Second-row Transition Metal Atoms Research Articles

Revised model core potentials for third-row transition–metal atoms from Lu to Hg

We have produced new relativistic model core potentials (spdsMCPs) for the third-row transition–metal atoms from Lu to Hg explicitly treating explicitly 5s and 5p electrons in addition to 5d and 6s electrons in the same manner for the first- and second-row transition–metal atoms given in the previous Letters [Y. Osanai, M.S. Mon, T. Noro, H. Mori, H. Nakashima, M. Klobukowski, E. Miyoshi, Chem. Phys. Lett. 452 (2008) 210; Y. Osanai, E. Soejima, T. Noro, H. Mori, M.S. Mon, M. Klobukowski, E. Miyoshi, Chem. Phys. Lett. 463 (2008) 230]. Using suitable correlating functions with the split-valence MCP functions, we demonstrate that the present MCP basis sets show reasonable performance in describing the electronic structures of atoms and molecules, bringing about accurate excitation energies for atoms and proper spectroscopic constants for Au 2, Hg 2, and AuH.

Revised model core potentials for second-row transition metal atoms from Y to Cd

We have produced new relativistic model core potentials (spdsMCPs) for the second-row transition-metal atoms from Y to Cd treating explicitly 4s and 4p electrons in addition to 4d and 5s electrons in the same manner as for the first-row transition-metal atoms given in [Y. Osanai, M.S. Mon, T. Noro, H. Mori, H. Nakashima, M. Klobukowski, E. Miyoshi, Chem. Phys. Lett. 452 (2008) 210]. Using suitable correlating functions together with the split valence MCP functions, we demonstrate that the present MCP basis sets show reasonable performance in predicting the electronic structures of atoms and molecules, bringing about accurate excitation energies for atoms and reasonable spectroscopic constants for AgH.

C−C versus C−H Bond Activation of Alkynes by Early Second-Row Transition Metal Atoms

The reactions of Y (a2D), Zr (a3F), Nb (a6D), Mo (a7S), and electronically excited-state Mo* (a5S) with propyne (methylacetylene) and 2-butyne (1,2-dimethylacetylene) were investigated using crossed molecular beams. For all of the metals studied, reactions with propyne led to H2 elimination, forming MC3H2. For Y + propyne, C-C bond cleavage forming YCCH + CH3 also was observed, with an energetic threshold in good agreement with an earlier determination of D0(Y-CCH). For Y + 2-butyne, three reactive channels were observed: YC4H4 + H2, YC3H3 + CH3, and YC3H2 + CH4. The C-C bond cleavage products accounted for 21 and 27% of the total products at Ecoll = 69 and 116 kJ/mol, respectively. For Zr and Nb reactions with 2-butyne, competition between H2 and CH4 elimination was observed, with C-C bond cleavage accounting for 12 and 4% of the total product signal at Ecoll = 71 kJ/mol, respectively. For reactions of Mo and Mo* with 2-butyne, only H2 elimination was observed. The similarity between reactions involving two isomeric species, propyne and allene, suggests that H atom migration is facile in these systems.

Infrared Spectroscopic Studies of Mono-, Di-, and Trihydrido C−H Insertion Complexes Formed in Reaction of Ethylene with Laser-Ablated Hafnium Atoms and Isolated in a Solid Argon Matrix

The C−H insertion reaction of laser-ablated Hf atoms with ethylene in excess argon has been carried out during codeposition at 7 K, and the reaction products have been investigated by means of infrared spectroscopy. Parallel to the case of Zr, mono-, di-, and trihydrido C−H insertion complexes are identified. Among them, the mono- and dihydrido C−H insertion complexes are reaction intermediates of hydrogen elimination from ethylene by second-row transition-metal atoms presumed in previous reaction dynamics studies. The higher Hf−H stretching frequencies and shorter Hf−H and C−Hf bond lengths of the hafnium C−H insertion products than those of the zirconium products are attributed to the shortened bonds of the heavier metal atom by relativistic effects.

Gas Phase Reactions of Second-Row Transition Metal Atoms with Small Hydrocarbons: Experiment and Theory

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTGas Phase Reactions of Second-Row Transition Metal Atoms with Small Hydrocarbons: Experiment and TheoryJohn J. Carroll, Kerstin L. Haug, James C. Weisshaar, Margareta R. A. Blomberg, Per E. M. Siegbahn, and Mats SvenssonCite this: J. Phys. Chem. 1995, 99, 38, 13955–13969Publication Date (Print):September 1, 1995Publication History Published online1 May 2002Published inissue 1 September 1995https://doi.org/10.1021/j100038a030RIGHTS & PERMISSIONSArticle Views457Altmetric-Citations152LEARN 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 InReddit PDF (4 MB) Get e-Alerts

Theoretical Study of Methane Activation by Re, Os, Ir, and Pt

The activation of methane C-H bonds by the third-row transition metal atoms Re, Os, Ir, and Pt has been studied using relativistic effective core potentials (RECPs) and electron correlation. Activation and reaction energies are calculated and compared to earlier results on dissociation of H 2 on the same atoms and of CH 4 and H 2 on first- and second-row transition metal atoms

Carbonyl insertion into metal-hydrogen and metal-methyl bonds for second-row transition metal atoms

