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LnCl 3 (THF) 3 (Ln = Y, La ÷ Nd, Sm ÷ Lu) readily react with the tridentate 1,3,5-trimethyl-1,3,5-triazacyclohexane (Me 3 tach) 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 3 (Me 3 tach) 2 ], (Ln = Y, La ÷ Ho) or binuclear complexes [Ln 2 Cl 6 (Me 3 tach) 3 ], or [LnCl 3 (Me 3 tach)(THF)] 2 (Ln = Sm, Tb). Detailed analysis of the NMR data of [LnCl 3 (Me 3 tach) 2 ] complexes with paramagnetic lanthanide ions showed that their structures remained unchanged in the toluene solution. A series of isomorphous complexes [LnCl 3 (Me 3 tach)(Py) 2 ] (Ln = La, Sm, Tb, Er, Lu; Py = pyridine) have been obtained by the recrystallization of either mononuclear or binuclear complexes from pyridine. Complexes of terbium and europium ions with the Me 3 tach ligand exhibit relatively high quantum yields of metal-centered luminescence (0.39 and 0.32, respectively).

A 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%.

The air- and moisture-sensitive title compound, [Tb(C 5 H 5 ) 2 (C 14 H 12 NO 2 )], was synthesized from tris-(cyclo-penta-dien-yl)(tetra-hydro-furan)-terbium and 2-{[(2-meth-oxy-phen-yl)imino]-meth-yl}phenol. Each Tb atom is coordinated by two cyclo-penta-dienyl ligands in an η 5 -coordination mode and by one N and two O atoms of the organic ligand in a tridentate κ 3 O , N , O '-mode., (© Minyaev et al. 2022.)

Organophosphate-chloride complexes [{(2,6- i Pr 2 C 6 H 3 -O) 2 POO} 2 LnCl(CH 3 OH) 4 ]·2CH 3 OH, Ln = Nd ( 1 ), Eu ( 2 ), Gd ( 3 ), and Tb ( 4 ) have been obtained and structurally characterized. Their reaction with 2,2':6',2″-terpyridine leads to the formation of 1:1 adducts ([{(2,6- i Pr 2 C 6 H 3 -O) 2 POO} 2 LnCl(terpy)(H 2 O) 2 (CH 3 OH)], Ln = Eu ( 5 ), Gd ( 6 ), Tb ( 7 ) with exception of Nd, where tris-diisopropylphenylphosphate complex [{(2,6- i Pr 2 C 6 H 3 -O) 2 POO} 3 Nd) (terpy)(H 2 O)(CH 3 OH)] ( 8 ) 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. Photophysical properties of all complexes were analyzed by optical spectroscopy and an energy transfer scheme was discussed. A combination of two types of ligands into the coordination sphere (phosphate and phenanthroline) allows designing the Eu surrounding with very high intrinsic quantum yield QEuEu (0.92) and highly luminescent Ln complexes for both visible and near-infrared (NIR) regions.

The mononuclear title complex, [Eu(C 24 H 34 O 4 P) 3 (CH 4 O) 5 ]·CH 4 O, ( 1 ), has been obtained as a minor product in the reaction between EuCl 3 (H 2 O) 6 and lithium bis-(2,6-diiso-propyl-phen-yl) phosphate in a 1:3 molar ratio in a methanol medium. Its structure exhibits monoclinic ( P 2 1 / c ) symmetry at 120 K and is isostructural with the La, Ce and Nd analogs reported previously [Minyaev et al. (2018 a ▸). Acta Cryst. C 74 , 590-598]. In ( 1 ), all three bis-(2,6-diiso-propyl-phen-yl) phosphate ligands display the terminal κ 1 O -coordination mode. All of the hy-droxy H atoms are involved in O-H⋯O hydrogen bonding, exhibiting four intra-molecular and two inter-molecular hydrogen bonds. Photophysical studies have demonstrated luminescence of ( 1 ) with a low quantum yield., (© Kalugin et al. 2019.)

