Mononuclear coordination complexes of Mn(II) and Co(II) with ferrocenecarboxylic acid (FcCOOH) with the composition (NBu
4
)
2
M
(FcCOO)
3
(H
2
O)
2
)(FcCOO) are prepared. The XRD study showed that ...the distorted octahedral environment of the metal atom is formed by oxygen atoms of two water molecules and three FcCOO
–
anions in such a way that two anions are monodentate coordinated and one anion is bidentate-cyclic. The fourth anion is H-bonded with coordinated water molecules. Negatively charged {
M
(FcCOO)
3
(H
2
O)
2
)(FcCOO)}
–
fragments, containing a new type of mononuclear transition metal carboxylate complex, are separated by tetrabutylammonium cations.
The reactions of 5,6-dichlorofurazano3,4-
b
pyrazine with phenyl- and methylhydrazines were studied in order to prepare furazano3,4-
b
pyrazine derivatives potentially capable of being oxidized to ...paramagnetic derivatives. The synthesis of new polyheterocyclic compounds containing the furazano3,4-
b
pyrazine structural moiety annulated to the tetrazine or triazole ring is described. The structures of all compounds were confirmed by X-ray diffraction.
2-Hydroxy-3,5-dinitrophenyl-substituted nitronyl nitroxides (L
NN
) and imino nitroxides (L
IN
) were isolated as stable sodium salts NaL
NN
and NaL
IN
. The reaction of NaL
NN
with NaNO
2
—AcOH ...affords both NaL
IN
and products of deeper reduction. The structures of NaL
NN
, NaL
IN
, and the reduced substrates were determined by single-crystal X-ray diffraction.
Activation of an apical Ca2+-dependent Cl− channel (CaCC) is the rate-limiting step for fluid secretion in many exocrine tissues. Here, we compared the properties of native CaCC in mouse ...submandibular salivary gland acinar cells to the Ca2+-gated Cl− currents generated by Tmem16A and Best2, members from two distinct families of Ca2+-activated Cl− channels found in salivary glands. Heterologous expression of Tmem16A and Best2 transcripts in HEK293 cells produced Ca2+-activated Cl− currents with time and voltage dependence and inhibitor sensitivity that resembled the Ca2+-activated Cl− current found in native salivary acinar cells. Best2−/− and Tmem16A−/− mice were used to further characterize the role of these channels in the exocrine salivary gland. The amplitude and the biophysical footprint of the Ca2+-activated Cl− current in submandibular gland acinar cells from Best2-deficient mice were the same as in wild type cells. Consistent with this observation, the fluid secretion rate in Best2 null mice was comparable with that in wild type mice. In contrast, submandibular gland acinar cells from Tmem16A−/− mice lacked a Ca2+-activated Cl− current and a Ca2+-mobilizing agonist failed to stimulate Cl− efflux, requirements for fluid secretion. Furthermore, saliva secretion was abolished by the CaCC inhibitor niflumic acid in wild type and Best2−/− mice. Our results demonstrate that both Tmem16A and Best2 generate Ca2+-activated Cl− current in vitro with similar properties to those expressed in native cells, yet only Tmem16A appears to be a critical component of the acinar Ca2+-activated Cl− channel complex that is essential for saliva production by the submandibular gland.
The structures of Ni(II), Cu(II), and Zn(II) complexes with anions of 2,5-pyrrolyl-disubstituted nitronyl nitroxide (L
1
) and iminonitroxide (L
2
) diradicals (HL
1
is 2,2′-(1
H
...-pyrrole-2,5diyl)-bis(4,4,5,5-tetramethyl-4,5-dihydro-1
H
-imidazole-3-oxide-1-oxyl; HL
2
is 2,2′-(1
H
-pyrrole-2,5-diyl)-bis(4,4,5,5-tetramethyl-4,5-dihydro-1
H
-imidazole-1-oxyl) are studied. It is established that in all synthesized compounds, a tridentate meridional coordination of paramagnetic ligands is responsible for a distorted octahedral environment of the metal ion. In
bis-chelates, the metal ion environment is an octahedron compressed along the N
Pyr
–
M
–
M
Pyr
axis. When one of the ligands in the
molecule is replaced by a reduced L
2H
monoradical, a typical Cu(II) environment in the form of elongated octahedron arises in CuL
2
L
2H
. It is found that in
complexes with bis-nitronyl nitroxide, the character of the temperature dependence of the effective magnetic moment μ
eff
(
T
) is determined by antiferromagnetic exchange in coordinated diradicals. In
complexes with iminonitroxides, ferromagnetic exchange interactions between unpaired electrons of the metal ion and diradicals dominate.
New nitronyl nitroxide radicals, 2-(4′(5′)-methylimidazol-2′-yl)- and 2-(4′(5′)-trifluoromethylimidazol-2′-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1
H
-imidazole-1-oxyl 3-oxide, were synthesized. The ...molecular and crystal structures of the paramagnetic trifluoromethyl derivative were determined. A previously unknown type of hydrogen bonding of imidazol-2-yl-substituted nitronyl nitroxides to form ribbons was established. Within the ribbons, the molecules face in the same direction, with all oxygen atoms of the paramagnetic moieties being involved in H-bonding. The spectral and electrochemical properties of the radicals were compared. The first quantum chemical calculations of the electronic spectra of nitronyl nitroxide radicals taking account of the vibrational structure were performed.
Is to identify the effectiveness of cooperation between forensic expert institutions on the basis of approaches to determining their one-pointedness. Legislative and regulatory legal acts regulating ...forensic expert activity have been studied. Methods of synthesis, analysis and comparison have been used for their processing. The comparison of the carrying out of targeted diversified studies has been conducted. The article substantiates a necessity of uniform approaches to determination of one-pointedness of forensic expert institutions in order to increase the effectiveness of interdepartmental interaction.
Crystalline Cs salts with the difurazanopyrazine radical anion are synthesized: Cs(L
•
)(H
2
O)
2
-I, Cs(L
•
)(H
2
O)
2
-II, Cs
2
(L
•
)
2
(HL
•
)(H
2
O), Cs
3
(L
•
)
3
(L
••
)
2
(H
2
O)
3
. In the ...solid phase, Cs ions are surrounded by water molecules and are located between the stacks of difurazanopyrazines, forming a framework. The study of the structure and magnetic properties of the compounds shows that Cs(L
•
)(H
2
O)
2
-I represents a metastable phase that transforms into Cs(L
•
)(H
2
O)
2
-II on cooling and differs from the initial compound by a shift of radical anions relative to each other in the stacks. It is found that in Cs(L
•
)(H
2
O)
2
-II there is strong antiferromagnetic exchange between paramagnetic centers.
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