Solution reactivity studies of group 15 Zintl ions

Thesis

The reactivity of group 15 Zintl ions, E₇^3– (E = P, As), towards a number of transition and post-transition metal reagents has been studied. The synthesis and characterisation of the resulting novel cluster anions are described herein.

The reactions of E₇^3– with [Cu₅(mes)₅], MPh₂ (M = Zn, Cd) and InPh₃ yielded the Cu–Cu bridged species [Cu₂(E₇)₂]^4– (E = P, As), the group 12 bridged cluster anions [M(E₇)₂]^4– (M = Zn: E = P, As; M= Cd: E = P), and the In-functionalised Zintl ions [E₇InPh_{2]^2–, respectively.}

P₇^3– and As₇^3– have been found to react with a number of metal salts, namely [M(nbe)₃][SbF₆] and MCl (M = Ag, Au), InCl₃, TlCl and MI₂ (M = Sn, Pb). These reactions formed the Ag–Ag and Au–Au bridged complexes [M₂(HP₇)₂]^2– (M = Ag, Au), the In-bridged species [In(E₇)₂]^3– (E = P, As), the Tl-derivatised Zintl ions [TlE₇]^2– (E = P, As), and the sixteen vertex cluster anions [ME₁₅]^3– (M = Sn, Pb; E = P, As).

The reactivity of P₇^3– towards a series of group 8 compounds has also been studied. The reactions of P₇^3– with FeCl₂ and [Ru(PPh₃)₃Cl₂] produced [M(HP₇)₂]^2- (M = Fe, Ru). NMR studies showed that these species can be deprotonated to form [M(P₇)₂]^4– (M = Fe, Ru). These Fe and Ru complexes are isoelectronic with ferrocene. In addition, P₇^3– reacts with [Ru(COD)(η³-CH₂C(CH₃)CH₂)₂] to form [(C₄H₇)P₇Ru(COD)]^2–.

Both P₇^3– and As₇^3– undergo transition metal mediated activation reactions in the presence of [Co(PEt₂Ph₂)(mes)₂], yielding [Co(η⁵-P₅){η²-HP₂(mes)}]^2– and [Co([η³-As₃){η⁴-As₄(mes)₂}]^2–, respectively.

Authors: Knapp, CM

• Publication date: 2013
• DOI: 10.5287/ora-ozqqyddz0
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: Zintl ions; clusters
• Subjects: Inorganic chemistry; Organometallic Chemistry; Co-ordination chemistry