Theory is developed to enable the density matrix results of CNDO self-consistent field molecular orbital calculations be correlated with chemists' ideas 'valency.' Both valencies atoms and anisotropy an atom in a given environment are derived quantitatively. Examples chosen from carbon, nitrogen, borane chemistry yield which gratifyingly consistent system.

Alkali metal zincate reagents are attracting considerable attention at present in respect to their often special reactivity/selectivity hydrogen-metal and halogen-metal interconversion reactions. Heteroleptic diorgano-amidozincates, typified by lithium di-tert-butyltetramethylpiperidinozincate, have proved be especially useful such applications. In this paper the related sodium TMP-zincate, prepared as its TMEDA (N,N,N',N'-tetramethylethylenediamine) adduct,...

Move over directed ortho-metalation, here comes meta-metalation. The unprecedented meta-zincation of two anilides by a synergic mixed sodium/zinc dialkyl–amide base is presented. orientation the deprotonation remarkably switched to meta site using this heterometallic mixed-metal system. Supporting information for article available on WWW under http://www.wiley-vch.de/contents/jc_2002/2006/z600720_s.pdf or from author. Please note: publisher not responsible content functionality any...

Turbocharged! A neutral dimeric molecule in crystal form, the diisopropylamido turbo-Grignard reagent "(iPr2N)MgCl⋅LiCl" (see structure; blue N, red O, green Mg, yellow Cl, black C) separates into several charged ate species dynamic exchange with each other THF solution as determined by a combination of EXSY and DOSY NMR studies. Detailed facts importance to specialist readers are published "Supporting Information". Such documents peer-reviewed, but not copy-edited or typeset. They made...

Merging two evolving areas in synthesis, namely cooperative bimetallics and N-heterocyclic carbenes (NHCs), this study reports the isolation of first intermediates alkali-metal-mediated zincation (AMMZn) a free NHC Zn–NHC complex using sodium zincate [(TMEDA)NaZn(TMP)(tBu)2] (1) as metallating reagent. The structural authentication (THF)3Na[:C{[N(2,6-iPr2C6H3)]2CHCZn(tBu2)}] (2) [Na(THF)6]+[tBu2Zn:C{[N(2,6-iPr2C6H3)]2CHCZn(tBu2)}]− (4), resulting from reactions 1 with unsaturated IPr (IPr =...

Surprisingly lithium TMP-aluminate reagents are not capable of directly aluminating anisole as previously thought but operate<italic>via</italic>sequential lithiation–alkylaluminium trapping.

The hydrotris(methimazolyl)borate anion (Tm), a soft analogue of the hydrotris(pyrazolyl)borate (Tp), has been synthesized. This novel ligand system designed to maintain tripodal geometry around boron while allowing replacement three nitrogen donor atoms by sulfur (thione) atoms, thus providing complementary soft, tridentate, face capping system. two ions, Tm and Tp were compared X-ray analysis ab initio calculations in an attempt explore effects exchanging hard for this type ligand....

Subjecting ferrocene, ruthenocene, or osmocene to the synergic amide base sodium-magnesium tris(diisopropylamido) affords a unique homologous series of metallocene derivatives general formula [(M(C(5)H(3))(2))Na(4)Mg(4)(i-Pr(2)N)(8)] (where M = Fe (1), Ru (2), Os (3)). X-ray crystallographic studies 1-3 reveal common molecular "inverse crown" structure comprising 16-membered [(NaNMgN)(4)](4+) "host" ring and metallocenetetraide [M(C(5)H(3))(2)](4-) "guest" core, cleaved protons which are...

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTVibrational Analysis of trans-AzobenzeneD. R. Armstrong, J. Clarkson, and W. E. SmithCite this: Phys. Chem. 1995, 99, 51, 17825–17831Publication Date (Print):December 1, 1995Publication History Published online1 May 2002Published inissue 1 December 1995https://pubs.acs.org/doi/10.1021/j100051a005https://doi.org/10.1021/j100051a005research-articleACS PublicationsRequest reuse permissionsArticle Views1142Altmetric-Citations100LEARN ABOUT THESE...

Back to bases: Conventional organometallic bases usually deprotonate toluene at the methyl position generate resonance-stabilized benzyl anions, but using a new type of bimetallic metalation, sodium-mediated magnesiation, thermodynamic for deprotonation can be switched aromatic ring (see picture).

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTLadder structures in lithium amide chemistry: syntheses, solid-state, and solution of donor-deficient pyrrolidide complexes, [cyclic] {[H2C(CH2)3NLi]3.cntdot.PMDETA}2 {[H2C(CH2)3NLi]2.cntdot.TMEDA}2, ab initio MO calculations probing ring vs ladder stack structural preferencesDavid R. Armstrong, Donald Barr, William Clegg, Susan M. Hodgson, Robert E. Mulvey, David Reed, Ronald Snaith, Dominic S. WrightCite this: J. Am. Chem. Soc. 1989, 111, 13,...

