Trapping Aluminum Hydroxide Clusters with Trisilanols during Speciation in Aluminum(III)–Water Systems: Reproducible,Large Scale Access to Molecular Aluminate Models

To gain molecular level insights into the properties of certain functions and units of extended oxides/hydroxides, suitable molecular model compounds are needed. As an attractive route to access such compounds the trapping of early intermediates during the hydrolysis of suitable precursor compounds with the aid of stabilizing ligands is conceivable, which was tested for the aluminum(III)/water system. Indeed, trisilanols proved suitable trapping reagents: their presence during the hydrolysis of AlⁱBu₂H in dependence on the amount of water used allowed for the isolation of tri‐ and octanuclear aluminum hydroxide cluster complexes [Al₃(μ₂‐OH)₃(THF)₃(PhSi(OSiPh₂O)₃)₂] ( 1 ) and [Al₈(μ₃‐OH)₂(μ₂‐OH)₁₀(THF)₃(p‐anisylSi(OSiPh₂O)₃)₄] ( 2 ). 1 can be regarded as the Al(OH)₃ cyclic trimer, where six protons have been replaced by silyl residues. While 2 features a unique [Al₈(μ₃‐OH)₂(μ₂‐OH)₁₀]¹²⁺ core. In contrast to most other known aggregates of this type, 1 and 2 can be readily prepared at reasonable scales, dissolve in common solvents, and retain an intact framework even in the presence of excessive amounts of water. This finding paves the way to future research addressing the reactivity of the individual functional groups.     

Structure and Reactivity of Al−O(H)−Al Moieties in Siloxide Frameworks: Solution and Gas‐Phase Model Studies

Even though aluminas and aluminosilicates have found widespread application, a consistent molecular understanding of their surface heterogeneity and the behavior of defects resulting from hydroxylation/dehydroxylation remains unclear. Here, we study the well‐defined molecular model compound, [Al₃(μ₂‐OH)₃(THF)₃(PhSi(OSiPh₂O)₃)₂], 1 , to gain insight into the acid–base reactivity of cyclic trinuclear Al₃(μ₂‐OH)₃ moieties at the atomic level. We find that, like zeolites, they are sufficiently acidic to catalyze the isomerization of olefins. DFT and gas phase vibrational spectroscopy on solvent‐free and deprotonated 1 show that the six‐membered ring structure of its Al₃(μ₂‐OH)₃ core is unstable with respect to deprotonation of one of its hydroxy groups and rearranges into two edge‐sharing four‐membered rings. This renders Al_IV?O(H)?Al_IV units strong acid sites, and all results together suggest that their acidity is similar to that of zeolitic Si_IV?O(H)?Al_IV groups.     

Synthesen und Strukturen der Titan(III)‐siloxane [Ti(OSiPh3)3(thf)2] und [Ti(OSiPh3)3(py)2]

Syntheses and Structures of the Titanium(III) Siloxanes [Ti(OSiPh₃)₃(thf)₂] and [Ti(OSiPh₃)₃(py)₂] The new titaniumtrioxysilanes [Ti(OSiPh₃)₃(thf)₂] ( 1 ) and [Ti(OSiPh₃)₃(py)₂] ( 2 ) have been obtained from the reaction of titaniumtrichloride with LiOSiPh₃ in the presence of the corresponding bases tetrahydrofurane (thf) and pyridine (py). From the crystal structures of both compounds it is evident that the titanium atoms are in the centres of trigonal‐bipyramidal coordination figures, with the donor atoms in axial positions. The compounds 1 and 2 have slightly different structures (mean values: 1 : Ti‐O(Si) 1.897(9), Ti‐O(C) 2.136(8) Å; 2 : Ti‐O 1.902(9), Ti‐N2.252(8) Å) and have a single absorption band in the visible region of the UV‐spectrum. The exchange of the thf‐ligands in 1 by pyridine (in high molar excess) seems to be hindered as deduced from UV‐spectroscopy.     

