Alkane Metathesis with the Tantalum Methylidene [(≡SiO)Ta(═CH2)Me2]/[(≡SiO)2Ta(═CH2)Me] Generated from Well-Defined Surface Organometallic Complex [(≡SiO)TaVMe4]

A Vanadium Methylidene

Examples of stable 3d transition metal methylidene complexes are extremely rare. Here we report an isolable and stable vanadium methylidene complex, [(PNP)V(=NAr)(=CH2)] (PNP = N[2-PiPr2-4-methylphenyl]-, Ar = 2,6-iPr2C6H3), via H atom transfer (HAT) from [(PNP)V(NHAr)(CH3)] or [(PNP)V(=NAr)(CH3)] using two or one equivalents of the TEMPO radical (TEMPO = (2,2,6,6-tetramethylpiperidin-1-yl)oxyl), respectively. Alternatively, the vanadium methylidene moiety can also be formed via the treatment of transient [(PNP)V=NAr] with the Wittig reagent, H2CPPh3. Structural and spectroscopic analysis, including 13C enriched labeling of the methylidene ligand, unequivocally confirmed the terminal nature of a rare 3d methylidene complex, featuring a V=CH2 bond distance of 1.908(2) Å and a highly downfield 13C NMR spectral shift at 298 ppm. In the absence of the ylide, intermediate [(PNP)V=NAr] activates dinitrogen to form an end-on bridging N2 complex, [(PNP)V(=NAr)]2(μ2-η1:η1-N2), having a singlet ground state. Complex [(PNP)V(=NAr)(=CH2)] reacts with H3COTf to form [(PNP)V(=NAr)(OTf)], accompanied by the release of ethylene as evidenced by 1H NMR spectroscopy, and reactivity studies suggest a β-hydride elimination pathway.

Surface-Immobilized ZnNx Sites as High-Performance Catalysts for Continuous Flow Knoevenagel Condensation in Water

By immobilizing the metal complex on the substrate surface, our previous results have demonstrated that heterogeneous catalysts with well-dispersed active MNC (metal-nitrogen-carbon) sites can be prepared in a rational and efficient manner. In this study, we employed agarose aerogel (AA) as the substrate to illustrate a straightforward strategy for immobilizing ZnNx sites on the surface. Under relatively low temperatures, the amine group of the ligand condenses with the surface carbonyl group generated in situ, resulting in the surface immobilized Zn sites. This can be supported by the IR, PXRD, and XPS data. Comprehensive characterization methods, including synchrotron powder XRD and spherical aberration-corrected TEM, confirmed the absence of ZnNx site aggregation in the surface immobilization process, even with a high Zn content (up to 8 wt %). The immobilized ZnNx sites exhibited high catalytic performance in Knoevenagel condensation, and α,β-unsaturated compounds were obtained with high yield in both batch and continuous flow reactions. AA-ZnNx-200 showed the best catalytic activity, which was processed under 200 °C with a Zn content of 4.62 wt %. The immobilized ZnNx sites activated both the aldehyde and nitrile substrates, which were quantitatively converted into the corresponding α,β-unsaturated compounds, with water as the solvent at room temperature. In continuous flow reaction conditions, a conversion rate up to 99% can be achieved with malononitrile. This heterogeneous catalyst can be facilely produced with quantitative yield in a large scale from cheap starting material under mild conditions. No catalyst deactivation was observed after seven batch reaction cycles or 80 h of continuous flow reaction, indicating its high robustness under catalytic reaction conditions. This catalyst enables a separation-free, energy-saving, and environment-friendly production process, offering a practical way for the industrial production.

Rapid Polyolefin Hydrogenolysis by a Single-Site Organo-Tantalum Catalyst on a Super-Acidic Support: Structure and Mechanism

The novel electrophilic organo-tantalum catalyst AlS/TaNpx (1) (Np=neopentyl) is prepared by chemisorption of the alkylidene Np3 Ta=CHt Bu onto highly Brønsted acidic sulfated alumina (AlS). The proposed catalyst structure is supported by EXAFS, XANES, ICP, DRIFTS, elemental analysis, and SSNMR measurements and is in good agreement with DFT analysis. Catalyst 1 is highly effective for the hydrogenolysis of diverse linear and branched hydrocarbons, ranging from C2 to polyolefins. To the best of our knowledge, 1 exhibits one of the highest polyolefin hydrogenolysis activities (9,800 (CH2 units) ⋅ mol(Ta)-1  ⋅ h-1 at 200 °C/17 atm H2 ) reported to date in the peer-reviewed literature. Unlike the AlS/ZrNp2 analog, the Ta catalyst is more thermally stable and offers multiple potential C-C bond activation pathways. For hydrogenolysis, AlS/TaNpx is effective for a wide variety of pre- and post-consumer polyolefin plastics and is not significantly deactivated by standard polyolefin additives at typical industrial concentrations.

