In this article, thin films of bare Alq3 and hybrid sandwich (Alq3/In/Alq3) structure were fabricated over the glass substrate are taken for investigations. The Altered properties by incorporation of ...metal In between the polymeric layers have been investigated. The metal ‘In’ phase in Alq3/In/Alq3 structure was observed in structural analysis. SEM analysis insists an altered surface comprising spherical ‘In’ grains and polymeric Alq3 rods. Optical absorbance spectra revealed a strong absorption in the visible region and transmittance in the infrared region. The optical transitions are direct allowed transitions, and the estimated values are 2.86 eV and 2.43 eV for bare and multilayered systems, respectively. A characteristic green emission was observed in both cases, with a slight blue shift upon indium incorporation. The fluorescence decay profiles confirmed a delayed relaxation at 19.6 ns against 15.6 ns of bare Alq3 film.
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•The XRD analysis has affirmed the existence of Indium with a sharp crystalline peak.•The incorporated indium has led to a hierarchical growth of polymeric nanorods over the closely packed spherical indium nanoparticles.•The vibrational bands ensured the presence of α phase mer-Alq3 in both bare and multilayer thin film structure.•The metal-organic interface narrowed the bandgap from 2.86 to 2.49 eV by metal screening effect.•The PL and CIE analysis have confirmed the green emission of meridional Alq3 with a delayed fluorescence at 19.6 ns.
A series of facial
fac
-Ir(5-R-bzq)
3
and meridional
mer
-Ir(5-R-bzq)
3
Ir(III) complexes bearing benzo
h
quinoline-based ligands have been studied with the help of density functional theory (DFT) ...methods. A detailed electronic structure comparison of the two isomers has been addressed to point out the differences in their stability and photophysical properties. An influence of substituent impact on optical and electronic properties of Ir(III) homoleptic complexes was also explored by introducing into the cyclometalated ligands substituents characterized with different electronic properties, e.g., R = H, F, OPh, NMe
2
, C
6
F
5
, and
p
-C
6
H
4
-NPh
2
. The results herein show that
fac
and
mer
isomers exhibit remarkable differences in stability and photophysical properties. The introduction of different functional groups into bzq ligands, despite very similar geometrical structures, significantly affected HOMO and LUMO energy levels and energy gaps of the examined Ir(III) complexes.
A mononuclear molecular complex fac-VCl3(diglyme) (1) resulted from the reaction of VCl3 and diglyme (diglyme = di(2-methoxyethyl)ether) in dichloromethane. The violet complex 1 is a sensitive ...substance which slowly oxidized to a new, blue mononuclear molecular complex, fac-VOCl2(diglyme) (2) in the presence of air. The synthesis of iron(II), iron(III) complex FeCl(diglyme)(THF)2FeCl4)2 (3) was achieved by the reaction of yellow-green, partly oxidized FeCl2.4H2O, diglyme and chlorotrimethyl-silane in tetrahydofuran. The compound consists of the dinuclear cations with octahedral environment of iron(II) and the tetrahedral anions of iron(III). A pure iron(II) chloride-diglyme complex FeCl2(diglyme)2 (4) was gained by the reaction of freshly prepared iron(II) chloride hydrate, diglyme and chlorotrimethylsilane in dichloromethane. Diglyme is coordinated in the meridional mode to octahedral iron(II) in dinuclear cations of 3 and in dinuclear molecules 4.
A complex of BiCl
3 with 1-methyl-2(3
H)-imidazolethione (
meimtH) has been prepared and characterized. The structure consists of two different bismuth coordination spheres. One is distorted ...octahedral with three
meimtH in meridional configuration and is tethered via hydrogen bonding to a dimeric pair of octahedra sharing a common edge through bridging chlorine atoms.
A new bismuth(III) chloride complex with 1-methyl-2(3
H)-imidazolethione (
meimtH) has been synthesized and characterized via standard methods including solid state
13C nuclear magnetic resonance (NMR) and single crystal X-ray diffractometry. The complex, BiCl
3
meimtH
2.5
·
H
2O, crystallizes in a triclinic space group. The complex has two different coordination spheres for bismuth, which are linked together in the solid state via hydrogen bonding. One coordination sphere is distorted octahedral with the ligands in meridional positions, while the other is a dimer consisting of two octahedra sharing a common edge through bridging chlorine atoms. The ligands are
cis to each other and
trans to the chlorine bridges, while the remaining four chlorine atoms are
trans to each other and perpendicular to the chlorine–sulfur plane. There is no strong evidence for a stereoactive lone pair in either coordination sphere.
