Intercluster Compounds Consisting of Gold Clusters and Fullerides: [Au7(PPh3)7]C60⋅THF and [Au8(PPh3)8](C60)2

Mixed-ligand strategy for synthesizing water-soluble chiral gold clusters with phosphine ligands

Water-soluble chiral metal clusters have drawn much attention by virtue of their fascinating physicochemical properties and potential biomedical applications, but currently, phosphine-protected Au clusters with both chirality and water-solubility are still very limited. In this article, we demonstrate a mixed-ligand strategy for the facile synthesis of atomically precise, water-soluble chiral Au clusters protected by phosphine alone. The clusters are obtained by the reduction of aurate ions in the presence of a phosphine mixture consisting of highly hydrophilic monophosphine (i.e., triphenylphosphine trisulfonate; TPPTS) and hydrophobic chiral diphosphine (i.e., S-Segphos or S-BINAP), both of which are commercially available. The clusters are size/composition-separated via gel electrophoresis, and notably, heptanuclear cluster Au₇(S-Segphos)₃(TPPTS)₂ exhibits a large chiroptical activity with the maximum anisotropy factor (g-factor) of 4.7 × 10^-3, one of the largest values in such Au clusters. Quantum chemical calculations for model Au₇ cluster species suggest two important factors to obtain large chiroptical activity: (i) more than two axially-chiral diphosphine ligands, and (ii) the absence of configurational isomer averaging. Consequently, despite the experimental use of a mixture containing both chiral and achiral phosphines, a large chiroptical activity can be created in Au clusters with high water-solubility.

Assembling Atomically Precise Noble Metal Nanoclusters Using Supramolecular Interactions

Supramolecular chemistry (SC) of noble metal nanoclusters (NMNCs) is one of the fascinating areas of contemporary materials science. It is principally concerned with the noncovalent interactions between NMNCs, as well as between NMNCs and molecules or nanoparticles. This review focuses on recent advances in the supramolecular assembly of NMNCs and applications of the resulting structures. We have divided the topics into four distinct subgroups: (i) SC of NMNCs in gaseous and solution phases, (ii) supramolecular interactions of NMNCs in crystal lattices, (iii) supramolecular assemblies of NMNCs with nanoparticles and NMNCs, and (iv) SC of NMNCs with other molecules. The last explores their interactions with fullerenes, cyclodextrins, cucurbiturils, crown ethers, and more. After discussing these topics concisely, various emerging properties of the assembled systems in terms of their mechanical, optical, magnetic, charge-transfer, etc. properties and applications are presented. SC is seen to provide a crucial role to induce new physical and chemical properties in such hybrid nanomaterials. Finally, we highlight the scope for expansion and future research in the area. This review would be useful to those working on functional nanostructures in general and NMNCs in particular.

A Review of State of the Art in Phosphine Ligated Gold Clusters and Application in Catalysis

Atomically precise gold clusters are highly desirable due to their well-defined structure which allows the study of structure-property relationships. In addition, they have potential in technological applications such as nanoscale catalysis. The structural, chemical, electronic, and optical properties of ligated gold clusters are strongly defined by the metal-ligand interaction and type of ligands. This critical feature renders gold-phosphine clusters unique and distinct from other ligand-protected gold clusters. The use of multidentate phosphines enables preparation of varying core sizes and exotic structures beyond regular polyhedrons. Weak gold-phosphorous (Au-P) bonding is advantageous for ligand exchange and removal for specific applications, such as catalysis, without agglomeration. The aim of this review is to provide a unified view of gold-phosphine clusters and to present an in-depth discussion on recent advances and key developments for these clusters. This review features the unique chemistry, structural, electronic, and optical properties of gold-phosphine clusters. Advanced characterization techniques, including synchrotron-based spectroscopy, have unraveled substantial effects of Au-P interaction on the composition-, structure-, and size-dependent properties. State-of-the-art theoretical calculations that reveal insights into experimental findings are also discussed. Finally, a discussion of the application of gold-phosphine clusters in catalysis is presented.

