LnCl(THF) (Ln = Y, La ÷ Nd, Sm ÷ Lu) readily react with the tridentate 1,3,5-trimethyl-1,3,5-triazacyclohexane (Metach) ligand to form mono- or binuclear lanthanide trichloride complexes, depending on the stoichiometry of the reaction and the ionic radius of the metal: mononuclear pseudosandwich [LnCl(Metach)], (Ln = Y, La ÷ Ho) or binuclear complexes [LnCl(Metach)], or [LnCl(Metach)(THF)] (Ln = Sm, Tb). Detailed analysis of the NMR data of [LnCl(Metach)] complexes with paramagnetic lanthanide ions showed that their structures remained unchanged in the toluene solution. A series of isomorphous complexes [LnCl(Metach)(Py)] (Ln = La, Sm, Tb, Er, Lu; Py = pyridine) have been obtained by the recrystallization of either mononuclear or binuclear complexes from pyridine.
View Article and Find Full Text PDFA series of potassium salts of di- and tri-arylsubstituted cyclopentadienes has been obtained by the metalation of the corresponding cyclopentadienes with benzylpotassium in THF media. Crystals of all compounds, afforded by recrystallization from THF/hexane, diglyme-THF/hexane and toluene/hexane mixtures, have been studied by X-ray diffraction. All studied potassium cyclopentadienides exhibit the luminescence at room temperature and overall quantum yield of photoluminescence for potassium salt of diarylsubstituted cyclopentadiene is 18%.
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July 2021
A series of heterometallic carboxylate 1D polymers of the general formula [LnCd(piv)(HO)]·nMeCN (Ln = Sm (), Eu (), Tb (), Dy (), Ho (), Er (), Yb (); piv = anion of trimethylacetic acid) was synthesized and structurally characterized. The use of Cd instead of Zn under similar synthetic conditions resulted in the formation of 1D polymers, in contrast to molecular trinuclear complexes with LnZn cores. All complexes - are isostructural.
View Article and Find Full Text PDFA series of bis-cyclometalated iridium(iii) complexes with 2-arylphenanthroimidazole "antenna" ligands containing electron-donor or withdrawing substituents and a more flexible ancillary aromatic β-diketone bearing the "anchoring" carboxymethyl function has been prepared. Thorough X-ray study of the complexes revealed significant structural strains caused by bulky cyclometalated 2-arylphenanthroimidazoles resulting in dramatic distortions of the iridium octahedron and even in twist of the phenanthrene fragment. The crystal data were corroborated by gas-phase DFT calculations whereby the geometry of the complexes was distorted in the same way.
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December 2020
Varying the temperature of the reaction of [{Cd(pfb)(HO)}·(pfb)], [Ln(pfb)(HO)]·HO (Hpfb = pentafluorobenzoic acid), and 1,10-phenanthroline (phen) in MeCN followed by crystallization resulted in the isolation of two type of products: 1D-polymers [LnCd(pfb)(phen)]1.5MeCN (Ln = Eu (I), Gd (II), Tb (III), Dy (IV)) which were isolated at 25 °C, and molecular compounds [TbCd(pfb)(phen)] (V) formed at 75 °C. The transition from a molecular to a polymer structure becomes possible because of intra- and intermolecular interactions between the aromatic cycles of phen and pfb from neighboring tetranuclear LnCd fragments.
View Article and Find Full Text PDFOrganophosphate-chloride complexes [{(2,6-PrCH-O)POO}LnCl(CHOH)]·2CHOH, Ln = Nd (), Eu (), Gd (), and Tb () have been obtained and structurally characterized. Their reaction with 2,2':6',2″-terpyridine leads to the formation of 1:1 adducts ([{(2,6-PrCH-O)POO}LnCl(terpy)(HO)(CHOH)], Ln = Eu (), Gd (), Tb () with exception of Nd, where tris-diisopropylphenylphosphate complex [{(2,6-PrCH-O)POO}Nd) (terpy)(HO)(CHOH)] () was obtained due to the ligand metathesis. A bright luminescence observed for the Eu and Tb organophosphate complexes is the first example of an application of organophosphate ligands for 4f-ions luminescence sensitization.
View Article and Find Full Text PDFThe mononuclear title complex, [Eu(CHOP)(CHO)]·CHO, (), has been obtained as a minor product in the reaction between EuCl(HO) and lithium bis-(2,6-diiso-propyl-phen-yl) phosphate in a 1:3 molar ratio in a methanol medium. Its structure exhibits monoclinic (2/) symmetry at 120 K and is isostructural with the La, Ce and Nd analogs reported previously [Minyaev (2018 ▸). C, 590-598].
View Article and Find Full Text PDFThe possibility of using a single light-emitting layer consisting of newly synthesized fluorescent small organic molecules of D-A-π-A type incorporated into a conductive matrix together with an electron conductive Alq layer in order to form radiation in candle light-style OLEDs was shown for the first time. A record low color temperature of 1722 K OLED radiation was achieved, which is by 80 K lower than that of the best devices reported previously.
View Article and Find Full Text PDFA new approach to design "antenna-ligands" to enhance the photoluminescence of lanthanide coordination compounds has been developed based on a π-type ligand-the polyphenyl-substituted cyclopentadienyl. The complexes of di-, tri-, and tetraphenyl cyclopentadienyl ligands with Tb and Gd have been synthesized and all the possible structural types from mononuclear to di- and tetranuclear complexes, as well as a coordination polymer were obtained. All types of the complexes have been studied by single-crystal X-ray diffraction and optical spectroscopy.
View Article and Find Full Text PDFA family of brightly luminescent dinuclear complexes of [Cu(μ-X)(N^N)] type (X = I or SCN) has been synthesized in 76-90% yields by the reaction of bis(2-pyridyl)phosphine oxides (N^N) with the corresponding Cu(i) salts. The X-ray diffraction study reveals that the CuI core of the [Cu(μ-I)(N^N)] complexes has either a butterfly- or rhomboid-shaped structure, while the eighth-membered [Cu()Cu] ring in the [Cu(SCN)(N^N)] complexes is nearly planar. In the solid state, these compounds exhibit a strong green-to-yellow emission (λ = 536-592 nm) with high PLQYs (up to 63%) and short lifetimes (1.
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