title: Enantiomerically pure quaternary ammonium salts with a chiral alkyl chain N(CH3)(n-C3H7)2(sec-C4H9)I: synthesis and physical studies.
abstract: A pair of enantiomerically pure quaternary ammonium salts with a chiral side chain, methyl-(R)-(1-methylpropyl)di(n-propyl)ammonium iodide 1 and methyl-(S)-(1-methylpropyl)di(n-propyl)ammonium iodide 2, and the related racemate, methyl-(rac)-(1-methylpropyl)di(n-propyl)ammonium iodide 3, were synthesized through a reductive alkylation procedure, starting from enantiomerically pure and, also, racemic forms of (rac)-(1-methylpropyl)amine. A spectroscopic chiroptical signature in solution was provided by the Raman optical activity spectra of compounds 1 and 2. The crystallographic structures of 1, 2, and 3 were examined by single crystal X-ray diffraction. 1 crystallizes in the tetragonal space group P4(3)2(1)2 (no. 96), a = b = 12.826 (2) A, c = 17.730 (2) A, V = 2916.9 (5) A(3), Z = 8, Flack coefficient 0.04 (2). 2 crystallizes in the tetragonal space group P4(1)2(1)2 (no. 92), a = b = 12.842 (1) A, c = 17.749 (2) A, V = 2927.0 (5) A(3), Z = 8, Flack coefficient 0.05 (2). The crystal structures and space groups for 1 and 2 are enantiomorphs and the crystallographic investigation confirmed the absolute configuration of the stereocenter in both compounds. 3 crystallizes in the monoclinic space group P2(1)/n(no. 14), a = 8.178 (1) A, b = 14.309 (2) A, c = 12.328 (2) A, beta = 96.811 (6) degrees, V = 1432.4 (2) A(3), Z = 4.
authors.affiliation: Laboratoire de Chimie Inorganique et Matériaux Moléculaires, UMR-CNRS 7071, IFR 2769,Université Pierre et Marie Curie-Paris 6, F-75252 Paris Cedex 05, France.
authors.forename: Ruxandra
authors.initials: R
authors.lastname: Gheorghe
authors.forename: Lise-Marie
authors.initials: LM
authors.lastname: Chamoreau
authors.forename: Josef
authors.initials: J
authors.lastname: Kapitan
authors.forename: Nikolaï S
authors.initials: NS
authors.lastname: Ovanesyan
authors.forename: Sergei M
authors.initials: SM
authors.lastname: Aldoshin
authors.forename: Lutz
authors.initials: L
authors.lastname: Hecht
authors.forename: Laurence D
authors.initials: LD
authors.lastname: Barron
authors.forename: Cyrille
authors.initials: C
authors.lastname: Train
authors.forename: Michel
authors.initials: M
authors.lastname: Gruselle