The novel seven-coordinated BiF72- and SbF72- dianions have been prepared and characterized. The Cs2BiF7, Rb2BiF7, K2BiF7, and Na2BiF7 salts were obtained in high yield by heating BiF5 with an excess of the corresponding alkali metal fluorides to about 250 °C. Attempts failed to prepare the corresponding BiF83- salts or Li2BiF7 under similar conditions. The [N(CH3)4]2BiF7 salt was obtained by the combination of excess N(CH3)4F with BiF5 in CH3CN solution at −31 °C. The (NO2)2BiF7 salt was prepared from BiF5 and a large excess of liquid FNO at −78 °C and decomposes at room temperature to NOBiF6 and FNO. The corresponding Cs2SbF7, K2SbF7, and [N(CH3)4]2SbF7 salts were also synthesized in a similar fashion, but Na2SbF7 was not formed. The pronounced fluoride ion affinity of SbF6- was further demonstrated by the formation of some Cs2SbF7 when dry CsF and CsSbF6 were ball-milled at room temperature. The BiF72- and SbF72- anions, which are the first examples of binary pnicogen compounds with coordination numbers in excess of six, were characterized by vibrational spectroscopy and ab initio electronic structure calculations. They possess pentagonal bipyramidal, highly fluxional structures of D5h symmetry, similar to those of IF7 and TeF7-, which are isoelectronic with SbF72-. Although our theoretical calculations indicate that AsF72- is also vibrationally stable, experiments to prepare this dianion were unsuccessful.
Abstract : New theoretical methods are reported for ab initio calculations of the adiabatic (Born-Oppenheimer) electronic wave functions and potential energy surfaces of molecules and other atomic aggregates. An outer product of complete seets of atomic eigenstates familiar from perturbation-theoretical treatments of long-range interactions is employed as a representational basis without prior enforcement of aggregate wave function antisymmetry. The nature and attributes of this atomic spectral-product basis are indicated, completeness proofs for representation of antisymmetric stated provided, convergence of Schrodinger eigenstates in the basis established, and strategies for computational implementation of the theory described.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTAb initio study of some methylene and silylene insertion reactionsDavid R. Gano, Mark S. Gordon, and Jerry A. BoatzCite this: J. Am. Chem. Soc. 1991, 113, 18, 6711–6718Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://pubs.acs.org/doi/10.1021/ja00018a001https://doi.org/10.1021/ja00018a001research-articleACS PublicationsRequest reuse permissionsArticle Views151Altmetric-Citations31LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
Experimental and theoretical studies show that neither CF3+ nor FCO+ can be stabilized in the condensed phase with presently known Lewis acids. In the case of ClCO+, stabilization with SbF6- was also not possible, but Sb3F15 possesses sufficient acidity to abstract a fluoride ion from ClFCO in the formation of ClCO+Sb3F16-. This salt was fully characterized, providing the first well-established proof for the existence of a halocarbonyl cation in the condensed phase. Theoretical calculations and thermochemical cycles were used to corroborate our experimental findings, demonstrating that is possible to predict correctly whether a molecule with three different donor sites, such as ClFCO, will form an oxygen-coordinated donor−acceptor adduct or undergo either F- or Cl- abstraction. Furthermore, a method is described for extending natural bond orbital (NBO) analyses to systems containing two different types of competing, p(π) back-donating ligands.
First-principles density functional theory (DFT) calculations using the generalized gradient approximation (GGA) have been conducted to study the adsorption of a series of high-nitrogen compounds of increasing sizes and complexity on the Al(lll) surface. The calculations employ periodic slab models with 4 Al layers, ranging in size from (3times3) to (7times7) surface unit cells, and containing up to 196 Al atoms. Complementary quantum chemical calculations, utilizing DFT and second-order perturbation theory methods, of the ground state potential energy surfaces of the corresponding polynitrogen/high nitrogen species in the absence of the aluminum surface also have been performed. For the set of chemical species N x (x=1,5), NH x (x=1-3), N 2 H x (x=1-4) and N 3 H, N 3 H 3 , and N 4 H 4 , the adsorption configurations at different surface sites and the corresponding binding energies have been determined. This analysis has been further extended to high-nitrogen compounds N 5 H and N 6 H 2 . For these two systems it was found that the initial bonding to the surface takes place through a molecular mechanism (nondissociatively) with involvement of single or multiple N atoms of the molecule. However, dissociation on the surface can take place with small activation energies. This set of calculations has been further extended to include 1,3,5-triazene and 1,2,3-triazine (C 3 H 3 N 3 ) as well as larger substituted triazene systems such as C 9 N 30 and C 15 N 18 . For these large systems it was found that bonding takes place through multiple N centers with formation of highly strained and deformed adsorption configurations. In a number of instances the adsorption takes place dissociatively with N 2 elimination.
Abstract The insertions of methylene into the CH and CC bonds of ethane and into a CC bond of cyclopropane are calculated by using third‐order perturbation theory with the 6‐31G(d) basis set.
The structures of protonated pentazole cations (RN5H+), oxygen-containing anions such as N(NO2)2-, NO3-, and ClO4- and the corresponding ion pairs are investigated by ab initio quantum chemistry calculations. The stability of the pentazole cation is explored by examining the decomposition pathways of several monosubstituted cations (RN5H+) to yield N2 and the corresponding azidinium cation. The heats of formation of these cations, which are based on isodesmic (bond-type conserving) reactions, are calculated. The proton-transfer reaction from the cation to the anion is investigated.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Inversion of Bicyclobutane and BicyclodiazoxaneKiet A. Nguyen, Mark S. Gordon, and Jerry A. BoatzCite this: J. Am. Chem. Soc. 1994, 116, 20, 9241–9249Publication Date (Print):October 1, 1994Publication History Published online1 May 2002Published inissue 1 October 1994https://pubs.acs.org/doi/10.1021/ja00099a047https://doi.org/10.1021/ja00099a047research-articleACS PublicationsRequest reuse permissionsArticle Views188Altmetric-Citations54LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts
