Co-ordination studies of polyarene and halocarbon functionalised tertiary phosphines for explosives detection

Schiff base condensation of Polyaromatic Hydrocarbon (PAH) functionalised aldehydes and a range of alkyl functionalised primary amines was successfully undertaken. Subsequent reduction yielded new PAH‒substituted amines and the Mannich‒based condensation chemistry of these new amines was explored using HOCH2PR2 precursors to yield (9‒anth)CH2N(R)CH2X (X = PAd or PR’2) ligands. The co‒ordination of these new monophosphines to a readily available dichloroplatinum(II) metal centre was explored to form cis complexes cis–PtCl2{9– (anth)CH2N(iPr)CH2PAd}2 (2.1d), cis–PtCl2{9–(anth)CH2N(Bz)CH2PAd}2 (2.2d),

cis–PtCl2{9–(anth)CH2N(nPr)CH2PAd}2 (2.3d), cis–PtCl2{9– (anth)CH2N(iPr)CH2PPh2} (2.1g) and cis–PtCl2{9–(anth)CH2N(iPr)CH2P(C6H4 o–OCH3)2} (2.1h). Further studies involving synthesis of the chelating bisphosphines [(2‒anth)CH2N(CH2PR2)2 and (1‒pyr)CH2N(CH2PR2)2] were undertaken. This was achieved using Mannich‒based condensation of PAH‒functionalised primary amines with HOCH2P(C6H4–o–OCH3)2 and gave rise to interesting behaviour upon co-ordination to a Pt(II) metal centre, with significant broadening observed in both the 1H and 31P{1H} NMR (ω1/2 ca. 73 Hz) spectra of these compounds.