We present the ioChem-BD platform ( www.iochem-bd.org ) as a multiheaded tool aimed to manage large volumes of quantum chemistry results from a diverse group of already common simulation packages. The platform has an extensible structure. The key modules managing the main tasks are to (i) upload of output files from common computational chemistry packages, (ii) extract meaningful data from the results, and (iii) generate output summaries in user-friendly formats. A heavy use of the Chemical Mark-up Language (CML) is made in the intermediate files used by ioChem-BD. From them and using XSL techniques, we manipulate and transform such chemical data sets to fulfill researchers' needs in the form of HTML5 reports, supporting information, and other research media.

In the thematic review dedicated to polyoxometalate (POM) chemistry published in Chemical Reviews in 1998, no contribution was devoted to theory. This is not surprising because computational modelling of molecular metal-oxide clusters was in its infancy at that time. Nowadays, the situation has completely changed and modern computational methods have been successfully applied to study the structure, electronic properties, spectroscopy and reactivity of POM clusters. Indeed, the progress achieved during the past decade has been spectacular and herein we critically review the most important papers to provide the reader with an almost complete perspective of the field.

Density functional calculations have been performed on Sc3N@C80 and Sc3N@C78 to examine the bonding between the scandium atoms and the fullerene cage. The encapsulation of the Sc3N unit is a strongly exothermic process that is accompanied by a formal transfer of six electrons from the scandium atoms to the fullerene cage in both complexes. In the case of Sc3N@C78, the metal ions are strongly linked to three [6:6] ring junctions of three different pyracylene patches, which are located at the midsection of the fullerene cage. This bonding restricts the Sc3N unit from freely rotating inside the cage. Geometric optimization of the structure of Sc3N@C78 indicates that the carbon cage expands to accommodate the Sc3N unit within the cage. This optimized structure has been used to re-refine the crystallographic data for {Sc3N@C78}·{Co(OEP)}·1.5(C6H6)·0.3(CHCl3). In contrast, in Sc3N@C80, the Sc3N unit is not trapped in a specific position within the inner surface of the I h cage, which is an unusual fullerene that lacks pyracylene patches. Thus, free rotation of the Sc3N group within the C80 cage is expected. Despite the electronic transfer from the Sc3N unit to the carbon cage, Sc3N@C78 and Sc3N@C80 have relatively large electron affinities and ionization potentials.

A series of systematic DFT calculations were conducted on Keggin [SiW(9)M(3)O(40)](n-), M = Mo, V, and Nb; and Wells-Dawson anions [P(2)M(18)O(62)],(6-) M = W and Mo; [P(2)M(15)M(3)'O(62)](m-), M = W and Mo, M' = W, Mo, and V to analyze the redox properties and the basicity of the external oxygen sites in polyoxometalates with nonequivalent addenda metals. The energy and composition of the lowest unoccupied orbitals, formally delocalized over the addenda atoms, determine the redox properties of a polyoxometalate. When a Mo(6+) substitutes one W(6+) in the 1:12 tungstate, the energy of the LUMO decreases and the cluster is more easily reduced. The tungstoniobates behave differently because the niobium orbitals insert into the tungsten band and the reduction of [SiW(9)Nb(3)O(40)](7-) yields the blue species SiW(9)Nb(3) 1e and not the cluster SiW(9)Nb(2)Nb(IV). In Wells-Dawson structures, the polar and equatorial sites have different electron affinities and the reduction preferentially occurs in the equatorial sites. Inserting ions with larger electron affinities into the polar sites can modify this traditional conduct. Hence, the trisubstituted [P(2)W(15)V(3)O(62)](9-) anion is reduced in the vanadium polar sites. By means of molecular electrostatic potential maps and the relative energy of the various protonated forms of [SiW(9)V(3)O(40)](7-) and [SiW(9)Mo(3)O(40)](4-), we established the basicity scale: OV(2) > OMo(2) > OW(2) > OV > OW > OMo. Finally, a continuum model for the solvent enabled us to compare anions with different total charges.

The reaction mechanism for the Zn(salphen)/NBu4X (X = Br, I) mediated cycloaddition of CO2 to a series of epoxides, affording five-membered cyclic carbonate products has been investigated in detail by using DFT methods. The ring-opening step of the process was examined and the preference for opening at the methylene (Cβ) or methine carbon (Cα) was established. Furthermore, calculations were performed to clarify the reasons for the lethargic behavior of internal epoxides in the presence of the binary catalyst. Also, the CO2 insertion and the ring-closing steps have been explored for six differently substituted epoxides and proved to be significantly more challenging compared with the ring-opening step. The computational findings should allow the design and application of more efficient catalysts for organic carbonate formation.