Siloxanediolates of the Rare Earth Elements – An Eight‐Membered Inorganic Ring System containing Ytterbium

Treatment of anhydrous YbCl₃ with LiN(SiMe₃)₂ followed by reaction with 1 equivalent of 1,1,3,3,5,5‐hexaphenyl‐1,3,5‐trisiloxanediol afforded the first mono(trisiloxanediolate) complex of a rare earth element. The compound [Ph₂Si(OSiPh₂O)₂]Yb(THF)(μ‐Cl)₃Li₂(THF)₃ ( 1 ) was isolated in the form of colorless crystals in very high yield (93%). A single‐crystal X‐ray diffraction study confirmed the presence of an eight‐membered inorganic ring system containing ytterbium. Coordination of one THF ligand and retention of two equivalents of lithium chloride lead to formation of an “ate” complex.     

Two Self‐assembled Water Clusters Stabilized by Cu‐containing Compounds Based on MoO42–

Two copper‐containing compounds based on MoO₄^2–, [Cu₄(phen)₄(μ₂‐OH)₂(μ₃‐OH)₂(H₂O)₂][MoO₄]₂ · 10H₂O ( 1 ) and [Cu(phen)₂Mo₂O₇(phen)] · 8H₂O ( 2 ) (phen = 1,10‐phenanthroline), were hydrothermally synthesized. In the crystal lattices of 1 and 2 , discrete octameric water cycles and 2D layer water clusters were observed. The cyclic water octamer clusters exist stably in the channels constructed by [Cu₄(phen)₄(OH)₄(H₂O)₂]²⁺ and MoO₄^2– by hydrogen bonds in 1 at low temperature and 2D layer water clusters are formed by (H₂O)₁₆ units in 2 .     

Mechanistic Insight into the NN Bond‐Cleavage of Azo‐Compounds that was Induced by an Al?Al‐bonded Compound [L2−AlII?AlIIL2−]

An α‐diimine‐stabilized Al? Al‐bonded compound [L^2?Al^II? Al^IIL^2?] (L=[{(2,6‐iPr₂C₆H₃)NC(Me)}₂]; 1 ) consists of dianionic α‐diimine ligands and sub‐valent Al²⁺ ions and thus could potentially behave as a multielectron reductant. The reactions of compound 1 with azo‐compounds afforded phenylimido‐bridged products [L^?Al^III(μ₂‐NPh)(μ₂‐NAr)Al^IIIL^?] ( 2 – 4 ). During the reaction, the dianionic ligands and Al²⁺ ions were oxidized into monoanions and Al³⁺, respectively, whilst the [NAr]^2? imides were produced by the four‐electron reductive cleavage of the N?N double bond. Upon further reduction by Na, the monoanionic ligands in compound 2 were reduced to the dianion to give [(L^2?)₂Al^III₂(μ₂‐NPh)₂Na₂(thf)₄] ( 5 ). Interestingly, when asymmetric azo‐compounds were used, the asymmetric adducts were isolated as the only products (compounds 3 and 4 ). DFT calculations indicated that the reaction was quite feasible in the singlet electronic state, but the final product with the triplet‐state monoanionic ligands could result from an exothermic singlet‐to‐triplet conversion during the reaction process.     

Synthesis and crystal structures of supramolecular compounds of polynuclear aluminum(III) aqua hydroxo complexes with cucurbit[6]uril

Supramolecular compounds of the di-, trideca-, and triacontanuclear aluminum aqua hydroxo complexes, viz., [Al₂(OH)₂(H₂O)₈]⁴⁺, [Al₁₂(AlO₄)(OH)₂₄(H₂O)₁₂]⁷⁺, and [Al₃₀O₈(OH)₅₆(H₂O)₂₆]¹⁸⁺, respectively, with the organic macrocyclic cavitand cucurbit[6]uril (C₃₆H₃₆N₂₄O₁₂) were prepared by evaporation of aqueous solutions of aluminum nitrate and cucurbit[6]uril after the addition of pyridine, ammonia, KOH, or NaOH at pH 3.1–3.8. X-ray diffraction study demonstrated that the aqua hydroxo complexes are linked to the macrocycle through hydrogen bonds between the hydroxo and aqua ligands of the polycations and the portal oxygen atoms of cucurbit[6]uril. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 261—268, February, 2006.     

