Inorganics, Volume 6, Issue 1 (March 2018) – 35 articles

We report the synthesis, structure, and magnetic properties of a new dinuclear dysprosium(III) complex based on a 3-methoxycinnamate ligand. The centrosymmetric complex exhibits a field-induced SMM behavior. In contrast to the previously reported lanthanide-based systems with cinnamate derivatives that relax through a combination of Raman and direct processes, an Orbach process is also involved in highlighting the role of the structural organization over the spin-lattice relaxations. Full article

Atomic layer deposition (ALD) offers exciting possibilities for controlling the structure and composition of surfaces on the atomic scale in heterogeneous catalysts and solid oxide fuel cell (SOFC) electrodes. However, while ALD procedures and equipment are well developed for applications involving flat surfaces, the conditions required for ALD in porous materials with a large surface area need to be very different. The materials (e.g., rare earths and other functional oxides) that are of interest for catalytic applications will also be different. For flat surfaces, rapid cycling, enabled by high carrier-gas flow rates, is necessary in order to rapidly grow thicker films. By contrast, ALD films in porous materials rarely need to be more than 1 nm thick. The elimination of diffusion gradients, efficient use of precursors, and ligand removal with less reactive precursors are the major factors that need to be controlled. In this review, criteria will be outlined for the successful use of ALD in porous materials. Examples of opportunities for using ALD to modify heterogeneous catalysts and SOFC electrodes will be given. Full article

The preparation of non-symmetric Schiff base ligands possessing one oxime function that is associated to a second function such as pyrrole or phenol function is first described. These ligands, which possess inner N4 or N3O coordination sites, allow formation of cationic or neutral non-symmetric Cu^II or Ni^II metallo-ligand complexes under their mono- or di-deprotonated forms. In presence of Lanthanide ions the neutral complexes do not coordinate to the Ln^III ions, the oxygen atom of the oxime function being only hydrogen-bonded to a water molecule that is linked to the Ln^III ion. This surprising behavior allows for the isolation of Ln^III ions by non-interacting metal complexes. Reaction of cationic Ni^II complexes possessing a protonated oxime function with Ln^III ions leads to the formation of original and dianionic (Gd(NO₃)₅)²⁻ entities that are well separated from each other. This work highlights the preparation of well isolated mononuclear Ln^III entities into a matrix of diamagnetic metal complexes. These new complexes complete our previous work dealing with the complexing ability of the oxime function toward Lanthanide ions. It could open the way to the synthesis of new entities with interesting properties, such as single-ion magnets for example. Full article

Charged and neutral silicon clusters comprising Si atoms that are exclusively connected to atoms of the same type serve as models for bulk silicon surfaces. The experimentally known nido-[Si₉]⁴⁻ Zintl cluster is investigated as a building block and allows for a theoretical prediction of novel silicon-rich oligomers and polymers by interconnection of such building units to larger aggregates. The stability and electronic properties of the polymers $\{{}_{\infty }{}^1([{\mathrm{Si}}_9]–{\left({\mathrm{SiCl}}_2\right)}_2){}_n\}$ and $\{{}_{\infty }{}^1([{\mathrm{Si}}_9]–{\left({\mathrm{SiH}}_2\right)}_2){}_n\}$ , as well as of related oligomers are presented. Full article

The reactions of the fused-ring bulky Eind-substituted 1,2-dibromodisilene, (Eind)BrSi=SiBr(Eind) (1a) (Eind = 1,1,3,3,5,5,7,7-octaethyl-s-hydrindacen-4-yl (a)), with N-heterocyclic carbenes (NHCs) (Im-Me₄ = 1,3,4,5-tetramethylimidazol-2-ylidene and Im-ⁱPr₂Me₂ = 1,3-diisopropyl-4,5-dimethylimidazol-2-ylidene) are reported. While the reaction of 1a with the sterically more demanding Im-ⁱPr₂Me₂ led to the formation of the mono-NHC adduct of arylbromosilylene, (Im-ⁱPr₂Me₂)→SiBr(Eind) (2a′), a similar reaction using the less bulky Im-Me₄ affords the bis-NHC adduct of formal arylsilyliumylidene cation, [(Im-Me₄)₂→Si(Eind)]⁺[Br⁻] (3a). The NHC adducts 2a′ and 3a can also be prepared by the dehydrobromination of Eind-substituted dibromohydrosilane, (Eind)SiHBr₂ (4a), with NHCs. The NHC-coordinated silicon compounds have been characterized by spectroscopic methods. The molecular structures of bis-NHC adduct, [(Im-ⁱPr₂Me₂)₂→Si(Eind)]⁺[Br⁻] (3a′), and 4a have been determined by X-ray crystallography. Full article

