We examine a recently introduced descriptor of chemical bonding, the localized-orbital locator (LOL), which is based on kinetic-energy density (τ). Examples are presented for prototypical bonds, such as single, double, and triple bonding in transition metal complexes, three-center two-electron well hypervalent molecules. The topology LOL analyzed terms (3,–3) attractors (Γ). influence core electrons investigated, LOL-VSEPR (valence shell electron pair repulstion) relationship established....

A variety of donor adducts tris(pentafluorophenyl)borane were experimentally generated by reaction a Lewis base with an excess B(C6F5)3 in pentane. In this way, nitrile complexes (C6F5)3B·NCR (R = CH3 1a, p-CH3−C6H4 1b, p-NO2−C6H4 1c), isonitrile (C6F5)3B·CNR C(CH3)3 3a, C(CH3)2CH2C(CH3)3 3b, 2,6-(CH3)2−C6H3 3c), and the phosphine adduct (C6F5)3B·P(C6H5)3 (6) could be prepared. The compounds characterized IR NMR spectroscopy X-ray structure analyses (1a, 1c, 6). Coordination nitriles as well...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNonclassical double bonds in ethylene analogs: influence of Pauli repulsion on trans bending and .pi.-bond strength. A density functional studyHeiko Jacobsen Tom ZieglerCite this: J. Am. Chem. Soc. 1994, 116, 9, 3667–3679Publication Date (Print):May 1, 1994Publication History Published online1 May 2002Published inissue 1 1994https://pubs.acs.org/doi/10.1021/ja00088a001https://doi.org/10.1021/ja00088a001research-articleACS PublicationsRequest reuse...

N-Heterocyclic carbene complexes of platinum(II) have been synthesized, notably monocarbene cis-[(IPr)Pt(dmso)(Cl)2], 6, cis-[(IMes)Pt(dmso)(Cl)2], 7, cis-[(SIPr)Pt(dmso)(Cl)2], 8, cis-[(SIMes)Pt(dmso)(Cl)2], 9, and cis-[(TTP)Pt(dmso)(Cl)2], 10. All fully characterized by multinuclear NMR spectroscopy. Complex 10 X-ray crystallography. The data obtained allowed for the differentiation between electronic contributions (σ π) present in Pt−NHC bond. Supported computational analyses, percentage...

Density functional theory calculations have been used to investigate the activation mechanism for precatalyst series [Pd]-X-1–4 derived from [Pd(IPr)(R-allyl)X] species by substitutions at terminal position of allyl moiety ([Pd] = Pd(IPr); R H (1), Me (2), gem-Me2 (3), Ph (4), X Cl, Br). Next, we investigated Suzuki–Miyaura cross-coupling reaction active catalyst IPr-Pd(0) using 4-chlorotoluene and phenylboronic acid as substrates isopropyl alcohol a solvent. Our theoretical findings predict...

The performance of a series density functionals when tested on the prediction phosphane substitution energy transition metal complexes is evaluated. Fe-BDA and Ru-COD (BDA=benzylideneacetone, COD=cyclooctadiene) serve as reference systems, calculated values are compared with experimental in THF obtained from calorimetry. Results clearly indicate that specifically developed to include dispersion interactions usually outperform other BDA or COD considered. However, phosphanes different sizes...

Presented are density functional calculations on various Mn(salen) systems that active catalysts in the epoxidation of olefins. Correlation structural properties such as MnO bond strengths, atomic charges, and C−O distances evolving bonds transition state geometries with modified Hammett constants reveal a mechanistic picture reaction, supporting previous experimental results. Enantioselectivity is tied to position along reaction coordinate for first formation step, when an olefin...

The origin of enantioselectivity in the Jacobsen-Katsuki reaction has been investigated by applying density functional calculations combination with molecular mechanics methodologies. suggest that a high enantiomeric excess is connected to three specific features: 1) chiral diimine bridge, which induces folding salen ligand(H2salen = bis(salicylidene)ethylenediamine), and hence formation pocket; 2) bulky groups at 3,3'-positions ligand, cause preferential approach from side aromatic rings;...

Insight into the controversial mechanism of Mn - salen-catalyzed epoxidation olefins is provided in a theoretical study based on density functional theory. The calculations suggest that radical species A, but not manganaoxetanes B, are likely candidates for viable intermediates.

The electronic and molecular structures of several isomers the title compound have been studied by approximate density functional theory. A geometric arrangement with two bridging CO ligands was identified as most stable structure, similar to that Co2(CO)8. However, terminal in Fe2(CO)8 adopt a staggered rather than an eclipsed arrangement. unbridged isomer is shown be stabilized trans bent distortion. stretching frequencies are reported for isomers. theoretical findings compared...