Chemical Liquid Phase Deposition of Thin Aluminum Oxide Films

Introduction Inorganic oxide films have attracted a lot of interest in the last several decades. Among them, silicon dioxide films are widely used in modern microelectronics, optics and mechanics. This material has been grown by various methods including thermal oxidation, chemical vapor phase deposition, plasma-enhanced chemical vapor phase deposition, and so on.1,2 Recently, Nagayama et al.3 have reported that SiO2 thin films could be produced by a new chemical method of liquid phase depos…     

Mapping the Transformation [{RuII(CO)3Cl2}2]→[RuI2(CO)4]2+: Implications in Binuclear Water–Gas Shift Chemistry

The complete sequence of reactions in the base‐promoted reduction of [{Ru^II(CO)₃Cl₂}₂] to [Ru^I₂(CO)₄]²⁺ has been unraveled. Several μ‐OH, μ:κ²‐CO₂H‐bridged diruthenium(II) complexes have been synthesized; they are the direct results of the nucleophilic activation of metal‐coordinated carbonyls by hydroxides. The isolated compounds are [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐OH)(NP^F‐Am)₂][PF₆] ( 1 ; NP^F‐Am=2‐amino‐5,7‐trifluoromethyl‐1,8‐naphthyridine) and [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)(μ‐OH)(NP‐Me₂)₂][BF₄]₂ ( 2 ), secured by the applications of naphthyridine derivatives. In the absence of any capping ligand, a tetranuclear complex [Ru₄(CO)₈(H₂O)₂(μ³‐OH)₂(μ:κ²‐C,O‐CO₂H)₄][CF₃SO₃]₂ ( 3 ) is isolated. The bridging hydroxido ligand in 1 is readily replaced by a π‐donor chlorido ligand, which results in [Ru₂(CO)₄(μ:κ²‐C,O‐CO₂H)₂(μ‐Cl)(NP‐PhOMe)₂][BF₄] ( 4 ). The production of [Ru₂(CO)₄]²⁺ has been attributed to the thermally induced decarboxylation of a bis(hydroxycarbonyl)–diruthenium(II) complex to a dihydrido–diruthenium(II) species, followed by dinuclear reductive elimination of molecular hydrogen with the concomitant formation of the Ru^I? Ru^I single bond. This work was originally instituted to find a reliable synthetic protocol for the [Ru₂(CO)₄(CH₃CN)₆]²⁺ precursor. It is herein prescribed that at least four equivalents of base, complete removal of chlorido ligands by Tl^I salts, and heating at reflux in acetonitrile for a period of four hours are the conditions for the optimal conversion. Premature quenching of the reaction resulted in the isolation of a trinuclear Ru^I₂Ru^II complex [{Ru(NP‐Am)₂(CO)}{Ru₂(NP‐Am)₂(CO)₂(μ‐CO)₂}(μ₃:κ³‐C,O,O′‐CO₂)][BF₄]₂ ( 6 ). These unprecedented diruthenium compounds are the dinuclear congeners of the water–gas shift (WGS) intermediates. The possibility of a dinuclear pathway eliminates the inherent contradiction of pH demands in the WGS catalytic cycle in an alkaline medium. A cooperative binuclear elimination could be a viable route for hydrogen production in WGS chemistry.     

Synthesis of an Aluminum Hydroxide Octamer through a Simple Dissolution Method

Multimeric oxo‐hydroxo Al clusters function as models for common mineral structures and reactions. Cluster research, however, is often slowed by a lack of methods to prepare clusters in pure form and in large amounts. Herein, we report a facile synthesis of the little known cluster Al₈(OH)₁₄(H₂O)₁₈(SO₄)₅ ( Al₈ ) through a simple dissolution method. We confirm its structure by single‐crystal X‐ray diffraction and show by ²⁷Al NMR spectroscopy, electrospray‐ionization mass spectrometry, and small‐ and wide‐angle X‐ray scattering that it also exists in solution. We speculate that Al₈ may form in natural water systems through the dissolution of aluminum‐containing minerals in acidic sulfate solutions, such as those that could result from acid rain or mine drainage. Additionally, the dissolution method produces a discrete Al cluster on a scale suitable for studies and applications in materials science.     

Facile Hydrolysis and Alcoholysis of Palladium Acetate

Palladium(II) acetate is readily converted into [Pd₃(μ²‐OH)(OAc)₅] ( 1 ) in the presence of water in a range of organic solvents and is also slowly converted in the solid state. Complex 1 can also be formed in nominally anhydrous solvents. Similarly, the analogous alkoxide complexes [Pd₃(μ²‐OR)(OAc)₅] ( 3 ) are easily formed in solutions of palladium(II) acetate containing a range of alcohols. An examination of a representative Wacker‐type oxidation shows that the Pd‐OH complex 1 and a related Pd‐oxo complex 4 can be excluded as potential catalytic intermediates in the absence of exogenous water.     