Emergent electronic properties in Co-deposited superatomic clusters

We report an intercluster compound based on co-deposition of the Au cluster [Au₉(PPh₃)₈](NO₃)₃ and the fulleride KC₆₀(THF). Electronic properties characteristic for a charge interaction between superatoms emerge within the solid state material [Au₉(PPh₃)₈](NO₃)_3-x(C₆₀)_x, as confirmed by UV-VIS and Raman spectroscopy and I-V measurements. These emergent properties are related to the superatomic electronic states of the initial clusters. The material is characterized by Fourier-transform infrared spectroscopy, x-ray diffraction, Raman spectroscopy, and electrical measurements. Structural optimization and ab initio band structure calculations are performed with density functional theory to interpret the nature of the electronic states in the material; Bader charge calculations assign effective oxidation states in support of the superatomic model of cluster interactions.

Constructing the bonding interactions between endohedral metallofullerene superatoms by embedded atomic regulation

We present a possible principle that controls intercluster bonding through embedding different kinds of actinide atoms into the centre of fullerenes, thereby exhibiting different bonding forms. Moreover, these superatoms maintain the robustness of electronic structures.

Toward Controlling the Electronic Structures of Chemically Modified Superatoms of Gold and Silver

Atomically precise gold/silver clusters protected by organic ligands L, [(Au/Ag)_x L_y ]^z , have gained increasing interest as building units of functional materials because of their novel photophysical and physicochemical properties. The properties of [(Au/Ag)_x L_y ]^z are intimately associated with the quantized electronic structures of the metallic cores, which can be viewed as superatoms from the analogy of naked Au/Ag clusters. Thus, establishment of the correlation between the geometric and electronic structures of the superatomic cores is crucial for rational design and improvement of the properties of [(Au/Ag)_x L_y ]^z . This review article aims to provide a qualitative understanding on how the electronic structures of [(Au/Ag)_x L_y ]^z are affected by geometric structures of the superatomic cores with a focus on three factors: size, shape, and composition, on the basis of single-crystal X-ray diffraction data. The knowledge accumulated here will constitute a basis for the development of ligand-protected Au/Ag clusters as new artificial elements on a nanometer scale.

Cocrystallization of Chiral 3d-4f Clusters {Mn10Ln6} and {Mn6Ln2}

Cocrystallization of different metal nanoclusters facilitates the preparation of cluster-based nanomaterials with enhanced properties. Herein, two pairs of enantiomeric 3d-4f cocrystallization structures of clusters R/S-[Mn₁₀Ln₆] and R/S-[Mn₆Ln₂] (Ln = Dy for 1R and 1S, Y for 2R and 2S) have been reported. Compounds R/S-[Mn₁₀Ln₆][Mn₆Ln₂] exhibit a large optical activity and magneto-optic effect as verified by natural circular dichroism (NCD) and magnetic circular dichroism (MCD). In addition, alternating current (ac) magnetic measurements show that the chiral R/S-[Mn₁₀Dy₆][Mn₆Dy₂] cocrystallization structure displays slow magnetic relaxation with U_eff = 25.1 K.

Density-functional tight-binding for phosphine-stabilized nanoscale gold clusters

We report a parameterization of the second-order density-functional tight-binding (DFTB2) method for the quantum chemical simulation of phosphine-ligated nanoscale gold clusters, metalloids, and gold surfaces. Our parameterization extends the previously released DFTB2 "auorg" parameter set by connecting it to the electronic parameter of phosphorus in the "mio" parameter set. Although this connection could technically simply be accomplished by creating only the required additional Au-P repulsive potential, we found that the Au 6p and P 3d virtual atomic orbital energy levels exert a strong influence on the overall performance of the combined parameter set. Our optimized parameters are validated against density functional theory (DFT) geometries, ligand binding and cluster isomerization energies, ligand dissociation potential energy curves, and molecular orbital energies for relevant phosphine-ligated Au n clusters (n = 2-70), as well as selected experimental X-ray structures from the Cambridge Structural Database. In addition, we validate DFTB simulated far-IR spectra for several phosphine- and thiolate-ligated gold clusters against experimental and DFT spectra. The transferability of the parameter set is evaluated using DFT and DFTB potential energy surfaces resulting from the chemisorption of a PH3 molecule on the gold (111) surface. To demonstrate the potential of the DFTB method for quantum chemical simulations of metalloid gold clusters that are challenging for traditional DFT calculations, we report the predicted molecular geometry, electronic structure, ligand binding energy, and IR spectrum of Au108S24(PPh3)16.