Atomically Dispersed NiNx Site with High Oxygen Electrocatalysis Performance Facilely Produced via a Surface Immobilization Strategy

Nonprecious-metal heterogeneous catalysts with atomically dispersed active sites demonstrated high activity and selectivity in different reactions, and the rational design and large-scale preparation of such catalysts are of great interest but remain a huge challenge. Current approaches usually involve extremely high-temperature and tedious procedures. Here, we demonstrated a straightforward and scalable preparation strategy. In two simple steps, the atomically dispersed Ni electrocatalyst can be synthesized in a tens grams scale with quantitative yield under mild conditions, and the active Ni sites were produced by immobilizing preorganized NiN_x complex on the substrate surface via organic thermal reactions. This catalyst exhibits excellent catalysis performances in both oxygen evolution and reduction reactions. It also exhibited tunable catalysis activity, high catalysis reproducibility, and high stability. The atomically dispersed NiN_x sites are tolerant at high Ni concentration, as the random reactions and metal nanoparticle formation that generally occurred at high temperatures were avoided. This strategy illustrated a practical and green method for the industrial manufacture of nonprecious-metal single-site catalysts with a predictable structure.

Surface and Interface Coordination Chemistry Learned from Model Heterogeneous Metal Nanocatalysts: From Atomically Dispersed Catalysts to Atomically Precise Clusters

The surface and interface coordination structures of heterogeneous metal catalysts are crucial to their catalytic performance. However, the complicated surface and interface structures of heterogeneous catalysts make it challenging to identify the molecular-level structure of their active sites and thus precisely control their performance. To address this challenge, atomically dispersed metal catalysts (ADMCs) and ligand-protected atomically precise metal clusters (APMCs) have been emerging as two important classes of model heterogeneous catalysts in recent years, helping to build bridge between homogeneous and heterogeneous catalysis. This review illustrates how the surface and interface coordination chemistry of these two types of model catalysts determines the catalytic performance from multiple dimensions. The section of ADMCs starts with the local coordination structure of metal sites at the metal-support interface, and then focuses on the effects of coordinating atoms, including their basicity and hardness/softness. Studies are also summarized to discuss the cooperativity achieved by dual metal sites and remote effects. In the section of APMCs, the roles of surface ligands and supports in determining the catalytic activity, selectivity, and stability of APMCs are illustrated. Finally, some personal perspectives on the further development of surface coordination and interface chemistry for model heterogeneous metal catalysts are presented.

Mechanism of Coupling of Methylidene to Ethylene Ligands in Dimetallic Assemblies; Computational Investigation of a Model for a Key Step in Catalytic C1 Chemistry

