvinylcarbazole (PVK) differ substantially. Compound
generates green luminescence
with a brightness of 356 cd/m
, whereas white EL with a brightness of 36 cd/m
is observed in the case of com