Reductive cyclization of 1,3,5-triphenyl- and 3-(2-meth-oxy-phen-yl)-1,5-di-phenyl-pentane-1,5-diones by zinc in acetic acid medium leads to the formation of 1,2,4-tri-phenyl-cyclo-pentane-1,2-diol [1,2,4-Ph 3 C 5 H 5 -1,2-(OH) 2 , C 23 H 22 O 2 , ( I )] and 4-(2-meth-oxy-phen-yl)-1,2-di-phenyl-cyclo-pentane-1,2-diol [4-(2-MeOC 6 H 4 )-1,2-Ph 2 C 5 H 5 -1,2-(OH) 2 , C 24 H 24 O 3 , ( II )]. Their single crystals have been obtained by crystallization from a THF/hexane solvent mixture. Diols ( I ) and ( II ) crystallize in ortho-rhom-bic ( Pbca ) and triclinic ( P ) space groups, respectively, at 150 K. Their asymmetric units comprise one [in the case of ( I )] and three [in the case of ( II )] crystallographically independent mol-ecules of the achiral (1 R ,2 S ,4 r )-diol isomer. Each hydroxyl group is involved in one intra-molecular and one inter-molecular O-H⋯O hydrogen bond, forming one-dimensional chains. Compounds ( I ) and ( II ) have been used successfully as precatalyst activators for the ring-opening polymerization of ∊-caprolactone.

The solvated centrosymmmtric title compound, [Li 2 (C 24 H 34 O 4 P) 2 (C 10 H 8 N 2 ) 2 ]·2C 7 H 8 , was formed in the reaction between {Li[(2,6- i Pr 2 C 6 H 3 -O) 2 POO](MeOH) 3 }(MeOH) and 2,2'-bi-pyridine (bipy) in toluene. The structure has monoclinic ( P 2 1 / n ) symmetry at 120 K and the asymmetric unit consists of half a complex mol-ecule and one mol-ecule of toluene solvent. The diaryl phosphate ligand demonstrates a μ-κ O :κ O '-bridging coordination mode and the 2,2'-bi-pyridine ligand is chelating to the Li + cation, generating a distorted tetra-hedral LiN 2 O 2 coordination polyhedron. The complex exhibits a unique dimeric Li 2 O 4 P 2 core. One isopropyl group is disordered over two orientations in a 0.621 (4):0.379 (4) ratio. In the crystal, weak C-H⋯O and C-H⋯π inter-actions help to consolidate the packing. Catalytic systems based on the title complex and on the closely related complex {Li[(2,6- i Pr 2 C 6 H 3 -O) 2 POO](MeOH) 3 }(MeOH) display activity in the ring-opening polymerization of ∊-caprolactone and l-dilactide.

The title compound, [Al 2 La 2 (C 20 H 15 O 2 ) 4 (CH 3 ) 6 (CH 3 O) 2 ]·4CH 3 C 6 H 5 or [{La(Ph 3 CCOO) 2 (Me 3 AlOMe)} 2 ]·4CH 3 C 6 H 5 , was formed in a reaction between lanthanum tris-(tetra-methyl-aluminate) and tri-phenyl-acetic acid (1:1) with unintended partial oxidation. The tri-phenyl-acetate ligand exhibits μ 2 -κ 1 O :κ 1 O ' bridging and μ 2 -κ 2 O , O ':κ 1 O semi-bridging coordination modes, forming a dimeric La 2 (μ-OCO) 4 core. The semi-bridging tri-phenyl-acetate group provides additional bonding with an La 3+ cation via the π-system of one of its phenyl rings. The tri-methyl-meth-oxy-aluminate anion, which is coordinated to the La 3+ cation by its O atom, displays a rather long La-C Me bond. Two toluene mol-ecules are each disordered over two orientations about centres of symmetry with site occupancy factors of 0.5. The title compound represents the first example of an Ln III complex containing both alkyl alkoxide aluminate and π-bounded arene fragments.

