Synthesis and molecular structure of [Al(CH3)2]2[C10H22N4] [Al(CH3)3]2: Condensation product of trimethylaluminum and a multidentate open-chain amine

The crystalline condensation product [Al(CH₃)₂]₂[C₁₀H₂₂N₄][Al(CH₃)₃]₂ is prepared from reaction of the multidentate open-chain amine 1,4-bis(3-aminopropyl)piperazine with trimethylaluminum in methylene chloride. The compound crystallized in the monoclinic space groupC2/c with unit cell parametersa=25.166(12),b=7.268(4),c=17.316(4) Å,=115.3(4)°, andD _c =1.06 g cm^–3 forZ=4. Least-squares refinement based on 1054 observed reflections with intensitiesI 3(I) in the range 2<2<45° led to a finalR factor of 0.053 (R _w =0.064). The title compound resides on a crystallographic center of symmetry with independent Al-N distances of 1.889(5), 2.058(5), and 2.030(5) Å.     

Reduction electrochimique du ferrocene

A well characterized 1e^? reversible polarographic wave is observed at low temperature (? ?30°C) for ferrocene and methylferrocene in dimethylformamide. At higher temperatures, a 2e reductive cleavage of the molecule occurs.     

π Coordination de diazoalcanes sur le dicyclopentadienylvanadium (II)

The X-ray crystal and molecular structure of η⁵-cyclopentadienyl-η¹-2,4-diphenylcyclobut-1-en-3-oneiron dicarbonyl (I) was determined (monoclinic crystals, a 9.2371(9), b 26.4502(9), c 8.2450(7) Å, β 115.502(6)°, Z = 4, space group P2₁ /c, 1902 unique reflections, R = 0.068). Molecule I contains the η¹-cyclobut-1-en-3-one ligand with three sp² and one sp³ carbon atoms in a four-membered cycle, σ-bonded to the CpFe(CO)₂ fragment (bond distance FeC 1.935(6) Å).     

Stereochemistry at titanium in the sulfur dioxide insertion reaction of titanocene compounds

The insertion reaction of SO₂ has been studied for the two diastereoisomeric forms of η⁵-C₅H₅-η⁵-C₅H₄ CHMePhTi(C₆F₅)CH₃. The reaction is regioselective and stereospecific. Arguments that it involves a retention at the titanium atom are given.     

Insertion de so2 dans la liaison titane—carbone: I. Diastereotopie et diastereoisomerie engendrees par la presence d'un atome de soufre chiral dans les produits d'insertion

Sulfur dioxide insertion reactions in titanium—carbon bonds are studied with two types of titanocene complexes: Cp₂Ti(C₆F₅)R and CpCp′Ti(C₆F₅)R. The NMR spectra of the insertion products from the first type of complex are typical for O-sulfinated complexes having a chiral sulfur atom. Starting from the second type or complex two diastereoisomers have been detected (diastereoisomery Ti, S).     

The use of metallocenic esters of n-hydroxysuccinimide for metallohapten synthesis

Different organometallic markers have been described in a new technique for the labelling of many drugs. Thus metallocenic esters of [M = (;CO)₃CrC₆H₅?; (;CO)₃CrC₆H₅?(;CH₂)₃?; η-C₅H₅?FeC₅H₄?; (;CO)₃MnηC₅H₄?; (;CO)₃Mn?ηC₅H₄COCH₂CH₂?; ηC₅H₄(;ηC₅H₅)Co⁺PF^?₆] react with primary or secondary amine drugs [DRUG?NHR] for a psychostimulant drug: amphetamine; tricyclic antidepressants—desipramine and nortriptyline; a vasodilator—histamine; an adrenergic substance—norfenefrine; and for a central stimulant—meth-amphetamine, to give the metallohaptens MCON(;R)—DRUG. All these compounds have been fully characterized by different analytical methods and have potentialities for biological assays. This synthetic route was found better than one presented previously which utilized the metallocenic acid chloride MCOCI as intermediate, and could be proposed as a general synthetic route for labelling biological compounds which possess an amino group.     

Uncertainty Relations in the Madelung Picture

Madelung showed how the complex Schrödinger equation can be rewritten in terms of two real equations, one for the phase and one for the amplitude of the complex wave function, where both equations are not independent of each other, but coupled. Although these equations formally look like classical hydrodynamic equations, they contain all the information about the quantum system. Concerning the quantum mechanical uncertainties of position and momentum, however, this is not so obvious at first sight. We show how these uncertainties are related to the phase and amplitude of the wave function in position and momentum space and, particularly, that the contribution from the phase essentially depends on the position–momentum correlations. This will be illustrated explicitly using generalized coherent states as examples.