A Valence Bond Perspective on the Molecular Shapes of Simple Metal Alkyls and Hydrides

1998 ◽  
Vol 120 (8) ◽  
pp. 1842-1854 ◽  
Author(s):  
Clark R. Landis ◽  
Timothy K. Firman ◽  
Daniel M. Root ◽  
Thomas Cleveland
Keyword(s):  
Valence Bond ◽  
Simple Metal ◽  
Metal Alkyls

Resolving the Quadruple Bonding Conundrum in C2 Using Insights Derived from Excited State Potential Energy Surfaces: A Molecular Orbital Perspective

2019 ◽  
Author(s):  
Ishita Bhattacharjee ◽  
Debashree Ghosh ◽  
Ankan Paul
Keyword(s):  
Excited State ◽  
Potential Energy ◽  
Molecular Orbital ◽  
High Spin ◽  
Potential Energy Surfaces ◽  
Valence Bond ◽  
Deep Minimum ◽  
State Potential ◽  
Energy Surfaces ◽  
Mo Theory

The question of quadruple bonding in C<sub>2</sub> has emerged as a hot button issue, with opinions sharply divided between the practitioners of Valence Bond (VB) and Molecular Orbital (MO) theory. Here, we have systematically studied the Potential Energy Curves (PECs) of low lying high spin sigma states of C<sub>2</sub>, N<sub>2</sub> and Be<sub>2</sub> and HC≡CH using several MO based techniques such as CASSCF, RASSCF and MRCI. The analyses of the PECs for the<sup> 2S+1</sup>Σ<sub>g/u</sub> (with 2S+1=1,3,5,7,9) states of C<sub>2</sub> and comparisons with those of relevant dimers and the respective wavefunctions were conducted. We contend that unlike in the case of N<sub>2</sub> and HC≡CH, the presence of a deep minimum in the <sup>7</sup>Σ state of C<sub>2</sub> and CN<sup>+</sup> suggest a latent quadruple bonding nature in these two dimers. Hence, we have struck a reconciliatory note between the MO and VB approaches. The evidence provided by us can be experimentally verified, thus providing the window so that the narrative can move beyond theoretical conjectures.

Infra-Red Reflectance Microscopy (IRRM) for Daisy Chain Flip Chip Device Failure Analysis

2004 ◽  
Author(s):  
Carlo Grilletto ◽  
Steve Hsiung ◽  
Andrew Komrowski ◽  
John Soopikian ◽  
Daniel J.D. Sullivan ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Flip Chip ◽  
State Of The Art ◽  
Failure Mechanisms ◽  
Simple Metal ◽  
X Ray ◽  
Infra Red ◽  
Cause Of Failure ◽  
Reflectance Microscopy ◽  
Ir Emission

Abstract This paper describes a method to "non-destructively" inspect the bump side of an assembled flip-chip test die. The method is used in conjunction with a simple metal-connecting "modified daisy chain" die and makes use of the fact that polished silicon is transparent to infra-red (IR) light. The paper describes the technique, scope of detection and examples of failure mechanisms successfully identified. It includes an example of a shorting anomaly that was not detectable with the state of the art X-ray equipment, but was detected by an IR emission microscope. The anomalies, in many cases, have shown to be the cause of failure. Once this has been accomplished, then a reasonable deprocessing plan can be instituted to proceed with the failure analysis.

Kekulé index for valence bond structures of conjugated systems containing cyclobutadiene

1978 ◽  
Vol 43 (5) ◽  
pp. 1375-1392 ◽  
Author(s):  
Ante Graovac ◽  
Ivan Gutman ◽  
Milan Randić ◽  
Nenad Trinajstić
Keyword(s):  
Valence Bond ◽  
Conjugated Systems

Unique reactivity of an α-ketiminopyridine ligand with metal–alkyls: Synthesis and ROP of ε-caprolactone

2021 ◽  
Author(s):  
Miroslav Novák ◽  
Roman Jambor ◽  
Zdeňka Růžičková ◽  
Štěpán Podzimek
Keyword(s):  
Metal Alkyls

The reaction of an α-ketimininopyridine ligand 2-((Me)CN(C6H3-2,6-iPr2))-6-(OMe)C5H3N (L1) with metal–alkyls, such as MeLi, Et2Zn, Me3Al and Me2AlCl, was studied.

