0000000000608600
AUTHOR
Mike Beuter
On heterocyclic systems containing bismuth(III) 2. Eight-membered heterocycles Cl/Br/I-M(CH2CH2CH2)2X with lewis acidic group 15 atoms M As, Sb, Bi and donor atoms X NR, S: a contribution to the value of the electronegativity of bismuth(III)
Abstract Paths to the ligands (Cl/Br-CH2CH2CH2)2NR/O/S/Se, R Me, Bz, iPr, iBu, to the diGrignard reagents (Cl/BrMg-CH2CH2CH2)2NR/O/S, R Me, Bz, iPr, iBu and to the eight-membered group 15 heterocycles (Cl/Br/I-As/Sb/Bi(CH2CH2CH2)2NR/S, R Me, Bz, iBu are given. 13C-NMR, IR and Raman spectra are discussed; for the compound ClSb(CH2CH2CH2)2NMe the crystal structure analysis is given : the antimony atom is clearly Lewis acidic with ψ-trigonal-bipyramidal coordination and a transannular Sb⋯N interaction of 2.385(2) A. For such a configuration the values of the 13C-NMR chemical shifts of the α-CH2-groups (e.g. Cl-As/Sb/Bi(αCH2CH2CH2)2NMe 34.6, 25.9, 46.6 ppm) display clearly a sequence N > …
Nucleophilic attack within Ge, Sn and Pb complexes containing Me2N(CH2)(3) - as a potential intramolecular donor ligand
Abstract Thirteen tin compounds LxPhySnClz and LPh2SnPhX (x=1–4, y=0–3, z=0–2, XPh, F, Cl, Br, I, OPh), six germanium compounds LxPhyGeClz and four lead compounds LPh2PbPhX (XPh, Cl, Br, I) containing the potential intramolecular donor LMe2N(CH2)3—have been synthesized by Grignard reactions, redistribution, halogenation, exchange of halide and phenylation. Evidence for 1,5-chelation in which the donor Me2N intramolecularly attacks the Lewis-acidic atoms Ge, Sn or Pb is provided by six crystal structure determinations: Me2N(CH2)3SnPh2Cl, 5; Me2N(CH2)3SnPh2Br, 5a; Me2N(CH2)3SnPh2I, 5b; Me2N(CH2)3SnPh2OPh, 5d; Me2N(CH2)3SnPh3·HCl·H2O. 1a; Me2N(CH2)3PbPh2I, 17b), and by solution 13C, 119Sn a…
Heterocyclic systems containing tin(IV)—XIII [1]. Possible ceasing or inversion of the structuraltrans influence during the course of a bimolecular nucleophilic attack of a donor group in a series of SnIV rings
Abstract In the series of the heterocycles X[(CH2)3]2SnR2 (16 newly synthesized compounds and two taken from the literature) and in the germanium analog BuiN[(CH2)3]2GeCl2, the donor group X (= NMe, NBz, NBui, NPri, O, S) intramolecularly attacks the Lewis acidic atoms Sn or Ge. Eight structure determinations (and, in addition, 2 taken from the literature) are compared. The nucleophilic attack at Sn is stronger for the ligands R2 =Cl2 than for the more electronegative R2 = (OSiPh3)2. Overall the familiartrans influence holds: simultaneous approach of X and weakening of the ligand R (trans). In three cases of subtly graded donor strength a slight inversion or ceasing is observed: shorter dis…