Preparation of cis-[MoI 4(Ph 2PCH 2CH 2PPh 2)] − and structure of (THF) 3Na(μ-I) 3MoI(Ph 2PCH 2CH 2PPh 2) with a new coordination environment around sodium

Abstract

The complex cis-[MoI 4(dppe)] − is obtained in good yields from trans-[MoI 4(THF) 2] − and dppe (dppe = 1,2-bis(diphenylphosphino)ethane) or directly from the interaction of MoI 3(THF) 3, I − and dppe and has been isolated as the PPh 4 and Na(THF) 3 salts. The sodium salt has been characterized crystallographically; monoclinic P2 1/n, a = 12.790(2), b = 16.512(7), c = 23.117(4) A ̊ , β = 103.65(1)°, V = 4744(1) A ̊ 3, D calc = 1.84 g cm −3, Z = 4, R = 0.039 for 4485 independent observed reflections ( F o 2 ⩾ 3 σ( F o 2). The structure features an octahedral coordination aroung both Na and Mo atoms in an overall face-sharing bioctahedral structure with the two metals being bridged by three iodide ligands. This is an unprecedented case of a structure containing an O 3I 3 coordination for Na ions and iodide ligands bridging sodium with a transition metal. The 1H NMR properties of the complex are also examined in comparison to those of the MoI 3(dppe)(THF) precursor.