Keggin heteropolyanions [XM(12)O(40)](n-) have various isomeric structures, alpha and beta being the most common. Conventionally, the alpha structure appears to be the most stable, but calculations carried out at the DFT level for X = P(V), Si(IV), Al(III), As(V), Ge(IV), and Ga(III) and M = W(VI) and Mo(VI) show that this stability depends on several factors, particularly on the nature of the heteroatom (X) and the total charge of the cluster. In this paper, we apply the clathrate model to the Keggin molecule to carry out a fragment-interaction study to elucidate when and why the traditional relative stability of various isomers can be inverted. The fully oxidized anions that have inverted the traditional stability trend in this series are [AlW(12)O(40)](5-) and [GaW(12)O(40)](5-), both of which contain a third-group heteroatom and an overall charge of -5. beta-isomers are always more easily reduced than alpha-isomers. This experimental observation suggests that reduction favors the stability of beta-isomers and one of the most important results of this study is that the alpha/beta inversion is achieved in most cases after the second reduction. The alpha- and beta-isomers may have different properties because the energy of the LUMO, a symmetry-adapted d(xy)-metal orbital, is different.

Calculations based on density functional theory (DFT) have been carried out to investigate the electronic and magnetic properties of the alpha-Keggin anions mentioned in the title. The atomic populations and the distribution of the electron density computed for the studied clusters support the hypothesis that an oxidized Keggin anion is an XO(4)(n-) clathrate inside a neutral M(12)O(36) cage. The energy gap between the band of occupied orbitals, formally delocalized over the oxo ligands, and the unoccupied d-metal orbitals, delocalized over the addenda, has been found to be independent of the central ion. However, substitution of a W or a Mo by V modifies the relative energy of the LUMO and then induces important changes in the redox properties of the cluster. In agreement with the most recent X-ray determination of [Co(III)W(12)O(40)](5-) and with the simplicity of the (183)W NMR and (17)O NMR spectra observed for this anion the calculations suggest that [Co(III)W(12)O(40)](5-) has a slightly distorted T(d ) geometry. For the parent cluster [CoW(12)O(40)](6-) the quadruplet corresponding to the anion encapsulating a Co(II) was found to be approximately 1 eV more stable than the species formed by a Co(III) and 1 e delocalized over the sphere of tungstens. The one-electron reduction of [Co(II)W(12)O(40)](6-) and [Fe(III)W(12)O(40)](5-) leads to the formation of the 1 e blue species [Co(II)W(12)O(40)](7-) and [Fe(III)W(12)O(40)](6-). The blue-iron cluster is considerably antiferromagnetic, and in full agreement with this behavior the low-spin state computed via a Broken Symmetry approach is 196 cm(-1) lower than the high-spin solution. In contrast, the cobalt blue anion has a low ferromagnetic coupling with an S-T energy gap of +20 cm(-1). This blue species is more stable than the alternative reduction product [Co(I)W(12)O(40)](7-) by more than 0.7 eV.

Fullerenes containing a trimetallic nitride template (TNT) within the cage are a particularly interesting class of endohedral metallofullerenes. Not only are the cage properties modified by the presence of the incarcerated group but, almost uniquely among endohedral metallofullerenes, they are quite stable. Furthermore, they can be produced in multimilligram quantities, and these amounts should increase in the future. The electronic effect of the TNT is such that some fullerenes of sizes and symmetry that are otherwise relatively unstable become available for investigation.[1] The general formula of these TNT endohedral metallofullerenes is A 3Àn B n N@C k (n = 0-3; A,B = group III, IV, and rare-earth metals; k = 68, 78, and 80) with the archetypal examples of: Sc 3 N@C 80 , [2,3] Sc 3 N@C 68 , [4] and Sc 3 N@C 78 .[5] The structures of Sc 3 N@C 78 , Sc 3 N@C 80 , and Sc 3 N@C 68 are displayed in Figure 1.Special attention has been paid to lutetium-based TNT endohedral metallofullerenes, Lu 3Àn A n N@C 80 (n = 0-2; A = Gd, Ga, and Ho), because they may prove useful as multifunctional contrast agents for X-ray, magnetic resonance imaging, and radiopharmaceuticals.[6] The aim of this research is to use methods based on density functional theory (DFT) to answer the questions: How can the stability of the TNT endohedral metallofullerenes be predicted? Which fullerene cages between C 60 and C 84 will be capable of encapsulating TNTs? Aihara and co-workers proposed the bond resonance energy (BRE) [7] to be an indicator of the particular stabilization of free fullerene cages when they encapsulate metal units.[8] However, this method was not a predictive tool because it could not answer whether or not new cages will be capable of encapsulating TNTs.Up to now, only four carbon cages have been capable of encapsulating TNT units: D 3 -C 68 :6140, D 3h' -C 78 :5, D 5h -C 80 :6 and I h -C 80 :7. All these cages, except C 68 , satisfy the isolatedpentagon rule (IPR). But it is interesting to see that in all cases the empty IPR fullerene isomers isolated so far are different from the carbon cages found in isolable TNT endohedral metallofullerenes. The incorporation of a TNT into the fullerene results in an electron transfer from the metal atoms to the carbon cage, in other words, the formation of a stable ion pair. It should be noted that these fullerene cages are produced only when they are negatively charged by the encapsulated species. Theoretical calculations indicated that the thermodynamic stability of a fullerene molecule depends heavily on the negative charge that resides on it. [9] The bond between the nitride and the cage is markedly defined by the ionic model Sc 3 N 6+ @C k 6À (k = 68, 78, and 80).[10] From the geometric point of view, although the free Sc 3 N molecule is pyramidal, this fragment has a planar structure inside the fullerene cage. When the Sc 3 N unit is