N4Mg6M (M = Li, Na, K) superalkalis for CO2 activation

Superatoms have exciting properties, including diverse functionalization, redox activity, and magnetic ordering, so the resulting cluster-assembled solids hold the promise of high tunability, atomic precision, and robust architectures. By utilizing adamantane-like clusters as building blocks, a new class of superatoms N₄Mg₆M (M = Li, Na, K) is proposed here. The studied superalkalis feature low adiabatic ionization energies, an antibonding character in the interactions between magnesium and nitrogen atoms, and highly delocalized highest occupied molecular orbital (HOMO). Consequently, the N₄Mg₆M superalkalis might easily lose their HOMO electrons when interacting with superhalogen electrophiles to form stable superatom [superalkali]⁺[superhalogen]^- compounds. Moreover, the studied superalkalis interact strongly with carbon dioxide, and the resulting N₄Mg₆M/CO₂ systems represent two strongly interacting ionic fragments (i.e., N₄Mg₆M⁺ and CO₂ ^-). In turn, the electron affinity of the N₂ molecule (of -1.8 eV) is substantially lower than that observed for carbon dioxide (EA = -0.6 eV) and consequently, the N₂ was found to form the weakly bound [N₄Mg₆M][N₂] complex rather than the desired ionic [N₄Mg₆M]⁺[N₂]^- product. Thus, the N₄Mg₆M superalkalis have high selectivity over N₂ when it comes to CO₂ reduction and also are themselves stable. We believe that the results described within this paper will be useful for understanding CO₂ activation, which is the first step for producing fuels from CO₂. Moreover, we demonstrate that designing novel superatomic systems and exploring their physicochemical features might be used to create desirable functional materials.

Stepwise Assembly of an Electroactive Framework from a Co6 S8 Superatomic Metalloligand and Cuprous Iodide Building Units

The design of metal-organic frameworks (MOFs) that incorporate more than one metal cluster constituent is a challenging task. Conventional one-pot reaction protocols require judicious selection of ligand and metal ion precursors, yet remain unpredictable. Stable, preformed nanoclusters, with ligand shells that can undergo additional coordination-driven reactions, provide a platform for assembling multi-cluster solids with precision. Herein, a discrete Co₆ S₈ (PTA)₆ (PTA=1,3,5-triaza-7-phosphaadamantane) superatomic-metalloligand is assembled into a three-dimensional (3D) coordination polymer comprising Cu₄ I₄ secondary building units (SBUs). The resulting heterobimetallic framework (1) contains two distinct cluster constituents and bifunctional PTA linkers. Solid-state diffuse reflectance studies reveal that 1 is an optical semiconductor with a band-gap of 1.59 eV. Framework-modified electrodes exhibit reversible redox behavior in the solid state arising from the Co₆ S₈ superatoms, which remain intact during framework synthesis.

A family of lead clusters with precious metal cores

Gold nanoparticles have been used for centuries, both for decoration and in medical applications. More recently, many of the major advances in cluster chemistry have involved well-defined clusters containing tens or hundreds of atoms, either with or without a ligand shell. In this paper we report the synthesis of two gold/lead clusters, [Au₈Pb₃₃]⁶⁻ and [Au₁₂Pb₄₄]⁸⁻, both of which contain nido [Au@Pb₁₁]³⁻ icosahedra surrounding a core of Au atoms. Analogues of these large clusters are not found in the corresponding Ag chemistry: instead, the Ag-centered nido icosahedron, [Ag@Pb₁₁]³⁻, is the only isolated product. The structural chemistry, along with the mass spectrometry which shows the existence of [Au₂Pb₁₁]²⁻ but not [Ag₂Pb₁₁]²⁻, leads us to propose that the former species is the key intermediate in the growth of the larger clusters. Density functional theory indicates that secondary π-type interactions between the [Au@Pb₁₁]³⁻ ligands and the gold core play a significant part in stabilizing the larger clusters.

Many Zintl ions with a single endohedrally encapsulated transition metal ion are known, but relatively few where clusters of two or more metals are present. Here, the authors report the synthesis and characterization of two clusters, [Au₈Pb₃₃]⁶⁻ and [Au₁₂Pb₄₄]¹²⁻, which contain Au₈ and Au₁₂ cores surrounded by Pb shells.