A study by band-structure methods of the boron carbide B IaC 2 is presented. All symmetry directions are considered and it found that, in general, valence bands flat almost all - nowhere does a band width exceed 3 eV (1 = 1.60 x 10 -19 J). There slightly greater curvature conduction band. The valence-band structure, containing 47 electrons, incompletely filled Fermi level lies at -7.6 eV. Above edge, gap exists amounting to just over 4 density states partial compound both calculated. Using...

The synthesis, structure and reactivity of donor-free sodium potassium magnesiates are assessed culminating in the unique 1,4-dimetallation naphthalene.

A theoretical investigation of the Cossee mechanism for Ziegler-type catalysis has been made by use all valence electron self-consistent field method. The electronic structure a titanium–aluminium–ethylene complex was studied, as well sequence steps in which ethylene inserts into titanium–methyl bond. study olefin reveals that (a) titanium–olefin bond no retrodative character and antibonding π* orbital acquires little stability result interaction with titanium d orbitals; (b) σ-bond is...

Using two alternative methodologies, new light has been shed on the stability and rational formation of abnormal NHC–gallium complexes.

A remarkable pair of macrocyclic amides has been synthesized and crystallographically characterized; these consist a twelve-membered (N6Na4Mg2)2+ cationic ring host with [C6H3(CH3)]2− or (C6H4)2− dianionic guests (see picture) derived from toluene benzene, respectively.

The title compound, {[H2[graphic omitted]NLi]3·PMDETA}n, (1)(PMDETA = pentamethyldiethylenetriamine), is shown to be the first example of an organonitrogen–lithium laddered structure, consisting in solid (n= 2) two attached (NLi)2 rings, or alternatively four (N–Li) rungs, with terminal NLi units complexes by PMDETA, so preventing further association; cryoscopic and 7Li n.m.r. spectroscopic studies imply that extension ladder framework can occur arene solutions (1), these results, together...

Calculations, within the CNDO framework, have been performed on a wide range of molecules containing elements first and second rows Periodic Table. By use density matrix elements, valencies all atoms are calculated their significance is discussed. It found that in many essentially same as classical ones. Deviations from ‘normal’ discussed terms chemistry particular molecule. Anisotropies for some bond indices bonds selected also shown to correlate well with electronic distribution.

A general theoretical approach to the calculation of electronic excited states for molecules is described. good ground state not required and method allows arbitrary multiplicity states.

The series of alkali-metal (Li, Na, K) complexes the substituted benzyl anion 3,5-dimethylbenzyl (Me2C6H3CH2(-)) derived from 1,3,5-trimethylbenzene (mesitylene) have been coerced into monomeric forms by supporting them with tripodal tetradentate Lewis donor tris(N,N-dimethyl-2-aminoethyl)amine, [N(CH2CH2NMe2)3, Me6TREN]. Molecular structure analysis X-ray crystallography establishes that cation-anion interaction varies as a function alkali-metal, carbanion binding to lithium mainly in σ...

Building on recent advances in synthesis showing that the addition of inorganic salts to Grignard reagents can greatly enhance their performance alkylation reactions ketones, this study explores EtMgCl with benzophenone presence stoichiometric or catalytic amounts ZnCl(2) aim furthering understanding role and constitution organometallic species involved these transformations. Investigations into metathesis three molar equivalents led isolation characterisation (X-ray crystallography (1)H...

Histone deacetylases (HDACs) are an attractive therapeutic target for a variety of human diseases. Currently, all four FDA-approved HDAC-targeting drugs nonselective, pan-HDAC inhibitors, exhibiting adverse side effects at doses. Although selective HDAC inhibition has been proposed to mitigate toxicity, the targeted catalytic domains highly conserved. Herein, we describe series rationally designed, conformationally constrained, benzanilide foldamers which selectively bind tunnel HDAC8. The...

Abstract Reaction of benzylpotassium, n , s ‐dibutylmagnesium and diisopropylamine in boiling toluene produces a rare example molecular magnesium hydride with Mg‐(μ‐H) 2 ‐Mg double bridge, [K Mg (N i Pr ) 4 (μ‐H) ·(toluene) ] ( 1 ). In an effort to rationalise the formation series DFT calculations were performed. This report establishes first isostructural pair Na K complexes solvated by be reported Cambridge Crystallographic Database. comparison its previously analogue, metal‐arene centroid...

Lithium cages containing hydride: The reaction of tBuLi with Me(2)AlN(2-Pyr)Ph in toluene gave [Li(8)(H){N(2-Pyr)Ph}(6)](+)[Li(Me(2)AltBu(2))(2)](-), whose cation is the first molecular main group metal species to contain interstitial hydride (the cluster core shown picture). Treatment mixture THF neutral Li(7)(H)[N(2-Pyr)Ph](6), which has a capped octahedral (Li(+))(7) core. 2-Pyr=2-pyridyl.