Knowing the possible structures of individual clusters in nanostructured materials is an important first step in their design. With previous structure prediction data for BaO nanoclusters as a basis, data mining techniques were used to investigate candidate structures for magnesium oxide, calcium oxide and strontium oxide clusters. The lowest-energy structures and analysis of some of their structural properties are presented here. Clusters that are predicted to be ideal targets for synthesis, based on being both the only thermally accessible minimum for their size, and a size that is thermally accessible with respect to neighbouring sizes, include global minima for: sizes $n=9,15,16,18$ and 24 for (MgO) ${}_n$ ; sizes $n=8,9,12,16,18$ and 24 for (CaO) ${}_n$ ; the greatest number of sizes of (SrO) ${}_n$ clusters ( $n=8,9,10,12,13,15,16,18$ and 24); and for (BaO) ${}_n$ sizes of $n=8,10$ and 16. Full article

The investigation of the reactivity of six membered N-heterocyclic carbene 1,3-bis(2,4,6-trimethylphenyl)-3,4,5,6-tetrahydropyrimidin-1-ylidene (6-Mes) towards dialkylgallium and dialkylindium alkoxides/aryloxides has shown that both steric hindrances and donor properties of 6-Mes significantly influence the strength of M–C_6-Mes bond, as well as the formation, structure and reactivity of Me₂MOR(6-Mes) (M = Ga, In) complexes. While the reactions of simple dimethylgallium alkoxides with 6-Mes lead to the formation of stable monomeric Me₂Ga(OCH₂CH₂OMe)(6-Mes) (1) and Me₂GaOMe(6-Mes) complexes, the analogous Me₂InOR(6-Mes) are unstable and disproportionate to methylindium alkoxides and Me₃In(6-Mes) (2). The use of bulky alkoxide ligand—OCPh₂Me or aryloxide ligand—OC₆H₄OMe allowed for the synthesis of stable Me₂M(OCPh₂Me)(6-Mes) (M = Ga (3) and In (4)) as well as Me₂M(OC₆H₄OMe)(6-Mes) (M = Ga (5) and In (6)). The structures of 1–6 have been determined using both spectroscopic methods in solution and X-ray diffraction studies, which confirmed the effect of both steric hindrances and donor properties of 6-Mes on their structure and catalytic properties in the ring-opening polymerization (ROP) of rac-lactide. Full article

Protic NHC (PNHC) complexes with N¹H, N²-alkyl/aryl imidazolylidene ligands are relatively rare, and routes for their synthesis differ from what is used to make non-protic analogs. Prior work from our group and others showed that in the presence of a tethering ligand (phosphine or in one case, pyridine), CpM and Cp*M (M = Ir, Ru) PNHC complexes could be made by heating. Here, we find that the use of ionizing agents to activate [Cp*M^IIICl(μ-Cl)]₂ (M = Ir, Rh) allows for what we believe is unprecedented ambient temperature formation of PNHC complexes from neutral imidazoles; the product complexes are able to perform transfer hydrogenation. Full article

Single Molecule Magnets (SMMs) based on transition metals and rare earths have been the object of considerable attention for the past 25 years. These systems exhibit slow relaxation of the magnetization, arising from a sizeable anisotropy barrier, and magnetic hysteresis of purely molecular origin below a given blocking temperature. Despite initial predictions that SMMs based on 5f-block elements could outperform most others, the results obtained so far have not met expectations. Exploiting the versatile chemistry of actinides and their favorable intrinsic magnetic properties proved, indeed, to be more difficult than assumed. However, the large majority of studies reported so far have been dedicated to uranium molecules, thus leaving the largest part of the 5f-block practically unexplored. Here, we present a short review of the progress achieved up to now and discuss some options for a possible way forward. Full article