Methylidene complexes often couple to ethylene complexes, but the mechanistic insight is scant. The path by which two cations [(η⁵-C₅H₅)Re(NO)(PPh₃)(═CH₂)]⁺ (5⁺) transform (CH₂Cl₂/acetonitrile) to [(η⁵-C₅H₅)Re(NO)(PPh₃)(H₂C═CH₂)]⁺ (6⁺) and [(η⁵-C₅H₅)Re(NO)(PPh₃)(NCCH₃)]⁺ is studied by density functional theory. Experiments provide a number of constraints such as the second-order rate in 5⁺; no prior ligand dissociation/exchange; a faster reaction of (S)-5⁺ with (S)-5⁺ than with (R)-5⁺ ("enantiomer self-recognition"). Although dirhenium dications with Re(μ-CH₂)₂Re cores represent energy minima, they are not accessible by 2 + 2 cycloadditions of 5⁺. Transition states leading to ReCH₂CH₂Re linkages are prohibitively high in energy. However, 5⁺ can give non-covalent S_Re/S_Re or S_Re/R_Re dimers with π interactions between the PPh₃ ligands but long ReCH₂···H₂CRe and H₂CRe···H₂CRe distances (3.073-3.095 Å and 3.878-4.529 Å, respectively). In rate-determining steps, these afford [(η⁵-C₅H₅)Re(NO)(PPh₃)(μ-η²:η²-H₂C···CH₂)(Ph₃P)(ON)Re(η⁵-C₅H₅)]²⁺ (13²⁺), in which one rhenium binds the bridging ethylene more tightly than the other (2.115-2.098 vs 2.431-2.486 Å to the centroid). In the S_Re/R_Re adduct, Dewar-Chatt-Duncanson optimization leads to unfavorable PPh₃/PPh₃ contacts. Ligand interactions are further dissected in the preceding transition states via component analyses, and ΔΔG^‡ (1.2 kcal/mol, CH₂Cl₂) favors the S_Re/S_Re pathway, in accordance with the experiment. Acetonitrile then displaces 6⁺ from the more weakly bound rhenium of 13²⁺. The formation of similar μ-H₂C···CH₂ intermediates is found to be rate-determining for varied coordinatively saturated M═CH₂ species [M = Fe(d⁶)/Re(d⁴)/Ta(d²)], establishing generality and enhancing relevancy to catalytic CH₄ and CO/H₂ chemistry.

Evidence for πCHR→dM bonding in transition metal carbene compounds (LnMCHR) and its decisive role in the α-agostic effect

It has been generally recognized that the α-agostic interaction (M⋯H-C) in transition metal carbene compounds L_nMCHR (R = H, Me etc.) can be interpreted with a double metal-carbon bonding model. This bonding model involves the reorganization of the σ component, which can be illustrated in terms of three-center two-electron (3c-2e) M-H-C covalent bond as in transition metal alkyl compounds. Herein, we propose an alternative partial triple metal-carbon bonding model to elucidate the agostic interaction in L_nMCHR. Apart from the well-defined σ and π bonds, there exists a seemingly weak but decisive third force, namely the π_CHR→d_M bonding between an occupied π-like symmetric CHR orbital and a vacant metal d orbital, which is the true origin of the α-agostic effect. This partial triple bonding model is authenticated on both Fischer- and Schrock-type carbenes by an ab initio valence bond (VB) method or the block-localized wavefunction (BLW) method, which has the capability to quantify this notable π bonding and further demonstrate its geometric, energetic and spectral impacts on agostic transition metal carbene compounds. We also show that ancillary ligands can modulate the π_CHR→d_M bonding through electronic and steric effects.

The coordination chemistry of oxide and nanocarbon materials

Understanding how a ligand affects the steric and electronic properties of a metal is the cornerstone of the inorganic chemistry enterprise. What happens when the ligand is an extended surface? This question is central to the design and implementation of state-of-the-art functional materials containing transition metals. This perspective will describe how these two very different sets of extended surfaces can form well-defined coordination complexes with metals. In the Green formalism, functionalities on oxide surfaces react with inorganics to form species that contain X-type or LX-type interactions between the metal and the oxide. Carbon surfaces are neutral L-type ligands; this perspective focuses on carbons that donate six electrons to a metal. The nature of this interaction depends on the curvature, and thereby orbital overlap, between the metal and the extended π-system from the nanocarbon.

Reductive Hydrogenation under Single-Site Control: Generation and Reactivity of a Transient NHC-Stabilized Tantalum(III) Alkoxide

One of the most attractive routes for the preparation of reactive tantalum(III) species relies on the efficient salt-free hydrogenolysis of tantalum(V) alkyls or tantalum(V) alkylidenes, a process known as reductive hydrogenation. For silica-crafted tantalum alkyls and alkylidenes, this process necessarily proceeds at well-separated tantalum centers, while related reductive hydrogenations in homogeneous solution commonly involve dimeric complexes. Herein, an NHC scaffold was coordinated to a novel tri(alkoxido)tantalum(V) alkylidene to circumvent the formation of dimers during reductive hydrogenation. Employing this new model system, a key intermediate of the process, namely a hydrido-tantalum alkyl, was isolated for the first time and shown to exhibit a bidirectional reactivity. Upon being heated, the latter complex was found to undergo either an α-elimination or a reductive alkane elimination. In the (overall unproductive) α-elimination step, H₂ and the parent alkylidene were regenerated, while the sought-after transient d²-configured tantalum(III) derivative was produced along the reaction coordinate of the reductive alkane elimination. The reactive low-valence metal center was found to rapidly attack one of the NHC substituents via an oxidative C-H activation, which led to the formation of a cyclometalated tantalum(V) hydride. The proposed elemental steps are in line with kinetic data, deuterium labeling experiments, and density functional theory (DFT) modeling studies. DFT calculations also indicated that the S = 0 spin ground state of the Ta(III) center plays a crucial role in the cyclometalation reaction. The cyclometalated Ta(V) hydride was further investigated and reacted with several alkenes and alkynes. In addition to a rich insertion and isomerization chemistry, these studies also revealed that the former hydride may undergo a formal cycloreversion and thus serve as a tantalum(III) synthon, although the original tantalum(III) intermediate is not involved in this process. The latter reactivity was observed upon reaction with internal alkynes and led to the corresponding η²-alkyne derivatives via vinyl intermediates, which rearrange via a remarkable, hitherto unprecedented, hydrogen shift reaction.