Effect of Charge and Phosphine Ligands on the Electronic Structure of the Au8 Cluster

In this work, we use density functional theory calculations with a hybrid exchange-correlation functional and effective core pseudopotentials to determine the geometry of bare and phosphine-protected Au₈ nanoclusters and characterize their electronic structure. Au₈ clusters were bonded to four and eight PH₃ ligands in order to evaluate the effect of ligand concentration on the electronic structure, while different positional configurations were also tried for four ligands attached to the cluster. We show that the neutral clusters become more nucleophilic as the ligands bind to the clusters at stable sites. The ground-state planar configuration of Au₈ is maintained depending on the concentration and position of ligands. The effect of ionizing to the +2 charge state results in disruption of planar geometry in some cases because of inoccupation of a molecular orbital with the Au-Au bonding character. Natural bond order charge analyses showed that Au atoms oxidize upon ionization, instead of phosphine. The net positive charge makes the clusters more electrophilic with a capacity to absorb electrons from nucleophiles depending on the concentration and position of ligands and on the concentration of low-coordinated gold atoms. Besides, ionization energies and electron affinities were calculated through different mechanisms, finding that both variables are much higher for charged systems and change inversely with the concentration of ligands.

Approaching Materials with Atomic Precision Using Supramolecular Cluster Assemblies

Supramolecular chemistry is a major area of chemistry that utilizes weaker non-covalent interactions between molecules, including hydrogen bonding, van der Waals, electrostatic, π···π, and C-H···π interactions. Such forces have been the basis of several molecular self-assemblies and host-guest complexes in organic, inorganic, and biological systems. Atomically precise nanoclusters (NCs) are materials of growing interest that display interesting structure-property correlations. The evolving science of such systems reaffirms their molecular behavior. This gives a possibility of exploring their supramolecular chemistry, leading to assemblies with similar or dissimilar cluster molecules. Such assemblies with compositional, structural, and conformational precision may ultimately result in cluster-assembled hybrid materials. In this Account, we present recent advancements on different possibilities of supramolecular interactions in atomically precise cluster systems that can occur at different length scales. We first present a brief discussion of the aspicule model of clusters, considering Au₂₅(SR)₁₈ as an example, that can explain various aspects of its atomic precision and distinguish the similar or dissimilar interacting sites in their structures. The supramolecular interaction of 4- tert-butylbenzyl mercaptan (BBSH)-protected [Au₂₅(SBB)₁₈]^- NCs with cyclodextrins (CD) to form Au₂₅SBB₁₈∩CD _n ( n = 1-4) and that of [Ag₂₉(BDT)₁₂]^3- with fullerenes to form [Ag₂₉(BDT)₁₂(C₆₀) _n]^3- ( n = 1-9) (BDT = 1,3-benzenedithiolate) are discussed subsequently. The formation of these adducts was studied by electrospray ionization mass spectrometry (ESI MS), optical absorption and NMR spectroscopy. In the subsequent sections, we discuss how variation in intercluster interactions can lead to polymorphic crystals, which are observable in single-crystal X-ray diffraction. Taking [Ag₂₉(BDT)₁₂(TPP)₄]^3- (TPP = triphenylphosphine) clusters as an example, we discuss how the different patterns of C-H···π and π···π interactions between the secondary ligands can alter the packing of the NCs into cubic and trigonal lattices. Finally, we discuss how the supramolecular interactions of atomically precise clusters can result in their hybrid assemblies with plasmonic nanostructures. The interaction of p-mercaptobenzoic acid ( p-MBA)-protected Ag₄₄( p-MBA)₃₀ NCs with tellurium nanowires (Te NWs) can form crossed-bilayer precision assemblies with a woven-fabric-like structure with an angle of 81° between the layers. Similar crossed-bilayer assemblies show an angle of 77° when Au₁₀₂( p-MBA)₄₄ clusters are used to form the structure. Such assemblies were studied by transmission electron microscopy (TEM). Precision in these hybrid assemblies of Te NWs was highly controlled by the geometry of the ligands on the NC surface. Moreover, we also present how Ag₄₄( p-MBA)₃₀ clusters can encapsulate gold nanorods to form cage-like nanostructures. Such studies involved TEM, scanning transmission electron microscopy (STEM), and three-dimensional tomographic reconstructions of the nanostructures. The hydrogen bonding interactions of the -COOH groups of the p-MBA ligands were the major driving force in both of these cases. An important aspect that is central to the advancement of the area is the close interplay of molecular tools such as MS with structural tools such as TEM along with detailed computational modeling. We finally conclude this Account with a future perspective on the supramolecular chemistry of clusters. Advancements in this field will help in developing new materials with potential optical, electrical, and mechanical properties.

Discovery of two types of new porphyrin–C70 co-crystals: influence of intermolecular contact on the inherent resistance

Two types of supramolecular aggregates based on C₇₀ were synthesised and their inherent resistances were analysed.