Although the nitrogen-fixing enzyme nitrogenase critically requires both a reductase component (Fe protein) and a catalytic component, considerably more work has focused on the latter species. Properties of the catalytic component, which contains two highly complex metallocofactors and catalyzes the reduction of N₂ into ammonia, understandably making it the “star” of nitrogenase. However, as its obligate redox partner, the Fe protein is a workhorse with multiple supporting roles in both cofactor maturation and catalysis. In particular, the nitrogenase Fe protein utilizes nucleotide binding and hydrolysis in concert with electron transfer to accomplish several tasks of critical importance. Aside from the ATP-coupled transfer of electrons to the catalytic component during substrate reduction, the Fe protein also functions in a maturase and insertase capacity to facilitate the biosynthesis of the two-catalytic component metallocofactors: fusion of the [Fe₈S₇] P-cluster and insertion of Mo and homocitrate to form the matured [(homocitrate)MoFe₇S₉C] M-cluster. These and key structural-functional relationships of the indispensable Fe protein and its complex with the catalytic component will be covered in this review. Full article

Rational, fine tuning of magnetic anisotropy is critical to obtain new coordination compounds with enhanced single molecule magnet properties. For mononuclear transition metal complexes, the largest contribution to zero-field splitting is usually related to the excited states of the same spin as the ground level. Thus, the contribution of lower multiplicity roots tends to be overlooked due to its lower magnitude. In this article, we explore the role of lower multiplicity excited states in zero-field splitting parameters in model structures of Fe(II) and Co(II). Model aquo complexes with coordination numbers ranging from 2 to 6 were constructed. The magnetic anisotropy was calculated by state of the art ab initio methodologies, including spin-orbit coupling effects. For non-degenerate ground states, contributions to the zero-field splitting parameter (D) from highest and lower multiplicity roots were of the same sign. In addition, their relative magnitude was in a relatively narrow range, irrespective of the coordination geometry. For degenerate ground states, the contribution from lower multiplicity roots was significantly smaller. Results are rationalized in terms of general expressions for D and are expected to be reasonably transferable to real molecular systems. Full article

The sterically bulky Ga(III) and In(III) (IPr*)MMe₃ adducts (1 and 2) and (SItBu)MMe₃ adducts (3 and 4) (M = Ga, In; IPr* = 1,3-bis{2,6-bis(diphenylmethyl)-4-methylphenyl}-1,3-dihydro- imidazol-2-ylidene; SItBu = 1,3-bis(1,1-dimethylethyl)-imidazolidin-2-ylidene) were prepared and structurally characterized, allowing an estimation of the steric hindrance of such Lewis pairs (yields in 1–4: 92%, 90%, 73%, and 42%, respectively). While the IPr* adducts 1 and 2 are robust species, the more severely congested SItBu adducts 3 and 4 are more reactive and exhibit a limited stability in solution. Adduct (SItBu)GaMe₃ (3) reacts quickly with H₂ at room temperature to afford the corresponding aminal product, 1,3-di-tert-butylimidazolidine (5), along with free GaMe₃. Such Frustrated Lewis Pair (FLP) reactivity constitutes the first instance of a H₂ activation involving a simple trialkyl GaR₃ species. Adduct 3 also mediates the ring-opening polymerization (ROP) of rac-lactide at room temperature to afford cyclic polylactide (PLA). Full article

Re(pyNHC-PhCF₃)(CO)₃Br is a highly active photocatalyst for CO₂ reduction. The PhCF₃ derivative was previously empirically shown to be a robust catalyst. Here, the role of the PhCF₃ group is probed computationally and the robust nature of this catalyst is analyzed with regard to the presence of water and oxygen introduced in controlled amounts during the photocatalytic reduction of CO₂ to CO with visible light. This complex was found to work well from 0–1% water concentration reproducibly; however, trace amounts of water were required for benchmark Re(bpy)(CO)₃Cl to give reproducible reactivity. When ambient air is added to the reaction mixture, the NHC complex was found to retain substantial performance (~50% of optimized reactivity) at up to 40% ambient atmosphere and 60% CO₂ while the Re(bpy)(CO)₃Cl complex was found to give a dramatically reduced CO₂ reduction reactivity upon introduction of ambient atmosphere. Through the use of time-correlated single photon counting studies and prior electrochemical results, we reasoned that this enhanced catalyst resilience is due to a mechanistic difference between the NHC- and bpy-based catalysts. These results highlight an important feature of this NHC-ligated catalyst: substantially enhanced stability toward common reaction contaminates. Full article

π-Electron compounds that include multiple bonds between silicon atoms have received much attention as novel functional silicon compounds. In the present paper, 1,2-bis(trimethylsilyl)-1,2-disilacyclohexene 1 was successfully synthesized as thermally stable yellow crystals. Disilene 1 was easily converted to the corresponding potassium disilenide 4, which furnished novel functionalized disilenes after the subsequent addition of an electrophile. Interestingly, two trimethylsilyl groups in 1 can be stepwise converted to anthryl groups. The novel disilenes derived from 1 were characterized by a combination of nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry (MS), elemental analyses, and X-ray single crystal diffraction analysis. The present study demonstrates that disilene 1 can serve as a unit of cis-1,2-dialkyldisilene. Full article