A simple and effective synthetic route to homo- and heteroleptic rare-earth (Ln = Y, La and Nd) complexes with a tridentate Schiff base anion has been demonstrated using exchange reactions of rare-earth chlorides with in-situ-generated sodium (E)-2-{[(2-methoxyphenyl)imino]methyl}phenoxide in different molar ratios in absolute methanol. Five crystal structures have been determined and studied, namely tris(2-{[(2-methoxyphenyl)imino]methyl}phenolato-κ 3 O 1 ,N,O 2 )lanthanum, [La(C 14 H 12 NO 2 ) 3 ], (1), tris(2-{[(2-methoxyphenyl)imino]methyl}phenolato-κ 3 O 1 ,N,O 2 )neodymium tetrahydrofuran disolvate, [La(C 14 H 12 NO 2 ) 3 ]·2C 4 H 8 O, (2)·2THF, tris(2-{[(2-methoxyphenyl)imino]methyl}phenolato)-κ 3 O 1 ,N,O 2 ;κ 3 O 1 ,N,O 2 ;κ 2 N,O 1 -yttrium, [Y(C 14 H 12 NO 2 ) 3 ], (3), dichlorido-1κCl,2κCl-μ-methanolato-1:2κ 2 O:O-methanol-2κO-(μ-2-{[(2-methoxyphenyl)imino]methyl}phenolato-1κ 3 O 1 ,N,O 2 :2κO 1 )bis(2-{[(2-methoxyphenyl)imino]methyl}phenolato)-1κ 3 O 1 ,N,O 2 ;2κ 3 O 1 ,N,O 2 -diyttrium-tetrahydrofuran-methanol (1/1/1), [Y 2 (C 14 H 12 NO 2 ) 3 (CH 3 O)Cl 2 (CH 4 O)]·CH 4 O·C 4 H 8 O, (4)·MeOH·THF, and bis(μ-2-{[(2-methoxyphenyl)imino]methyl}phenolato-1κ 3 O 1 ,N,O 2 :2κO 1 )bis(2-{[(2-methoxyphenyl)imino]methyl}phenolato-2κ 3 O 1 ,N,O 2 )sodiumyttrium chloroform disolvate, [NaY(C 14 H 12 NO 2 ) 4 ]·2CHCl 3 , (5)·2CHCl 3 . Structural peculiarities of homoleptic tris(iminophenoxide)s (1)-(3), binuclear tris(iminophenoxide) (4) and homoleptic ate tetrakis(iminophenoxide) (5) are discussed. The nonflat Schiff base ligand displays μ 2 -κ 3 O 1 ,N,O 2 :κO 1 bridging, and κ 3 O 1 ,N,O 2 and κ 2 N,O 1 terminal coordination modes, depending on steric congestion, which in turn depends on the ionic radii of the rare-earth metals and the number of coordinated ligands. It has been demonstrated that interligand dihedral angles of the phenoxide ligand are convenient for comparing steric hindrance in complexes. (4)·MeOH has a flat Y 2 O 2 rhomboid core and exhibits both inter- and intramolecular MeO-H...Cl hydrogen bonding. Catalytic systems based on complexes (1)-(3) and (5) have demonstrated medium catalytic performance in acrylonitrile polymerization, providing polyacrylonitrile samples with narrow polydispersity.

A 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. All terbium complexes are luminescent at ambient temperature and two of them have relatively high quantum yields (50 and 60%). Analysis of energy transfer process has been performed and supported by quantum chemical calculations. The role of a low-lying intraligand charge transfer state formed by extra coordination with K + in the Tb 3+ ion luminescence sensitization is discussed. New aspects for design of lanthanide complexes containing π-type ligands with desired luminescence properties have been proposed.

The title compounds, C 9 H 12 O 6 and C 10 H 14 O 6 , were formed by careful hydrolysis of the corresponding diethyl esters. Their single crystals were grown from an ethyl acetate/hexane mixture. Crystals of both compounds have monoclinic ( P 2 1 ) symmetry with a single mol-ecule in the asymmetric unit. Both crystal structures are very similar and display four -CO-OH⋯O=C(OH)- hydrogen bonds, forming a two-dimensional double-layered framework.

The first synthesized and X-ray structurally characterized "classical" iron(i) dioximate showed an unrivaled stability towards strong acids, thus calling for a reassessment of the origins of the electrocatalytic activity of similar low-valent cobalt and iron cage complexes with electron-withdrawing ribbed substituents, shown previously to be effective electrocatalysts of the HER.

