Alkali metal complexes of a naphthylamine-substituted phosphanide.
The reaction between {(Me3Si)2CH}PCl2 and one equivalent of [C10H6-8-NMe2]Li, followed by in situ reduction with LiAlH4, gives the secondary phosphane {(Me3Si)2CH}(C10H6-8-NMe2)PH(1) in good yield as a colourless crystalline solid. Metalation of 1 with Bu(n)Li in diethyl ether gives the lithium phosphanide [{[{(Me3Si)2CH}(C10H6-8-NMe2)P]Li}2(OEt2)](2), which undergoes metathesis with either NaOBu(t) or KOBu(t) to give the heavier alkali metal derivatives [[{(Me3Si)2CH}(C10H6-8-NMe2)P]-Na(tmeda)](3) and [[{(Me3Si)2CH}(C10H6-8-NMe2)P]K(pmdeta)](4), after recrystallisation in the presence of the corresponding amine co-ligand [tmeda = N,N,N',N'-tetramethylethylenediamine, pmdeta = N,N,N',N",N"-pentamethyldiethylenetriamine]. Compounds 2-4 have been characterised by 1H, 13C{1H} and 31P{1H} NMR spectroscopy, elemental analyses and X-ray crystallography. Dinuclear 2 crystallises with the phosphanide ligands arranged in a head-to-head fashion and is subject to dynamic exchange in toluene solution; in contrast, compounds 3 and 4 crystallise as discrete monomers which exhibit no dynamic behaviour in solution. DFT calculations on the model compound [{[(Me)(C10H6-8-NMe2)P]Li},(OMe2)] (2a) indicate that the most stable head-to-head form is favoured by 15.0 kcal mol(-1) over the corresponding head-to-tail form.
Izod
Keith
K
Main Group Chemistry Laboratories, Department of Chemistry, School of Natural Sciences, Bedson Building, University of Newcastle, Newcastle upon Tyne, UK. k.j.izod@ncl.ac.uk
Stewart
John C
JC
Clegg
William
W
Harrington
Ross W
RW
D008024:Ligands; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D008672:Metals, Alkali / Q000737:chemistry*; D008956:Models, Chemical; D008958:Models, Molecular; D009281:Naphthalenes / Q000737:chemistry*; D009942:Organometallic Compounds / Q000138:chemical synthesis / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000138:chemical synthesis* / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry
D008024:Ligands; D008672:Metals, Alkali; D009281:Naphthalenes; D009942:Organometallic Compounds; D009943:Organophosphorus Compounds; D017646:Organosilicon Compounds