Using NMR in Structural Studies of Aluminum Hydroxide Intercalation Compounds with Lithium Salts

The effect of the anion charge on the structure of [LiAl₂(OH)₆]_nX (X = Cl^-, Br^-, I^-, SO₄ ^2-, C₆H₈O₄ ^2-) intercalation compounds and the water effect on the structure of [LiAl₂(OH)₆]Cl·nH₂O have been studied using ¹H, ⁷Li, and ²⁷Al NMR. A change in the charge on the anion leads to significant changes in the asymmetry parameter for the lithium and aluminum nuclei with relatively small changes in the quadrupolar coupling constant and the broadening factor. The structure of the intermediate [LiAl₂(OH)₆]Cl·0.5H₂O hydrate can be represented as a derivative of the structure of the anhydrous [LiAl₂(OH)₆]Cl intercalate with a slightly increased layer thickness and a minor orthorhombic distortion of the hexagonal cell; the water molecules partially fill the interlayer voids and participate in the diffusion process. Further hydration of the intercalate (x 1) leads to a minor (0.2) increase in the layer thickness and is accompanied by disordering of chloride ions and water molecules in the interlayer space.     

A Comparative Study of (Poly)ether Adducts of Alkaline Earth Iodides – An Overview Including New Compounds

New homoligand and mixed‐ligand adducts of the heavier alkaline earth metal (Ca, Sr, Ba) halides with oxygen‐donor polyether ligands have been isolated and characterized and are compared with previously obtained compounds of the same class in order to give an overview on structures and properties. Homoligand halide adducts, discussed herein, are [CaI(DME)₃]I ( 1 ), trans‐[SrI₂(DME)₃] ( 2 ), trans‐[BaI₂(DME)₃] ( 3 ), (DME = ethylene glycol dimethyl ether), [CaI(diglyme)₂]I ( 4 ), cis‐[SrI₂(diglyme)₂] ( 5 ), trans‐[BaI₂(diglyme)₂] ( 6 ),(diglyme = diethylene glycol dimethyl ether, [SrI(triglyme)₂]I ( 7 ), and [BaI(triglyme)₂]I ( 8 ), (triglyme = triethylene glycol dimethyl ether). Introduction of the mono‐coordinating THF ligand (THF = tetrahydrofuran) in the coordination sphere of 1 , 2 , 3 , 4 allows the formation of the new mixed‐ligand compounds trans‐[CaI₂(DME)₂(THF)] ( 9 ), trans‐[SrI₂(DME)₂(THF)] ( 10 ), trans‐[BaI₂(DME)₂(THF)₂] ( 11 ), and trans‐[CaI₂(diglyme)₂(THF)₂] ( 12 ). These compounds were obtained from the metal halide salts in solution with pure or mixtures of ether solvents. While compounds 1 – 8 appear to be very stable and non‐reactive, adducts 9 – 12 present a comparable reactivity to the well known THF adducts [MI₂(thf)_n] (M = Ca, n = 4; Sr, Ba, n = 5).     

Aluminum alkyls with intramolecularly coordinated oxygen

Organoaluminum alkyls L¹AlMe₂ ( 1 ), L²AlMe₂ ( 2 ) and L²AlⁱBu₂ ( 3 ) with O,C,O‐chelating ligands L¹ and L² [L¹ = 2, 6‐(MeOCH₂)₂C₆H₃ and L² = 2, 6‐(^tBuOCH₂)₂C₆H₃] were prepared. The compounds have been characterized by elemental analysis, ¹H, ¹³C, ²⁷Al NMR spectroscopy and X‐ray diffraction analysis ( 3 ). Solution NMR studies indicated the four coordinated aluminum atom and dissociation/association dynamic process in solution of 1 – 3 . The X‐ray diffraction analysis of 3 showed that the aluminum atom is [4 + 1] coordinated with the trans‐trigonal bipyramidal geometry. The reactivity of 2 was investigated. Reactions of 2 with MeOH and I₂ resulted in aluminum alkoxide [L²Al(OMe)₂ ( 4 )] and iodides [L²AlI₂· THF ( 5 ) and L²AlI₂ ( 6 )], respectively, characterized by elemental analysis, IR and ¹H, ¹³C and ²⁷Al NMR spectroscopy. Copyright © 2005 John Wiley & Sons, Ltd.     

