Various strategies for producing lanthanide-containing luminescent sensors, which were used mainly in the studies of 2015–2021, are considered. The review is structured according to the types of ...sensor response and analyte nature. Particular attention is focused on the mechanisms of sensor response to a certain analyte.
DFT B3LYP/6-311+G* density functional calculations for a model of the thermal degradation of 1.1'-diacetylferrocene show that at the first stage, redox disproportionation of 1.1'-diacetylferrocene ...proceeds with traces of water and the formation of unstable coordinatively unsaturated 17-electron compounds. It is established that the decomposition of these compounds under conditions of the dehydration of resin products results in the formation of magnetite.
Nuclear gamma resonance (NGR) is used to study powders of externally homogeneous magnetite-like substances that form in the reaction between 1,1'-diacetylferrocene and ε-caprolactam or ...2-aminoethanesulfonic acid in a relatively low range of temperatures (100–180°C). The powders are shown to consist of magnetite and a ferrocene-containing matrix that contains 1,1'-diacetyleferrocene and an organic nitrogen-containing component. In studying the temperature dependence of the NGR spectra in the range of 295–80 K, it is established that a fast effective exchange of electrons occurs in the samples both internally and between two Fe
2+
/Fe
3+
subsystems, ferrocene/ferricenium and sublattice
B
of magnetite. As a result, classical mechanisms of electron exchange retardation and the phase ordering of the magnetite structure do not work, and no Verwey transition is observed in the samples.
A series of 32 heterometallic ionic complexes CeNi
6
(Ala)
12
(Ln
x
Ce
1 –
x
)(NO
3
)
3
(OH)
3
(H
2
O) (Ln = Tb, Ho, Er, Tm, Yb, Lu) have been synthesized and characterized by XRD and IPC-MS. The ...dependence of the degree of substitution of lanthanides in the anionic position on the nature of Ln
3+
and precipitation conditions has been determined. The processes occurring during the formation of the complexes have been studied by UV-Vis, diffuse reflectance electronic spectroscopy, and ICP-MS. Based on these data, a model of equilibria in the system was proposed to explain the increase in the degree of substitution of Ln in the anionic position in the lanthanide series and with a decrease in the concentration of Ce and Ln in the solution from which precipitation is performed.
This paper presents the results of an experiment determining (n,2n), (n,p), (n,pn), (n,α), (n,n'γ), and (n,γ) reaction rates in 15 test samples of both natural and high-enriched composition:
nat
Mg,
...27
Al,
nat
Ti,
nat
Fe,
59
Co,
nat
Ni,
63
Сu (99.5%),
65
Cu (99.7%),
64
Zn (99.4%),
nat
Zr,
93
Nb,
nat
Cd,
nat
In,
169
Tm, and
197
Au. Computer simulations in the NG-24M neutron generator spectrum were carried out using the MCNP5 and KIR2 radiation transport codes with different nuclear data libraries (JEFF-3.2, JEFF-3.3, JENDL-4.0, ENDF/B-VII.0, ENDF/B-VII.1, ENDF/B-VIII.0, ROSFOND-2010, FENDL-3.0, TENDL-2019, and IRDFF-II). The elaborated full-scale model for neutron transport analysis included the geometry and composition of the neutron generator, experimental samples, and laboratory room. The mean square deviation factor was used to compare the experimental and the simulated results. The best predictive results for both the MCNP5 code and the KIR2 code were obtained with the FENDL-3.0 and ENDF/B-VIII.0 libraries.
The reaction of α-ferrocenyl(phenyl)methanol with various azoles under the phase transfer catalysis conditions afforded a series of ferrocenyl(alkyl)azoles in high yields. The structure of ...ferrocenyl(phenylmethyl)-3-trifluoromethyl-5-(2-thienyl)pyrazole was established by X-ray diffraction. The formation of a biradical cation from the intermediately formed ferrocenyl(phenyl)-carbenium ion, FcCH(Ph)
+
, was detected by ESR spin trap technique. Despite the demonstrated possibility of the formation of biradical cations, no products characteristic of the radical reaction pathway were found, which may serve as an indirect evidence that the reaction follows the S
N
1
-mechanism.
The reaction of 4,4,5,5,6,6,6-heptafluoro-1-(1-methyl-1
H
-pyrazol-4-yl)hexane-1,3-dione (HPyrC
3
F
7
) with freshly precipitated hydrated europium(ɪɪɪ) and samarium(ɪɪɪ) hydroxides in EtOH afforded ...crystalline complexes of the composition Ln(PyrC
3
F
7
)
3
(EtOH)
2
, the features of their formation depending on the stoichiometric ligand/metal ratios were studied. The structure and composition of the complexes were characterized by physicochemical methods, including single-crystal X-ray diffraction. The luminescent properties of these compounds in the crystalline state and in solutions were studied in detail. Possible ways of transferring electronic excitation in the complex Eu(PyrC
3
F
7
)
3
(EtOH)
2
were considered.
New complex RuL(Dmdcbp)
2
PF
6
(
I
) is synthesized by the consecutive reactions of Ru-
p
-cymene
2
Cl
4
with 3,3',5,5'-tetramethyl-1,1'-biphenyl-4,4'-bipyrazole (L) and ...4,4'-dicarboxy-2,2'-bipyridine in a methanol–chloroform medium. The composition of complex
I
is confirmed by NMR and elemental analysis, and the optical and luminescence properties of the complex are studied. Ligand L is characterized for the first time by X-ray diffraction (CIF file CCDC no. 2118676). Quantum chemical calculations in terms of the density functional theory are performed for the interpretation of the absorption and emission spectra. Complex
I
is promising for using as a photosensitizer.
The oxidation reaction of 3,3′,5,5′-tetramethyl-1H,1′H-4,4′-bipyrazole in the HNO
3
–Fe
3+
system unexpectedly resulted in the formation of 1Н-pyrazole-3,4,5-tricarboxylic acid (H
3
PTCA) isolated as ...the acid sodium salt Na(H
2
O)
2
H
2
PTCA. The compound has a polymeric structure stabilized by rare seven-membered Н-bonded rings.
Complexes {(NMe
2
H
2
)Ln(TDA)(HCOO) ∙ 0.5H
2
O)} are prepared by the solvothermal synthesis in a water–dimethylformamide (1 : 1) system from a mixture of 1,2,3-triazole-4,5-dicarboxylic acid (H
3
...TDA), NaOH, and Ln(NO
3
)
3
(Ln = Eu, Gd). The crystal structure of the europium complex is determined by X-ray structure analysis (CIF file CCDC no. 1939689). This compound is shown to be the ionic metal-organic framework, where the cavities in the anionic structure of Eu(TDA)(HCOO)
–
are partially occupied by the dimethylammonium cations and water molecules. The study of the luminescence spectra of the gadolinium derivative gives the energy of the triplet level of the H
3
TDA ligand (~25 300 cm
–1
), the value of which makes it possible to efficiently sensitize the luminescence of rare-earth metal ions, in particular, Eu
3+
. The decay kinetics and the emission and excitation spectra of the heterometallic derivatives {(NMe
2
H
2
)Gd
1 –
x
Eu
x
(TDA)(HCOO) ∙ 0.5H
2
O)} are studied. The dilution of europium with gadolinium results in a substantial decrease in the concentration quenching of the europium luminescence and an increase in the observed lifetimes of the excited state of Eu
3+
.