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbonyl insertion into metal-hydrogen and metal-methyl bonds for second-row transition metal atomsMargareta R. A. Blomberg, Christina A. M. Karlsson, and Per E. M. SiegbahnCite this: J. Phys. Chem. 1993, 97, 37, 9341–9350Publication Date (Print):September 1, 1993Publication History Published online1 May 2002Published inissue 1 September 1993https://doi.org/10.1021/j100139a015RIGHTS & PERMISSIONSArticle Views180Altmetric-Citations28LEARN 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 InReddit PDF (3 MB) Get e-Alerts

The olefin insertion reaction into a metal-hydrogen bond for second-row transition-metal atoms, including the effects of covalent ligands

The olefin insertion into a transition metal-hydrogen bond has been studied for the entire sequence of second row transition metal atoms. Energies including correlation of all valence electrons have been obtained for geometry optimized structures of the reactants, of the π-bonded olefin complexes, of the transition states, and finally of the product metal-alkyl systems. To study the effects of covalent ligands the calculations were repeated with one and two additional hydride ligands

The effects of covalent ligands on the oxidative addition reaction between second-row transition-metal atoms and methane

Calculations including electron correlation of all valence electrons have been performed to study covalent ligand effects in the oxidative addition reaction of methane to second-row transition-metal complexes. Both reaction energies and barrier heights have been determined. As a comparison the reaction energies for the oxidative addition of the hydrogen molecule have also been evaluated. The entire sequence of second-row transition metals from yttrium to palladium has been studied. Hydrogen ligands have been added to systematically saturate all valencies of each metal, which means that results for 23 different reactions each for the oxidative addition of methane and of molecular hydrogen have been obtained

The Ziegler—Natta olefin insertion reaction into a metal—alkyl bond for second-row transition metal atoms

The Ziegler—Natta olefin insertion reaction into a metal—alkyl bond has been studied for the second-row transition metal atoms, without additional ligands and with two hydride ligands added. Correlation effects of all valence electrons are included in the calculations using reasonably large basis sets. The results are compared to the corresponding insertion into a metal—hydride bond which has been studied previously. For most metals the barrier height for the olefin insertion into the metal—alkyl bond is about 20 kcal/mol higher than for insertion into the metal—hydride bond. The origin of this difference is the directional character of the methyl bond. The hydride can continuously change the direction of its bond from the metal to the olefin, but for the methyl group a large part of the metal—methyl bond has to be broken before the methyl group can start to bind towards the olefin. For the reaction mechanism, the d character of the bond at the transition state and the importance of repulsion between non-bonding electrons on the metal and the electrons on the olefin is emphasized.

A theoretical study of the activation of the carbon-hydrogen bond in ethylene by second-row transition-metal atoms

Calculations including electron correlation of all the valence electrons have been performed for the activation of the C-H bond in ethylene by second row transition metal atoms. The resulting binding energies for the vinyl hydride products are compared to previously calculated binding energies for the π-coordinated ethylene complexes. For the atoms to the right the binding energy difference is 18-28 kcal/mol in favor of the π-coordinated complex. For the atoms to the left the binding energy difference is much smaller, and for zirconium as the only atom, the vinyl hydride product is lower in energy. The product energies and the barrier heights for the ethylene reaction are also compared to previous results for the corresponding methane reaction

Theoretical study of the activation of the oxygen-hydrogen bond in water by second-row transition-metal atoms

The reaction between the entire sequence of second-row transition-metal atoms and water has been studied using methods including electron correlation of all valence electrons. Three regions of the potential surface were investigated, the molecular complexes, the O-H insertion products and the transition states for the oxidative addition reaction. The results are compared to previous studies on the C-H insertion reaction in methane and the N-H insertion reaction in ammonia. The molecular complexes are found to be weaker bound than the corresponding ammonia adducts.

Theoretical study of the binding of ethylene to second-row transition metal atoms

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical study of the binding of ethylene to second-row transition metal atomsMargareta R. A. Blomberg, Per E. M. Siegbahn, and Mats SvenssonCite this: J. Phys. Chem. 1992, 96, 24, 9794–9800Publication Date (Print):November 1, 1992Publication History Published online1 May 2002Published inissue 1 November 1992https://doi.org/10.1021/j100203a040RIGHTS & PERMISSIONSArticle Views201Altmetric-Citations90LEARN 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 InReddit PDF (2 MB) Get e-Alerts

Reaction of second-row transition-metal atoms with methane

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReaction of second-row transition-metal atoms with methaneMats Svensson, Margareta R. A. Blomberg, and Per E. M. SiegbahnCite this: J. Am. Chem. Soc. 1991, 113, 18, 7076–7077Publication Date (Print):August 1, 1991Publication History Published online1 May 2002Published inissue 1 August 1991https://doi.org/10.1021/ja00018a077RIGHTS & PERMISSIONSArticle Views128Altmetric-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 InReddit PDF (296 KB) Get e-Alerts Get e-Alerts

The well-tempered GTF basis sets in calculations on the s2d n, s1d n+1, and d n+2 configurations of the first- and second-row transition metal atoms

Calculations on the lowest states of the excited electronic configurations of transition metal atoms were performed using the recently developed well-tempered Gaussian basis sets. The basis function space for d-symmetry orbitals was augmented using a single exponent from the exponent pool optimized in the ground state total energy minimization. After augmentation, the excitation energies differed from the Hartree–Fock values by 0.04 and 0.01 eV for the first- and second-row transition metal atoms, respectively.

Ab initio calculations on transition metal compounds using small minimal GTO basis sets

A group of small minimal GTO basis sets was tested for a set of molecules containing first- and second-row transition metal atoms. The results are more uniform in quality than those obtained by the use of the STO-3G basis sets.