Preparation of new nickel(0) naphthalene complexes, crystal structure of [Ni(C10H8)(i-C3H7)2PCH2CH2P(i-C3H7)2]

Abstract The reduction of the nickel(II) chloride complexes [NiCl 2 (dippm)] ( 1a , dippm = 1,1-bis(diisopropylphosphino)methane), [NiCl 2 (dippe)] ( 1b , dippe = 1,2-bis(diisopropylphosphino)ethane), and [NiCl 2 (dippp)] ( 1c , dippp = 1,3-bis(diisopropylphosphino)propane) with one equivalent of potassium naphthalenide in tetrahydrofuran (THF) gives the corresponding nickel(I) chlorides [NiCl(dippm)] ( 2a ), [NiCl(dippe)] ( 2b ) and [NiCl(dippp)] ( 2c ). The bidentate phosphine-Ni 0 intermediates formed by reduction of the Ni II chlorides 1a and 1b with an excess of magnesium, also give the mono-chlorides 2a and 2b on reaction with equal molar amounts of 1a and 1b , respectively. The reduction of 1b and 1c with magnesium in the presence of naphthalene produces the nickel(0) complexes [Ni(C 10 H 8 )(dippe)] ( 4b ) and [Ni(C 10 H 8 )(dippp)] ( 4c , C 10 H 8 = naphthalene). A crystal structure study of 4b showed that the naphthalene molecule is η 2 -bonded to the P 2 Ni unit.