Stalke's dilemma, stating that different chemical interpretations are obtained when one and the same density is interpreted either by means of natural bond orbital (NBO) subsequent resonance theory (NRT) application or quantum atoms in molecules (QTAIM), reinvestigated. It shown within framework QTAIM, question as to whether for a given molecule two bonded not only meaningful context well-defined reference geometry. The localized-orbital-locator (LOL) applied map out patterns covalent...

The electronic and molecular structures of the title compounds have been investigated using density functional theory within local approximation, adding nonlocal corrections to exchange correlation energy as a perturbation. transition metal main group double bond was analyzed in terms σ π contributions. difference between chromium pentacarbonyl complexes with carbene fragment compared their higher homologues is significant drop intrinsic strength: Dπ,int(MC) = 202 kJ/mol, Dπ,int (MSi) 82...

The interactions of the title compounds ReH2(CO)(NO)L2 (L = PMe3, PEt3, PiPr3) with perfluoro-tert-butyl alcohol (PFTB) have been studied by IR spectroscopy. steric requirements phosphine ligands take a strong influence on hydrogen-bonding site at metal center and determine whether RO−H···H−M and/or RO−H···ON−M bonding modes are realized. experimental findings supported density functional calculations.

Abstract The mechanism of the Jacobsen−Katsuki epoxidation has been investigated by application density functional theory; results a series calculations for simplified model systems different spin states are presented. In chosen computational approach, ethylene with cationic five‐coordinate catalyst is predicted to occur through radical intermediate, similarly reaction calculated corresponding neutral six‐coordinate species. Although intermediate shows small energetic preference quintet...

An even split: In sharp contrast with the general behavior of Pd(0) complexes, [Pd(IPr)(PCy(3))] is able to activate H-H bond. The resulting trans-[Pd(H)(2)(IPr)(PCy(3))] first isolated mononuclear dihydride palladium compound. Its formation supported by multinuclear NMR spectroscopy, density functional calculations, and X-ray diffraction studies. stability reactivity this new species are examined.

A bond descriptor based on the kinetic-energy density, localized-orbital locator (LOL), is used to characterize nature of chemical in transition-metal hydride and dihydrogen complexes. Cationic complexes iron triad [MH 3 (PMe ) 4 ] + (M = Fe, Ru, Os) serve as model compounds for hydrogen bonding, since these not only present examples well complexes, but certain representatives, two different types metal–hydrogen bonds are realized within same molecule. Both ligands show characteristic LOL...

The paramagnetic rhenium complex [NEt4]2[Re(Br)5(NO)] (1) has been used to prepare a series of novel mononitrosyl hydride and dihydrogen complexes: [Re(Br)2(NO)(η2-H2)(PR3)2] (R = iPr, 2a; Cy, 2b) [Re(H)(BH4)(NO)(PR3)2] 3a; 3b). coordinated BH3 the derivatives 3 can be replaced by H2 or NO ligand, thus leading tetrahydride dinitrosyl species [Re(H)4(NO)L2] 4a; 4b) [Re(H)(NO)2(PR3)2] 5a; 5b). While [Re(H)4(NO)(PPh3)2] does not seem stable, [Re(H)(NO)2(PPh3)2] (5c) obtained in fashion similar...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTrends in Structure and Bonding of Fischer Type Chromium Carbenes Silylenes. A Density Functional StudyHeiko Jacobsen Tom ZieglerCite this: Organometallics 1995, 14, 1, 224–230Publication Date (Print):January 1995Publication History Published online1 May 2002Published inissue 1 January 1995https://doi.org/10.1021/om00001a034RIGHTS & PERMISSIONSArticle Views250Altmetric-Citations54LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum...

BP86 density functional calculations for the title reaction are presented, where a model catalyst with hypochlorite as oxygen-containing counter ligand, (ClO)(O)Mn(acacen') (acacen' = -O(CH)3N-C2H4-N(CH)3O-), is employed. The epoxidation on potential energy surfaces corresponding to an overall spin-density of two and four unpaired electrons investigated. presence ligand found cause proceed under conservation spin. Further, causes reoxidation Mn-center, thus closing catalytic cycle. A scheme...

Deprotonation of sodium acetylcyclopentadienide (11) was achieved by treatment with LDA in THF to generate the dianion equivalent [Cp-C(=CH(2))-O](2-)(12). Transmetalation Cl(2)Ti(NMe(2))(2) gave ([Cp-C(=CH(2))-O]Ti(NMe(2))(2))(2) (17); 12 Cl(2)Zr(NEt(2))(2)(THF)(2) furnished (([Cp-C(=CH(2))-O]Zr(NEt(2))(2))(2) (18). Cryoscopy benzene revealed a dimeric structure 18 solution. Complex characterized further an X-ray crystal analysis and DFT calculations. The two zirconium centers are connected...