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卷 49, 编号 8 (2023)
Articles
Reactions of Triangular Molybdenum and Tungsten Clusters with Tetrabromocatechol
摘要
The reaction of cluster complex (nBu4N)2[Mo3Se7Br6] with tetrabromocatechol (H2Tbc) in the presence of Et3N and Ph4PBr results in the formation of (Ph4P)2[Mo3Se7(Tbc)3]∙2MeOH (Ia∙2MeOH). Under the same conditions, the tungsten analogue (nBu4N)2[W3S7Br6] is completely or partly destroyed to give the complex (Ph4P)(Et3NH)[WO2(Tbc)2] (II). The structures of Ia·2MeOH and II were established by X-ray diffraction analysis (CCDC nos. 2213900 and 2213901, respectively). The redox properties of complex Ia and related (Ph4P)2[Mo3S7(Tbc)3] (Ib) and (Ph4P)2[Mo3S7(Tcc)3] (Ic) (Tcc is tetrachlorocatecholate) were also studied by cyclic voltammetry.
451-457
Spin Order Transfer from a Parahydrogen Molecule to a Cyanide Ion in the Iridium Complex under the SABRE Conditions
摘要
A possibility of generating a high degree of spin polarization of 13C and 15N nuclei in the cyanide ion, which forms the coordination bond with the metal ion, using parahydrogen is demonstrated for the first time for the new iridium carbene complex as an example. The spin–spin interaction constants in the synthesized complex and the structure of the hydride intermediate are determined by an analysis of the 13С NMR spectra detected using broadband and selective heteronuclear decoupling. The cyanide ion is shown to coordinate to the metal ion by the carbon atom in one of two equatorial positions, and two pyridine molecules are arranged in the axial and equatorial positions. The signal amplification factors for 13С and 15N nuclei of the cyanide anion (5665 and –49 555, respectively) are estimated by NMR spectroscopy of the polarized substrate using the SABRE method from an ultralow magnetic field of 0.5 μT. This amplification corresponds to 15.5% polarization of nitrogen nuclei achieved within several seconds at room temperature.
458-465
Tetranuclear Heterometallic Iron(II)–Lithium Carboxylates Stabilized by N-Donor Ligands: Synthesis and Structure
摘要
The multicomponent chemical reactions of Fe(SO4)∙7H2O, Li(Рiv), K(Рiv) (Рiv is pivalate anion), and heterocyclic N-donor ligands (pyridine (Рy), 1,10-phenanthroline (Рhen)) in anhydrous acetonitrile under an inert atmosphere afford new heterometallic tetranuclear complexes [FeII2
Li2(Рiv)6(Рy)4] (I) and [FeII2
Li2(Рiv)6(Рhen)2] (II) in which all carboxylate anions act as bridging ligands. The molecular and crystal structures of the compounds are determined by X-ray diffraction (XRD) (CIF files CCDC nos. 2220576 (I) and 2220577 (II·2CH3CN). In the studied complexes, the iron(II) atoms exist in the distorted octahedral ligand environment.
466-473
Complexes of Cu(II), Co(II), and Zn(II) Terephthalates with Hydroxyalkylamines
摘要
The reactions of Cu(II), Co(II), and Zn(II) terephthalates with hydroxyalkylamines (tris(2-hydroxyethyl)amine, bis(2-hydroxyethyl)amine, tris(hydroxymethyl)aminomethane, and bis(2-hydroxyethyl)aminotris(hydroxymethyl)methane) are studied for the first time. The structures and properties of the synthesized complexes are studied by IR spectroscopy, electronic absorption spectroscopy, mass spectrometry, and elemental and thermal analyses. The structure of the binuclear heteroligand [Cu2(TEA)2(Tph)]n·H2O complex is studied by single-crystal X-ray diffraction (XRD) (CIF file CCDC no. 2224437).
474-484
Molecular Switches of the LD-CISSS Type Based on Ni(II) Azomethine Bis-Chelate Complexes. Quantum Chemical Modeling
摘要
(DFT/B3LYP/6-311++G(d,p)) calculations were performed to study Ni(II) azomethine bis-chelates with photoactive moieties (imidazole and benzimidazole derivatives of azo compounds, azomethines, and stilbenes) exhibiting the behavior of molecular magnetic switches by the light-driven coordination-induced spin state switching (LD-CISSS) mechanism. The structural and energy characteristics of the complexes favorable to or restricting the applicability of these complexes as molecular switches were determined.
485-492
Trimethylplatinum(IV) Complexes for MOCVD Applications: A Physicochemical Study
摘要
The structure of trimethylplatinum(IV) iodide [(CH3)3PtI]4 (I) (CIF file CCDC no. 22330007) is refined. The structure of the synthesized for the first time trimethylplatinum(IV) complex with tridentate N,N,O-iminoketonate [(CH3)3Pt(C9H17N2O)] (II) is determined by X-ray diffraction (XRD) (CIF file CCDC no. 22330008). The purity of the isolated phases is confirmed by elemental analysis and IR and NMR spectroscopy. The thermal behavior of complex II is studied by thermogravimetry. The energies of ionization and fragmentation of the molecules of complex II leading to the formation of the most stable fragment [(CH3)3Pt]+ are estimated by quantum-chemical calculations. Complex II is tested in the MOCVD processes. The Pt films with the pronounced (111) texture and particle sizes about 100 nm are prepared on Si plates in the presence of oxygen.
493-503
Praseodymium and Erbium 1,2,4-Triphenylcyclopentadienyl Complexes
摘要
The reaction of triphenylcyclopentadienyl potassium with praseodymium and erbium chloride tetrahydrofuranates gives, depending on the reactant ratio, tetranuclear ate complexes, [{(Ph3C5H2)-Pr(THF)}2(µ2-Cl)2(µ3-Cl)3K]2(C7H8)4 (I) and [{(Ph3C5H2)Er(THF)}2(µ2-Cl)2(µ3-Cl)3K(THF)]2 (III), or binuclear ate complexes [(Ph3C5H2)2LnCl(KCl)]2 Ln = Pr (II), Er (IV) (CCDC nos. 2224244 (I), 2224243 (II), 2224245 (III), 2224242 (IV)). The structurally similar complexes I and III are based on the {[Ln2(µ-Cl)3]2(µ-Cl)2K2} core, and in III, the potassium cation is additionally coordinated to the THF molecule. The isostructural complexes II and IV have the binuclear [Ln(µ-Cl)2K]2 core.
504-512