Probing β-alkyl elimination and selectivity in polyolefin hydrogenolysis through DFT

A long chain substrate with [(SiO)3ZrH] has been investigated to elucidate selectivity rules in β-alkyl elimination. DFT studies indicate that polypropylene preferentially undergoes β-Me elimination.

Titanium methyl tamed on silica: synthesis of a well-defined pre-catalyst for hydrogenolysis of n-alkane

Alkylation of Ti(CH₃)₂Cl₂1 by MeLi gives the homoleptic Ti(CH₃)₄2 for the first time in the absence of any coordinating solvent. The reaction of 2 with silica pretreated at 700 °C (SiO_2-700) gives two inequivalent silica-supported Ti-methyl species 3. Complex 3 was characterized by IR, microanalysis (ICP-OES, CHNS, and gas quantification), and advanced solid-state NMR spectroscopy (¹H, ¹³C, DQ, TQ, and HETCOR). The catalytic activity of the pre-catalyst 3 is investigated in low-temperature hydrogenolysis of propane and n-butane with TONs of 419 and 578, respectively.

Metal Alkyls with Alkylidynic Metal-Carbon Bond Character: Key Electronic Structures in Alkane Metathesis Precatalysts

The homologation of alkanes via alkane metathesis is catalyzed at low temperatures (150 °C) by the silica-supported species (≡SiO)WMe₅ and (≡SiO)TaMe₄ , while (≡SiO)TaMe₃ Cp* is inactive. The contrasting reactivity is paralleled by differences in the ¹³ C NMR signature; the former display significantly more deshielded isotropic chemical shifts (δ_iso ) and almost axially symmetric chemical shift tensors, similar to what is observed in their molecular precursors TaMe₅ and WMe₆ . Analysis of the chemical shift tensors reveals the presence of a triple-bond character in their metal-carbon (formally single) bond. This electronic structure is reflected in their propensity to generate alkylidynes and to participate in alkane metathesis, further supporting the role of alkylidynes as key reaction intermediates. This study establishes chemical shift as a descriptor to identify potential alkane metathesis catalysts.

Docking of tetra-methyl zirconium to the surface of silica: a well-defined pre-catalyst for conversion of CO2 to cyclic carbonates

The metal complex (Zr(CH3)4(THF)2) has been fully synthesized, characterized and grafted onto partially dehydroxylated silica to give two surface species [([triple bond, length as m-dash]Si-O-)Zr(CH3)3(THF)2] (minor) and [([triple bond, length as m-dash]Si-O-)2Zr(CH3)2(THF)2] (major) which have been characterized by SS NMR, IR, and elemental analysis. These supported pre-catalysts exhibit the best conversion of CO2 to cyclic carbonates, as compared to the previously reported SOMC catalysts.

A mononuclear tantalum catalyst with a peroxocarbonate ligand for olefin epoxidation in compressed CO2

A mononuclear tantalum complex bonded to a peroxocarbonate ligand has been proved to be particularly important in the epoxidation reactions.

Polymer immobilized tantalum(v)–amino acid complexes as selective and recyclable heterogeneous catalysts for oxidation of olefins and sulfides with aqueous H2O2

Polymer supported peroxotantalate based heterogeneous catalysts served as highly efficient, selective and recyclable catalysts for alkene epoxidation and sulfide oxidation with green oxidant aqueous H₂O₂ under mild reaction conditions.