Hepta­aqua­tetra‐μ3‐hydroxy‐hexa‐μ2‐l‐leucine‐(l‐leucine)­tetraytterbium(III) tetrachlorozinc(II) tri­chloro­hydroxyzinc(II) tetrachloride octahydrate

The title bimetallic compound, [Yb₄(μ₃‐OH)₄(C₆H₁₃NO₂)₇(H₂O)₇][ZnCl₄][ZnCl₃(OH)]Cl₄·8H₂O, was synthesized at near physiological pH (6.0). The compound exhibits some novel structural features, including an asymmetric [Yb₄(μ₃‐OH)₄(l ‐leucine)₇(H₂O)₇]⁸⁺ complex cation in which four OH groups act as bridging ligands, linking four Yb³⁺ cations into a Yb₄O₄ structural unit. Each pair of adjacent Yb³⁺ ions is further bridged by one carboxy group from a leucine ligand. Water mol­ecules and a monodentate leucine ligand also coordinate to Yb³⁺ ions, completing their eight‐coordinate square‐antiprismatic coordination. The Yb₄(μ₃‐OH)₄(l ‐leu­cine)₇(H₂O)₇]⁸⁺ cation, the [ZnCl₄]²⁻, [ZnCl₃OH]²⁻ and Cl⁻ anions, and the lattice water mol­ecules are linked via hydrogen bonds.     

Synthesis and Structure of the Clusters [Hg2(μ—SePh)2(SePh)2(PPh3)2] and [Hg3Br3(μ—SePh)3] · 2 DMSO

The compounds [Hg₂(μ—SePh)₂(SePh)₂(PPh₃)₂] ( I ) and [Hg₃Br₃(μ—SePh)₃] · 2 DMSO ( II ) are formed by reactions of [Hg(SePh)₂] with PPh₃ in THF( I ) or with HgBr₂ in DMSO ( II ) at room temperature. X—ray crystallography reveals that the cluster I consists of a distorted square built by each two Hg and Se atoms. The Hg atoms have almost tetrahedral co‐ordination environments formed by selenium atoms of two (μ‐^—SePh) ligands and Se and P atoms of terminal ^—SePh and PPh₃ ligands. The compound II is a six‐membered ring with alternating Hg and Se atoms in the chair conformation. Two DMSO molecules occupy positions below and above the [Hg₃Se₃] ring with the oxygen atoms directed to the centre of the ring.     

Molecular Nitrides with Titanium and Group 13–15 Elements

Several heterometallic nitrido complexes were prepared by reaction of the imido–nitrido titanium complex [{Ti(η⁵‐C₅Me₅)(μ‐NH)}₃(μ₃‐N)] ( 1 ) with amido derivatives of Group 13–15 elements. Treatment of 1 with bis(trimethylsilyl)amido [M{N(SiMe₃)₂}₃] derivatives of aluminum, gallium, or indium in toluene at 150–190 °C affords the single‐cube amidoaluminum complex [{(Me₃Si)₂N}Al{(μ₃‐N)₂(μ₃‐NH)Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}] ( 2 ) or the corner‐shared double‐cube compounds [M(μ₃‐N)₃(μ₃‐NH)₃{Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}₂] [M=Ga ( 3 ), In ( 4 )]. Complexes 3 and 4 were also obtained by treatment of 1 with the trialkyl derivatives [M(CH₂SiMe₃)₃] (M=Ga, In) at high temperatures. The analogous reaction of 1 with [{Ga(NMe₂)₃}₂] at 110 °C leads to [{Ga(μ₃‐N)₂(μ₃‐NH)Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}₂] ( 5 ), in which two [GaTi₃N₄] cube‐type moieties are linked through a gallium–gallium bond. Complex 1 reacts with one equivalent of germanium, tin, or lead bis(trimethylsilyl)amido derivatives [M{N(SiMe₃)₂}₂] in toluene at room temperature to give cube‐type complexes [M{(μ₃‐N)₂(μ₃‐NH)Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}] [M=Ge ( 6 ), Sn ( 7 ), Pb ( 8 )]. Monitoring the reaction of 1 with [Sn{N(SiMe₃)₂}₂] and [Sn(C₅H₅)₂] by NMR spectroscopy allows the identification of intermediates [RSn{(μ₃‐N)(μ₃‐NH)₂Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}] [R=N(SiMe₃)₂ ( 9 ), C₅H₅ ( 10 )] in the formation of 7 . Addition of one equivalent of the metalloligand 1 to a solution of lead derivative 8 or the treatment of 1 with a half equivalent of [Pb{N(SiMe₃)₂}₂] afford the corner‐shared double‐cube compound [Pb(μ₃‐N)₂(μ₃‐NH)₄{Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}₂] ( 11 ). Analogous antimony and bismuth derivatives [M(μ₃‐N)₃(μ₃‐NH)₃{Ti₃(η⁵‐C₅Me₅)₃(μ₃‐N)}₂] [M=Sb ( 12 ), Bi ( 13 )] were obtained through the reaction of 1 with the tris(dimethylamido) reagents [M(NMe₂)₃]. Treatment of 1 with [AlCl₂{N(SiMe₃)₂}(OEt₂)] affords the precipitation of the singular aluminum–titanium square‐pyramidal aggregate [{{(Me₃Si)₂N}Cl₃Al₂}(μ₃‐N)(μ₃‐NH)₂{Ti₃(η⁵‐C₅Me₅)₃(μ‐Cl)(μ₃‐N)}] ( 14 ). The X‐ray crystal structures of 5 , 11 , 13 , 14 , and [AlCl{N(SiMe₃)₂}₂] were determined.     