Binding for endohedral-metallofullerene superatoms induced by magnetic coupling

To design new materials based on artificial superatoms, clarifying their involved interaction is particularly important. In this study, we discuss first-principle calculations to show that the interaction between endohedral metallofullerenes (EMFs) of U@C28 can lead to different chemical and physical adsorption structures. Especially, these structures are derived from different magnetic coupling resonances, and they can transform by changing the distance between U@C28 superatoms. These findings will promote the future development for bottom-up assembling of new functional materials and even devices.

Cluster assemblies as superatomic solids: a first principles study of bonding & electronic structure

The synthesis of cluster based materials poses an exciting challenge for experimental chemistry. The main advantage of these materials compared to conventional bulk compounds is the simple tunability of the chemical and physical characteristics of individual clusters. As a consequence, cluster assemblies can theoretically be used for the creation of designer materials exhibiting specifically desired properties. Since superatoms reveal a large intrinsic thermodynamic stability and often very interesting tunable electronic characteristics, they seem to be an excellent choice as building blocks for the bulk. Here, we present a detailed first principles analysis of carefully chosen superatomic cluster binary and bulk assemblies, in order to determine which forces control the attractive interaction in superatomic solids, and how the individual cluster properties affect these assemblies. This study uses the highly tunable and stable Au₁₃(RS(AuSR)₂)₆ cluster with a variety of dopants as a model system, while the principles are likely transferable to other ligand protected systems with a straightforward superatomic electron count, such as aluminum or sodium clusters. Three different superatomic materials based on doped gold clusters, boranes and C₆₀s are constructed and evaluated. Beyond the verification that superatoms can be used to create materials that reveal emergent atom-based solid like properties, various factors influencing superatomic materials, such as the EA, IP and relative sizes of the clusters, have been identified and critically evaluated.

Assembly of titanium-oxo cations with copper-halide anions to form supersalt-type cluster-based materials

A facile approach for the synthesis of binary titanium-oxo and copper-halide cluster-based crystalline materials with salt-like packing has been successfully established.

First-principles calculations of the electronic structure and bonding in metal cluster-fullerene materials considered within the superatomic framework

Inspired by recent success of synthesizing cluster assembled compounds we address the question to what extent the three new materials [Co₆Se₈(PEt₃)₆][C₆₀]₂, [Cr₆Te₈(PEt₃)₆][C₆₀]₂, and [Ni₉Te₆(PEt₃)₈]C₆₀, upon forming bulk compounds, imitate atomic analogues. Although experimental results suggest the latter, a theoretical approach is the method of choice for offering a conclusive answer and for studying the actual superatomic character. The concept of superatoms for describing atom-imitating clusters is very intriguing since it allows chemists to apply their chemical intuition - a useful tool for predicting new materials - when it comes to inter-cluster reactions. Thus, we systematically study the lattice structure, the intercluster binding, and the electronic structure by density functional theory and assess them in terms of their superatomic features. We show that collective properties arise upon bulk formation, which promotes arguments for the formation of solids in which the constituent clusters have a superatomic character that determines some form of chemical bonding. Additionally, we find evidence for the formation of superatomic states. Unfortunately, however, due to the mixing of electronic states of transition metals and chalcogen atoms, no typical electronic shell closing in the cluster cores can be identified.

Polynuclear Gold [Au(I) ]4 , [Au(I) ]8 , and Bimetallic [Au(I) 4 Ag(I) ] Complexes: C-H Functionalization of Carbonyl Compounds and Homogeneous Carbonylation of Amines

The synthesis of tetranuclear gold complexes, a structurally unprecedented octanuclear complex with a planar [Au(I) 8 ] core, and pentanuclear [Au(I) 4 M(I) ] (M=Cu, Ag) complexes is presented. The linear [Au(I) 4 ] complex undergoes C-H functionalization of carbonyl compounds under mild reaction conditions. In addition, [Au(I) 4 Ag(I) ] catalyzes the carbonylation of primary amines to form ureas under homogeneous conditions with efficiencies higher than those achieved by gold nanoparticles.