Synthesis and Characterization of Cationic Tetramethyl Tantalum(V) Complex

A novel method for the synthesis of the homogeneous homoleptic cationic tantalum(V)tetramethyl complex [(TaMe4)+ MeB(C6F5)3−] from neutral tantalumpentamethyl (TaMe5) has been described, by direct demethylation using B(C6F5)3 reagent. The aforesaid higher valent cationic tantalum complex was characterized precisely by liquid state 1H-NMR, 13C-NMR, and 1H-13C-NMR correlation spectroscopy.

Diazomethane umpolung atop anthracene: an electrophilic methylene transfer reagent

Formal addition of diazomethane's terminal nitrogen atom to the 9,10-positions of anthracene yields H₂CN₂A (1, A = C₁₄H₁₀ or anthracene).

Formal addition of diazomethane's terminal nitrogen atom to the 9,10-positions of anthracene yields H₂CN₂A (1, A = C₁₄H₁₀ or anthracene). The synthesis of this hydrazone is reported from Carpino's hydrazine H₂N₂A through treatment with paraformaldehyde. Compound 1 has been found to be an easy-to-handle solid that does not exhibit dangerous heat or shock sensitivity. Effective umpolung of the diazomethane unit imbues 1 with electrophilicity at the methylene carbon center. Its reactivity with nucleophiles such as H₂CPPh₃ and N-heterocyclic carbenes is exploited for C Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> C bond formation with elimination of dinitrogen and anthracene. Similarly, 1 is demonstrated to deliver methylene to a nucleophilic singlet d² transition metal center, W(ODipp)₄ (2), to generate the robust methylidene complex [2 Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> CH₂]. This behavior is contrasted with that of the Wittig reagent H₂CPPh₃, a more traditional and Brønsted basic methylene source that upon exposure to 2 contrastingly forms the methylidyne salt [MePPh₃][2 Created by potrace 1.16, written by Peter Selinger 2001-2019 ]]> CH].

Surface organometallic chemistry in heterogeneous catalysis

Surface organometallic chemistry has been reviewed with a special focus on environmentally relevant transformations (C–H activation, CO₂conversion, oxidation).

From single-site tantalum complexes to nanoparticles of Ta x N y and TaO x N y supported on silica: elucidation of synthesis chemistry by dynamic nuclear polarization surface enhanced NMR spectroscopy and X-ray absorption spectroscopy

Air-stable catalysts consisting of tantalum nitride nanoparticles represented as a mixture of Ta x N y and TaO x N y with diameters in the range of 0.5 to 3 nm supported on highly dehydroxylated silica were synthesized from TaMe5 (Me = methyl) and dimeric Ta2(OMe)10 with guidance by the principles of surface organometallic chemistry (SOMC). Characterization of the supported precursors and the supported nanoparticles formed from them was carried out by IR, NMR, UV-Vis, extended X-ray absorption fine structure, and X-ray photoelectron spectroscopies complemented with XRD and high-resolution TEM, with dynamic nuclear polarization surface enhanced NMR spectroscopy being especially helpful by providing enhanced intensities of the signals of 1H, 13C, 29Si, and 15N at their natural abundances. The characterization data provide details of the synthesis chemistry, including evidence of (a) O2 insertion into Ta-CH3 species on the support and (b) a binuclear to mononuclear transformation of species formed from Ta2(OMe)10 on the support. A catalytic test reaction, cyclooctene epoxidation, was used to probe the supported nanoparticles, with 30% H2O2 serving as the oxidant. The catalysts gave selectivities up to 98% for the epoxide at conversions as high as 99% with a 3.4 wt% loading of Ta present as Ta x N y /TaO x N y .

Atomically dispersed supported metal catalysts: perspectives and suggestions for future research

Catalysts consisting of metal atoms that are atomically dispersed on supports are gaining wide attention because of the rapidly developing understanding of their structures and functions and the discovery of new, stable catalysts with new properties.

Single site silica supported tetramethyl niobium by the SOMC strategy: synthesis, characterization and structure–activity relationship in the ethylene oligomerization reaction

Facile synthesis of two SOMC-based niobium methyl complexes which showed different selectivity in ethylene oligomerization.