Metal salen/salophen complexes have been used as fluorescent probes for cell imaging with various metal centers. Herein we synthesized cryptand-type aluminum salophen complexes LAl₃ and the corresponding mononuclear compound LAl. X-ray crystal diffraction verifies the cryptand-type structure of LAl₃ with C_3h symmetry. Both LAl₃ and LAl show moderate green fluorescence with quantum yields of 0.17 and 0.05, respectively. The hydrophilic and cationic nature of these aluminum salophen complexes renders them enhanced cellular uptake. Both complexes are internalized into cells by energy-dependent pathways and they distribute in lysosomal organelles. Full article

Man-made homogeneous catalysis with the aid of transition metal compounds looks back on a long history of almost one hundred years. Still, more detailed insight into the underlying mechanisms is warranted. The knowledge of how transition metals with their specific/characteristic properties, such as oxidations states, redox chemistry, spin states, kinetics, and coordination preference will contribute to these processes paving the way to optimize existing processes, and to finding new exciting organic, inorganic, and organometallic transformations and to broaden the substrate scope through catalyst design. This special issue collects very recent mechanistic insight from experimental, theoretical, and mixed experimental–theoretical approaches. Full article

In recent years, nickel has entered the stage for catalyzed C–C cross-coupling reactions, replacing expensive palladium, and in some cases enabling the use of new substrate classes. Polypyridine ligands have played an important role in this development, and the prototypical tridentate 2,2′:6′,2′′-terpyridine (tpy) stands as an excellent example of these ligands. This review summarizes research that has been devoted to exploring the mechanistic details in catalyzed C–C cross-coupling reactions using tpy-based nickel systems. Full article

Using density functional theory (DFT) methods, we analyze the adsorption of acetylene and ethylene on the Si(001) surface in an unusual bond insertion mode. The insertion takes place at a saturated tetravalent silicon atom and the insight gained can thus be transferred to other saturated silicon compounds in molecular and surface chemistry. Molecular orbital analysis reveals that the distorted and symmetry-reduced coordination of the silicon atoms involved due to surface reconstruction raises the electrophilicity and, additionally, makes certain σ bond orbitals more accessible. The affinity towards bond insertion is, therefore, caused by the structural constraints of the surface. Additionally, periodic energy decomposition analysis (pEDA) is used to explain why the bond insertion structure is much more stable for acetylene than for ethylene. The increased acceptor abilities of acetylene due to the presence of two π*-orbitals (instead of one π*-orbital and a set of σ*(C–H) orbitals for ethylene), as well as the lower number of hydrogen atoms, which leads to reduced Pauli repulsion with the surface, are identified as the main causes. While our findings imply that this structure might be an intermediate in the adsorption of acetylene on Si(001), the predicted product distributions are in contradiction to the experimental findings. This is critically discussed and suggestions to resolve this issue are given. Full article

The syntheses, structural characterization, and magnetic properties of three lanthanide complexes with formulas [Ln(L¹)₃] (Ln = Dy (1Dy); Er (1Er)); and [Dy(L²)₂] (2Dy) were reported. Complexes 1Dy and 1Er are isostructural with the metal ion in distorted trigonal-prismatic coordination geometry, but exhibit distinct magnetic properties due to the different shapes of electron density for Dy^III (oblate) and Er^III (prolate) ions. Complex 1Dy shows obvious SMM behavior under a zero direct current (dc) field with an effective energy barrier of 31.4 K, while complex 1Er only features SMM behavior under a 400 Oe external field with an effective energy barrier of 23.96 K. In stark contrast, complex 2Dy with the octahedral geometry only exhibits the frequency dependence of alternating current (ac) susceptibility signals without χ″ peaks under a zero dc field. Full article

Host-guest chemistry was performed with disilane-bearing crown ethers and the ammonium cation. Equimolar reactions of 1,2-disila[18]crown-6 (1) or 1,2-disila-benzo[18]crown-6 (2) and NH₄PF₆ in dichloromethane yielded the respective compounds [NH₄(1,2-disila[18]crown-6)]PF₆ (3) and [NH₄(1,2-disila-benzo[18]crown-6)]PF₆ (4). According to X-ray crystallographic, NMR, and IR experiments, the uncommon hydrogen bonding motif O_(Si)∙∙∙H could be observed and the use of cooperative effects of ethylene and disilane bridges as an effective way to incorporate guest molecules was illustrated. Full article