Novel heptavalent actinide compounds: tetrasodium dihydroxidotetraoxidoneptunate(VII) hydroxide dihydrate and its plutonium analogue

The title compounds, Na₄[NpO₄(OH)₂]OH·2H₂O and Na₄[PuO₄(OH)₂]OH·2H₂O, are isostructural and isomorphous, and contain complex [AnO₄(OH)₂]³⁻ anions (Ac is an actinide) in the form of distorted tetragonal bipyramids, Na⁺ cations, crystallization water molecules and outer‐sphere OH groups. The complex [AnO₄(OH)₂]³⁻ anions occupy general positions and the coordinated OH groups deviate significantly from a centrosymmetric relative orientation. The [AnO₄(OH)₂]³⁻ anions exhibit anisotropic actinide contraction; the shortening of the An—O(hydroxide) bonds on going from Np to Pu is greater than that of the AnO₄ groups.     

Synthesis,Structure, and Reactivity of a Tetranuclear Cerium(IV) Oxo Cluster Supported by the Kläui Tripodal Ligand [Co(η5‐C5H5){P(O)(OEt)2}3]−

A tetranuclear Ce^IV oxo cluster compound containing the Kläui tripodal ligand [Co(η⁵‐C₅H₅){P(O)(OEt)₂}₃]^? (L_OEt^?) has been synthesized and its reactions with H₂O₂, CO₂, NO, and Brønsted acids have been studied. The treatment of [Ce(L_OEt)(NO₃)₃] with Et₄NOH in acetonitrile afforded the tetranuclear Ce^IV oxo cluster [Ce₄(L_OEt)₄O₇H₂] ( 1 ) containing an adamantane‐like {Ce₄(μ₂‐O)₆} core with a μ₄‐oxo ligand at the center. The reaction of 1 with H₂O₂ resulted in the formation of the peroxo cluster [Ce₄(L_OEt)₄(μ₄‐O)(μ₂‐O₂)₄(μ₂‐OH)₂] ( 2 ). The treatment of 1 with CO₂ and NO led to isolation of [Ce(L_OEt)₂(CO₃)] and [Ce(L_OEt)(NO₃)₃], respectively. The protonation of 1 with HCl, ROH (R=2,4,6‐trichlorophenyl), and Ph₃SiOH yielded [Ce(L_OEt)Cl₃] ( 3 ), [Ce(L_OEt)(OR)₃] ( 4 ), and [Ce(L_OEt)(OSiPh₃)₃] ( 5 ), respectively. The chloride ligands in 3 are labile and can be abstracted by silver(I) salts. The treatment of 3 with AgOTs (OTs^?=tosylate) and Ag₂O afforded [Ce(L_OEt)(OTs)₃] ( 6 ) and 1 , respectively. The electrochemistry of the Ce‐L_OEt complexes has been studied by using cyclic voltammetry. The crystal structures of complexes 1 – 5 have been determined.