The synthesis of 2-(2′-hydroxy-3′-allylphenyl)-4,4-dimethyl-2-oxazoline, H-Allox (
3
), and lanthanide tris chelate complexes, mer-Ln(Allox)
3
(Ln = La (
4
), Ce (
5
), Sm (
6
), Er (
7
), and Y (
8
...)), derived from it are reported. A six-coordinate mer geometry without alkene coordination was confirmed in the solid state by X-ray crystallography for
5
and
7
. Variable-temperature NMR experiments suggested that this is the most stable isomer in solution as well, although the inequivalent ligand environments undergo rapid averaging at room temperature for all five complexes. A mechanistic investigation indicated that this fluxional process is an intramolecular six-coordinate rearrangement, but it was not possible to distinguish between a Bailar (trigonal) or RâyDutt (rhombic) twist. Kinetic parameters for the fluxional process were determined by line shape analysis for
8
yielding ΔH
= 24 ± 2 kJ mol
1
and ΔS
= 99 ± 10 J mol
1
K
1
. The structural and dynamic features of
4
8
were compared with the related In, Ga, and Al tris(2-oxazolylphenoxides).Key words: oxazoline, phenoxide, lanthanide, Group 3, RâyDutt twist, Bailar twist, Eyring plot, X-ray crystallography, mer isomer, variable-temperature NMR, line shape analysis, dynamic NMR, paramagnetic NMR, bidentate ligands.
The stereoselective synthesis of geometrical iron(II) complexes bearing azine-NHC ligands is described. Facial and meridional selectivity is achieved as a function of the steric demand of the azine ...unit, with no remarkable influence of the carbene nature. More specifically, meridional complexes are obtained upon selecting bulky 5-mesityl-substituted pyridyl coordinating units. Unexpectedly, increase of the steric hindrance in the α position with respect to the N coordinating atom results in an exclusive facial configuration, which is in stark contrast to the meridional selectivity induced by other reported α-substituted bidentate ligands. Investigation of the structure and the optical and electrochemical properties of the here-described complexes has revealed the non-negligible effect of the fac/mer ligand configuration around the metal center.
Two geometrical isomers pink-Co(bbes)
2
2+ and blue-Co(bbes)
2
2+ were obtained when the complexes were prepared by using with bis(benzimidazol-2-ylethyl)sulfide (bbes). The octahedral structure of ...pink-Co(bbes)
2
2+ was resolved by X-ray analysis. The electronic spectra of pink-Co(bbes)
2
2+ differs markedly with those of blue-Co(bbes)
2
2+. The redox potentials Co(II)/Co(I) of the complexes follow the trend Co(bbma)
2
2+
<
Co(bbms)
2
2+
≈
Co(bbes)
2
2+ which demonstrates the stabilization of the Co(II) ion is more by both weak σ-donor and weak π-acceptor ligands rather than by σ-donor ligand.
1:1 and 1:2 cobalt complexes of bis(benzimidazol-2-ylmethyl)amine (bbma) bis(benzimidazol-2-ylmethyl)sulfide (bbms), bis(benzimidazol-2-ylethyl)sulfide (bbes) and diethylenetriamine (dien) were prepared and their spectral and redox behavior studied. Two geometrical isomers pink-Co(bbes)
2
2+ and blue-Co(bbes)
2
2+ were obtained when the complexes were prepared by using with bbes and they were separated manually and recrystallized. The octahedral structure of pink-Co(bbes)
2
2+ was resolved by X-ray analysis. The electronic spectra show the presence of two geometrical isomers for Co(bbes)
2
2+ in the solid state; for example, the spectral bands of pink-Co(bbes)
2
2+ differs markedly with those of blue-Co(bbes)
2
2+. This is consistent with the results obtained from magnetic measurements (5.10 BM for pink-Co(bbes)
2
2+ and 4.72 BM for blue-Co(bbes)
2
2+). Further, the behavior of the ligands (bbma, bbms, bbes) at different pH conditions was determined on the basis of
13C NMR studies. The redox potentials Co(II)/Co(I) of the complexes follow the trend Co(bbma)
2
2+
<
Co(bbms)
2
2+
≈
Co(bbes)
2
2+ which demonstrates the stabilization of the Co(II) ion is more by both weak σ-donor and weak π-acceptor ligands rather than by σ-donor ligand.
The tris(2-chloromethyl-4-oxo-4H-pyran-5-olato-κ
2
O
5
,O
4
)iron(III), Fe(kaCl)
3
, has been synthesized and characterized by the crystal structure analysis, magnetic susceptibility measurements, ...Mössbauer, and EPR spectroscopic methods. The X-ray single crystal analysis of Fe(kaCl)
3
revealed a mer isomer. The magnetic susceptibility measurements indicated the paramagnetic character in the temperature range of 2 K-298 K. The EPR and Mössbauer spectroscopy confirmed the presence of an iron center in a high-spin state. Additionally, the temperature-independent Mössbauer magnetic hyperfine interactions were observed down to 77 K. These interactions may result from spin-spin relaxation due to the interionic Fe
3+
distances of 7.386 Å.
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