J.-F. Labarre

Analyse conformationnelle theorique du cyclopropanecarbaldehyde, de la cyclopropylmethylcetone et des methyl-2 cyclopropyl-1 (methyl) cetones cis et trans

Abstract A SCF-LCAO-MO calculation, carried out on cyclopropylcarboxaldehyde (I), cyclopropyl-methylketone (II) and cis and trans-2-methylcyclopropylmethylketones (III and IV) (Chart 1) shows that (a) I, II and IV are only in s-cis and s-trans conformations, the s-cis form being favoured over the s-trans by 0-8 kcal/mole for I and by 1·6 kcal/mole for II and IV; (b) molecule III, of cis configuration, exists in s-cis and gauche conformations (Chart 10) with the former very predominant.

An Answer To the Spiro Versus Ansa Dilemma in Cyclophosphazenes .5. the Dispiro N3p3cl2 [hn-(ch2)3,4-nh]2 and Trispiro N3p3 [hn-(ch2)3-nh]3 Derivatives

Abstract The reaction of N3P3Cl6 with 1,3-diaminopropane and 1,4-diaminobutane (putrescine) in suitable non-polar solvents allows the synthesis, with a very high yield of the PN H R-containing DISPIRO and TRISPIRO derivatives without any significant side-polymerization.

On the conformational analysis of (CH3)3M (M = N, P, CH, SiH) molecules: CNDO/2 calculations versus experimental data. LEM or calder conformation?

Abstract CNDO/2 calculations are performed for the homogeneous series of (CH 3 ) 3 M compounds (M = N, P, CH, SiH) in order to determine the molecular equilibrium conformation. In agreement with available experimental data for the amine, the phosphine and the silane, the theoretical energy minimum is found for the (60, 60, 60) - so-called LEM - conformation in which each methyl group is staggered with respect to the two opposite (MC) bonds. The same LEM conformation is predicted to be theoretically preferred for the isobutane molecule, this result being very sensitive to the “C 3V or not” quality of the methyl groups. The values of optimized CMC angles, rotational barriers and dipole moments are well reproduced.

Analyse conformationnelle theorique en serie cyclopropanique le methylcyclopropane, la cyclopropylamine et la cyclopropylphosphine☆

Abstract The conformational analysis of methylcyclopropane, cyclopropylamine and cyclopropylphosphine is investigated within the framework of the CNDO/2 and INDO approximations. The preferred conformations-experimentally detected by microwave spectroscopy-are correctly predicted. Good agreement is obtained between the calculated and the measured values of rotational barriers, torsional potentials and dipole moments.

Analyse conformationnelle de l'aminodifluorophosphine H2N-PF2 et de la diméthylaminodifluorophosphine (CH3)2N-PF2: Une analyse critique des données expérimentales

Abstract The inconsistency which was recently observed in the conformational analysis experimental data on H 2 N-PF 2 and (CH 3 ) 2 N-PF 2 molecules is investigated within the framework of the CNDO/2 approximation. The X-ray determination made by Nordman and Morris on the latter molecule seems to be the most realistic. However, it was impossible to select the actual set of experimental parameters amongst the various works dealing with the conformational analysis of H 2 N-PF 2 . It seems that, in such conditions, a semi-empirical approach like the CNDO/2 procedure could be considered as a method of solving problems of conformational analysis in highly localized systems.

Transferable 31P NMR data in B.A.S.I.C. (BINO—ANSA—SPIRO in Cyclophosphazenes) systems

Abstract An overall survey of 31 P NMR data for more than twenty B.A.S.I.C. ( B INO A NSA S PIRO i n C yclophosphazenes) systems reveals transferable chemical shift moduli characterizing basic bricks, i.e. BINO bridge, ANSA arch and SPIRO loop. These moduli are linearly related to the plus or minus T d -character of corresponding phosphorus atoms and such linear relationships allow some predictions about geometries of new B.A.S.I.C. systems X-ray structures of which are still unknown.

SYNTHESIS AND CHARACTERIZATION OF THE FIRST DISPIRODIANSABINO-CYCLOTRIPHOSPHAZENE AND OF THE SECOND SPIROANSA-CYCLOTRIPHOSPHAZENE DESCRIBED IN THE LITERATURE

Die Ansa-Verbindung (I) reagiert mit IJ-Diaminopropan zu dem Spiroansacyclotriphosphazen (II), dessen verbliebener labiler Chloridsubstituent mit Diaminohexan zu dem neuen Verbindungstyp Dispirodiansabino-cyclotriphosphazen (III) reagiert.

Effet faraday en solution et strobilisme: La technique des solvants equi-polarisables

Abstract The magneto-optical behaviour of some strobilic compounds in solution in different solvents is described. The strobilic character vanishes when the electric polarisabilities of solute and solvent are equal, and in such cases the magnetic properties of the strobilic compounds are independent of concentration. An “equi-polarisable solvents” technique is proposed.

Analyse conformationnelle théorique du biaziridyle

Abstract The semi-empirical CNDO and INDO methods are applied to a theoretical conformational analysis of biaziridyl. In agreement with infrared and electron diffraction data, this molecule is found to be in its s-trans conformation. The origins of such a conformation are discussed in terms of Fourier developments. The prediction that some alterations of angles occur when going from the s-trans to the s-cis form, arises from these calculations.

An amazibg example of yin-yang aminolysis in cyclophosphazenes

Abstract Aminolysis of hexachlorocyrocyclotriphosphazene, N3P3Cl6, by the spermine-like derivative coded as SPM (323), namely N,N′-bis-(3-aminopropyl)-ethylendiamin H2N-(CH2)3-NH--(CH2)2-NH-(CH2)3-NH2, yields regiospecifically either to the DISPIRANSA or to the DISPIRBINO moiety depending on which chemical is used as the yin reactant. Indeed, if N3P3Cl6 is added as the yang active reactant to the tetramine as the yin passive receptor, the former configuration is obtained whereas the the latter proceeds from an addition of the tetraamine as the yang active reactant on the N3P3Cl6 as the yin receptor.