title: Selective halogenation at the pnictogen atom in Lewis-acid/base-stabilised phosphanylboranes and arsanylboranes.
abstract: The halogenation of Lewis-acid/base-stabilised phosphanylboranes () and arsanylboranes () with CX4 (X=Cl, Br) leads selectively to the substitution of both protons at the pentel atom and the new compounds [(CO)5W(X2PBH2.NMe3)] (:X=Cl, :X=Br) and [(CO)5W(X2AsBH2.NMe3)] (:X=Cl, :X=Br), respectively, are obtained. The new products were comprehensively characterised by spectroscopic methods and by X-ray crystallography. While compounds and show an antiperiplanar arrangement of the Lewis acid (W(CO)5) and the Lewis base (NMe3) in the solid state, a synclinal arrangement in and , respectively, was observed. Computational calculations of the optimised antiperiplanar and synclinal geometries of the compounds and in the gas phase slightly favour the antiperiplanar arrangement of the Lewis acid and the Lewis base for both compounds.
authors.affiliation: Institute of Inorganic Chemistry, University of Regensburg, D-93040, Regensburg, Germany.
authors.forename: Karl-Christian
authors.initials: KC
authors.lastname: Schwan
authors.forename: Ariane
authors.initials: A
authors.lastname: Adolf
authors.forename: Christine
authors.initials: C
authors.lastname: Thoms
authors.forename: Manfred
authors.initials: M
authors.lastname: Zabel
authors.forename: Alexey Y
authors.initials: AY
authors.lastname: Timoshkin
authors.forename: Manfred
authors.initials: M
authors.lastname: Scheer
mesh_terms: D000136:Acid-Base Equilibrium; D000143:Acids / Q000737:chemistry; D001152:Arsenicals / Q000737:chemistry*; D001880:Boranes / Q000138:chemical synthesis* / Q000737:chemistry*; D003198:Computer Simulation; D018360:Crystallography, X-Ray; D054879:Halogenation; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure; D010720:Phosphines / Q000138:chemical synthesis / Q000737:chemistry*; D011522:Protons; D013237:Stereoisomerism
chemical_list: D000143:Acids; D001152:Arsenicals; D001880:Boranes; D010720:Phosphines; D011522:Protons; C006633:arsine