scholarly journals Oxidation of Organic Compounds with Peroxides Catalyzed by Polynuclear Metal Compounds

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 186
Author(s):  
Georgiy B. Shul’pin ◽  
Lidia S. Shul’pina
Keyword(s):  
Catalytic Reactions ◽  
Metal Salts ◽  
Polynuclear Complexes ◽  
Simple Metal ◽  
Metal Compounds ◽  
Mononuclear Complexes ◽  
Iron Copper ◽  
Linear Alkanes ◽  
Oxidation Of Organic Compounds ◽  
Nickel Manganese

The review describes articles that provide data on the synthesis and study of the properties of catalysts for the oxidation of alkanes, olefins, and alcohols. These catalysts are polynuclear complexes of iron, copper, osmium, nickel, manganese, cobalt, vanadium. Such complexes for example are: [Fe2(HPTB)(m-OH)(NO3)2](NO3)2·CH3OH·2H2O, where HPTB-¼N,N,N0,N0-tetrakis(2-benzimidazolylmethyl)-2-hydroxo-1,3-diaminopropane; complex [(PhSiO1,5)6]2[CuO]4[NaO0.5]4[dppmO2]2, where dppm-1,1-bis(diphenylphosphino)methane; (2,3-η-1,4-diphenylbut-2-en-1,4-dione)undecacarbonyl triangulotriosmium; phenylsilsesquioxane [(PhSiO1.5)10(CoO)5(NaOH)]; bi- and tri-nuclear oxidovanadium(V) complexes [{VO(OEt)(EtOH)}2(L2)] and [{VO(OMe)(H2O)}3(L3)]·2H2O (L2 = bis(2-hydroxybenzylidene)terephthalohydrazide and L3 = tris(2-hydroxybenzylidene)benzene-1,3,5-tricarbohydrazide); [Mn2L2O3][PF6]2 (L = 1,4,7-trimethyl-1,4,7-triazacyclononane). For comparison, articles are introduced describing catalysts for the oxidation of alkanes and alcohols with peroxides, which are simple metal salts or mononuclear metal complexes. In many cases, polynuclear complexes exhibit higher activity compared to mononuclear complexes and exhibit increased regioselectivity, for example, in the oxidation of linear alkanes. The review contains a description of some of the mechanisms of catalytic reactions. Additionally presented are articles comparing the rates of oxidation of solvents and substrates under oxidizing conditions for various catalyst structures, which allows researchers to conclude about the nature of the oxidizing species. This review is focused on recent works, as well as review articles and own original studies of the authors.

ChemInform Abstract: The Electronic Structure of Cyclooctatetraene and the Modern Valence- Bond Understanding of Antiaromaticity.

ChemInform ◽  
2010 ◽  
Vol 26 (40) ◽  
pp. no-no
Author(s):  
P. B. KARADAKOV ◽  
J. GERRATT ◽  
D. L. COOPER ◽  
M. RAIMONDI
Keyword(s):  
Electronic Structure ◽  
Valence Bond

scholarly journals Correlating Axial and Equatorial Ligand Field Effects to the Single-Molecule Magnet Performances of a Family of Dysprosium Bis-Methanediide Complexes

2021 ◽  
Author(s):  
Lewis Thomas-Hargreaves ◽  
Marcus Giansiracusa ◽  
Matthew Gregson ◽  
Emanuele Zanda ◽  
Felix O'Donnell ◽  
...  
Keyword(s):  
Alkali Metal ◽  
Single Molecule ◽  
Ligand Field ◽  
Single Molecule Magnet ◽  
Field Effects ◽  
Equatorial Ligand ◽  
Metal Alkyls

Treatment of the new methanediide-methanide complex [Dy(SCS)(SCSH)(THF)] (1Dy, SCS = {C(PPh2S)2}2-) with alkali metal alkyls and auxillary ethers produces the bis-methanediide complexes [Dy(SCS)2][Dy(SCS)2(K(DME)2)2] (2Dy), [Dy(SCS)2][Na(DME)3] (3Dy) and [Dy(SCS)2][K(2,2,2-cryptand)] (4Dy). For...

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