Cation tracer diffusion in polycrystalline AZrO₃ (A = Ca, Sr, Ba) perovskites was studied at 1300–1500 °C in air using the stable isotope ⁹⁶Zr. Thin films of ⁹⁶ZrO₂ were deposited on polished ceramic pellets by drop casting of an aqueous precursor solution containing the tracer. The pellets were subjected to thermal annealing, and the isotope depth profiles were measured by secondary ion mass spectrometry. Two distinct regions with different slopes in the profiles enabled to assess separately the lattice and grain boundary diffusion coefficients using Fick’s second law and Whipple–Le Clair’s equation. The cation diffusion along grain boundaries was 4–5 orders of magnitude faster than the corresponding lattice diffusion. The magnitude of the diffusivity of Zr⁴⁺ was observed to increase with decreasing size of the A-cation in AZrO₃, while the activation energy for the diffusion was comparable 435 ± 67, 505 ± 56, and 445 ± 45 and kJ·mol⁻¹ for BaZrO₃, SrZrO₃, and CaZrO₃, respectively. Several diffusion mechanisms for Zr⁴⁺ were considered, including paths via Zr- and A-site vacancies. The Zr⁴⁺ diffusion coefficients reported here were compared to previous data reported on B-site diffusion in perovskites, and Zr⁴⁺ diffusion in fluorite-type compounds. Full article

We analyzed the effect of the interfacial free energy on the thermodynamics of hydrogen sorption in nano-scaled materials. When the enthalpy and entropy terms are the same for all interfaces, as in an isotropic bi-phasic system, one obtains a compensation temperature, which does not depend on the system size nor on the relative phase abundance. The situation is different and more complex in a system with three or more phases, where the interfaces have different enthalpy and entropy. We also consider the possible effect of elastic strains on the stability of the hydride phase and on hysteresis. We compare a simple model with experimental data obtained on two different systems: (1) bi-phasic nanocomposites where ultrafine TiH₂ crystallite are dispersed within a Mg nanoparticle and (2) Mg nanodots encapsulated by different phases. Full article

The potential of 1-butyl-3-methylimidazolium tetrachloroferrate ([bmim]Fe(III)Cl₄) for replacing an iron(III) chelate catalytic solution in the catalytic oxidation of H₂S is attributed to its no side reaction and no degradation of the chelating agent. The catalytic oxidation product of water in non-aqueous [bmim]Fe(III)Cl₄ possibly has an influence on the oxidative absorption of H₂S. Water and hydrophobic [bmim]Fe(III)Cl₄ mixtures at water volume percents from 40% to 70% formed separate phases after srirring, without affecting the oxidative absorption of hydrogen sulfide. Then, studies on the properties of homogeneous [bmim]Fe(III)Cl₄–H₂O mixtures at water volume percents in the range of 5.88–30% and above 80% reveal that these mixtures are both Brønsted and Lewis acids at vol % (H₂O) ≤ 30%, and only Lewis acids at vol % (H₂O) ≥ 80%. Raman spectra showed that [bmim]Fe(III)Cl₄ was the dominating species at vol % (H₂O) ≤ 30%, in contrast, [bmim]Fe(III)Cl₄ decomposed into FeCl₃·2H₂O and [bmim]Cl at vol % (H₂O) ≥ 80%. Further research on oxidative absorption of H₂S by homogeneous [bmim]Fe(III)Cl₄–H₂O mixtures demonstrated that [bmim]Fe(III)Cl₄ was reduced by H₂S to [bmim]Fe(II)Cl₄H and FeCl₃·2H₂O was reduced to FeCl₂, at the same time, H₂S was oxidized to S₈. In addition, the decrease in acidity caused by increasing the water content increased the weight percent of absorbed H₂S, and decreased volatile HCl emissions. However, it is difficult to prevent the suspended S₈ generated at vol % (H₂O) ≥ 80% from the formation of sulfur blockage. Therefore, oxidative absorption of H₂S by [bmim]Fe(III)Cl₄–H₂O mixtures is feasible at vol % (H₂O) < 80% without sulfur blockage. Full article