The significant variety in the crystal structures of rare-earth carboxylate complexes is due to both the large coordination numbers of the rare-earth cations and the ability of the carboxylate anions to form several types of bridges between rare-earth metal atoms. Therefore, these complexes are represented by mono-, di- and polynuclear complexes, and by coordination polymers. The interaction of LnCl3(thf)x (Ln = Eu or Y; thf is tetrahydrofuran) with sodium or diethylammonium diphenylacetate in methanol followed by recrystallization from a DME/THF/hexane solvent mixture (DME is 1,2-dimethoxyethane) leads to crystals of the non-isomorphic dinuclear complexes tetrakis(μ-2,2-diphenylacetato)-κ(4)O:O';κ(3)O,O':O';κ(3)O:O,O'-bis[(1,2-dimethoxyethane-κ(2)O,O')(2,2-diphenylacetato-κ(2)O,O')europium(III)], [Eu(C14H11O2)6(C4H10O2)2], (I), and tetrakis(μ-2,2-diphenylacetato)-κ(4)O:O';κ(3)O,O':O';κ(3)O:O,O'-bis[(1,2-dimethoxyethane-κ(2)O,O')(2,2-diphenylacetato-κ(2)O,O')yttrium(III)], [Y(C14H11O2)6(C4H10O2)2], (II), possessing monoclinic (P21/c) symmetry. The [Ln(Ph2CHCOO)3(dme)]2 molecule (Ln = Eu or Y) lies on an inversion centre and exhibits three different coordination modes of the diphenylacetate ligands, namely bidentate κ(2)O,O'-terminal, bidentate μ2-κ(1)O:κ(1)O'-bridging and tridentate μ2-κ(1)O:κ(2)O,O'-semibridging. The terminal and bridging ligands in (I) are disordered over two positions, with an occupancy ratio of 0.806 (2):0.194 (2). The interaction of EuCl3(thf)2 with Na[Ph3CCOO] in methanol followed by crystallization from hot methanol produces crystals of tetrakis(methanol-κO)tris(2,2,2-triphenylacetato)-κ(4)O:O';κO-europium(III) methanol disolvate, [Eu(C19H15O2)3(CH3OH)4]·2CH3OH, (III)·2MeOH, with triclinic (P-1) symmetry. The molecule of (III) contains two O,O'-bidentate and one O-monodentate terminal triphenylacetate ligand. (III)·2MeOH possesses one intramolecular and four intermolecular hydrogen bonds, forming a [(III)·2MeOH]2 dimer with two bridging methanol molecules.

(1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-1,3,5-triphenylcyclohexan-1-ol or (4-hydroxy-2,4,6-triphenylcyclohexane-1,3-diyl)bis(phenylmethanone), C38H32O3, (1), is formed as a by-product in the NaOH-catalyzed synthesis of 1,3,5-triphenylpentane-1,5-dione from acetophenone and benzaldehyde. Single crystals of the chloroform hemisolvate, C38H32O3·0.5CHCl3, were grown from chloroform. The structure has triclinic (P1) symmetry. One diastereomer [as a pair of (1RS,2SR,3RS,4SR,5RS)-enantiomers] of (1) has been found in the crystal structure and confirmed by NMR studies. The dichoromethane hemisolvate has been reported previously [Zhang et al. (2007). Acta Cryst. E63, o4652]. (1RS,2SR,3RS,4SR,5RS)-2,4-Dibenzoyl-3,5-bis(2-methoxyphenyl)-1-phenylcyclohexan-1-ol or [4-hydroxy-2,6-bis(2-methoxyphenyl)-4-phenylcyclohexane-1,3-diyl]bis(phenylmethanone), C40H36O5, (2), is also formed as a by-product, under the same conditions, from acetophenone and 2-methoxybenzaldehyde. Crystals of (2) have been grown from chloroform. The structure has orthorhombic (Pca2₁) symmetry. A diastereomer of (2) possesses the same configuration as (1). In both structures, the cyclohexane ring adopts a chair conformation with all bulky groups (benzoyl, phenyl and 2-methoxyphenyl) in equatorial positions. The molecules of (1) and (2) both display one intramolecular O-H···O hydrogen bond.