On the Activation of Methane and Carbon Dioxide by [HTaO](+) and [TaOH](+) in the Gas Phase: A Mechanistic Study

The thermal reactions of [Ta,O,H](+) with methane and carbon dioxide have been investigated experimentally and theoretically by using electrospray ionization mass spectrometry (ESI MS) and density functional theory calculations. Although the activation of methane proceeds by liberation of H2 , the activation of CO2 gives rise to the formation of [OTa(OH)](+) under the elimination of CO. Computational studies of the reactions of methane and carbon dioxide with the two isomers of [Ta,O,H](+) , namely, [HTaO](+) and [Ta(OH)](+) , have been performed to elucidate mechanistic aspects and to explain characteristic reaction patterns.

Catalysis by Design: Well-Defined Single-Site Heterogeneous Catalysts

Heterogeneous catalysis, a field important industrially and scientifically, is increasingly seeking and refining strategies to render itself more predictable. The main issue is due to the nature and the population of catalytically active sites. Their number is generally low to very low, their "acid strengths" or " redox properties" are not homogeneous, and the material may display related yet inactive sites on the same material. In many heterogeneous catalysts, the discovery of a structure-activity reationship is at best challenging. One possible solution is to generate single-site catalysts in which most, if not all, of the sites are structurally identical. Within this context and using the right tools, the catalyst structure can be designed and well-defined, to reach a molecular understanding. It is then feasible to understand the structure-activity relationship and to develop predictable heterogeneous catalysis. Single-site well-defined heterogeneous catalysts can be prepared using concepts and tools of surface organometallic chemistry (SOMC). This approach operates by reacting organometallic compounds with surfaces of highly divided oxides (or of metal nanoparticles). This strategy has a solid track record to reveal structure-activity relationship to the extent that it is becoming now quite predictable. Almost all elements of the periodical table have been grafted on surfaces of oxides (from simple oxides such as silica or alumina to more sophisticated materials regarding composition or porosity). Considering catalytic hydrocarbon transformations, heterogeneous catalysis outcome may now be predicted based on existing mechanistic proposals and the rules of molecular chemistry (organometallic, organic) associated with some concepts of surface sciences. A thorough characterization of the grafted metal centers must be carried out using tools spanning from molecular organometallic or surface chemistry. By selection of the metal, its ligand set, and the support taken as a X, L ligands in the Green formalism, the catalyst can be designed and generated by grafting the organometallic precursor containing the functional group(s) suitable to target a given transformation (surface organometallic fragments (SOMF)). The choice of these SOMF is based on the elementary steps known in molecular chemistry applied to the desired reaction. The coordination sphere necessary for any catalytic reaction involving paraffins, olefins, and alkynes also can thus be predicted. Only their most complete understanding can allow development of catalytic reactions with the highest possible selectivity, activity, and lifetime. This Account will examine the results of SOMC for hydrocarbon transformations on oxide surfaces bearing metals of group 4-6. The silica-supported catalysts are exhibiting remarkable performances for Ziegler-Natta polymerization and depolymerization, low temperature hydrogenolysis of alkanes and waxes, metathesis of alkanes and cycloalkanes, olefins metathesis, and related reactions. In the case of reactions involving molecules that do not contain carbon (water-gas shift, NH3 synthesis, etc.) this single site approach is also valid but will be considered in a later review.

Smart Grafting of Lanthanides onto Silica via N,N-Dialkylcarbamato Complexes

The grafting and the postgrafting functionalization of lanthanide ions on commercial amorphous silica have been herein carried out by using as a precursor the terbium N,N-dibutylcarbamato derivative [Tb(O2CNBu2)3]. The reaction of the complex with the surface silanols involved only a fraction of the carbamato ligands. The following protolytic substitution of the residual carbamato ligands was carried out by exploiting the Brønsted's acidity of the β-diketone dibenzoylmethane (Hdbm), in view of the antenna effect of the β-diketonato groups, which are commonly used in lanthanide photoluminescence studies. The reaction proceeded at room temperature in a clean and easy way affording the introduction of the chosen functionality in the lanthanide coordination sphere. The same procedure has been followed by using as a precursor the X-ray characterized heterometallic N,N-dibutylcarbamato complex [NH2Bu2]2[Ln4(CO3)(O2CNBu2)12] (Ln = Eu, Tb, Tm). In both cases, X-ray photoelectron spectroscopy evidenced the chemical implantation of the lanthanide ions on the silica surface, and photoluminescence studies pointed out the potentiality of the proposed synthetic approach in the preparation of highly luminescent materials.