NaBH₄ hydrolysis can generate pure hydrogen on demand at room temperature, but suffers from the difficult regeneration for practical application. In this work, we overview the state-of-the-art progress on the regeneration of NaBH₄ from anhydrous or hydrated NaBO₂ that is a byproduct of NaBH₄ hydrolysis. The anhydrous NaBO₂ can be regenerated effectively by MgH₂, whereas the production of MgH₂ from Mg requires high temperature to overcome the sluggish hydrogenation kinetics. Compared to that of anhydrous NaBO₂, using the direct hydrolysis byproduct of hydrated NaBO₂ as the starting material for regeneration exhibits significant advantages, i.e., omission of the high-temperature drying process to produce anhydrous NaBO₂ and the water included can react with chemicals like Mg or Mg₂Si to provide hydrogen. It is worth emphasizing that NaBH₄ could be regenerated by an energy efficient method and a large-scale regeneration system may become possible in the near future. Full article

A photo-switchable single molecule-magnet (SMM) with two Dy ions bridged by a bis-bipyridine-dithienylethene ligand was synthesised. Isomerisation effects on the magnetic properties were investigated. Particular attention was paid to the slow relaxation of the magnetisation in order to determine precisely the role played by the ligand. Photo-isomerization of the ligand induced a geometric rearrangement of the complex and an electronic reconfiguration. The changes were studied by solid and solution state magnetic measurements. Full article

In this contribution is reported the synthesis, characterization, and aggregation properties in solution of a novel Zn(II) complex, (R)-2, derived from the enantiopure chiral trans-1,2-diaminocyclohexane and a substituted salicylaldehyde. Detailed ¹H NMR, DOSY NMR, optical absorption, and circular dichroism spectroscopic studies and chemical evidence allowed to investigate the nature of aggregate species in solution. The high solubility of (R)-2 in solution of the non-coordinating chloroform solvent leads to formation of various aggregates, some of them consisting of large oligomers estimated to contain up to 27 monomeric units. The chiral trans-stereochemistry of the bridging diamine favors a different aggregation mode in these complexes, both in the oligomers and dimers, involving a tetrahedral coordination geometry around the metal center. Overall data suggest the formation of helical oligomers, (ZnL)_n, in freshly prepared chloroform solutions which, by standing or heating, evolve towards a more thermodynamically stable, dinuclear double-helicate Zn₂L₂ dimer. Full article

We synthesized the dinuclear and mononuclear dysprosium(III) complexes [{Dy(Tp)₂}₂(Cl₂An)]·2CH₂Cl₂ (1) and [Co(Cp)₂][Dy(Tp)₂(Cl₂An)] (3), where Cl₂An²⁻ and Tp⁻ are the chloranilate and hydrotris(pyrazolyl)borate ligand, respectively. In addition, the magnitude of the magnetic coupling between the lanthanide centers through the Cl₂An²⁻ bridge has been probed through the synthesis of [{Gd(Tp)₂}₂(Cl₂An)]·2CH₂Cl₂ (2), which is a gadolinium(III) analogue of 1. Complexes 1–3 were characterized by infrared (IR) spectroscopy, elemental analysis, single-crystal X-ray diffraction, and SQUID measurements. IR and single-crystal X-ray structural analyses confirm that the coordination environments of the lanthanide(III) centers in 1 and 3 are similar to each other; i.e., eight-coordinated metal centers, each occupied by an N₆O₂ donor set from two Tp⁻ ligands and one Cl₂An²⁻ ligand. The coordination geometries of the lanthanide(III) centers in 1 and 2 are distorted triangular dodecahedral, while that in the mononuclear complex 3 is square antiprismatic, where the Cl₂An²⁻ ligand takes the bi-separated delocalized form in 1 and 2, and the o-quinone form in 3. Alternating-current (AC) magnetic studies clearly reveal that both 1 and 3 exhibit field-induced slow relaxations of magnetization that occur via Raman and direct processes. Complexes 1 and 3 exhibit different spin relaxation behavior, which reflects the coordination geometry around each Dy^III center and its nuclearity, as well as the molecular packing in the crystal lattice. Although the magnetic analysis of 2 revealed negligible magnetic coupling, Cl₂An²⁻ bridges with small biases may form in the dinuclear complexes, which play roles in the spin relaxation dynamics through dipolar interactions. Full article

Peripherally functionalized low-valent main group species allow for the introduction/interconversion of functional groups without increasing the formal oxidation state of the main group center. Herein, we report a straightforward method for the incorporation of a α-chlorosilyl moiety adjacent to the NHC-coordinated germanium(II) center. Full article