Charge transfer complexes of fullerenes containing C₆₀˙⁻ and C₇₀˙⁻ radical anions with paramagnetic Co(II)(dppe)₂Cl⁺ cations (dppe: 1,2-bis(diphenylphosphino)ethane)

The reduction of Co(II)(dppe)Cl2 with sodium fluorenone ketyl produces a red solution containing the Co(I) species. The dissolution of C60 in the obtained solution followed by the precipitation of crystals with hexane yields a salt {Co(I)(dppe)2(+)}(C60˙(-))·2C6H4Cl2 and a novel complex {Co(dppe)2Cl}(C60) (). With C70, only the crystals of {Co(dppe)2Cl}(C70)·0.5C6H4Cl2 () are formed. Complex contains zig-zag fullerene chains whereas closely packed double chains are formed from fullerenes in . According to the optical spectra and magnetic data charge transfer occurs in both and with the formation of the Co(II)(dppe)2Cl(+) cations and the C60˙(-) or C70˙(-) radical anions. In spite of the close packing in crystals, C60˙(-) or C70˙(-) retain their monomeric form at least down to 100 K. The effective magnetic moments of and of 1.98 and 2.27μB at 300 K, respectively, do not attain the value of 2.45μB expected for the system with two non-interacting S = 1/2 spins at full charge transfer to fullerenes. Most probably diamagnetic {Co(I)(dppe)2Cl}(0) and neutral fullerenes are partially preserved in the samples which can explain the weak magnetic coupling of spins and the absence of fullerene dimerization in both complexes. The EPR spectra of and show asymmetric signals approximated by several lines with g-factors ranging from 2.0009 to 2.3325. These signals originate from the exchange interaction between the paramagnetic Co(II)(dppe)2Cl(+) cations and the fullerene˙(-) radical anions.

Phosphine passivated gold clusters: how charge transfer affects electronic structure and stability

First principle calculations of small charged phosphine ligand-protected gold clusters have been performed in order to understand the major factors determining stability, including its size, shape, and charge dependence.

[Au7](3+): a missing link in the four-electron gold cluster family

Ligand-stabilized ultrasmall gold clusters offer a library of diverse geometrical and electronic structures. Among them, clusters with four valence electrons form an exceptional but interesting family because of their unique geometrical structures and optical properties. Here, we report a novel diphosphine-ligated four-electron Au7 cluster (2). In good agreement with previous theoretical predictions, 2 has a "core+one" structure to exhibit a prolate shape. The absorption spectrum showed an isolated band, similar to the spectra of Au6 and Au8 clusters with "core+two" structures. TD-DFT studies demonstrated that the attachment of only one gold atom to a polyhedral core is sufficient to generate unique electronic structures and characteristic absorptions. The present result fills the missing link between Au6 and Au8 in the four-electron cluster family, showing that the HOMO-LUMO gap increases with increasing nuclearity in the case of the tetrahedron-based "core+exo" clusters.

Synthesis and structure analysis of (K[DB18 C6])4(C60)5·12THF containing C60 in three different bonding states

A new fulleride, (K[DB18C6])(4)(C(60))(5)·12THF, was prepared in solution using the "break-and-seal" approach by reacting potassium, fullerene, and dibenzo[18]crown-6 in tetrahydrofuran. Single crystals were grown from solution by the modified "temperature difference method". X-ray analysis was performed revealing a reversible phase transition occurring on cooling. Three different crystal structures of the title compound at different temperatures of data acquisition are addressed in detail: the "high-temperature phase" at 225 K (C2, Z=2, a=49.055(1), b=15.075(3), c=18.312(4) Å, β=97.89(3)°), the "transitional phase" at 175 K (C2 m, Z=2, a=48.436(5), b=15.128(1), c=18.280(2) Å, β=97.90(1)°), and the "low-temperature phase" at 125 K (Cc, Z=4, a=56.239(1), b=15.112(3), c=36.425(7) Å, β=121.99(1)°). On cooling, partial radical recombination of C(60)(·-) into the (C(60))(2)(2-) dimeric dianion occurs; this is first time that the fully ordered dimer has been observed. Further cooling leads to formation of a superstructure with doubled cell volume in a different space group. Below 125 K, C(60) exists in the structure in three different bonding states: in the form of C(60)(·-) radical ions, (C(60))(2)(2-) dianions, and neutral C(60), this being without precedent in the fullerene chemistry, as well. Experimental observations of one conformation exclusively of the fullerene dimer in the crystal structure are further explained on the basis of DFT calculations considering charge distribution patterns. Temperature-dependent measurements of magnetic susceptibility at different magnetic fields confirm the phase transition occurring at about 220 K as observed crystallographically, and enable for unambiguous charge assignment to the different C(60) species in the title fulleride.